chore: migrate to gitea

vendor/google.golang.org/grpc/AUTHORS

@@ -0,0 +1 @@
+Google Inc.

vendor/google.golang.org/grpc/CODE-OF-CONDUCT.md

@@ -0,0 +1,3 @@
+## Community Code of Conduct
+
+gRPC follows the [CNCF Code of Conduct](https://github.com/cncf/foundation/blob/master/code-of-conduct.md).

vendor/google.golang.org/grpc/CONTRIBUTING.md

@@ -0,0 +1,159 @@
+# How to contribute
+
+We welcome your patches and contributions to gRPC! Please read the gRPC
+organization's [governance
+rules](https://github.com/grpc/grpc-community/blob/master/governance.md) before
+proceeding.
+
+If you are new to GitHub, please start by reading [Pull Request howto](https://help.github.com/articles/about-pull-requests/)
+
+## Legal requirements
+
+In order to protect both you and ourselves, you will need to sign the
+[Contributor License
+Agreement](https://identity.linuxfoundation.org/projects/cncf). When you create
+your first PR, a link will be added as a comment that contains the steps needed
+to complete this process.
+
+## Getting Started
+
+A great way to start is by searching through our open issues. [Unassigned issues
+labeled as "help
+wanted"](https://github.com/grpc/grpc-go/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20label%3A%22Status%3A%20Help%20Wanted%22%20no%3Aassignee)
+are especially nice for first-time contributors, as they should be well-defined
+problems that already have agreed-upon solutions.
+
+## Code Style
+
+We follow [Google's published Go style
+guide](https://google.github.io/styleguide/go/). Note that there are three
+primary documents that make up this style guide; please follow them as closely
+as possible. If a reviewer recommends something that contradicts those
+guidelines, there may be valid reasons to do so, but it should be rare.
+
+## Guidelines for Pull Requests
+
+Please read the following carefully to ensure your contributions can be merged
+smoothly and quickly.
+
+### PR Contents
+
+- Create **small PRs** that are narrowly focused on **addressing a single
+  concern**. We often receive PRs that attempt to fix several things at the same
+  time, and if one part of the PR has a problem, that will hold up the entire
+  PR.
+
+- If your change does not address an **open issue** with an **agreed
+  resolution**, consider opening an issue and discussing it first. If you are
+  suggesting a behavioral or API change, consider starting with a [gRFC
+  proposal](https://github.com/grpc/proposal). Many new features that are not
+  bug fixes will require cross-language agreement.
+
+- If you want to fix **formatting or style**, consider whether your changes are
+  an obvious improvement or might be considered a personal preference. If a
+  style change is based on preference, it likely will not be accepted. If it
+  corrects widely agreed-upon anti-patterns, then please do create a PR and
+  explain the benefits of the change.
+
+- For correcting **misspellings**, please be aware that we use some terms that
+  are sometimes flagged by spell checkers. As an example, "if an only if" is
+  often written as "iff". Please do not make spelling correction changes unless
+  you are certain they are misspellings.
+
+- **All tests need to be passing** before your change can be merged. We
+  recommend you run tests locally before creating your PR to catch breakages
+  early on:
+
+  - `./scripts/vet.sh` to catch vet errors.
+  - `go test -cpu 1,4 -timeout 7m ./...` to run the tests.
+  - `go test -race -cpu 1,4 -timeout 7m ./...` to run tests in race mode.
+
+  Note that we have a multi-module repo, so `go test` commands may need to be
+  run from the root of each module in order to cause all tests to run.
+
+  *Alternatively*, you may find it easier to push your changes to your fork on
+  GitHub, which will trigger a GitHub Actions run that you can use to verify
+  everything is passing.
+
+- Note that there are two GitHub actions checks that need not be green:
+
+  1. We test the freshness of the generated proto code we maintain via the
+     `vet-proto` check. If the source proto files are updated, but our repo is
+     not updated, an optional checker will fail. This will be fixed by our team
+     in a separate PR and will not prevent the merge of your PR.
+
+  2. We run a checker that will fail if there is any change in dependencies of
+     an exported package via the `dependencies` check. If new dependencies are
+     added that are not appropriate, we may not accept your PR (see below).
+
+- If you are adding a **new file**, make sure it has the **copyright message**
+  template at the top as a comment. You can copy the message from an existing
+  file and update the year.
+
+- The grpc package should only depend on standard Go packages and a small number
+  of exceptions. **If your contribution introduces new dependencies**, you will
+  need a discussion with gRPC-Go maintainers.
+
+### PR Descriptions
+
+- **PR titles** should start with the name of the component being addressed, or
+  the type of change. Examples: transport, client, server, round_robin, xds,
+  cleanup, deps.
+
+- Read and follow the **guidelines for PR titles and descriptions** here:
+  https://google.github.io/eng-practices/review/developer/cl-descriptions.html
+
+  *particularly* the sections "First Line" and "Body is Informative".
+
+  Note: your PR description will be used as the git commit message in a
+  squash-and-merge if your PR is approved. We may make changes to this as
+  necessary.
+
+- **Does this PR relate to an open issue?** On the first line, please use the
+  tag `Fixes #<issue>` to ensure the issue is closed when the PR is merged. Or
+  use `Updates #<issue>` if the PR is related to an open issue, but does not fix
+  it. Consider filing an issue if one does not already exist.
+
+- PR descriptions *must* conclude with **release notes** as follows:
+
+  ```
+  RELEASE NOTES:
+  * <component>: <summary>
+  ```
+
+  This need not match the PR title.
+
+  The summary must:
+
+  * be something that gRPC users will understand.
+
+  * clearly explain the feature being added, the issue being fixed, or the
+    behavior being changed, etc. If fixing a bug, be clear about how the bug
+    can be triggered by an end-user.
+
+  * begin with a capital letter and use complete sentences.
+
+  * be as short as possible to describe the change being made.
+
+  If a PR is *not* end-user visible -- e.g. a cleanup, testing change, or
+  GitHub-related, use `RELEASE NOTES: n/a`.
+
+### PR Process
+
+- Please **self-review** your code changes before sending your PR. This will
+  prevent simple, obvious errors from causing delays.
+
+- Maintain a **clean commit history** and use **meaningful commit messages**.
+  PRs with messy commit histories are difficult to review and won't be merged.
+  Before sending your PR, ensure your changes are based on top of the latest
+  `upstream/master` commits, and avoid rebasing in the middle of a code review.
+  You should **never use `git push -f`** unless absolutely necessary during a
+  review, as it can interfere with GitHub's tracking of comments.
+
+- Unless your PR is trivial, you should **expect reviewer comments** that you
+  will need to address before merging. We'll label the PR as `Status: Requires
+  Reporter Clarification` if we expect you to respond to these comments in a
+  timely manner. If the PR remains inactive for 6 days, it will be marked as
+  `stale`, and we will automatically close it after 7 days if we don't hear back
+  from you. Please feel free to ping issues or bugs if you do not get a response
+  within a week.

vendor/google.golang.org/grpc/GOVERNANCE.md

@@ -0,0 +1 @@
+This repository is governed by the gRPC organization's [governance rules](https://github.com/grpc/grpc-community/blob/master/governance.md).

vendor/google.golang.org/grpc/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
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+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+      institute patent litigation against any entity (including a
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+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
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+      (c) You must retain, in the Source form of any Derivative Works
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+          of the NOTICE file are for informational purposes only and
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+          notices within Derivative Works that You distribute, alongside
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+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
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+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
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+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/google.golang.org/grpc/MAINTAINERS.md

@@ -0,0 +1,36 @@
+This page lists all active maintainers of this repository. If you were a
+maintainer and would like to add your name to the Emeritus list, please send us a
+PR.
+
+See [GOVERNANCE.md](https://github.com/grpc/grpc-community/blob/master/governance.md)
+for governance guidelines and how to become a maintainer.
+See [CONTRIBUTING.md](https://github.com/grpc/grpc-community/blob/master/CONTRIBUTING.md)
+for general contribution guidelines.
+
+## Maintainers (in alphabetical order)
+
+- [arjan-bal](https://github.com/arjan-bal), Google LLC
+- [arvindbr8](https://github.com/arvindbr8), Google LLC
+- [atollena](https://github.com/atollena), Datadog, Inc.
+- [dfawley](https://github.com/dfawley), Google LLC
+- [easwars](https://github.com/easwars), Google LLC
+- [gtcooke94](https://github.com/gtcooke94), Google LLC
+
+## Emeritus Maintainers (in alphabetical order)
+- [adelez](https://github.com/adelez)
+- [aranjans](https://github.com/aranjans)
+- [canguler](https://github.com/canguler)
+- [cesarghali](https://github.com/cesarghali)
+- [erm-g](https://github.com/erm-g)
+- [iamqizhao](https://github.com/iamqizhao)
+- [jeanbza](https://github.com/jeanbza)
+- [jtattermusch](https://github.com/jtattermusch)
+- [lyuxuan](https://github.com/lyuxuan)
+- [makmukhi](https://github.com/makmukhi)
+- [matt-kwong](https://github.com/matt-kwong)
+- [menghanl](https://github.com/menghanl)
+- [nicolasnoble](https://github.com/nicolasnoble)
+- [purnesh42h](https://github.com/purnesh42h)
+- [srini100](https://github.com/srini100)
+- [yongni](https://github.com/yongni)
+- [zasweq](https://github.com/zasweq)

vendor/google.golang.org/grpc/Makefile

@@ -0,0 +1,49 @@
+all: vet test testrace
+
+build:
+	go build google.golang.org/grpc/...
+
+clean:
+	go clean -i google.golang.org/grpc/...
+
+deps:
+	GO111MODULE=on go get -d -v google.golang.org/grpc/...
+
+proto:
+	@ if ! which protoc > /dev/null; then \
+		echo "error: protoc not installed" >&2; \
+		exit 1; \
+	fi
+	go generate google.golang.org/grpc/...
+
+test:
+	go test -cpu 1,4 -timeout 7m google.golang.org/grpc/...
+
+testsubmodule:
+	cd security/advancedtls && go test -cpu 1,4 -timeout 7m google.golang.org/grpc/security/advancedtls/...
+	cd security/authorization && go test -cpu 1,4 -timeout 7m google.golang.org/grpc/security/authorization/...
+
+testrace:
+	go test -race -cpu 1,4 -timeout 7m google.golang.org/grpc/...
+
+testdeps:
+	GO111MODULE=on go get -d -v -t google.golang.org/grpc/...
+
+vet: vetdeps
+	./scripts/vet.sh
+
+vetdeps:
+	./scripts/vet.sh -install
+
+.PHONY: \
+	all \
+	build \
+	clean \
+	deps \
+	proto \
+	test \
+	testsubmodule \
+	testrace \
+	testdeps \
+	vet \
+	vetdeps

vendor/google.golang.org/grpc/NOTICE.txt

@@ -0,0 +1,13 @@
+Copyright 2014 gRPC authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

vendor/google.golang.org/grpc/README.md

@@ -0,0 +1,108 @@
+# gRPC-Go
+
+[![GoDoc](https://pkg.go.dev/badge/google.golang.org/grpc)][API]
+[![GoReportCard](https://goreportcard.com/badge/grpc/grpc-go)](https://goreportcard.com/report/github.com/grpc/grpc-go)
+[![codecov](https://codecov.io/gh/grpc/grpc-go/graph/badge.svg)](https://codecov.io/gh/grpc/grpc-go)
+
+The [Go][] implementation of [gRPC][]: A high performance, open source, general
+RPC framework that puts mobile and HTTP/2 first. For more information see the
+[Go gRPC docs][], or jump directly into the [quick start][].
+
+## Prerequisites
+
+- **[Go][]**: any one of the **two latest major** [releases][go-releases].
+
+## Installation
+
+Simply add the following import to your code, and then `go [build|run|test]`
+will automatically fetch the necessary dependencies:
+
+
+```go
+import "google.golang.org/grpc"
+```
+
+> **Note:** If you are trying to access `grpc-go` from **China**, see the
+> [FAQ](#FAQ) below.
+
+## Learn more
+
+- [Go gRPC docs][], which include a [quick start][] and [API
+  reference][API] among other resources
+- [Low-level technical docs](Documentation) from this repository
+- [Performance benchmark][]
+- [Examples](examples)
+- [Contribution guidelines](CONTRIBUTING.md)
+
+## FAQ
+
+### I/O Timeout Errors
+
+The `golang.org` domain may be blocked from some countries. `go get` usually
+produces an error like the following when this happens:
+
+```console
+$ go get -u google.golang.org/grpc
+package google.golang.org/grpc: unrecognized import path "google.golang.org/grpc" (https fetch: Get https://google.golang.org/grpc?go-get=1: dial tcp 216.239.37.1:443: i/o timeout)
+```
+
+To build Go code, there are several options:
+
+- Set up a VPN and access google.golang.org through that.
+
+- With Go module support: it is possible to use the `replace` feature of `go
+  mod` to create aliases for golang.org packages.  In your project's directory:
+
+  ```sh
+  go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest
+  go mod tidy
+  go mod vendor
+  go build -mod=vendor
+  ```
+
+  Again, this will need to be done for all transitive dependencies hosted on
+  golang.org as well. For details, refer to [golang/go issue
+  #28652](https://github.com/golang/go/issues/28652).
+
+### Compiling error, undefined: grpc.SupportPackageIsVersion
+
+Please update to the latest version of gRPC-Go using
+`go get google.golang.org/grpc`.
+
+### How to turn on logging
+
+The default logger is controlled by environment variables. Turn everything on
+like this:
+
+```console
+$ export GRPC_GO_LOG_VERBOSITY_LEVEL=99
+$ export GRPC_GO_LOG_SEVERITY_LEVEL=info
+```
+
+### The RPC failed with error `"code = Unavailable desc = transport is closing"`
+
+This error means the connection the RPC is using was closed, and there are many
+possible reasons, including:
+ 1. mis-configured transport credentials, connection failed on handshaking
+ 1. bytes disrupted, possibly by a proxy in between
+ 1. server shutdown
+ 1. Keepalive parameters caused connection shutdown, for example if you have
+    configured your server to terminate connections regularly to [trigger DNS
+    lookups](https://github.com/grpc/grpc-go/issues/3170#issuecomment-552517779).
+    If this is the case, you may want to increase your
+    [MaxConnectionAgeGrace](https://pkg.go.dev/google.golang.org/grpc/keepalive?tab=doc#ServerParameters),
+    to allow longer RPC calls to finish.
+
+It can be tricky to debug this because the error happens on the client side but
+the root cause of the connection being closed is on the server side. Turn on
+logging on __both client and server__, and see if there are any transport
+errors.
+
+[API]: https://pkg.go.dev/google.golang.org/grpc
+[Go]: https://golang.org
+[Go module]: https://github.com/golang/go/wiki/Modules
+[gRPC]: https://grpc.io
+[Go gRPC docs]: https://grpc.io/docs/languages/go
+[Performance benchmark]: https://performance-dot-grpc-testing.appspot.com/explore?dashboard=5180705743044608
+[quick start]: https://grpc.io/docs/languages/go/quickstart
+[go-releases]: https://golang.org/doc/devel/release.html

vendor/google.golang.org/grpc/SECURITY.md

@@ -0,0 +1,3 @@
+# Security Policy
+
+For information on gRPC Security Policy and reporting potential security issues, please see [gRPC CVE Process](https://github.com/grpc/proposal/blob/master/P4-grpc-cve-process.md).

vendor/google.golang.org/grpc/attributes/attributes.go

@@ -0,0 +1,141 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package attributes defines a generic key/value store used in various gRPC
+// components.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package attributes
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Attributes is an immutable struct for storing and retrieving generic
+// key/value pairs.  Keys must be hashable, and users should define their own
+// types for keys.  Values should not be modified after they are added to an
+// Attributes or if they were received from one.  If values implement 'Equal(o
+// any) bool', it will be called by (*Attributes).Equal to determine whether
+// two values with the same key should be considered equal.
+type Attributes struct {
+	m map[any]any
+}
+
+// New returns a new Attributes containing the key/value pair.
+func New(key, value any) *Attributes {
+	return &Attributes{m: map[any]any{key: value}}
+}
+
+// WithValue returns a new Attributes containing the previous keys and values
+// and the new key/value pair.  If the same key appears multiple times, the
+// last value overwrites all previous values for that key.  To remove an
+// existing key, use a nil value.  value should not be modified later.
+func (a *Attributes) WithValue(key, value any) *Attributes {
+	if a == nil {
+		return New(key, value)
+	}
+	n := &Attributes{m: make(map[any]any, len(a.m)+1)}
+	for k, v := range a.m {
+		n.m[k] = v
+	}
+	n.m[key] = value
+	return n
+}
+
+// Value returns the value associated with these attributes for key, or nil if
+// no value is associated with key.  The returned value should not be modified.
+func (a *Attributes) Value(key any) any {
+	if a == nil {
+		return nil
+	}
+	return a.m[key]
+}
+
+// Equal returns whether a and o are equivalent.  If 'Equal(o any) bool' is
+// implemented for a value in the attributes, it is called to determine if the
+// value matches the one stored in the other attributes.  If Equal is not
+// implemented, standard equality is used to determine if the two values are
+// equal. Note that some types (e.g. maps) aren't comparable by default, so
+// they must be wrapped in a struct, or in an alias type, with Equal defined.
+func (a *Attributes) Equal(o *Attributes) bool {
+	if a == nil && o == nil {
+		return true
+	}
+	if a == nil || o == nil {
+		return false
+	}
+	if len(a.m) != len(o.m) {
+		return false
+	}
+	for k, v := range a.m {
+		ov, ok := o.m[k]
+		if !ok {
+			// o missing element of a
+			return false
+		}
+		if eq, ok := v.(interface{ Equal(o any) bool }); ok {
+			if !eq.Equal(ov) {
+				return false
+			}
+		} else if v != ov {
+			// Fallback to a standard equality check if Value is unimplemented.
+			return false
+		}
+	}
+	return true
+}
+
+// String prints the attribute map. If any key or values throughout the map
+// implement fmt.Stringer, it calls that method and appends.
+func (a *Attributes) String() string {
+	var sb strings.Builder
+	sb.WriteString("{")
+	first := true
+	for k, v := range a.m {
+		if !first {
+			sb.WriteString(", ")
+		}
+		sb.WriteString(fmt.Sprintf("%q: %q ", str(k), str(v)))
+		first = false
+	}
+	sb.WriteString("}")
+	return sb.String()
+}
+
+func str(x any) (s string) {
+	if v, ok := x.(fmt.Stringer); ok {
+		return fmt.Sprint(v)
+	} else if v, ok := x.(string); ok {
+		return v
+	}
+	return fmt.Sprintf("<%p>", x)
+}
+
+// MarshalJSON helps implement the json.Marshaler interface, thereby rendering
+// the Attributes correctly when printing (via pretty.JSON) structs containing
+// Attributes as fields.
+//
+// Is it impossible to unmarshal attributes from a JSON representation and this
+// method is meant only for debugging purposes.
+func (a *Attributes) MarshalJSON() ([]byte, error) {
+	return []byte(a.String()), nil
+}

vendor/google.golang.org/grpc/backoff.go

@@ -0,0 +1,61 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// See internal/backoff package for the backoff implementation. This file is
+// kept for the exported types and API backward compatibility.
+
+package grpc
+
+import (
+	"time"
+
+	"google.golang.org/grpc/backoff"
+)
+
+// DefaultBackoffConfig uses values specified for backoff in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+//
+// Deprecated: use ConnectParams instead. Will be supported throughout 1.x.
+var DefaultBackoffConfig = BackoffConfig{
+	MaxDelay: 120 * time.Second,
+}
+
+// BackoffConfig defines the parameters for the default gRPC backoff strategy.
+//
+// Deprecated: use ConnectParams instead. Will be supported throughout 1.x.
+type BackoffConfig struct {
+	// MaxDelay is the upper bound of backoff delay.
+	MaxDelay time.Duration
+}
+
+// ConnectParams defines the parameters for connecting and retrying. Users are
+// encouraged to use this instead of the BackoffConfig type defined above. See
+// here for more details:
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type ConnectParams struct {
+	// Backoff specifies the configuration options for connection backoff.
+	Backoff backoff.Config
+	// MinConnectTimeout is the minimum amount of time we are willing to give a
+	// connection to complete.
+	MinConnectTimeout time.Duration
+}

vendor/google.golang.org/grpc/backoff/backoff.go

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package backoff provides configuration options for backoff.
+//
+// More details can be found at:
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+//
+// All APIs in this package are experimental.
+package backoff
+
+import "time"
+
+// Config defines the configuration options for backoff.
+type Config struct {
+	// BaseDelay is the amount of time to backoff after the first failure.
+	BaseDelay time.Duration
+	// Multiplier is the factor with which to multiply backoffs after a
+	// failed retry. Should ideally be greater than 1.
+	Multiplier float64
+	// Jitter is the factor with which backoffs are randomized.
+	Jitter float64
+	// MaxDelay is the upper bound of backoff delay.
+	MaxDelay time.Duration
+}
+
+// DefaultConfig is a backoff configuration with the default values specified
+// at https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+//
+// This should be useful for callers who want to configure backoff with
+// non-default values only for a subset of the options.
+var DefaultConfig = Config{
+	BaseDelay:  1.0 * time.Second,
+	Multiplier: 1.6,
+	Jitter:     0.2,
+	MaxDelay:   120 * time.Second,
+}

vendor/google.golang.org/grpc/balancer/balancer.go

@@ -0,0 +1,394 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package balancer defines APIs for load balancing in gRPC.
+// All APIs in this package are experimental.
+package balancer
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net"
+	"strings"
+
+	"google.golang.org/grpc/channelz"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/credentials"
+	estats "google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	// m is a map from name to balancer builder.
+	m = make(map[string]Builder)
+
+	logger = grpclog.Component("balancer")
+)
+
+// Register registers the balancer builder to the balancer map. b.Name
+// (lowercased) will be used as the name registered with this builder.  If the
+// Builder implements ConfigParser, ParseConfig will be called when new service
+// configs are received by the resolver, and the result will be provided to the
+// Balancer in UpdateClientConnState.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple Balancers are
+// registered with the same name, the one registered last will take effect.
+func Register(b Builder) {
+	name := strings.ToLower(b.Name())
+	if name != b.Name() {
+		// TODO: Skip the use of strings.ToLower() to index the map after v1.59
+		// is released to switch to case sensitive balancer registry. Also,
+		// remove this warning and update the docstrings for Register and Get.
+		logger.Warningf("Balancer registered with name %q. grpc-go will be switching to case sensitive balancer registries soon", b.Name())
+	}
+	m[name] = b
+}
+
+// unregisterForTesting deletes the balancer with the given name from the
+// balancer map.
+//
+// This function is not thread-safe.
+func unregisterForTesting(name string) {
+	delete(m, name)
+}
+
+func init() {
+	internal.BalancerUnregister = unregisterForTesting
+	internal.ConnectedAddress = connectedAddress
+	internal.SetConnectedAddress = setConnectedAddress
+}
+
+// Get returns the resolver builder registered with the given name.
+// Note that the compare is done in a case-insensitive fashion.
+// If no builder is register with the name, nil will be returned.
+func Get(name string) Builder {
+	if strings.ToLower(name) != name {
+		// TODO: Skip the use of strings.ToLower() to index the map after v1.59
+		// is released to switch to case sensitive balancer registry. Also,
+		// remove this warning and update the docstrings for Register and Get.
+		logger.Warningf("Balancer retrieved for name %q. grpc-go will be switching to case sensitive balancer registries soon", name)
+	}
+	if b, ok := m[strings.ToLower(name)]; ok {
+		return b
+	}
+	return nil
+}
+
+// NewSubConnOptions contains options to create new SubConn.
+type NewSubConnOptions struct {
+	// CredsBundle is the credentials bundle that will be used in the created
+	// SubConn. If it's nil, the original creds from grpc DialOptions will be
+	// used.
+	//
+	// Deprecated: Use the Attributes field in resolver.Address to pass
+	// arbitrary data to the credential handshaker.
+	CredsBundle credentials.Bundle
+	// HealthCheckEnabled indicates whether health check service should be
+	// enabled on this SubConn
+	HealthCheckEnabled bool
+	// StateListener is called when the state of the subconn changes.  If nil,
+	// Balancer.UpdateSubConnState will be called instead.  Will never be
+	// invoked until after Connect() is called on the SubConn created with
+	// these options.
+	StateListener func(SubConnState)
+}
+
+// State contains the balancer's state relevant to the gRPC ClientConn.
+type State struct {
+	// State contains the connectivity state of the balancer, which is used to
+	// determine the state of the ClientConn.
+	ConnectivityState connectivity.State
+	// Picker is used to choose connections (SubConns) for RPCs.
+	Picker Picker
+}
+
+// ClientConn represents a gRPC ClientConn.
+//
+// This interface is to be implemented by gRPC. Users should not need a
+// brand new implementation of this interface. For the situations like
+// testing, the new implementation should embed this interface. This allows
+// gRPC to add new methods to this interface.
+//
+// NOTICE: This interface is intended to be implemented by gRPC, or intercepted
+// by custom load balancing polices.  Users should not need their own complete
+// implementation of this interface -- they should always delegate to a
+// ClientConn passed to Builder.Build() by embedding it in their
+// implementations. An embedded ClientConn must never be nil, or runtime panics
+// will occur.
+type ClientConn interface {
+	// NewSubConn is called by balancer to create a new SubConn.
+	// It doesn't block and wait for the connections to be established.
+	// Behaviors of the SubConn can be controlled by options.
+	//
+	// Deprecated: please be aware that in a future version, SubConns will only
+	// support one address per SubConn.
+	NewSubConn([]resolver.Address, NewSubConnOptions) (SubConn, error)
+	// RemoveSubConn removes the SubConn from ClientConn.
+	// The SubConn will be shutdown.
+	//
+	// Deprecated: use SubConn.Shutdown instead.
+	RemoveSubConn(SubConn)
+	// UpdateAddresses updates the addresses used in the passed in SubConn.
+	// gRPC checks if the currently connected address is still in the new list.
+	// If so, the connection will be kept. Else, the connection will be
+	// gracefully closed, and a new connection will be created.
+	//
+	// This may trigger a state transition for the SubConn.
+	//
+	// Deprecated: this method will be removed.  Create new SubConns for new
+	// addresses instead.
+	UpdateAddresses(SubConn, []resolver.Address)
+
+	// UpdateState notifies gRPC that the balancer's internal state has
+	// changed.
+	//
+	// gRPC will update the connectivity state of the ClientConn, and will call
+	// Pick on the new Picker to pick new SubConns.
+	UpdateState(State)
+
+	// ResolveNow is called by balancer to notify gRPC to do a name resolving.
+	ResolveNow(resolver.ResolveNowOptions)
+
+	// Target returns the dial target for this ClientConn.
+	//
+	// Deprecated: Use the Target field in the BuildOptions instead.
+	Target() string
+
+	// MetricsRecorder provides the metrics recorder that balancers can use to
+	// record metrics. Balancer implementations which do not register metrics on
+	// metrics registry and record on them can ignore this method. The returned
+	// MetricsRecorder is guaranteed to never be nil.
+	MetricsRecorder() estats.MetricsRecorder
+
+	// EnforceClientConnEmbedding is included to force implementers to embed
+	// another implementation of this interface, allowing gRPC to add methods
+	// without breaking users.
+	internal.EnforceClientConnEmbedding
+}
+
+// BuildOptions contains additional information for Build.
+type BuildOptions struct {
+	// DialCreds is the transport credentials to use when communicating with a
+	// remote load balancer server. Balancer implementations which do not
+	// communicate with a remote load balancer server can ignore this field.
+	DialCreds credentials.TransportCredentials
+	// CredsBundle is the credentials bundle to use when communicating with a
+	// remote load balancer server. Balancer implementations which do not
+	// communicate with a remote load balancer server can ignore this field.
+	CredsBundle credentials.Bundle
+	// Dialer is the custom dialer to use when communicating with a remote load
+	// balancer server. Balancer implementations which do not communicate with a
+	// remote load balancer server can ignore this field.
+	Dialer func(context.Context, string) (net.Conn, error)
+	// Authority is the server name to use as part of the authentication
+	// handshake when communicating with a remote load balancer server. Balancer
+	// implementations which do not communicate with a remote load balancer
+	// server can ignore this field.
+	Authority string
+	// ChannelzParent is the parent ClientConn's channelz channel.
+	ChannelzParent channelz.Identifier
+	// CustomUserAgent is the custom user agent set on the parent ClientConn.
+	// The balancer should set the same custom user agent if it creates a
+	// ClientConn.
+	CustomUserAgent string
+	// Target contains the parsed address info of the dial target. It is the
+	// same resolver.Target as passed to the resolver. See the documentation for
+	// the resolver.Target type for details about what it contains.
+	Target resolver.Target
+}
+
+// Builder creates a balancer.
+type Builder interface {
+	// Build creates a new balancer with the ClientConn.
+	Build(cc ClientConn, opts BuildOptions) Balancer
+	// Name returns the name of balancers built by this builder.
+	// It will be used to pick balancers (for example in service config).
+	Name() string
+}
+
+// ConfigParser parses load balancer configs.
+type ConfigParser interface {
+	// ParseConfig parses the JSON load balancer config provided into an
+	// internal form or returns an error if the config is invalid.  For future
+	// compatibility reasons, unknown fields in the config should be ignored.
+	ParseConfig(LoadBalancingConfigJSON json.RawMessage) (serviceconfig.LoadBalancingConfig, error)
+}
+
+// PickInfo contains additional information for the Pick operation.
+type PickInfo struct {
+	// FullMethodName is the method name that NewClientStream() is called
+	// with. The canonical format is /service/Method.
+	FullMethodName string
+	// Ctx is the RPC's context, and may contain relevant RPC-level information
+	// like the outgoing header metadata.
+	Ctx context.Context
+}
+
+// DoneInfo contains additional information for done.
+type DoneInfo struct {
+	// Err is the rpc error the RPC finished with. It could be nil.
+	Err error
+	// Trailer contains the metadata from the RPC's trailer, if present.
+	Trailer metadata.MD
+	// BytesSent indicates if any bytes have been sent to the server.
+	BytesSent bool
+	// BytesReceived indicates if any byte has been received from the server.
+	BytesReceived bool
+	// ServerLoad is the load received from server. It's usually sent as part of
+	// trailing metadata.
+	//
+	// The only supported type now is *orca_v3.LoadReport.
+	ServerLoad any
+}
+
+var (
+	// ErrNoSubConnAvailable indicates no SubConn is available for pick().
+	// gRPC will block the RPC until a new picker is available via UpdateState().
+	ErrNoSubConnAvailable = errors.New("no SubConn is available")
+	// ErrTransientFailure indicates all SubConns are in TransientFailure.
+	// WaitForReady RPCs will block, non-WaitForReady RPCs will fail.
+	//
+	// Deprecated: return an appropriate error based on the last resolution or
+	// connection attempt instead.  The behavior is the same for any non-gRPC
+	// status error.
+	ErrTransientFailure = errors.New("all SubConns are in TransientFailure")
+)
+
+// PickResult contains information related to a connection chosen for an RPC.
+type PickResult struct {
+	// SubConn is the connection to use for this pick, if its state is Ready.
+	// If the state is not Ready, gRPC will block the RPC until a new Picker is
+	// provided by the balancer (using ClientConn.UpdateState).  The SubConn
+	// must be one returned by ClientConn.NewSubConn.
+	SubConn SubConn
+
+	// Done is called when the RPC is completed.  If the SubConn is not ready,
+	// this will be called with a nil parameter.  If the SubConn is not a valid
+	// type, Done may not be called.  May be nil if the balancer does not wish
+	// to be notified when the RPC completes.
+	Done func(DoneInfo)
+
+	// Metadata provides a way for LB policies to inject arbitrary per-call
+	// metadata. Any metadata returned here will be merged with existing
+	// metadata added by the client application.
+	//
+	// LB policies with child policies are responsible for propagating metadata
+	// injected by their children to the ClientConn, as part of Pick().
+	Metadata metadata.MD
+}
+
+// TransientFailureError returns e.  It exists for backward compatibility and
+// will be deleted soon.
+//
+// Deprecated: no longer necessary, picker errors are treated this way by
+// default.
+func TransientFailureError(e error) error { return e }
+
+// Picker is used by gRPC to pick a SubConn to send an RPC.
+// Balancer is expected to generate a new picker from its snapshot every time its
+// internal state has changed.
+//
+// The pickers used by gRPC can be updated by ClientConn.UpdateState().
+type Picker interface {
+	// Pick returns the connection to use for this RPC and related information.
+	//
+	// Pick should not block.  If the balancer needs to do I/O or any blocking
+	// or time-consuming work to service this call, it should return
+	// ErrNoSubConnAvailable, and the Pick call will be repeated by gRPC when
+	// the Picker is updated (using ClientConn.UpdateState).
+	//
+	// If an error is returned:
+	//
+	// - If the error is ErrNoSubConnAvailable, gRPC will block until a new
+	//   Picker is provided by the balancer (using ClientConn.UpdateState).
+	//
+	// - If the error is a status error (implemented by the grpc/status
+	//   package), gRPC will terminate the RPC with the code and message
+	//   provided.
+	//
+	// - For all other errors, wait for ready RPCs will wait, but non-wait for
+	//   ready RPCs will be terminated with this error's Error() string and
+	//   status code Unavailable.
+	Pick(info PickInfo) (PickResult, error)
+}
+
+// Balancer takes input from gRPC, manages SubConns, and collects and aggregates
+// the connectivity states.
+//
+// It also generates and updates the Picker used by gRPC to pick SubConns for RPCs.
+//
+// UpdateClientConnState, ResolverError, UpdateSubConnState, and Close are
+// guaranteed to be called synchronously from the same goroutine.  There's no
+// guarantee on picker.Pick, it may be called anytime.
+type Balancer interface {
+	// UpdateClientConnState is called by gRPC when the state of the ClientConn
+	// changes.  If the error returned is ErrBadResolverState, the ClientConn
+	// will begin calling ResolveNow on the active name resolver with
+	// exponential backoff until a subsequent call to UpdateClientConnState
+	// returns a nil error.  Any other errors are currently ignored.
+	UpdateClientConnState(ClientConnState) error
+	// ResolverError is called by gRPC when the name resolver reports an error.
+	ResolverError(error)
+	// UpdateSubConnState is called by gRPC when the state of a SubConn
+	// changes.
+	//
+	// Deprecated: Use NewSubConnOptions.StateListener when creating the
+	// SubConn instead.
+	UpdateSubConnState(SubConn, SubConnState)
+	// Close closes the balancer. The balancer is not currently required to
+	// call SubConn.Shutdown for its existing SubConns; however, this will be
+	// required in a future release, so it is recommended.
+	Close()
+	// ExitIdle instructs the LB policy to reconnect to backends / exit the
+	// IDLE state, if appropriate and possible.  Note that SubConns that enter
+	// the IDLE state will not reconnect until SubConn.Connect is called.
+	ExitIdle()
+}
+
+// ExitIdler is an optional interface for balancers to implement.  If
+// implemented, ExitIdle will be called when ClientConn.Connect is called, if
+// the ClientConn is idle.  If unimplemented, ClientConn.Connect will cause
+// all SubConns to connect.
+//
+// Deprecated: All balancers must implement this interface. This interface will
+// be removed in a future release.
+type ExitIdler interface {
+	// ExitIdle instructs the LB policy to reconnect to backends / exit the
+	// IDLE state, if appropriate and possible.  Note that SubConns that enter
+	// the IDLE state will not reconnect until SubConn.Connect is called.
+	ExitIdle()
+}
+
+// ClientConnState describes the state of a ClientConn relevant to the
+// balancer.
+type ClientConnState struct {
+	ResolverState resolver.State
+	// The parsed load balancing configuration returned by the builder's
+	// ParseConfig method, if implemented.
+	BalancerConfig serviceconfig.LoadBalancingConfig
+}
+
+// ErrBadResolverState may be returned by UpdateClientConnState to indicate a
+// problem with the provided name resolver data.
+var ErrBadResolverState = errors.New("bad resolver state")

vendor/google.golang.org/grpc/balancer/base/balancer.go

@@ -0,0 +1,262 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package base
+
+import (
+	"errors"
+	"fmt"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/resolver"
+)
+
+var logger = grpclog.Component("balancer")
+
+type baseBuilder struct {
+	name          string
+	pickerBuilder PickerBuilder
+	config        Config
+}
+
+func (bb *baseBuilder) Build(cc balancer.ClientConn, _ balancer.BuildOptions) balancer.Balancer {
+	bal := &baseBalancer{
+		cc:            cc,
+		pickerBuilder: bb.pickerBuilder,
+
+		subConns: resolver.NewAddressMapV2[balancer.SubConn](),
+		scStates: make(map[balancer.SubConn]connectivity.State),
+		csEvltr:  &balancer.ConnectivityStateEvaluator{},
+		config:   bb.config,
+		state:    connectivity.Connecting,
+	}
+	// Initialize picker to a picker that always returns
+	// ErrNoSubConnAvailable, because when state of a SubConn changes, we
+	// may call UpdateState with this picker.
+	bal.picker = NewErrPicker(balancer.ErrNoSubConnAvailable)
+	return bal
+}
+
+func (bb *baseBuilder) Name() string {
+	return bb.name
+}
+
+type baseBalancer struct {
+	cc            balancer.ClientConn
+	pickerBuilder PickerBuilder
+
+	csEvltr *balancer.ConnectivityStateEvaluator
+	state   connectivity.State
+
+	subConns *resolver.AddressMapV2[balancer.SubConn]
+	scStates map[balancer.SubConn]connectivity.State
+	picker   balancer.Picker
+	config   Config
+
+	resolverErr error // the last error reported by the resolver; cleared on successful resolution
+	connErr     error // the last connection error; cleared upon leaving TransientFailure
+}
+
+func (b *baseBalancer) ResolverError(err error) {
+	b.resolverErr = err
+	if b.subConns.Len() == 0 {
+		b.state = connectivity.TransientFailure
+	}
+
+	if b.state != connectivity.TransientFailure {
+		// The picker will not change since the balancer does not currently
+		// report an error.
+		return
+	}
+	b.regeneratePicker()
+	b.cc.UpdateState(balancer.State{
+		ConnectivityState: b.state,
+		Picker:            b.picker,
+	})
+}
+
+func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
+	// TODO: handle s.ResolverState.ServiceConfig?
+	if logger.V(2) {
+		logger.Info("base.baseBalancer: got new ClientConn state: ", s)
+	}
+	// Successful resolution; clear resolver error and ensure we return nil.
+	b.resolverErr = nil
+	// addrsSet is the set converted from addrs, it's used for quick lookup of an address.
+	addrsSet := resolver.NewAddressMapV2[any]()
+	for _, a := range s.ResolverState.Addresses {
+		addrsSet.Set(a, nil)
+		if _, ok := b.subConns.Get(a); !ok {
+			// a is a new address (not existing in b.subConns).
+			var sc balancer.SubConn
+			opts := balancer.NewSubConnOptions{
+				HealthCheckEnabled: b.config.HealthCheck,
+				StateListener:      func(scs balancer.SubConnState) { b.updateSubConnState(sc, scs) },
+			}
+			sc, err := b.cc.NewSubConn([]resolver.Address{a}, opts)
+			if err != nil {
+				logger.Warningf("base.baseBalancer: failed to create new SubConn: %v", err)
+				continue
+			}
+			b.subConns.Set(a, sc)
+			b.scStates[sc] = connectivity.Idle
+			b.csEvltr.RecordTransition(connectivity.Shutdown, connectivity.Idle)
+			sc.Connect()
+		}
+	}
+	for _, a := range b.subConns.Keys() {
+		sc, _ := b.subConns.Get(a)
+		// a was removed by resolver.
+		if _, ok := addrsSet.Get(a); !ok {
+			sc.Shutdown()
+			b.subConns.Delete(a)
+			// Keep the state of this sc in b.scStates until sc's state becomes Shutdown.
+			// The entry will be deleted in updateSubConnState.
+		}
+	}
+	// If resolver state contains no addresses, return an error so ClientConn
+	// will trigger re-resolve. Also records this as a resolver error, so when
+	// the overall state turns transient failure, the error message will have
+	// the zero address information.
+	if len(s.ResolverState.Addresses) == 0 {
+		b.ResolverError(errors.New("produced zero addresses"))
+		return balancer.ErrBadResolverState
+	}
+
+	b.regeneratePicker()
+	b.cc.UpdateState(balancer.State{ConnectivityState: b.state, Picker: b.picker})
+	return nil
+}
+
+// mergeErrors builds an error from the last connection error and the last
+// resolver error.  Must only be called if b.state is TransientFailure.
+func (b *baseBalancer) mergeErrors() error {
+	// connErr must always be non-nil unless there are no SubConns, in which
+	// case resolverErr must be non-nil.
+	if b.connErr == nil {
+		return fmt.Errorf("last resolver error: %v", b.resolverErr)
+	}
+	if b.resolverErr == nil {
+		return fmt.Errorf("last connection error: %v", b.connErr)
+	}
+	return fmt.Errorf("last connection error: %v; last resolver error: %v", b.connErr, b.resolverErr)
+}
+
+// regeneratePicker takes a snapshot of the balancer, and generates a picker
+// from it. The picker is
+//   - errPicker if the balancer is in TransientFailure,
+//   - built by the pickerBuilder with all READY SubConns otherwise.
+func (b *baseBalancer) regeneratePicker() {
+	if b.state == connectivity.TransientFailure {
+		b.picker = NewErrPicker(b.mergeErrors())
+		return
+	}
+	readySCs := make(map[balancer.SubConn]SubConnInfo)
+
+	// Filter out all ready SCs from full subConn map.
+	for _, addr := range b.subConns.Keys() {
+		sc, _ := b.subConns.Get(addr)
+		if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
+			readySCs[sc] = SubConnInfo{Address: addr}
+		}
+	}
+	b.picker = b.pickerBuilder.Build(PickerBuildInfo{ReadySCs: readySCs})
+}
+
+// UpdateSubConnState is a nop because a StateListener is always set in NewSubConn.
+func (b *baseBalancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	logger.Errorf("base.baseBalancer: UpdateSubConnState(%v, %+v) called unexpectedly", sc, state)
+}
+
+func (b *baseBalancer) updateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	s := state.ConnectivityState
+	if logger.V(2) {
+		logger.Infof("base.baseBalancer: handle SubConn state change: %p, %v", sc, s)
+	}
+	oldS, ok := b.scStates[sc]
+	if !ok {
+		if logger.V(2) {
+			logger.Infof("base.baseBalancer: got state changes for an unknown SubConn: %p, %v", sc, s)
+		}
+		return
+	}
+	if oldS == connectivity.TransientFailure &&
+		(s == connectivity.Connecting || s == connectivity.Idle) {
+		// Once a subconn enters TRANSIENT_FAILURE, ignore subsequent IDLE or
+		// CONNECTING transitions to prevent the aggregated state from being
+		// always CONNECTING when many backends exist but are all down.
+		if s == connectivity.Idle {
+			sc.Connect()
+		}
+		return
+	}
+	b.scStates[sc] = s
+	switch s {
+	case connectivity.Idle:
+		sc.Connect()
+	case connectivity.Shutdown:
+		// When an address was removed by resolver, b called Shutdown but kept
+		// the sc's state in scStates. Remove state for this sc here.
+		delete(b.scStates, sc)
+	case connectivity.TransientFailure:
+		// Save error to be reported via picker.
+		b.connErr = state.ConnectionError
+	}
+
+	b.state = b.csEvltr.RecordTransition(oldS, s)
+
+	// Regenerate picker when one of the following happens:
+	//  - this sc entered or left ready
+	//  - the aggregated state of balancer is TransientFailure
+	//    (may need to update error message)
+	if (s == connectivity.Ready) != (oldS == connectivity.Ready) ||
+		b.state == connectivity.TransientFailure {
+		b.regeneratePicker()
+	}
+	b.cc.UpdateState(balancer.State{ConnectivityState: b.state, Picker: b.picker})
+}
+
+// Close is a nop because base balancer doesn't have internal state to clean up,
+// and it doesn't need to call Shutdown for the SubConns.
+func (b *baseBalancer) Close() {
+}
+
+// ExitIdle is a nop because the base balancer attempts to stay connected to
+// all SubConns at all times.
+func (b *baseBalancer) ExitIdle() {
+}
+
+// NewErrPicker returns a Picker that always returns err on Pick().
+func NewErrPicker(err error) balancer.Picker {
+	return &errPicker{err: err}
+}
+
+// NewErrPickerV2 is temporarily defined for backward compatibility reasons.
+//
+// Deprecated: use NewErrPicker instead.
+var NewErrPickerV2 = NewErrPicker
+
+type errPicker struct {
+	err error // Pick() always returns this err.
+}
+
+func (p *errPicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	return balancer.PickResult{}, p.err
+}

vendor/google.golang.org/grpc/balancer/base/base.go

@@ -0,0 +1,71 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package base defines a balancer base that can be used to build balancers with
+// different picking algorithms.
+//
+// The base balancer creates a new SubConn for each resolved address. The
+// provided picker will only be notified about READY SubConns.
+//
+// This package is the base of round_robin balancer, its purpose is to be used
+// to build round_robin like balancers with complex picking algorithms.
+// Balancers with more complicated logic should try to implement a balancer
+// builder from scratch.
+//
+// All APIs in this package are experimental.
+package base
+
+import (
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/resolver"
+)
+
+// PickerBuilder creates balancer.Picker.
+type PickerBuilder interface {
+	// Build returns a picker that will be used by gRPC to pick a SubConn.
+	Build(info PickerBuildInfo) balancer.Picker
+}
+
+// PickerBuildInfo contains information needed by the picker builder to
+// construct a picker.
+type PickerBuildInfo struct {
+	// ReadySCs is a map from all ready SubConns to the Addresses used to
+	// create them.
+	ReadySCs map[balancer.SubConn]SubConnInfo
+}
+
+// SubConnInfo contains information about a SubConn created by the base
+// balancer.
+type SubConnInfo struct {
+	Address resolver.Address // the address used to create this SubConn
+}
+
+// Config contains the config info about the base balancer builder.
+type Config struct {
+	// HealthCheck indicates whether health checking should be enabled for this specific balancer.
+	HealthCheck bool
+}
+
+// NewBalancerBuilder returns a base balancer builder configured by the provided config.
+func NewBalancerBuilder(name string, pb PickerBuilder, config Config) balancer.Builder {
+	return &baseBuilder{
+		name:          name,
+		pickerBuilder: pb,
+		config:        config,
+	}
+}

vendor/google.golang.org/grpc/balancer/conn_state_evaluator.go

@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package balancer
+
+import "google.golang.org/grpc/connectivity"
+
+// ConnectivityStateEvaluator takes the connectivity states of multiple SubConns
+// and returns one aggregated connectivity state.
+//
+// It's not thread safe.
+type ConnectivityStateEvaluator struct {
+	numReady            uint64 // Number of addrConns in ready state.
+	numConnecting       uint64 // Number of addrConns in connecting state.
+	numTransientFailure uint64 // Number of addrConns in transient failure state.
+	numIdle             uint64 // Number of addrConns in idle state.
+}
+
+// RecordTransition records state change happening in subConn and based on that
+// it evaluates what aggregated state should be.
+//
+//   - If at least one SubConn in Ready, the aggregated state is Ready;
+//   - Else if at least one SubConn in Connecting, the aggregated state is Connecting;
+//   - Else if at least one SubConn is Idle, the aggregated state is Idle;
+//   - Else if at least one SubConn is TransientFailure (or there are no SubConns), the aggregated state is Transient Failure.
+//
+// Shutdown is not considered.
+func (cse *ConnectivityStateEvaluator) RecordTransition(oldState, newState connectivity.State) connectivity.State {
+	// Update counters.
+	for idx, state := range []connectivity.State{oldState, newState} {
+		updateVal := 2*uint64(idx) - 1 // -1 for oldState and +1 for new.
+		switch state {
+		case connectivity.Ready:
+			cse.numReady += updateVal
+		case connectivity.Connecting:
+			cse.numConnecting += updateVal
+		case connectivity.TransientFailure:
+			cse.numTransientFailure += updateVal
+		case connectivity.Idle:
+			cse.numIdle += updateVal
+		}
+	}
+	return cse.CurrentState()
+}
+
+// CurrentState returns the current aggregate conn state by evaluating the counters
+func (cse *ConnectivityStateEvaluator) CurrentState() connectivity.State {
+	// Evaluate.
+	if cse.numReady > 0 {
+		return connectivity.Ready
+	}
+	if cse.numConnecting > 0 {
+		return connectivity.Connecting
+	}
+	if cse.numIdle > 0 {
+		return connectivity.Idle
+	}
+	return connectivity.TransientFailure
+}

vendor/google.golang.org/grpc/balancer/endpointsharding/endpointsharding.go

@@ -0,0 +1,389 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package endpointsharding implements a load balancing policy that manages
+// homogeneous child policies each owning a single endpoint.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package endpointsharding
+
+import (
+	"errors"
+	rand "math/rand/v2"
+	"sync"
+	"sync/atomic"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+var randIntN = rand.IntN
+
+// ChildState is the balancer state of a child along with the endpoint which
+// identifies the child balancer.
+type ChildState struct {
+	Endpoint resolver.Endpoint
+	State    balancer.State
+
+	// Balancer exposes only the ExitIdler interface of the child LB policy.
+	// Other methods of the child policy are called only by endpointsharding.
+	Balancer ExitIdler
+}
+
+// ExitIdler provides access to only the ExitIdle method of the child balancer.
+type ExitIdler interface {
+	// ExitIdle instructs the LB policy to reconnect to backends / exit the
+	// IDLE state, if appropriate and possible.  Note that SubConns that enter
+	// the IDLE state will not reconnect until SubConn.Connect is called.
+	ExitIdle()
+}
+
+// Options are the options to configure the behaviour of the
+// endpointsharding balancer.
+type Options struct {
+	// DisableAutoReconnect allows the balancer to keep child balancer in the
+	// IDLE state until they are explicitly triggered to exit using the
+	// ChildState obtained from the endpointsharding picker. When set to false,
+	// the endpointsharding balancer will automatically call ExitIdle on child
+	// connections that report IDLE.
+	DisableAutoReconnect bool
+}
+
+// ChildBuilderFunc creates a new balancer with the ClientConn. It has the same
+// type as the balancer.Builder.Build method.
+type ChildBuilderFunc func(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer
+
+// NewBalancer returns a load balancing policy that manages homogeneous child
+// policies each owning a single endpoint. The endpointsharding balancer
+// forwards the LoadBalancingConfig in ClientConn state updates to its children.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions, childBuilder ChildBuilderFunc, esOpts Options) balancer.Balancer {
+	es := &endpointSharding{
+		cc:           cc,
+		bOpts:        opts,
+		esOpts:       esOpts,
+		childBuilder: childBuilder,
+	}
+	es.children.Store(resolver.NewEndpointMap[*balancerWrapper]())
+	return es
+}
+
+// endpointSharding is a balancer that wraps child balancers. It creates a child
+// balancer with child config for every unique Endpoint received. It updates the
+// child states on any update from parent or child.
+type endpointSharding struct {
+	cc           balancer.ClientConn
+	bOpts        balancer.BuildOptions
+	esOpts       Options
+	childBuilder ChildBuilderFunc
+
+	// childMu synchronizes calls to any single child. It must be held for all
+	// calls into a child. To avoid deadlocks, do not acquire childMu while
+	// holding mu.
+	childMu  sync.Mutex
+	children atomic.Pointer[resolver.EndpointMap[*balancerWrapper]]
+
+	// inhibitChildUpdates is set during UpdateClientConnState/ResolverError
+	// calls (calls to children will each produce an update, only want one
+	// update).
+	inhibitChildUpdates atomic.Bool
+
+	// mu synchronizes access to the state stored in balancerWrappers in the
+	// children field. mu must not be held during calls into a child since
+	// synchronous calls back from the child may require taking mu, causing a
+	// deadlock. To avoid deadlocks, do not acquire childMu while holding mu.
+	mu sync.Mutex
+}
+
+// rotateEndpoints returns a slice of all the input endpoints rotated a random
+// amount.
+func rotateEndpoints(es []resolver.Endpoint) []resolver.Endpoint {
+	les := len(es)
+	if les == 0 {
+		return es
+	}
+	r := randIntN(les)
+	// Make a copy to avoid mutating data beyond the end of es.
+	ret := make([]resolver.Endpoint, les)
+	copy(ret, es[r:])
+	copy(ret[les-r:], es[:r])
+	return ret
+}
+
+// UpdateClientConnState creates a child for new endpoints and deletes children
+// for endpoints that are no longer present. It also updates all the children,
+// and sends a single synchronous update of the childrens' aggregated state at
+// the end of the UpdateClientConnState operation. If any endpoint has no
+// addresses it will ignore that endpoint. Otherwise, returns first error found
+// from a child, but fully processes the new update.
+func (es *endpointSharding) UpdateClientConnState(state balancer.ClientConnState) error {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+
+	es.inhibitChildUpdates.Store(true)
+	defer func() {
+		es.inhibitChildUpdates.Store(false)
+		es.updateState()
+	}()
+	var ret error
+
+	children := es.children.Load()
+	newChildren := resolver.NewEndpointMap[*balancerWrapper]()
+
+	// Update/Create new children.
+	for _, endpoint := range rotateEndpoints(state.ResolverState.Endpoints) {
+		if _, ok := newChildren.Get(endpoint); ok {
+			// Endpoint child was already created, continue to avoid duplicate
+			// update.
+			continue
+		}
+		childBalancer, ok := children.Get(endpoint)
+		if ok {
+			// Endpoint attributes may have changed, update the stored endpoint.
+			es.mu.Lock()
+			childBalancer.childState.Endpoint = endpoint
+			es.mu.Unlock()
+		} else {
+			childBalancer = &balancerWrapper{
+				childState: ChildState{Endpoint: endpoint},
+				ClientConn: es.cc,
+				es:         es,
+			}
+			childBalancer.childState.Balancer = childBalancer
+			childBalancer.child = es.childBuilder(childBalancer, es.bOpts)
+		}
+		newChildren.Set(endpoint, childBalancer)
+		if err := childBalancer.updateClientConnStateLocked(balancer.ClientConnState{
+			BalancerConfig: state.BalancerConfig,
+			ResolverState: resolver.State{
+				Endpoints:  []resolver.Endpoint{endpoint},
+				Attributes: state.ResolverState.Attributes,
+			},
+		}); err != nil && ret == nil {
+			// Return first error found, and always commit full processing of
+			// updating children. If desired to process more specific errors
+			// across all endpoints, caller should make these specific
+			// validations, this is a current limitation for simplicity sake.
+			ret = err
+		}
+	}
+	// Delete old children that are no longer present.
+	for _, e := range children.Keys() {
+		child, _ := children.Get(e)
+		if _, ok := newChildren.Get(e); !ok {
+			child.closeLocked()
+		}
+	}
+	es.children.Store(newChildren)
+	if newChildren.Len() == 0 {
+		return balancer.ErrBadResolverState
+	}
+	return ret
+}
+
+// ResolverError forwards the resolver error to all of the endpointSharding's
+// children and sends a single synchronous update of the childStates at the end
+// of the ResolverError operation.
+func (es *endpointSharding) ResolverError(err error) {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+	es.inhibitChildUpdates.Store(true)
+	defer func() {
+		es.inhibitChildUpdates.Store(false)
+		es.updateState()
+	}()
+	children := es.children.Load()
+	for _, child := range children.Values() {
+		child.resolverErrorLocked(err)
+	}
+}
+
+func (es *endpointSharding) UpdateSubConnState(balancer.SubConn, balancer.SubConnState) {
+	// UpdateSubConnState is deprecated.
+}
+
+func (es *endpointSharding) Close() {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+	children := es.children.Load()
+	for _, child := range children.Values() {
+		child.closeLocked()
+	}
+}
+
+func (es *endpointSharding) ExitIdle() {
+	es.childMu.Lock()
+	defer es.childMu.Unlock()
+	for _, bw := range es.children.Load().Values() {
+		if !bw.isClosed {
+			bw.child.ExitIdle()
+		}
+	}
+}
+
+// updateState updates this component's state. It sends the aggregated state,
+// and a picker with round robin behavior with all the child states present if
+// needed.
+func (es *endpointSharding) updateState() {
+	if es.inhibitChildUpdates.Load() {
+		return
+	}
+	var readyPickers, connectingPickers, idlePickers, transientFailurePickers []balancer.Picker
+
+	es.mu.Lock()
+	defer es.mu.Unlock()
+
+	children := es.children.Load()
+	childStates := make([]ChildState, 0, children.Len())
+
+	for _, child := range children.Values() {
+		childState := child.childState
+		childStates = append(childStates, childState)
+		childPicker := childState.State.Picker
+		switch childState.State.ConnectivityState {
+		case connectivity.Ready:
+			readyPickers = append(readyPickers, childPicker)
+		case connectivity.Connecting:
+			connectingPickers = append(connectingPickers, childPicker)
+		case connectivity.Idle:
+			idlePickers = append(idlePickers, childPicker)
+		case connectivity.TransientFailure:
+			transientFailurePickers = append(transientFailurePickers, childPicker)
+			// connectivity.Shutdown shouldn't appear.
+		}
+	}
+
+	// Construct the round robin picker based off the aggregated state. Whatever
+	// the aggregated state, use the pickers present that are currently in that
+	// state only.
+	var aggState connectivity.State
+	var pickers []balancer.Picker
+	if len(readyPickers) >= 1 {
+		aggState = connectivity.Ready
+		pickers = readyPickers
+	} else if len(connectingPickers) >= 1 {
+		aggState = connectivity.Connecting
+		pickers = connectingPickers
+	} else if len(idlePickers) >= 1 {
+		aggState = connectivity.Idle
+		pickers = idlePickers
+	} else if len(transientFailurePickers) >= 1 {
+		aggState = connectivity.TransientFailure
+		pickers = transientFailurePickers
+	} else {
+		aggState = connectivity.TransientFailure
+		pickers = []balancer.Picker{base.NewErrPicker(errors.New("no children to pick from"))}
+	} // No children (resolver error before valid update).
+	p := &pickerWithChildStates{
+		pickers:     pickers,
+		childStates: childStates,
+		next:        uint32(randIntN(len(pickers))),
+	}
+	es.cc.UpdateState(balancer.State{
+		ConnectivityState: aggState,
+		Picker:            p,
+	})
+}
+
+// pickerWithChildStates delegates to the pickers it holds in a round robin
+// fashion. It also contains the childStates of all the endpointSharding's
+// children.
+type pickerWithChildStates struct {
+	pickers     []balancer.Picker
+	childStates []ChildState
+	next        uint32
+}
+
+func (p *pickerWithChildStates) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+	nextIndex := atomic.AddUint32(&p.next, 1)
+	picker := p.pickers[nextIndex%uint32(len(p.pickers))]
+	return picker.Pick(info)
+}
+
+// ChildStatesFromPicker returns the state of all the children managed by the
+// endpoint sharding balancer that created this picker.
+func ChildStatesFromPicker(picker balancer.Picker) []ChildState {
+	p, ok := picker.(*pickerWithChildStates)
+	if !ok {
+		return nil
+	}
+	return p.childStates
+}
+
+// balancerWrapper is a wrapper of a balancer. It ID's a child balancer by
+// endpoint, and persists recent child balancer state.
+type balancerWrapper struct {
+	// The following fields are initialized at build time and read-only after
+	// that and therefore do not need to be guarded by a mutex.
+
+	// child contains the wrapped balancer. Access its methods only through
+	// methods on balancerWrapper to ensure proper synchronization
+	child               balancer.Balancer
+	balancer.ClientConn // embed to intercept UpdateState, doesn't deal with SubConns
+
+	es *endpointSharding
+
+	// Access to the following fields is guarded by es.mu.
+
+	childState ChildState
+	isClosed   bool
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	bw.es.mu.Lock()
+	bw.childState.State = state
+	bw.es.mu.Unlock()
+	if state.ConnectivityState == connectivity.Idle && !bw.es.esOpts.DisableAutoReconnect {
+		bw.ExitIdle()
+	}
+	bw.es.updateState()
+}
+
+// ExitIdle pings an IDLE child balancer to exit idle in a new goroutine to
+// avoid deadlocks due to synchronous balancer state updates.
+func (bw *balancerWrapper) ExitIdle() {
+	go func() {
+		bw.es.childMu.Lock()
+		if !bw.isClosed {
+			bw.child.ExitIdle()
+		}
+		bw.es.childMu.Unlock()
+	}()
+}
+
+// updateClientConnStateLocked delivers the ClientConnState to the child
+// balancer. Callers must hold the child mutex of the parent endpointsharding
+// balancer.
+func (bw *balancerWrapper) updateClientConnStateLocked(ccs balancer.ClientConnState) error {
+	return bw.child.UpdateClientConnState(ccs)
+}
+
+// closeLocked closes the child balancer. Callers must hold the child mutext of
+// the parent endpointsharding balancer.
+func (bw *balancerWrapper) closeLocked() {
+	bw.child.Close()
+	bw.isClosed = true
+}
+
+func (bw *balancerWrapper) resolverErrorLocked(err error) {
+	bw.child.ResolverError(err)
+}

vendor/google.golang.org/grpc/balancer/grpclb/state/state.go

@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package state declares grpclb types to be set by resolvers wishing to pass
+// information to grpclb via resolver.State Attributes.
+package state
+
+import (
+	"google.golang.org/grpc/resolver"
+)
+
+// keyType is the key to use for storing State in Attributes.
+type keyType string
+
+const key = keyType("grpc.grpclb.state")
+
+// State contains gRPCLB-relevant data passed from the name resolver.
+type State struct {
+	// BalancerAddresses contains the remote load balancer address(es).  If
+	// set, overrides any resolver-provided addresses with Type of GRPCLB.
+	BalancerAddresses []resolver.Address
+}
+
+// Set returns a copy of the provided state with attributes containing s.  s's
+// data should not be mutated after calling Set.
+func Set(state resolver.State, s *State) resolver.State {
+	state.Attributes = state.Attributes.WithValue(key, s)
+	return state
+}
+
+// Get returns the grpclb State in the resolver.State, or nil if not present.
+// The returned data should not be mutated.
+func Get(state resolver.State) *State {
+	s, _ := state.Attributes.Value(key).(*State)
+	return s
+}

vendor/google.golang.org/grpc/balancer/pickfirst/internal/internal.go

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains code internal to the pickfirst package.
+package internal
+
+import (
+	rand "math/rand/v2"
+	"time"
+)
+
+var (
+	// RandShuffle pseudo-randomizes the order of addresses.
+	RandShuffle = rand.Shuffle
+	// TimeAfterFunc allows mocking the timer for testing connection delay
+	// related functionality.
+	TimeAfterFunc = func(d time.Duration, f func()) func() {
+		timer := time.AfterFunc(d, f)
+		return func() { timer.Stop() }
+	}
+)

vendor/google.golang.org/grpc/balancer/pickfirst/pickfirst.go

@@ -0,0 +1,908 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pickfirst contains the pick_first load balancing policy which
+// is the universal leaf policy.
+package pickfirst
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"net/netip"
+	"sync"
+	"time"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/pickfirst/internal"
+	"google.golang.org/grpc/connectivity"
+	expstats "google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/grpclog"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
+	"google.golang.org/grpc/internal/pretty"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+func init() {
+	balancer.Register(pickfirstBuilder{})
+}
+
+// Name is the name of the pick_first balancer.
+const Name = "pick_first"
+
+// enableHealthListenerKeyType is a unique key type used in resolver
+// attributes to indicate whether the health listener usage is enabled.
+type enableHealthListenerKeyType struct{}
+
+var (
+	logger               = grpclog.Component("pick-first-leaf-lb")
+	disconnectionsMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.disconnections",
+		Description: "EXPERIMENTAL. Number of times the selected subchannel becomes disconnected.",
+		Unit:        "{disconnection}",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+	connectionAttemptsSucceededMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.connection_attempts_succeeded",
+		Description: "EXPERIMENTAL. Number of successful connection attempts.",
+		Unit:        "{attempt}",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+	connectionAttemptsFailedMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+		Name:        "grpc.lb.pick_first.connection_attempts_failed",
+		Description: "EXPERIMENTAL. Number of failed connection attempts.",
+		Unit:        "{attempt}",
+		Labels:      []string{"grpc.target"},
+		Default:     false,
+	})
+)
+
+const (
+	// TODO: change to pick-first when this becomes the default pick_first policy.
+	logPrefix = "[pick-first-leaf-lb %p] "
+	// connectionDelayInterval is the time to wait for during the happy eyeballs
+	// pass before starting the next connection attempt.
+	connectionDelayInterval = 250 * time.Millisecond
+)
+
+type ipAddrFamily int
+
+const (
+	// ipAddrFamilyUnknown represents strings that can't be parsed as an IP
+	// address.
+	ipAddrFamilyUnknown ipAddrFamily = iota
+	ipAddrFamilyV4
+	ipAddrFamilyV6
+)
+
+type pickfirstBuilder struct{}
+
+func (pickfirstBuilder) Build(cc balancer.ClientConn, bo balancer.BuildOptions) balancer.Balancer {
+	b := &pickfirstBalancer{
+		cc:              cc,
+		target:          bo.Target.String(),
+		metricsRecorder: cc.MetricsRecorder(),
+
+		subConns:              resolver.NewAddressMapV2[*scData](),
+		state:                 connectivity.Connecting,
+		cancelConnectionTimer: func() {},
+	}
+	b.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf(logPrefix, b))
+	return b
+}
+
+func (b pickfirstBuilder) Name() string {
+	return Name
+}
+
+func (pickfirstBuilder) ParseConfig(js json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+	var cfg pfConfig
+	if err := json.Unmarshal(js, &cfg); err != nil {
+		return nil, fmt.Errorf("pickfirst: unable to unmarshal LB policy config: %s, error: %v", string(js), err)
+	}
+	return cfg, nil
+}
+
+// EnableHealthListener updates the state to configure pickfirst for using a
+// generic health listener.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a later
+// release.
+func EnableHealthListener(state resolver.State) resolver.State {
+	state.Attributes = state.Attributes.WithValue(enableHealthListenerKeyType{}, true)
+	return state
+}
+
+type pfConfig struct {
+	serviceconfig.LoadBalancingConfig `json:"-"`
+
+	// If set to true, instructs the LB policy to shuffle the order of the list
+	// of endpoints received from the name resolver before attempting to
+	// connect to them.
+	ShuffleAddressList bool `json:"shuffleAddressList"`
+}
+
+// scData keeps track of the current state of the subConn.
+// It is not safe for concurrent access.
+type scData struct {
+	// The following fields are initialized at build time and read-only after
+	// that.
+	subConn balancer.SubConn
+	addr    resolver.Address
+
+	rawConnectivityState connectivity.State
+	// The effective connectivity state based on raw connectivity, health state
+	// and after following sticky TransientFailure behaviour defined in A62.
+	effectiveState              connectivity.State
+	lastErr                     error
+	connectionFailedInFirstPass bool
+}
+
+func (b *pickfirstBalancer) newSCData(addr resolver.Address) (*scData, error) {
+	sd := &scData{
+		rawConnectivityState: connectivity.Idle,
+		effectiveState:       connectivity.Idle,
+		addr:                 addr,
+	}
+	sc, err := b.cc.NewSubConn([]resolver.Address{addr}, balancer.NewSubConnOptions{
+		StateListener: func(state balancer.SubConnState) {
+			b.updateSubConnState(sd, state)
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	sd.subConn = sc
+	return sd, nil
+}
+
+type pickfirstBalancer struct {
+	// The following fields are initialized at build time and read-only after
+	// that and therefore do not need to be guarded by a mutex.
+	logger          *internalgrpclog.PrefixLogger
+	cc              balancer.ClientConn
+	target          string
+	metricsRecorder expstats.MetricsRecorder // guaranteed to be non nil
+
+	// The mutex is used to ensure synchronization of updates triggered
+	// from the idle picker and the already serialized resolver,
+	// SubConn state updates.
+	mu sync.Mutex
+	// State reported to the channel based on SubConn states and resolver
+	// updates.
+	state connectivity.State
+	// scData for active subonns mapped by address.
+	subConns              *resolver.AddressMapV2[*scData]
+	addressList           addressList
+	firstPass             bool
+	numTF                 int
+	cancelConnectionTimer func()
+	healthCheckingEnabled bool
+}
+
+// ResolverError is called by the ClientConn when the name resolver produces
+// an error or when pickfirst determined the resolver update to be invalid.
+func (b *pickfirstBalancer) ResolverError(err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.resolverErrorLocked(err)
+}
+
+func (b *pickfirstBalancer) resolverErrorLocked(err error) {
+	if b.logger.V(2) {
+		b.logger.Infof("Received error from the name resolver: %v", err)
+	}
+
+	// The picker will not change since the balancer does not currently
+	// report an error. If the balancer hasn't received a single good resolver
+	// update yet, transition to TRANSIENT_FAILURE.
+	if b.state != connectivity.TransientFailure && b.addressList.size() > 0 {
+		if b.logger.V(2) {
+			b.logger.Infof("Ignoring resolver error because balancer is using a previous good update.")
+		}
+		return
+	}
+
+	b.updateBalancerState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: fmt.Errorf("name resolver error: %v", err)},
+	})
+}
+
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.cancelConnectionTimer()
+	if len(state.ResolverState.Addresses) == 0 && len(state.ResolverState.Endpoints) == 0 {
+		// Cleanup state pertaining to the previous resolver state.
+		// Treat an empty address list like an error by calling b.ResolverError.
+		b.closeSubConnsLocked()
+		b.addressList.updateAddrs(nil)
+		b.resolverErrorLocked(errors.New("produced zero addresses"))
+		return balancer.ErrBadResolverState
+	}
+	b.healthCheckingEnabled = state.ResolverState.Attributes.Value(enableHealthListenerKeyType{}) != nil
+	cfg, ok := state.BalancerConfig.(pfConfig)
+	if state.BalancerConfig != nil && !ok {
+		return fmt.Errorf("pickfirst: received illegal BalancerConfig (type %T): %v: %w", state.BalancerConfig, state.BalancerConfig, balancer.ErrBadResolverState)
+	}
+
+	if b.logger.V(2) {
+		b.logger.Infof("Received new config %s, resolver state %s", pretty.ToJSON(cfg), pretty.ToJSON(state.ResolverState))
+	}
+
+	var newAddrs []resolver.Address
+	if endpoints := state.ResolverState.Endpoints; len(endpoints) != 0 {
+		// Perform the optional shuffling described in gRFC A62. The shuffling
+		// will change the order of endpoints but not touch the order of the
+		// addresses within each endpoint. - A61
+		if cfg.ShuffleAddressList {
+			endpoints = append([]resolver.Endpoint{}, endpoints...)
+			internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+		}
+
+		// "Flatten the list by concatenating the ordered list of addresses for
+		// each of the endpoints, in order." - A61
+		for _, endpoint := range endpoints {
+			newAddrs = append(newAddrs, endpoint.Addresses...)
+		}
+	} else {
+		// Endpoints not set, process addresses until we migrate resolver
+		// emissions fully to Endpoints. The top channel does wrap emitted
+		// addresses with endpoints, however some balancers such as weighted
+		// target do not forward the corresponding correct endpoints down/split
+		// endpoints properly. Once all balancers correctly forward endpoints
+		// down, can delete this else conditional.
+		newAddrs = state.ResolverState.Addresses
+		if cfg.ShuffleAddressList {
+			newAddrs = append([]resolver.Address{}, newAddrs...)
+			internal.RandShuffle(len(newAddrs), func(i, j int) { newAddrs[i], newAddrs[j] = newAddrs[j], newAddrs[i] })
+		}
+	}
+
+	// If an address appears in multiple endpoints or in the same endpoint
+	// multiple times, we keep it only once. We will create only one SubConn
+	// for the address because an AddressMap is used to store SubConns.
+	// Not de-duplicating would result in attempting to connect to the same
+	// SubConn multiple times in the same pass. We don't want this.
+	newAddrs = deDupAddresses(newAddrs)
+	newAddrs = interleaveAddresses(newAddrs)
+
+	prevAddr := b.addressList.currentAddress()
+	prevSCData, found := b.subConns.Get(prevAddr)
+	prevAddrsCount := b.addressList.size()
+	isPrevRawConnectivityStateReady := found && prevSCData.rawConnectivityState == connectivity.Ready
+	b.addressList.updateAddrs(newAddrs)
+
+	// If the previous ready SubConn exists in new address list,
+	// keep this connection and don't create new SubConns.
+	if isPrevRawConnectivityStateReady && b.addressList.seekTo(prevAddr) {
+		return nil
+	}
+
+	b.reconcileSubConnsLocked(newAddrs)
+	// If it's the first resolver update or the balancer was already READY
+	// (but the new address list does not contain the ready SubConn) or
+	// CONNECTING, enter CONNECTING.
+	// We may be in TRANSIENT_FAILURE due to a previous empty address list,
+	// we should still enter CONNECTING because the sticky TF behaviour
+	//  mentioned in A62 applies only when the TRANSIENT_FAILURE is reported
+	// due to connectivity failures.
+	if isPrevRawConnectivityStateReady || b.state == connectivity.Connecting || prevAddrsCount == 0 {
+		// Start connection attempt at first address.
+		b.forceUpdateConcludedStateLocked(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+		b.startFirstPassLocked()
+	} else if b.state == connectivity.TransientFailure {
+		// If we're in TRANSIENT_FAILURE, we stay in TRANSIENT_FAILURE until
+		// we're READY. See A62.
+		b.startFirstPassLocked()
+	}
+	return nil
+}
+
+// UpdateSubConnState is unused as a StateListener is always registered when
+// creating SubConns.
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
+	b.logger.Errorf("UpdateSubConnState(%v, %+v) called unexpectedly", subConn, state)
+}
+
+func (b *pickfirstBalancer) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.closeSubConnsLocked()
+	b.cancelConnectionTimer()
+	b.state = connectivity.Shutdown
+}
+
+// ExitIdle moves the balancer out of idle state. It can be called concurrently
+// by the idlePicker and clientConn so access to variables should be
+// synchronized.
+func (b *pickfirstBalancer) ExitIdle() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.state == connectivity.Idle {
+		// Move the balancer into CONNECTING state immediately. This is done to
+		// avoid staying in IDLE if a resolver update arrives before the first
+		// SubConn reports CONNECTING.
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+		b.startFirstPassLocked()
+	}
+}
+
+func (b *pickfirstBalancer) startFirstPassLocked() {
+	b.firstPass = true
+	b.numTF = 0
+	// Reset the connection attempt record for existing SubConns.
+	for _, sd := range b.subConns.Values() {
+		sd.connectionFailedInFirstPass = false
+	}
+	b.requestConnectionLocked()
+}
+
+func (b *pickfirstBalancer) closeSubConnsLocked() {
+	for _, sd := range b.subConns.Values() {
+		sd.subConn.Shutdown()
+	}
+	b.subConns = resolver.NewAddressMapV2[*scData]()
+}
+
+// deDupAddresses ensures that each address appears only once in the slice.
+func deDupAddresses(addrs []resolver.Address) []resolver.Address {
+	seenAddrs := resolver.NewAddressMapV2[bool]()
+	retAddrs := []resolver.Address{}
+
+	for _, addr := range addrs {
+		if _, ok := seenAddrs.Get(addr); ok {
+			continue
+		}
+		seenAddrs.Set(addr, true)
+		retAddrs = append(retAddrs, addr)
+	}
+	return retAddrs
+}
+
+// interleaveAddresses interleaves addresses of both families (IPv4 and IPv6)
+// as per RFC-8305 section 4.
+// Whichever address family is first in the list is followed by an address of
+// the other address family; that is, if the first address in the list is IPv6,
+// then the first IPv4 address should be moved up in the list to be second in
+// the list. It doesn't support configuring "First Address Family Count", i.e.
+// there will always be a single member of the first address family at the
+// beginning of the interleaved list.
+// Addresses that are neither IPv4 nor IPv6 are treated as part of a third
+// "unknown" family for interleaving.
+// See: https://datatracker.ietf.org/doc/html/rfc8305#autoid-6
+func interleaveAddresses(addrs []resolver.Address) []resolver.Address {
+	familyAddrsMap := map[ipAddrFamily][]resolver.Address{}
+	interleavingOrder := []ipAddrFamily{}
+	for _, addr := range addrs {
+		family := addressFamily(addr.Addr)
+		if _, found := familyAddrsMap[family]; !found {
+			interleavingOrder = append(interleavingOrder, family)
+		}
+		familyAddrsMap[family] = append(familyAddrsMap[family], addr)
+	}
+
+	interleavedAddrs := make([]resolver.Address, 0, len(addrs))
+
+	for curFamilyIdx := 0; len(interleavedAddrs) < len(addrs); curFamilyIdx = (curFamilyIdx + 1) % len(interleavingOrder) {
+		// Some IP types may have fewer addresses than others, so we look for
+		// the next type that has a remaining member to add to the interleaved
+		// list.
+		family := interleavingOrder[curFamilyIdx]
+		remainingMembers := familyAddrsMap[family]
+		if len(remainingMembers) > 0 {
+			interleavedAddrs = append(interleavedAddrs, remainingMembers[0])
+			familyAddrsMap[family] = remainingMembers[1:]
+		}
+	}
+
+	return interleavedAddrs
+}
+
+// addressFamily returns the ipAddrFamily after parsing the address string.
+// If the address isn't of the format "ip-address:port", it returns
+// ipAddrFamilyUnknown. The address may be valid even if it's not an IP when
+// using a resolver like passthrough where the address may be a hostname in
+// some format that the dialer can resolve.
+func addressFamily(address string) ipAddrFamily {
+	// Parse the IP after removing the port.
+	host, _, err := net.SplitHostPort(address)
+	if err != nil {
+		return ipAddrFamilyUnknown
+	}
+	ip, err := netip.ParseAddr(host)
+	if err != nil {
+		return ipAddrFamilyUnknown
+	}
+	switch {
+	case ip.Is4() || ip.Is4In6():
+		return ipAddrFamilyV4
+	case ip.Is6():
+		return ipAddrFamilyV6
+	default:
+		return ipAddrFamilyUnknown
+	}
+}
+
+// reconcileSubConnsLocked updates the active subchannels based on a new address
+// list from the resolver. It does this by:
+//   - closing subchannels: any existing subchannels associated with addresses
+//     that are no longer in the updated list are shut down.
+//   - removing subchannels: entries for these closed subchannels are removed
+//     from the subchannel map.
+//
+// This ensures that the subchannel map accurately reflects the current set of
+// addresses received from the name resolver.
+func (b *pickfirstBalancer) reconcileSubConnsLocked(newAddrs []resolver.Address) {
+	newAddrsMap := resolver.NewAddressMapV2[bool]()
+	for _, addr := range newAddrs {
+		newAddrsMap.Set(addr, true)
+	}
+
+	for _, oldAddr := range b.subConns.Keys() {
+		if _, ok := newAddrsMap.Get(oldAddr); ok {
+			continue
+		}
+		val, _ := b.subConns.Get(oldAddr)
+		val.subConn.Shutdown()
+		b.subConns.Delete(oldAddr)
+	}
+}
+
+// shutdownRemainingLocked shuts down remaining subConns. Called when a subConn
+// becomes ready, which means that all other subConn must be shutdown.
+func (b *pickfirstBalancer) shutdownRemainingLocked(selected *scData) {
+	b.cancelConnectionTimer()
+	for _, sd := range b.subConns.Values() {
+		if sd.subConn != selected.subConn {
+			sd.subConn.Shutdown()
+		}
+	}
+	b.subConns = resolver.NewAddressMapV2[*scData]()
+	b.subConns.Set(selected.addr, selected)
+}
+
+// requestConnectionLocked starts connecting on the subchannel corresponding to
+// the current address. If no subchannel exists, one is created. If the current
+// subchannel is in TransientFailure, a connection to the next address is
+// attempted until a subchannel is found.
+func (b *pickfirstBalancer) requestConnectionLocked() {
+	if !b.addressList.isValid() {
+		return
+	}
+	var lastErr error
+	for valid := true; valid; valid = b.addressList.increment() {
+		curAddr := b.addressList.currentAddress()
+		sd, ok := b.subConns.Get(curAddr)
+		if !ok {
+			var err error
+			// We want to assign the new scData to sd from the outer scope,
+			// hence we can't use := below.
+			sd, err = b.newSCData(curAddr)
+			if err != nil {
+				// This should never happen, unless the clientConn is being shut
+				// down.
+				if b.logger.V(2) {
+					b.logger.Infof("Failed to create a subConn for address %v: %v", curAddr.String(), err)
+				}
+				// Do nothing, the LB policy will be closed soon.
+				return
+			}
+			b.subConns.Set(curAddr, sd)
+		}
+
+		switch sd.rawConnectivityState {
+		case connectivity.Idle:
+			sd.subConn.Connect()
+			b.scheduleNextConnectionLocked()
+			return
+		case connectivity.TransientFailure:
+			// The SubConn is being re-used and failed during a previous pass
+			// over the addressList. It has not completed backoff yet.
+			// Mark it as having failed and try the next address.
+			sd.connectionFailedInFirstPass = true
+			lastErr = sd.lastErr
+			continue
+		case connectivity.Connecting:
+			// Wait for the connection attempt to complete or the timer to fire
+			// before attempting the next address.
+			b.scheduleNextConnectionLocked()
+			return
+		default:
+			b.logger.Errorf("SubConn with unexpected state %v present in SubConns map.", sd.rawConnectivityState)
+			return
+
+		}
+	}
+
+	// All the remaining addresses in the list are in TRANSIENT_FAILURE, end the
+	// first pass if possible.
+	b.endFirstPassIfPossibleLocked(lastErr)
+}
+
+func (b *pickfirstBalancer) scheduleNextConnectionLocked() {
+	b.cancelConnectionTimer()
+	if !b.addressList.hasNext() {
+		return
+	}
+	curAddr := b.addressList.currentAddress()
+	cancelled := false // Access to this is protected by the balancer's mutex.
+	closeFn := internal.TimeAfterFunc(connectionDelayInterval, func() {
+		b.mu.Lock()
+		defer b.mu.Unlock()
+		// If the scheduled task is cancelled while acquiring the mutex, return.
+		if cancelled {
+			return
+		}
+		if b.logger.V(2) {
+			b.logger.Infof("Happy Eyeballs timer expired while waiting for connection to %q.", curAddr.Addr)
+		}
+		if b.addressList.increment() {
+			b.requestConnectionLocked()
+		}
+	})
+	// Access to the cancellation callback held by the balancer is guarded by
+	// the balancer's mutex, so it's safe to set the boolean from the callback.
+	b.cancelConnectionTimer = sync.OnceFunc(func() {
+		cancelled = true
+		closeFn()
+	})
+}
+
+func (b *pickfirstBalancer) updateSubConnState(sd *scData, newState balancer.SubConnState) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	oldState := sd.rawConnectivityState
+	sd.rawConnectivityState = newState.ConnectivityState
+	// Previously relevant SubConns can still callback with state updates.
+	// To prevent pickers from returning these obsolete SubConns, this logic
+	// is included to check if the current list of active SubConns includes this
+	// SubConn.
+	if !b.isActiveSCData(sd) {
+		return
+	}
+	if newState.ConnectivityState == connectivity.Shutdown {
+		sd.effectiveState = connectivity.Shutdown
+		return
+	}
+
+	// Record a connection attempt when exiting CONNECTING.
+	if newState.ConnectivityState == connectivity.TransientFailure {
+		sd.connectionFailedInFirstPass = true
+		connectionAttemptsFailedMetric.Record(b.metricsRecorder, 1, b.target)
+	}
+
+	if newState.ConnectivityState == connectivity.Ready {
+		connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+		b.shutdownRemainingLocked(sd)
+		if !b.addressList.seekTo(sd.addr) {
+			// This should not fail as we should have only one SubConn after
+			// entering READY. The SubConn should be present in the addressList.
+			b.logger.Errorf("Address %q not found address list in %v", sd.addr, b.addressList.addresses)
+			return
+		}
+		if !b.healthCheckingEnabled {
+			if b.logger.V(2) {
+				b.logger.Infof("SubConn %p reported connectivity state READY and the health listener is disabled. Transitioning SubConn to READY.", sd.subConn)
+			}
+
+			sd.effectiveState = connectivity.Ready
+			b.updateBalancerState(balancer.State{
+				ConnectivityState: connectivity.Ready,
+				Picker:            &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+			})
+			return
+		}
+		if b.logger.V(2) {
+			b.logger.Infof("SubConn %p reported connectivity state READY. Registering health listener.", sd.subConn)
+		}
+		// Send a CONNECTING update to take the SubConn out of sticky-TF if
+		// required.
+		sd.effectiveState = connectivity.Connecting
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+		sd.subConn.RegisterHealthListener(func(scs balancer.SubConnState) {
+			b.updateSubConnHealthState(sd, scs)
+		})
+		return
+	}
+
+	// If the LB policy is READY, and it receives a subchannel state change,
+	// it means that the READY subchannel has failed.
+	// A SubConn can also transition from CONNECTING directly to IDLE when
+	// a transport is successfully created, but the connection fails
+	// before the SubConn can send the notification for READY. We treat
+	// this as a successful connection and transition to IDLE.
+	// TODO: https://github.com/grpc/grpc-go/issues/7862 - Remove the second
+	// part of the if condition below once the issue is fixed.
+	if oldState == connectivity.Ready || (oldState == connectivity.Connecting && newState.ConnectivityState == connectivity.Idle) {
+		// Once a transport fails, the balancer enters IDLE and starts from
+		// the first address when the picker is used.
+		b.shutdownRemainingLocked(sd)
+		sd.effectiveState = newState.ConnectivityState
+		// READY SubConn interspliced in between CONNECTING and IDLE, need to
+		// account for that.
+		if oldState == connectivity.Connecting {
+			// A known issue (https://github.com/grpc/grpc-go/issues/7862)
+			// causes a race that prevents the READY state change notification.
+			// This works around it.
+			connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+		}
+		disconnectionsMetric.Record(b.metricsRecorder, 1, b.target)
+		b.addressList.reset()
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Idle,
+			Picker:            &idlePicker{exitIdle: sync.OnceFunc(b.ExitIdle)},
+		})
+		return
+	}
+
+	if b.firstPass {
+		switch newState.ConnectivityState {
+		case connectivity.Connecting:
+			// The effective state can be in either IDLE, CONNECTING or
+			// TRANSIENT_FAILURE. If it's  TRANSIENT_FAILURE, stay in
+			// TRANSIENT_FAILURE until it's READY. See A62.
+			if sd.effectiveState != connectivity.TransientFailure {
+				sd.effectiveState = connectivity.Connecting
+				b.updateBalancerState(balancer.State{
+					ConnectivityState: connectivity.Connecting,
+					Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+				})
+			}
+		case connectivity.TransientFailure:
+			sd.lastErr = newState.ConnectionError
+			sd.effectiveState = connectivity.TransientFailure
+			// Since we're re-using common SubConns while handling resolver
+			// updates, we could receive an out of turn TRANSIENT_FAILURE from
+			// a pass over the previous address list. Happy Eyeballs will also
+			// cause out of order updates to arrive.
+
+			if curAddr := b.addressList.currentAddress(); equalAddressIgnoringBalAttributes(&curAddr, &sd.addr) {
+				b.cancelConnectionTimer()
+				if b.addressList.increment() {
+					b.requestConnectionLocked()
+					return
+				}
+			}
+
+			// End the first pass if we've seen a TRANSIENT_FAILURE from all
+			// SubConns once.
+			b.endFirstPassIfPossibleLocked(newState.ConnectionError)
+		}
+		return
+	}
+
+	// We have finished the first pass, keep re-connecting failing SubConns.
+	switch newState.ConnectivityState {
+	case connectivity.TransientFailure:
+		b.numTF = (b.numTF + 1) % b.subConns.Len()
+		sd.lastErr = newState.ConnectionError
+		if b.numTF%b.subConns.Len() == 0 {
+			b.updateBalancerState(balancer.State{
+				ConnectivityState: connectivity.TransientFailure,
+				Picker:            &picker{err: newState.ConnectionError},
+			})
+		}
+		// We don't need to request re-resolution since the SubConn already
+		// does that before reporting TRANSIENT_FAILURE.
+		// TODO: #7534 - Move re-resolution requests from SubConn into
+		// pick_first.
+	case connectivity.Idle:
+		sd.subConn.Connect()
+	}
+}
+
+// endFirstPassIfPossibleLocked ends the first happy-eyeballs pass if all the
+// addresses are tried and their SubConns have reported a failure.
+func (b *pickfirstBalancer) endFirstPassIfPossibleLocked(lastErr error) {
+	// An optimization to avoid iterating over the entire SubConn map.
+	if b.addressList.isValid() {
+		return
+	}
+	// Connect() has been called on all the SubConns. The first pass can be
+	// ended if all the SubConns have reported a failure.
+	for _, sd := range b.subConns.Values() {
+		if !sd.connectionFailedInFirstPass {
+			return
+		}
+	}
+	b.firstPass = false
+	b.updateBalancerState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: lastErr},
+	})
+	// Start re-connecting all the SubConns that are already in IDLE.
+	for _, sd := range b.subConns.Values() {
+		if sd.rawConnectivityState == connectivity.Idle {
+			sd.subConn.Connect()
+		}
+	}
+}
+
+func (b *pickfirstBalancer) isActiveSCData(sd *scData) bool {
+	activeSD, found := b.subConns.Get(sd.addr)
+	return found && activeSD == sd
+}
+
+func (b *pickfirstBalancer) updateSubConnHealthState(sd *scData, state balancer.SubConnState) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	// Previously relevant SubConns can still callback with state updates.
+	// To prevent pickers from returning these obsolete SubConns, this logic
+	// is included to check if the current list of active SubConns includes
+	// this SubConn.
+	if !b.isActiveSCData(sd) {
+		return
+	}
+	sd.effectiveState = state.ConnectivityState
+	switch state.ConnectivityState {
+	case connectivity.Ready:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Ready,
+			Picker:            &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+		})
+	case connectivity.TransientFailure:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.TransientFailure,
+			Picker:            &picker{err: fmt.Errorf("pickfirst: health check failure: %v", state.ConnectionError)},
+		})
+	case connectivity.Connecting:
+		b.updateBalancerState(balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
+	default:
+		b.logger.Errorf("Got unexpected health update for SubConn %p: %v", state)
+	}
+}
+
+// updateBalancerState stores the state reported to the channel and calls
+// ClientConn.UpdateState(). As an optimization, it avoids sending duplicate
+// updates to the channel.
+func (b *pickfirstBalancer) updateBalancerState(newState balancer.State) {
+	// In case of TransientFailures allow the picker to be updated to update
+	// the connectivity error, in all other cases don't send duplicate state
+	// updates.
+	if newState.ConnectivityState == b.state && b.state != connectivity.TransientFailure {
+		return
+	}
+	b.forceUpdateConcludedStateLocked(newState)
+}
+
+// forceUpdateConcludedStateLocked stores the state reported to the channel and
+// calls ClientConn.UpdateState().
+// A separate function is defined to force update the ClientConn state since the
+// channel doesn't correctly assume that LB policies start in CONNECTING and
+// relies on LB policy to send an initial CONNECTING update.
+func (b *pickfirstBalancer) forceUpdateConcludedStateLocked(newState balancer.State) {
+	b.state = newState.ConnectivityState
+	b.cc.UpdateState(newState)
+}
+
+type picker struct {
+	result balancer.PickResult
+	err    error
+}
+
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	return p.result, p.err
+}
+
+// idlePicker is used when the SubConn is IDLE and kicks the SubConn into
+// CONNECTING when Pick is called.
+type idlePicker struct {
+	exitIdle func()
+}
+
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	i.exitIdle()
+	return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+}
+
+// addressList manages sequentially iterating over addresses present in a list
+// of endpoints. It provides a 1 dimensional view of the addresses present in
+// the endpoints.
+// This type is not safe for concurrent access.
+type addressList struct {
+	addresses []resolver.Address
+	idx       int
+}
+
+func (al *addressList) isValid() bool {
+	return al.idx < len(al.addresses)
+}
+
+func (al *addressList) size() int {
+	return len(al.addresses)
+}
+
+// increment moves to the next index in the address list.
+// This method returns false if it went off the list, true otherwise.
+func (al *addressList) increment() bool {
+	if !al.isValid() {
+		return false
+	}
+	al.idx++
+	return al.idx < len(al.addresses)
+}
+
+// currentAddress returns the current address pointed to in the addressList.
+// If the list is in an invalid state, it returns an empty address instead.
+func (al *addressList) currentAddress() resolver.Address {
+	if !al.isValid() {
+		return resolver.Address{}
+	}
+	return al.addresses[al.idx]
+}
+
+func (al *addressList) reset() {
+	al.idx = 0
+}
+
+func (al *addressList) updateAddrs(addrs []resolver.Address) {
+	al.addresses = addrs
+	al.reset()
+}
+
+// seekTo returns false if the needle was not found and the current index was
+// left unchanged.
+func (al *addressList) seekTo(needle resolver.Address) bool {
+	for ai, addr := range al.addresses {
+		if !equalAddressIgnoringBalAttributes(&addr, &needle) {
+			continue
+		}
+		al.idx = ai
+		return true
+	}
+	return false
+}
+
+// hasNext returns whether incrementing the addressList will result in moving
+// past the end of the list. If the list has already moved past the end, it
+// returns false.
+func (al *addressList) hasNext() bool {
+	if !al.isValid() {
+		return false
+	}
+	return al.idx+1 < len(al.addresses)
+}
+
+// equalAddressIgnoringBalAttributes returns true is a and b are considered
+// equal. This is different from the Equal method on the resolver.Address type
+// which considers all fields to determine equality. Here, we only consider
+// fields that are meaningful to the SubConn.
+func equalAddressIgnoringBalAttributes(a, b *resolver.Address) bool {
+	return a.Addr == b.Addr && a.ServerName == b.ServerName &&
+		a.Attributes.Equal(b.Attributes)
+}

vendor/google.golang.org/grpc/balancer/roundrobin/roundrobin.go

@@ -0,0 +1,72 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package roundrobin defines a roundrobin balancer. Roundrobin balancer is
+// installed as one of the default balancers in gRPC, users don't need to
+// explicitly install this balancer.
+package roundrobin
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/endpointsharding"
+	"google.golang.org/grpc/balancer/pickfirst"
+	"google.golang.org/grpc/grpclog"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
+)
+
+// Name is the name of round_robin balancer.
+const Name = "round_robin"
+
+var logger = grpclog.Component("roundrobin")
+
+func init() {
+	balancer.Register(builder{})
+}
+
+type builder struct{}
+
+func (bb builder) Name() string {
+	return Name
+}
+
+func (bb builder) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer {
+	childBuilder := balancer.Get(pickfirst.Name).Build
+	bal := &rrBalancer{
+		cc:       cc,
+		Balancer: endpointsharding.NewBalancer(cc, opts, childBuilder, endpointsharding.Options{}),
+	}
+	bal.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[%p] ", bal))
+	bal.logger.Infof("Created")
+	return bal
+}
+
+type rrBalancer struct {
+	balancer.Balancer
+	cc     balancer.ClientConn
+	logger *internalgrpclog.PrefixLogger
+}
+
+func (b *rrBalancer) UpdateClientConnState(ccs balancer.ClientConnState) error {
+	return b.Balancer.UpdateClientConnState(balancer.ClientConnState{
+		// Enable the health listener in pickfirst children for client side health
+		// checks and outlier detection, if configured.
+		ResolverState: pickfirst.EnableHealthListener(ccs.ResolverState),
+	})
+}

vendor/google.golang.org/grpc/balancer/subconn.go

@@ -0,0 +1,134 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package balancer
+
+import (
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/resolver"
+)
+
+// A SubConn represents a single connection to a gRPC backend service.
+//
+// All SubConns start in IDLE, and will not try to connect. To trigger a
+// connection attempt, Balancers must call Connect.
+//
+// If the connection attempt fails, the SubConn will transition to
+// TRANSIENT_FAILURE for a backoff period, and then return to IDLE.  If the
+// connection attempt succeeds, it will transition to READY.
+//
+// If a READY SubConn becomes disconnected, the SubConn will transition to IDLE.
+//
+// If a connection re-enters IDLE, Balancers must call Connect again to trigger
+// a new connection attempt.
+//
+// Each SubConn contains a list of addresses.  gRPC will try to connect to the
+// addresses in sequence, and stop trying the remainder once the first
+// connection is successful.  However, this behavior is deprecated.  SubConns
+// should only use a single address.
+//
+// NOTICE: This interface is intended to be implemented by gRPC, or intercepted
+// by custom load balancing polices.  Users should not need their own complete
+// implementation of this interface -- they should always delegate to a SubConn
+// returned by ClientConn.NewSubConn() by embedding it in their implementations.
+// An embedded SubConn must never be nil, or runtime panics will occur.
+type SubConn interface {
+	// UpdateAddresses updates the addresses used in this SubConn.
+	// gRPC checks if currently-connected address is still in the new list.
+	// If it's in the list, the connection will be kept.
+	// If it's not in the list, the connection will gracefully close, and
+	// a new connection will be created.
+	//
+	// This will trigger a state transition for the SubConn.
+	//
+	// Deprecated: this method will be removed.  Create new SubConns for new
+	// addresses instead.
+	UpdateAddresses([]resolver.Address)
+	// Connect starts the connecting for this SubConn.
+	Connect()
+	// GetOrBuildProducer returns a reference to the existing Producer for this
+	// ProducerBuilder in this SubConn, or, if one does not currently exist,
+	// creates a new one and returns it.  Returns a close function which may be
+	// called when the Producer is no longer needed.  Otherwise the producer
+	// will automatically be closed upon connection loss or subchannel close.
+	// Should only be called on a SubConn in state Ready.  Otherwise the
+	// producer will be unable to create streams.
+	GetOrBuildProducer(ProducerBuilder) (p Producer, close func())
+	// Shutdown shuts down the SubConn gracefully.  Any started RPCs will be
+	// allowed to complete.  No future calls should be made on the SubConn.
+	// One final state update will be delivered to the StateListener (or
+	// UpdateSubConnState; deprecated) with ConnectivityState of Shutdown to
+	// indicate the shutdown operation.  This may be delivered before
+	// in-progress RPCs are complete and the actual connection is closed.
+	Shutdown()
+	// RegisterHealthListener registers a health listener that receives health
+	// updates for a Ready SubConn. Only one health listener can be registered
+	// at a time. A health listener should be registered each time the SubConn's
+	// connectivity state changes to READY. Registering a health listener when
+	// the connectivity state is not READY may result in undefined behaviour.
+	// This method must not be called synchronously while handling an update
+	// from a previously registered health listener.
+	RegisterHealthListener(func(SubConnState))
+	// EnforceSubConnEmbedding is included to force implementers to embed
+	// another implementation of this interface, allowing gRPC to add methods
+	// without breaking users.
+	internal.EnforceSubConnEmbedding
+}
+
+// A ProducerBuilder is a simple constructor for a Producer.  It is used by the
+// SubConn to create producers when needed.
+type ProducerBuilder interface {
+	// Build creates a Producer.  The first parameter is always a
+	// grpc.ClientConnInterface (a type to allow creating RPCs/streams on the
+	// associated SubConn), but is declared as `any` to avoid a dependency
+	// cycle.  Build also returns a close function that will be called when all
+	// references to the Producer have been given up for a SubConn, or when a
+	// connectivity state change occurs on the SubConn.  The close function
+	// should always block until all asynchronous cleanup work is completed.
+	Build(grpcClientConnInterface any) (p Producer, close func())
+}
+
+// SubConnState describes the state of a SubConn.
+type SubConnState struct {
+	// ConnectivityState is the connectivity state of the SubConn.
+	ConnectivityState connectivity.State
+	// ConnectionError is set if the ConnectivityState is TransientFailure,
+	// describing the reason the SubConn failed.  Otherwise, it is nil.
+	ConnectionError error
+	// connectedAddr contains the connected address when ConnectivityState is
+	// Ready. Otherwise, it is indeterminate.
+	connectedAddress resolver.Address
+}
+
+// connectedAddress returns the connected address for a SubConnState. The
+// address is only valid if the state is READY.
+func connectedAddress(scs SubConnState) resolver.Address {
+	return scs.connectedAddress
+}
+
+// setConnectedAddress sets the connected address for a SubConnState.
+func setConnectedAddress(scs *SubConnState, addr resolver.Address) {
+	scs.connectedAddress = addr
+}
+
+// A Producer is a type shared among potentially many consumers.  It is
+// associated with a SubConn, and an implementation will typically contain
+// other methods to provide additional functionality, e.g. configuration or
+// subscription registration.
+type Producer any

vendor/google.golang.org/grpc/balancer_wrapper.go

@@ -0,0 +1,521 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/experimental/stats"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/internal/balancer/gracefulswitch"
+	"google.golang.org/grpc/internal/channelz"
+	"google.golang.org/grpc/internal/grpcsync"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/status"
+)
+
+var (
+	setConnectedAddress = internal.SetConnectedAddress.(func(*balancer.SubConnState, resolver.Address))
+	// noOpRegisterHealthListenerFn is used when client side health checking is
+	// disabled. It sends a single READY update on the registered listener.
+	noOpRegisterHealthListenerFn = func(_ context.Context, listener func(balancer.SubConnState)) func() {
+		listener(balancer.SubConnState{ConnectivityState: connectivity.Ready})
+		return func() {}
+	}
+)
+
+// ccBalancerWrapper sits between the ClientConn and the Balancer.
+//
+// ccBalancerWrapper implements methods corresponding to the ones on the
+// balancer.Balancer interface. The ClientConn is free to call these methods
+// concurrently and the ccBalancerWrapper ensures that calls from the ClientConn
+// to the Balancer happen in order by performing them in the serializer, without
+// any mutexes held.
+//
+// ccBalancerWrapper also implements the balancer.ClientConn interface and is
+// passed to the Balancer implementations. It invokes unexported methods on the
+// ClientConn to handle these calls from the Balancer.
+//
+// It uses the gracefulswitch.Balancer internally to ensure that balancer
+// switches happen in a graceful manner.
+type ccBalancerWrapper struct {
+	internal.EnforceClientConnEmbedding
+	// The following fields are initialized when the wrapper is created and are
+	// read-only afterwards, and therefore can be accessed without a mutex.
+	cc               *ClientConn
+	opts             balancer.BuildOptions
+	serializer       *grpcsync.CallbackSerializer
+	serializerCancel context.CancelFunc
+
+	// The following fields are only accessed within the serializer or during
+	// initialization.
+	curBalancerName string
+	balancer        *gracefulswitch.Balancer
+
+	// The following field is protected by mu.  Caller must take cc.mu before
+	// taking mu.
+	mu     sync.Mutex
+	closed bool
+}
+
+// newCCBalancerWrapper creates a new balancer wrapper in idle state. The
+// underlying balancer is not created until the updateClientConnState() method
+// is invoked.
+func newCCBalancerWrapper(cc *ClientConn) *ccBalancerWrapper {
+	ctx, cancel := context.WithCancel(cc.ctx)
+	ccb := &ccBalancerWrapper{
+		cc: cc,
+		opts: balancer.BuildOptions{
+			DialCreds:       cc.dopts.copts.TransportCredentials,
+			CredsBundle:     cc.dopts.copts.CredsBundle,
+			Dialer:          cc.dopts.copts.Dialer,
+			Authority:       cc.authority,
+			CustomUserAgent: cc.dopts.copts.UserAgent,
+			ChannelzParent:  cc.channelz,
+			Target:          cc.parsedTarget,
+		},
+		serializer:       grpcsync.NewCallbackSerializer(ctx),
+		serializerCancel: cancel,
+	}
+	ccb.balancer = gracefulswitch.NewBalancer(ccb, ccb.opts)
+	return ccb
+}
+
+func (ccb *ccBalancerWrapper) MetricsRecorder() stats.MetricsRecorder {
+	return ccb.cc.metricsRecorderList
+}
+
+// updateClientConnState is invoked by grpc to push a ClientConnState update to
+// the underlying balancer.  This is always executed from the serializer, so
+// it is safe to call into the balancer here.
+func (ccb *ccBalancerWrapper) updateClientConnState(ccs *balancer.ClientConnState) error {
+	errCh := make(chan error)
+	uccs := func(ctx context.Context) {
+		defer close(errCh)
+		if ctx.Err() != nil || ccb.balancer == nil {
+			return
+		}
+		name := gracefulswitch.ChildName(ccs.BalancerConfig)
+		if ccb.curBalancerName != name {
+			ccb.curBalancerName = name
+			channelz.Infof(logger, ccb.cc.channelz, "Channel switches to new LB policy %q", name)
+		}
+		err := ccb.balancer.UpdateClientConnState(*ccs)
+		if logger.V(2) && err != nil {
+			logger.Infof("error from balancer.UpdateClientConnState: %v", err)
+		}
+		errCh <- err
+	}
+	onFailure := func() { close(errCh) }
+
+	// UpdateClientConnState can race with Close, and when the latter wins, the
+	// serializer is closed, and the attempt to schedule the callback will fail.
+	// It is acceptable to ignore this failure. But since we want to handle the
+	// state update in a blocking fashion (when we successfully schedule the
+	// callback), we have to use the ScheduleOr method and not the MaybeSchedule
+	// method on the serializer.
+	ccb.serializer.ScheduleOr(uccs, onFailure)
+	return <-errCh
+}
+
+// resolverError is invoked by grpc to push a resolver error to the underlying
+// balancer.  The call to the balancer is executed from the serializer.
+func (ccb *ccBalancerWrapper) resolverError(err error) {
+	ccb.serializer.TrySchedule(func(ctx context.Context) {
+		if ctx.Err() != nil || ccb.balancer == nil {
+			return
+		}
+		ccb.balancer.ResolverError(err)
+	})
+}
+
+// close initiates async shutdown of the wrapper.  cc.mu must be held when
+// calling this function.  To determine the wrapper has finished shutting down,
+// the channel should block on ccb.serializer.Done() without cc.mu held.
+func (ccb *ccBalancerWrapper) close() {
+	ccb.mu.Lock()
+	ccb.closed = true
+	ccb.mu.Unlock()
+	channelz.Info(logger, ccb.cc.channelz, "ccBalancerWrapper: closing")
+	ccb.serializer.TrySchedule(func(context.Context) {
+		if ccb.balancer == nil {
+			return
+		}
+		ccb.balancer.Close()
+		ccb.balancer = nil
+	})
+	ccb.serializerCancel()
+}
+
+// exitIdle invokes the balancer's exitIdle method in the serializer.
+func (ccb *ccBalancerWrapper) exitIdle() {
+	ccb.serializer.TrySchedule(func(ctx context.Context) {
+		if ctx.Err() != nil || ccb.balancer == nil {
+			return
+		}
+		ccb.balancer.ExitIdle()
+	})
+}
+
+func (ccb *ccBalancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+	ccb.cc.mu.Lock()
+	defer ccb.cc.mu.Unlock()
+
+	ccb.mu.Lock()
+	if ccb.closed {
+		ccb.mu.Unlock()
+		return nil, fmt.Errorf("balancer is being closed; no new SubConns allowed")
+	}
+	ccb.mu.Unlock()
+
+	if len(addrs) == 0 {
+		return nil, fmt.Errorf("grpc: cannot create SubConn with empty address list")
+	}
+	ac, err := ccb.cc.newAddrConnLocked(addrs, opts)
+	if err != nil {
+		channelz.Warningf(logger, ccb.cc.channelz, "acBalancerWrapper: NewSubConn: failed to newAddrConn: %v", err)
+		return nil, err
+	}
+	acbw := &acBalancerWrapper{
+		ccb:           ccb,
+		ac:            ac,
+		producers:     make(map[balancer.ProducerBuilder]*refCountedProducer),
+		stateListener: opts.StateListener,
+		healthData:    newHealthData(connectivity.Idle),
+	}
+	ac.acbw = acbw
+	return acbw, nil
+}
+
+func (ccb *ccBalancerWrapper) RemoveSubConn(balancer.SubConn) {
+	// The graceful switch balancer will never call this.
+	logger.Errorf("ccb RemoveSubConn(%v) called unexpectedly, sc")
+}
+
+func (ccb *ccBalancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
+	acbw, ok := sc.(*acBalancerWrapper)
+	if !ok {
+		return
+	}
+	acbw.UpdateAddresses(addrs)
+}
+
+func (ccb *ccBalancerWrapper) UpdateState(s balancer.State) {
+	ccb.cc.mu.Lock()
+	defer ccb.cc.mu.Unlock()
+	if ccb.cc.conns == nil {
+		// The CC has been closed; ignore this update.
+		return
+	}
+
+	ccb.mu.Lock()
+	if ccb.closed {
+		ccb.mu.Unlock()
+		return
+	}
+	ccb.mu.Unlock()
+	// Update picker before updating state.  Even though the ordering here does
+	// not matter, it can lead to multiple calls of Pick in the common start-up
+	// case where we wait for ready and then perform an RPC.  If the picker is
+	// updated later, we could call the "connecting" picker when the state is
+	// updated, and then call the "ready" picker after the picker gets updated.
+
+	// Note that there is no need to check if the balancer wrapper was closed,
+	// as we know the graceful switch LB policy will not call cc if it has been
+	// closed.
+	ccb.cc.pickerWrapper.updatePicker(s.Picker)
+	ccb.cc.csMgr.updateState(s.ConnectivityState)
+}
+
+func (ccb *ccBalancerWrapper) ResolveNow(o resolver.ResolveNowOptions) {
+	ccb.cc.mu.RLock()
+	defer ccb.cc.mu.RUnlock()
+
+	ccb.mu.Lock()
+	if ccb.closed {
+		ccb.mu.Unlock()
+		return
+	}
+	ccb.mu.Unlock()
+	ccb.cc.resolveNowLocked(o)
+}
+
+func (ccb *ccBalancerWrapper) Target() string {
+	return ccb.cc.target
+}
+
+// acBalancerWrapper is a wrapper on top of ac for balancers.
+// It implements balancer.SubConn interface.
+type acBalancerWrapper struct {
+	internal.EnforceSubConnEmbedding
+	ac            *addrConn          // read-only
+	ccb           *ccBalancerWrapper // read-only
+	stateListener func(balancer.SubConnState)
+
+	producersMu sync.Mutex
+	producers   map[balancer.ProducerBuilder]*refCountedProducer
+
+	// Access to healthData is protected by healthMu.
+	healthMu sync.Mutex
+	// healthData is stored as a pointer to detect when the health listener is
+	// dropped or updated. This is required as closures can't be compared for
+	// equality.
+	healthData *healthData
+}
+
+// healthData holds data related to health state reporting.
+type healthData struct {
+	// connectivityState stores the most recent connectivity state delivered
+	// to the LB policy. This is stored to avoid sending updates when the
+	// SubConn has already exited connectivity state READY.
+	connectivityState connectivity.State
+	// closeHealthProducer stores function to close the ref counted health
+	// producer. The health producer is automatically closed when the SubConn
+	// state changes.
+	closeHealthProducer func()
+}
+
+func newHealthData(s connectivity.State) *healthData {
+	return &healthData{
+		connectivityState:   s,
+		closeHealthProducer: func() {},
+	}
+}
+
+// updateState is invoked by grpc to push a subConn state update to the
+// underlying balancer.
+func (acbw *acBalancerWrapper) updateState(s connectivity.State, curAddr resolver.Address, err error) {
+	acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+		if ctx.Err() != nil || acbw.ccb.balancer == nil {
+			return
+		}
+		// Invalidate all producers on any state change.
+		acbw.closeProducers()
+
+		// Even though it is optional for balancers, gracefulswitch ensures
+		// opts.StateListener is set, so this cannot ever be nil.
+		// TODO: delete this comment when UpdateSubConnState is removed.
+		scs := balancer.SubConnState{ConnectivityState: s, ConnectionError: err}
+		if s == connectivity.Ready {
+			setConnectedAddress(&scs, curAddr)
+		}
+		// Invalidate the health listener by updating the healthData.
+		acbw.healthMu.Lock()
+		// A race may occur if a health listener is registered soon after the
+		// connectivity state is set but before the stateListener is called.
+		// Two cases may arise:
+		// 1. The new state is not READY: RegisterHealthListener has checks to
+		//    ensure no updates are sent when the connectivity state is not
+		//    READY.
+		// 2. The new state is READY: This means that the old state wasn't Ready.
+		//    The RegisterHealthListener API mentions that a health listener
+		//    must not be registered when a SubConn is not ready to avoid such
+		//    races. When this happens, the LB policy would get health updates
+		//    on the old listener. When the LB policy registers a new listener
+		//    on receiving the connectivity update, the health updates will be
+		//    sent to the new health listener.
+		acbw.healthData = newHealthData(scs.ConnectivityState)
+		acbw.healthMu.Unlock()
+
+		acbw.stateListener(scs)
+	})
+}
+
+func (acbw *acBalancerWrapper) String() string {
+	return fmt.Sprintf("SubConn(id:%d)", acbw.ac.channelz.ID)
+}
+
+func (acbw *acBalancerWrapper) UpdateAddresses(addrs []resolver.Address) {
+	acbw.ac.updateAddrs(addrs)
+}
+
+func (acbw *acBalancerWrapper) Connect() {
+	go acbw.ac.connect()
+}
+
+func (acbw *acBalancerWrapper) Shutdown() {
+	acbw.closeProducers()
+	acbw.ccb.cc.removeAddrConn(acbw.ac, errConnDrain)
+}
+
+// NewStream begins a streaming RPC on the addrConn.  If the addrConn is not
+// ready, blocks until it is or ctx expires.  Returns an error when the context
+// expires or the addrConn is shut down.
+func (acbw *acBalancerWrapper) NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error) {
+	transport := acbw.ac.getReadyTransport()
+	if transport == nil {
+		return nil, status.Errorf(codes.Unavailable, "SubConn state is not Ready")
+
+	}
+	return newNonRetryClientStream(ctx, desc, method, transport, acbw.ac, opts...)
+}
+
+// Invoke performs a unary RPC.  If the addrConn is not ready, returns
+// errSubConnNotReady.
+func (acbw *acBalancerWrapper) Invoke(ctx context.Context, method string, args any, reply any, opts ...CallOption) error {
+	cs, err := acbw.NewStream(ctx, unaryStreamDesc, method, opts...)
+	if err != nil {
+		return err
+	}
+	if err := cs.SendMsg(args); err != nil {
+		return err
+	}
+	return cs.RecvMsg(reply)
+}
+
+type refCountedProducer struct {
+	producer balancer.Producer
+	refs     int    // number of current refs to the producer
+	close    func() // underlying producer's close function
+}
+
+func (acbw *acBalancerWrapper) GetOrBuildProducer(pb balancer.ProducerBuilder) (balancer.Producer, func()) {
+	acbw.producersMu.Lock()
+	defer acbw.producersMu.Unlock()
+
+	// Look up existing producer from this builder.
+	pData := acbw.producers[pb]
+	if pData == nil {
+		// Not found; create a new one and add it to the producers map.
+		p, closeFn := pb.Build(acbw)
+		pData = &refCountedProducer{producer: p, close: closeFn}
+		acbw.producers[pb] = pData
+	}
+	// Account for this new reference.
+	pData.refs++
+
+	// Return a cleanup function wrapped in a OnceFunc to remove this reference
+	// and delete the refCountedProducer from the map if the total reference
+	// count goes to zero.
+	unref := func() {
+		acbw.producersMu.Lock()
+		// If closeProducers has already closed this producer instance, refs is
+		// set to 0, so the check after decrementing will never pass, and the
+		// producer will not be double-closed.
+		pData.refs--
+		if pData.refs == 0 {
+			defer pData.close() // Run outside the acbw mutex
+			delete(acbw.producers, pb)
+		}
+		acbw.producersMu.Unlock()
+	}
+	return pData.producer, sync.OnceFunc(unref)
+}
+
+func (acbw *acBalancerWrapper) closeProducers() {
+	acbw.producersMu.Lock()
+	defer acbw.producersMu.Unlock()
+	for pb, pData := range acbw.producers {
+		pData.refs = 0
+		pData.close()
+		delete(acbw.producers, pb)
+	}
+}
+
+// healthProducerRegisterFn is a type alias for the health producer's function
+// for registering listeners.
+type healthProducerRegisterFn = func(context.Context, balancer.SubConn, string, func(balancer.SubConnState)) func()
+
+// healthListenerRegFn returns a function to register a listener for health
+// updates. If client side health checks are disabled, the registered listener
+// will get a single READY (raw connectivity state) update.
+//
+// Client side health checking is enabled when all the following
+// conditions are satisfied:
+// 1. Health checking is not disabled using the dial option.
+// 2. The health package is imported.
+// 3. The health check config is present in the service config.
+func (acbw *acBalancerWrapper) healthListenerRegFn() func(context.Context, func(balancer.SubConnState)) func() {
+	if acbw.ccb.cc.dopts.disableHealthCheck {
+		return noOpRegisterHealthListenerFn
+	}
+	cfg := acbw.ac.cc.healthCheckConfig()
+	if cfg == nil {
+		return noOpRegisterHealthListenerFn
+	}
+	regHealthLisFn := internal.RegisterClientHealthCheckListener
+	if regHealthLisFn == nil {
+		// The health package is not imported.
+		channelz.Error(logger, acbw.ac.channelz, "Health check is requested but health package is not imported.")
+		return noOpRegisterHealthListenerFn
+	}
+	return func(ctx context.Context, listener func(balancer.SubConnState)) func() {
+		return regHealthLisFn.(healthProducerRegisterFn)(ctx, acbw, cfg.ServiceName, listener)
+	}
+}
+
+// RegisterHealthListener accepts a health listener from the LB policy. It sends
+// updates to the health listener as long as the SubConn's connectivity state
+// doesn't change and a new health listener is not registered. To invalidate
+// the currently registered health listener, acbw updates the healthData. If a
+// nil listener is registered, the active health listener is dropped.
+func (acbw *acBalancerWrapper) RegisterHealthListener(listener func(balancer.SubConnState)) {
+	acbw.healthMu.Lock()
+	defer acbw.healthMu.Unlock()
+	acbw.healthData.closeHealthProducer()
+	// listeners should not be registered when the connectivity state
+	// isn't Ready. This may happen when the balancer registers a listener
+	// after the connectivityState is updated, but before it is notified
+	// of the update.
+	if acbw.healthData.connectivityState != connectivity.Ready {
+		return
+	}
+	// Replace the health data to stop sending updates to any previously
+	// registered health listeners.
+	hd := newHealthData(connectivity.Ready)
+	acbw.healthData = hd
+	if listener == nil {
+		return
+	}
+
+	registerFn := acbw.healthListenerRegFn()
+	acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+		if ctx.Err() != nil || acbw.ccb.balancer == nil {
+			return
+		}
+		// Don't send updates if a new listener is registered.
+		acbw.healthMu.Lock()
+		defer acbw.healthMu.Unlock()
+		if acbw.healthData != hd {
+			return
+		}
+		// Serialize the health updates from the health producer with
+		// other calls into the LB policy.
+		listenerWrapper := func(scs balancer.SubConnState) {
+			acbw.ccb.serializer.TrySchedule(func(ctx context.Context) {
+				if ctx.Err() != nil || acbw.ccb.balancer == nil {
+					return
+				}
+				acbw.healthMu.Lock()
+				defer acbw.healthMu.Unlock()
+				if acbw.healthData != hd {
+					return
+				}
+				listener(scs)
+			})
+		}
+
+		hd.closeHealthProducer = registerFn(ctx, listenerWrapper)
+	})
+}

vendor/google.golang.org/grpc/call.go

@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"context"
+)
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+//
+// All errors returned by Invoke are compatible with the status package.
+func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply any, opts ...CallOption) error {
+	// allow interceptor to see all applicable call options, which means those
+	// configured as defaults from dial option as well as per-call options
+	opts = combine(cc.dopts.callOptions, opts)
+
+	if cc.dopts.unaryInt != nil {
+		return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
+	}
+	return invoke(ctx, method, args, reply, cc, opts...)
+}
+
+func combine(o1 []CallOption, o2 []CallOption) []CallOption {
+	// we don't use append because o1 could have extra capacity whose
+	// elements would be overwritten, which could cause inadvertent
+	// sharing (and race conditions) between concurrent calls
+	if len(o1) == 0 {
+		return o2
+	} else if len(o2) == 0 {
+		return o1
+	}
+	ret := make([]CallOption, len(o1)+len(o2))
+	copy(ret, o1)
+	copy(ret[len(o1):], o2)
+	return ret
+}
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+//
+// DEPRECATED: Use ClientConn.Invoke instead.
+func Invoke(ctx context.Context, method string, args, reply any, cc *ClientConn, opts ...CallOption) error {
+	return cc.Invoke(ctx, method, args, reply, opts...)
+}
+
+var unaryStreamDesc = &StreamDesc{ServerStreams: false, ClientStreams: false}
+
+func invoke(ctx context.Context, method string, req, reply any, cc *ClientConn, opts ...CallOption) error {
+	cs, err := newClientStream(ctx, unaryStreamDesc, cc, method, opts...)
+	if err != nil {
+		return err
+	}
+	if err := cs.SendMsg(req); err != nil {
+		return err
+	}
+	return cs.RecvMsg(reply)
+}

vendor/google.golang.org/grpc/channelz/channelz.go

@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package channelz exports internals of the channelz implementation as required
+// by other gRPC packages.
+//
+// The implementation of the channelz spec as defined in
+// https://github.com/grpc/proposal/blob/master/A14-channelz.md, is provided by
+// the `internal/channelz` package.
+//
+// # Experimental
+//
+// Notice: All APIs in this package are experimental and may be removed in a
+// later release.
+package channelz
+
+import "google.golang.org/grpc/internal/channelz"
+
+// Identifier is an opaque identifier which uniquely identifies an entity in the
+// channelz database.
+type Identifier = channelz.Identifier

vendor/google.golang.org/grpc/codec.go

@@ -0,0 +1,105 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"google.golang.org/grpc/encoding"
+	_ "google.golang.org/grpc/encoding/proto" // to register the Codec for "proto"
+	"google.golang.org/grpc/mem"
+)
+
+// baseCodec captures the new encoding.CodecV2 interface without the Name
+// function, allowing it to be implemented by older Codec and encoding.Codec
+// implementations. The omitted Name function is only needed for the register in
+// the encoding package and is not part of the core functionality.
+type baseCodec interface {
+	Marshal(v any) (mem.BufferSlice, error)
+	Unmarshal(data mem.BufferSlice, v any) error
+}
+
+// getCodec returns an encoding.CodecV2 for the codec of the given name (if
+// registered). Initially checks the V2 registry with encoding.GetCodecV2 and
+// returns the V2 codec if it is registered. Otherwise, it checks the V1 registry
+// with encoding.GetCodec and if it is registered wraps it with newCodecV1Bridge
+// to turn it into an encoding.CodecV2. Returns nil otherwise.
+func getCodec(name string) encoding.CodecV2 {
+	if codecV1 := encoding.GetCodec(name); codecV1 != nil {
+		return newCodecV1Bridge(codecV1)
+	}
+
+	return encoding.GetCodecV2(name)
+}
+
+func newCodecV0Bridge(c Codec) baseCodec {
+	return codecV0Bridge{codec: c}
+}
+
+func newCodecV1Bridge(c encoding.Codec) encoding.CodecV2 {
+	return codecV1Bridge{
+		codecV0Bridge: codecV0Bridge{codec: c},
+		name:          c.Name(),
+	}
+}
+
+var _ baseCodec = codecV0Bridge{}
+
+type codecV0Bridge struct {
+	codec interface {
+		Marshal(v any) ([]byte, error)
+		Unmarshal(data []byte, v any) error
+	}
+}
+
+func (c codecV0Bridge) Marshal(v any) (mem.BufferSlice, error) {
+	data, err := c.codec.Marshal(v)
+	if err != nil {
+		return nil, err
+	}
+	return mem.BufferSlice{mem.SliceBuffer(data)}, nil
+}
+
+func (c codecV0Bridge) Unmarshal(data mem.BufferSlice, v any) (err error) {
+	return c.codec.Unmarshal(data.Materialize(), v)
+}
+
+var _ encoding.CodecV2 = codecV1Bridge{}
+
+type codecV1Bridge struct {
+	codecV0Bridge
+	name string
+}
+
+func (c codecV1Bridge) Name() string {
+	return c.name
+}
+
+// Codec defines the interface gRPC uses to encode and decode messages.
+// Note that implementations of this interface must be thread safe;
+// a Codec's methods can be called from concurrent goroutines.
+//
+// Deprecated: use encoding.Codec instead.
+type Codec interface {
+	// Marshal returns the wire format of v.
+	Marshal(v any) ([]byte, error)
+	// Unmarshal parses the wire format into v.
+	Unmarshal(data []byte, v any) error
+	// String returns the name of the Codec implementation.  This is unused by
+	// gRPC.
+	String() string
+}

vendor/google.golang.org/grpc/codes/code_string.go

@@ -0,0 +1,111 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package codes
+
+import (
+	"strconv"
+
+	"google.golang.org/grpc/internal"
+)
+
+func init() {
+	internal.CanonicalString = canonicalString
+}
+
+func (c Code) String() string {
+	switch c {
+	case OK:
+		return "OK"
+	case Canceled:
+		return "Canceled"
+	case Unknown:
+		return "Unknown"
+	case InvalidArgument:
+		return "InvalidArgument"
+	case DeadlineExceeded:
+		return "DeadlineExceeded"
+	case NotFound:
+		return "NotFound"
+	case AlreadyExists:
+		return "AlreadyExists"
+	case PermissionDenied:
+		return "PermissionDenied"
+	case ResourceExhausted:
+		return "ResourceExhausted"
+	case FailedPrecondition:
+		return "FailedPrecondition"
+	case Aborted:
+		return "Aborted"
+	case OutOfRange:
+		return "OutOfRange"
+	case Unimplemented:
+		return "Unimplemented"
+	case Internal:
+		return "Internal"
+	case Unavailable:
+		return "Unavailable"
+	case DataLoss:
+		return "DataLoss"
+	case Unauthenticated:
+		return "Unauthenticated"
+	default:
+		return "Code(" + strconv.FormatInt(int64(c), 10) + ")"
+	}
+}
+
+func canonicalString(c Code) string {
+	switch c {
+	case OK:
+		return "OK"
+	case Canceled:
+		return "CANCELLED"
+	case Unknown:
+		return "UNKNOWN"
+	case InvalidArgument:
+		return "INVALID_ARGUMENT"
+	case DeadlineExceeded:
+		return "DEADLINE_EXCEEDED"
+	case NotFound:
+		return "NOT_FOUND"
+	case AlreadyExists:
+		return "ALREADY_EXISTS"
+	case PermissionDenied:
+		return "PERMISSION_DENIED"
+	case ResourceExhausted:
+		return "RESOURCE_EXHAUSTED"
+	case FailedPrecondition:
+		return "FAILED_PRECONDITION"
+	case Aborted:
+		return "ABORTED"
+	case OutOfRange:
+		return "OUT_OF_RANGE"
+	case Unimplemented:
+		return "UNIMPLEMENTED"
+	case Internal:
+		return "INTERNAL"
+	case Unavailable:
+		return "UNAVAILABLE"
+	case DataLoss:
+		return "DATA_LOSS"
+	case Unauthenticated:
+		return "UNAUTHENTICATED"
+	default:
+		return "CODE(" + strconv.FormatInt(int64(c), 10) + ")"
+	}
+}

vendor/google.golang.org/grpc/codes/codes.go

@@ -0,0 +1,250 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package codes defines the canonical error codes used by gRPC. It is
+// consistent across various languages.
+package codes // import "google.golang.org/grpc/codes"
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// A Code is a status code defined according to the [gRPC documentation].
+//
+// Only the codes defined as consts in this package are valid codes. Do not use
+// other code values.  Behavior of other codes is implementation-specific and
+// interoperability between implementations is not guaranteed.
+//
+// [gRPC documentation]: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
+type Code uint32
+
+const (
+	// OK is returned on success.
+	OK Code = 0
+
+	// Canceled indicates the operation was canceled (typically by the caller).
+	//
+	// The gRPC framework will generate this error code when cancellation
+	// is requested.
+	Canceled Code = 1
+
+	// Unknown error. An example of where this error may be returned is
+	// if a Status value received from another address space belongs to
+	// an error-space that is not known in this address space. Also
+	// errors raised by APIs that do not return enough error information
+	// may be converted to this error.
+	//
+	// The gRPC framework will generate this error code in the above two
+	// mentioned cases.
+	Unknown Code = 2
+
+	// InvalidArgument indicates client specified an invalid argument.
+	// Note that this differs from FailedPrecondition. It indicates arguments
+	// that are problematic regardless of the state of the system
+	// (e.g., a malformed file name).
+	//
+	// This error code will not be generated by the gRPC framework.
+	InvalidArgument Code = 3
+
+	// DeadlineExceeded means operation expired before completion.
+	// For operations that change the state of the system, this error may be
+	// returned even if the operation has completed successfully. For
+	// example, a successful response from a server could have been delayed
+	// long enough for the deadline to expire.
+	//
+	// The gRPC framework will generate this error code when the deadline is
+	// exceeded.
+	DeadlineExceeded Code = 4
+
+	// NotFound means some requested entity (e.g., file or directory) was
+	// not found.
+	//
+	// This error code will not be generated by the gRPC framework.
+	NotFound Code = 5
+
+	// AlreadyExists means an attempt to create an entity failed because one
+	// already exists.
+	//
+	// This error code will not be generated by the gRPC framework.
+	AlreadyExists Code = 6
+
+	// PermissionDenied indicates the caller does not have permission to
+	// execute the specified operation. It must not be used for rejections
+	// caused by exhausting some resource (use ResourceExhausted
+	// instead for those errors). It must not be
+	// used if the caller cannot be identified (use Unauthenticated
+	// instead for those errors).
+	//
+	// This error code will not be generated by the gRPC core framework,
+	// but expect authentication middleware to use it.
+	PermissionDenied Code = 7
+
+	// ResourceExhausted indicates some resource has been exhausted, perhaps
+	// a per-user quota, or perhaps the entire file system is out of space.
+	//
+	// This error code will be generated by the gRPC framework in
+	// out-of-memory and server overload situations, or when a message is
+	// larger than the configured maximum size.
+	ResourceExhausted Code = 8
+
+	// FailedPrecondition indicates operation was rejected because the
+	// system is not in a state required for the operation's execution.
+	// For example, directory to be deleted may be non-empty, an rmdir
+	// operation is applied to a non-directory, etc.
+	//
+	// A litmus test that may help a service implementor in deciding
+	// between FailedPrecondition, Aborted, and Unavailable:
+	//  (a) Use Unavailable if the client can retry just the failing call.
+	//  (b) Use Aborted if the client should retry at a higher-level
+	//      (e.g., restarting a read-modify-write sequence).
+	//  (c) Use FailedPrecondition if the client should not retry until
+	//      the system state has been explicitly fixed. E.g., if an "rmdir"
+	//      fails because the directory is non-empty, FailedPrecondition
+	//      should be returned since the client should not retry unless
+	//      they have first fixed up the directory by deleting files from it.
+	//  (d) Use FailedPrecondition if the client performs conditional
+	//      REST Get/Update/Delete on a resource and the resource on the
+	//      server does not match the condition. E.g., conflicting
+	//      read-modify-write on the same resource.
+	//
+	// This error code will not be generated by the gRPC framework.
+	FailedPrecondition Code = 9
+
+	// Aborted indicates the operation was aborted, typically due to a
+	// concurrency issue like sequencer check failures, transaction aborts,
+	// etc.
+	//
+	// See litmus test above for deciding between FailedPrecondition,
+	// Aborted, and Unavailable.
+	//
+	// This error code will not be generated by the gRPC framework.
+	Aborted Code = 10
+
+	// OutOfRange means operation was attempted past the valid range.
+	// E.g., seeking or reading past end of file.
+	//
+	// Unlike InvalidArgument, this error indicates a problem that may
+	// be fixed if the system state changes. For example, a 32-bit file
+	// system will generate InvalidArgument if asked to read at an
+	// offset that is not in the range [0,2^32-1], but it will generate
+	// OutOfRange if asked to read from an offset past the current
+	// file size.
+	//
+	// There is a fair bit of overlap between FailedPrecondition and
+	// OutOfRange. We recommend using OutOfRange (the more specific
+	// error) when it applies so that callers who are iterating through
+	// a space can easily look for an OutOfRange error to detect when
+	// they are done.
+	//
+	// This error code will not be generated by the gRPC framework.
+	OutOfRange Code = 11
+
+	// Unimplemented indicates operation is not implemented or not
+	// supported/enabled in this service.
+	//
+	// This error code will be generated by the gRPC framework. Most
+	// commonly, you will see this error code when a method implementation
+	// is missing on the server. It can also be generated for unknown
+	// compression algorithms or a disagreement as to whether an RPC should
+	// be streaming.
+	Unimplemented Code = 12
+
+	// Internal errors. Means some invariants expected by underlying
+	// system has been broken. If you see one of these errors,
+	// something is very broken.
+	//
+	// This error code will be generated by the gRPC framework in several
+	// internal error conditions.
+	Internal Code = 13
+
+	// Unavailable indicates the service is currently unavailable.
+	// This is a most likely a transient condition and may be corrected
+	// by retrying with a backoff. Note that it is not always safe to retry
+	// non-idempotent operations.
+	//
+	// See litmus test above for deciding between FailedPrecondition,
+	// Aborted, and Unavailable.
+	//
+	// This error code will be generated by the gRPC framework during
+	// abrupt shutdown of a server process or network connection.
+	Unavailable Code = 14
+
+	// DataLoss indicates unrecoverable data loss or corruption.
+	//
+	// This error code will not be generated by the gRPC framework.
+	DataLoss Code = 15
+
+	// Unauthenticated indicates the request does not have valid
+	// authentication credentials for the operation.
+	//
+	// The gRPC framework will generate this error code when the
+	// authentication metadata is invalid or a Credentials callback fails,
+	// but also expect authentication middleware to generate it.
+	Unauthenticated Code = 16
+
+	_maxCode = 17
+)
+
+var strToCode = map[string]Code{
+	`"OK"`: OK,
+	`"CANCELLED"`:/* [sic] */ Canceled,
+	`"UNKNOWN"`:             Unknown,
+	`"INVALID_ARGUMENT"`:    InvalidArgument,
+	`"DEADLINE_EXCEEDED"`:   DeadlineExceeded,
+	`"NOT_FOUND"`:           NotFound,
+	`"ALREADY_EXISTS"`:      AlreadyExists,
+	`"PERMISSION_DENIED"`:   PermissionDenied,
+	`"RESOURCE_EXHAUSTED"`:  ResourceExhausted,
+	`"FAILED_PRECONDITION"`: FailedPrecondition,
+	`"ABORTED"`:             Aborted,
+	`"OUT_OF_RANGE"`:        OutOfRange,
+	`"UNIMPLEMENTED"`:       Unimplemented,
+	`"INTERNAL"`:            Internal,
+	`"UNAVAILABLE"`:         Unavailable,
+	`"DATA_LOSS"`:           DataLoss,
+	`"UNAUTHENTICATED"`:     Unauthenticated,
+}
+
+// UnmarshalJSON unmarshals b into the Code.
+func (c *Code) UnmarshalJSON(b []byte) error {
+	// From json.Unmarshaler: By convention, to approximate the behavior of
+	// Unmarshal itself, Unmarshalers implement UnmarshalJSON([]byte("null")) as
+	// a no-op.
+	if string(b) == "null" {
+		return nil
+	}
+	if c == nil {
+		return fmt.Errorf("nil receiver passed to UnmarshalJSON")
+	}
+
+	if ci, err := strconv.ParseUint(string(b), 10, 32); err == nil {
+		if ci >= _maxCode {
+			return fmt.Errorf("invalid code: %d", ci)
+		}
+
+		*c = Code(ci)
+		return nil
+	}
+
+	if jc, ok := strToCode[string(b)]; ok {
+		*c = jc
+		return nil
+	}
+	return fmt.Errorf("invalid code: %q", string(b))
+}

vendor/google.golang.org/grpc/connectivity/connectivity.go

@@ -0,0 +1,94 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package connectivity defines connectivity semantics.
+// For details, see https://github.com/grpc/grpc/blob/master/doc/connectivity-semantics-and-api.md.
+package connectivity
+
+import (
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("core")
+
+// State indicates the state of connectivity.
+// It can be the state of a ClientConn or SubConn.
+type State int
+
+func (s State) String() string {
+	switch s {
+	case Idle:
+		return "IDLE"
+	case Connecting:
+		return "CONNECTING"
+	case Ready:
+		return "READY"
+	case TransientFailure:
+		return "TRANSIENT_FAILURE"
+	case Shutdown:
+		return "SHUTDOWN"
+	default:
+		logger.Errorf("unknown connectivity state: %d", s)
+		return "INVALID_STATE"
+	}
+}
+
+const (
+	// Idle indicates the ClientConn is idle.
+	Idle State = iota
+	// Connecting indicates the ClientConn is connecting.
+	Connecting
+	// Ready indicates the ClientConn is ready for work.
+	Ready
+	// TransientFailure indicates the ClientConn has seen a failure but expects to recover.
+	TransientFailure
+	// Shutdown indicates the ClientConn has started shutting down.
+	Shutdown
+)
+
+// ServingMode indicates the current mode of operation of the server.
+//
+// Only xDS enabled gRPC servers currently report their serving mode.
+type ServingMode int
+
+const (
+	// ServingModeStarting indicates that the server is starting up.
+	ServingModeStarting ServingMode = iota
+	// ServingModeServing indicates that the server contains all required
+	// configuration and is serving RPCs.
+	ServingModeServing
+	// ServingModeNotServing indicates that the server is not accepting new
+	// connections. Existing connections will be closed gracefully, allowing
+	// in-progress RPCs to complete. A server enters this mode when it does not
+	// contain the required configuration to serve RPCs.
+	ServingModeNotServing
+)
+
+func (s ServingMode) String() string {
+	switch s {
+	case ServingModeStarting:
+		return "STARTING"
+	case ServingModeServing:
+		return "SERVING"
+	case ServingModeNotServing:
+		return "NOT_SERVING"
+	default:
+		logger.Errorf("unknown serving mode: %d", s)
+		return "INVALID_MODE"
+	}
+}

vendor/google.golang.org/grpc/credentials/credentials.go

@@ -0,0 +1,337 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package credentials implements various credentials supported by gRPC library,
+// which encapsulate all the state needed by a client to authenticate with a
+// server and make various assertions, e.g., about the client's identity, role,
+// or whether it is authorized to make a particular call.
+package credentials // import "google.golang.org/grpc/credentials"
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+
+	"google.golang.org/grpc/attributes"
+	icredentials "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/protobuf/proto"
+)
+
+// PerRPCCredentials defines the common interface for the credentials which need to
+// attach security information to every RPC (e.g., oauth2).
+type PerRPCCredentials interface {
+	// GetRequestMetadata gets the current request metadata, refreshing tokens
+	// if required. This should be called by the transport layer on each
+	// request, and the data should be populated in headers or other
+	// context. If a status code is returned, it will be used as the status for
+	// the RPC (restricted to an allowable set of codes as defined by gRFC
+	// A54). uri is the URI of the entry point for the request.  When supported
+	// by the underlying implementation, ctx can be used for timeout and
+	// cancellation. Additionally, RequestInfo data will be available via ctx
+	// to this call.
+	GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error)
+	// RequireTransportSecurity indicates whether the credentials requires
+	// transport security.
+	RequireTransportSecurity() bool
+}
+
+// SecurityLevel defines the protection level on an established connection.
+//
+// This API is experimental.
+type SecurityLevel int
+
+const (
+	// InvalidSecurityLevel indicates an invalid security level.
+	// The zero SecurityLevel value is invalid for backward compatibility.
+	InvalidSecurityLevel SecurityLevel = iota
+	// NoSecurity indicates a connection is insecure.
+	NoSecurity
+	// IntegrityOnly indicates a connection only provides integrity protection.
+	IntegrityOnly
+	// PrivacyAndIntegrity indicates a connection provides both privacy and integrity protection.
+	PrivacyAndIntegrity
+)
+
+// String returns SecurityLevel in a string format.
+func (s SecurityLevel) String() string {
+	switch s {
+	case NoSecurity:
+		return "NoSecurity"
+	case IntegrityOnly:
+		return "IntegrityOnly"
+	case PrivacyAndIntegrity:
+		return "PrivacyAndIntegrity"
+	}
+	return fmt.Sprintf("invalid SecurityLevel: %v", int(s))
+}
+
+// CommonAuthInfo contains authenticated information common to AuthInfo implementations.
+// It should be embedded in a struct implementing AuthInfo to provide additional information
+// about the credentials.
+//
+// This API is experimental.
+type CommonAuthInfo struct {
+	SecurityLevel SecurityLevel
+}
+
+// GetCommonAuthInfo returns the pointer to CommonAuthInfo struct.
+func (c CommonAuthInfo) GetCommonAuthInfo() CommonAuthInfo {
+	return c
+}
+
+// ProtocolInfo provides static information regarding transport credentials.
+type ProtocolInfo struct {
+	// ProtocolVersion is the gRPC wire protocol version.
+	//
+	// Deprecated: this is unused by gRPC.
+	ProtocolVersion string
+	// SecurityProtocol is the security protocol in use.
+	SecurityProtocol string
+	// SecurityVersion is the security protocol version.  It is a static version string from the
+	// credentials, not a value that reflects per-connection protocol negotiation.  To retrieve
+	// details about the credentials used for a connection, use the Peer's AuthInfo field instead.
+	//
+	// Deprecated: please use Peer.AuthInfo.
+	SecurityVersion string
+	// ServerName is the user-configured server name.  If set, this overrides
+	// the default :authority header used for all RPCs on the channel using the
+	// containing credentials, unless grpc.WithAuthority is set on the channel,
+	// in which case that setting will take precedence.
+	//
+	// This must be a valid `:authority` header according to
+	// [RFC3986](https://datatracker.ietf.org/doc/html/rfc3986#section-3.2).
+	//
+	// Deprecated: Users should use grpc.WithAuthority to override the authority
+	// on a channel instead of configuring the credentials.
+	ServerName string
+}
+
+// AuthInfo defines the common interface for the auth information the users are interested in.
+// A struct that implements AuthInfo should embed CommonAuthInfo by including additional
+// information about the credentials in it.
+type AuthInfo interface {
+	AuthType() string
+}
+
+// AuthorityValidator validates the authority used to override the `:authority`
+// header. This is an optional interface that implementations of AuthInfo can
+// implement if they support per-RPC authority overrides. It is invoked when the
+// application attempts to override the HTTP/2 `:authority` header using the
+// CallAuthority call option.
+type AuthorityValidator interface {
+	// ValidateAuthority checks the authority value used to override the
+	// `:authority` header. The authority parameter is the override value
+	// provided by the application via the CallAuthority option. This value
+	// typically corresponds to the server hostname or endpoint the RPC is
+	// targeting. It returns non-nil error if the validation fails.
+	ValidateAuthority(authority string) error
+}
+
+// ErrConnDispatched indicates that rawConn has been dispatched out of gRPC
+// and the caller should not close rawConn.
+var ErrConnDispatched = errors.New("credentials: rawConn is dispatched out of gRPC")
+
+// TransportCredentials defines the common interface for all the live gRPC wire
+// protocols and supported transport security protocols (e.g., TLS, SSL).
+type TransportCredentials interface {
+	// ClientHandshake does the authentication handshake specified by the
+	// corresponding authentication protocol on rawConn for clients. It returns
+	// the authenticated connection and the corresponding auth information
+	// about the connection.  The auth information should embed CommonAuthInfo
+	// to return additional information about the credentials. Implementations
+	// must use the provided context to implement timely cancellation.  gRPC
+	// will try to reconnect if the error returned is a temporary error
+	// (io.EOF, context.DeadlineExceeded or err.Temporary() == true).  If the
+	// returned error is a wrapper error, implementations should make sure that
+	// the error implements Temporary() to have the correct retry behaviors.
+	// Additionally, ClientHandshakeInfo data will be available via the context
+	// passed to this call.
+	//
+	// The second argument to this method is the `:authority` header value used
+	// while creating new streams on this connection after authentication
+	// succeeds. Implementations must use this as the server name during the
+	// authentication handshake.
+	//
+	// If the returned net.Conn is closed, it MUST close the net.Conn provided.
+	ClientHandshake(context.Context, string, net.Conn) (net.Conn, AuthInfo, error)
+	// ServerHandshake does the authentication handshake for servers. It returns
+	// the authenticated connection and the corresponding auth information about
+	// the connection. The auth information should embed CommonAuthInfo to return additional information
+	// about the credentials.
+	//
+	// If the returned net.Conn is closed, it MUST close the net.Conn provided.
+	ServerHandshake(net.Conn) (net.Conn, AuthInfo, error)
+	// Info provides the ProtocolInfo of this TransportCredentials.
+	Info() ProtocolInfo
+	// Clone makes a copy of this TransportCredentials.
+	Clone() TransportCredentials
+	// OverrideServerName specifies the value used for the following:
+	//
+	// - verifying the hostname on the returned certificates
+	// - as SNI in the client's handshake to support virtual hosting
+	// - as the value for `:authority` header at stream creation time
+	//
+	// The provided string should be a valid `:authority` header according to
+	// [RFC3986](https://datatracker.ietf.org/doc/html/rfc3986#section-3.2).
+	//
+	// Deprecated: this method is unused by gRPC.  Users should use
+	// grpc.WithAuthority to override the authority on a channel instead of
+	// configuring the credentials.
+	OverrideServerName(string) error
+}
+
+// Bundle is a combination of TransportCredentials and PerRPCCredentials.
+//
+// It also contains a mode switching method, so it can be used as a combination
+// of different credential policies.
+//
+// Bundle cannot be used together with individual TransportCredentials.
+// PerRPCCredentials from Bundle will be appended to other PerRPCCredentials.
+//
+// This API is experimental.
+type Bundle interface {
+	// TransportCredentials returns the transport credentials from the Bundle.
+	//
+	// Implementations must return non-nil transport credentials. If transport
+	// security is not needed by the Bundle, implementations may choose to
+	// return insecure.NewCredentials().
+	TransportCredentials() TransportCredentials
+
+	// PerRPCCredentials returns the per-RPC credentials from the Bundle.
+	//
+	// May be nil if per-RPC credentials are not needed.
+	PerRPCCredentials() PerRPCCredentials
+
+	// NewWithMode should make a copy of Bundle, and switch mode. Modifying the
+	// existing Bundle may cause races.
+	//
+	// NewWithMode returns nil if the requested mode is not supported.
+	NewWithMode(mode string) (Bundle, error)
+}
+
+// RequestInfo contains request data attached to the context passed to GetRequestMetadata calls.
+//
+// This API is experimental.
+type RequestInfo struct {
+	// The method passed to Invoke or NewStream for this RPC. (For proto methods, this has the format "/some.Service/Method")
+	Method string
+	// AuthInfo contains the information from a security handshake (TransportCredentials.ClientHandshake, TransportCredentials.ServerHandshake)
+	AuthInfo AuthInfo
+}
+
+// requestInfoKey is a struct to be used as the key to store RequestInfo in a
+// context.
+type requestInfoKey struct{}
+
+// RequestInfoFromContext extracts the RequestInfo from the context if it exists.
+//
+// This API is experimental.
+func RequestInfoFromContext(ctx context.Context) (ri RequestInfo, ok bool) {
+	ri, ok = ctx.Value(requestInfoKey{}).(RequestInfo)
+	return ri, ok
+}
+
+// NewContextWithRequestInfo creates a new context from ctx and attaches ri to it.
+//
+// This RequestInfo will be accessible via RequestInfoFromContext.
+//
+// Intended to be used from tests for PerRPCCredentials implementations (that
+// often need to check connection's SecurityLevel). Should not be used from
+// non-test code: the gRPC client already prepares a context with the correct
+// RequestInfo attached when calling PerRPCCredentials.GetRequestMetadata.
+//
+// This API is experimental.
+func NewContextWithRequestInfo(ctx context.Context, ri RequestInfo) context.Context {
+	return context.WithValue(ctx, requestInfoKey{}, ri)
+}
+
+// ClientHandshakeInfo holds data to be passed to ClientHandshake. This makes
+// it possible to pass arbitrary data to the handshaker from gRPC, resolver,
+// balancer etc. Individual credential implementations control the actual
+// format of the data that they are willing to receive.
+//
+// This API is experimental.
+type ClientHandshakeInfo struct {
+	// Attributes contains the attributes for the address. It could be provided
+	// by the gRPC, resolver, balancer etc.
+	Attributes *attributes.Attributes
+}
+
+// ClientHandshakeInfoFromContext returns the ClientHandshakeInfo struct stored
+// in ctx.
+//
+// This API is experimental.
+func ClientHandshakeInfoFromContext(ctx context.Context) ClientHandshakeInfo {
+	chi, _ := icredentials.ClientHandshakeInfoFromContext(ctx).(ClientHandshakeInfo)
+	return chi
+}
+
+// CheckSecurityLevel checks if a connection's security level is greater than or equal to the specified one.
+// It returns success if 1) the condition is satisfied or 2) AuthInfo struct does not implement GetCommonAuthInfo() method
+// or 3) CommonAuthInfo.SecurityLevel has an invalid zero value. For 2) and 3), it is for the purpose of backward-compatibility.
+//
+// This API is experimental.
+func CheckSecurityLevel(ai AuthInfo, level SecurityLevel) error {
+	type internalInfo interface {
+		GetCommonAuthInfo() CommonAuthInfo
+	}
+	if ai == nil {
+		return errors.New("AuthInfo is nil")
+	}
+	if ci, ok := ai.(internalInfo); ok {
+		// CommonAuthInfo.SecurityLevel has an invalid value.
+		if ci.GetCommonAuthInfo().SecurityLevel == InvalidSecurityLevel {
+			return nil
+		}
+		if ci.GetCommonAuthInfo().SecurityLevel < level {
+			return fmt.Errorf("requires SecurityLevel %v; connection has %v", level, ci.GetCommonAuthInfo().SecurityLevel)
+		}
+	}
+	// The condition is satisfied or AuthInfo struct does not implement GetCommonAuthInfo() method.
+	return nil
+}
+
+// ChannelzSecurityInfo defines the interface that security protocols should implement
+// in order to provide security info to channelz.
+//
+// This API is experimental.
+type ChannelzSecurityInfo interface {
+	GetSecurityValue() ChannelzSecurityValue
+}
+
+// ChannelzSecurityValue defines the interface that GetSecurityValue() return value
+// should satisfy. This interface should only be satisfied by *TLSChannelzSecurityValue
+// and *OtherChannelzSecurityValue.
+//
+// This API is experimental.
+type ChannelzSecurityValue interface {
+	isChannelzSecurityValue()
+}
+
+// OtherChannelzSecurityValue defines the struct that non-TLS protocol should return
+// from GetSecurityValue(), which contains protocol specific security info. Note
+// the Value field will be sent to users of channelz requesting channel info, and
+// thus sensitive info should better be avoided.
+//
+// This API is experimental.
+type OtherChannelzSecurityValue struct {
+	ChannelzSecurityValue
+	Name  string
+	Value proto.Message
+}

vendor/google.golang.org/grpc/credentials/insecure/insecure.go

@@ -0,0 +1,104 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package insecure provides an implementation of the
+// credentials.TransportCredentials interface which disables transport security.
+package insecure
+
+import (
+	"context"
+	"net"
+
+	"google.golang.org/grpc/credentials"
+)
+
+// NewCredentials returns a credentials which disables transport security.
+//
+// Note that using this credentials with per-RPC credentials which require
+// transport security is incompatible and will cause RPCs to fail.
+func NewCredentials() credentials.TransportCredentials {
+	return insecureTC{}
+}
+
+// insecureTC implements the insecure transport credentials. The handshake
+// methods simply return the passed in net.Conn and set the security level to
+// NoSecurity.
+type insecureTC struct{}
+
+func (insecureTC) ClientHandshake(_ context.Context, _ string, conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	return conn, info{credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity}}, nil
+}
+
+func (insecureTC) ServerHandshake(conn net.Conn) (net.Conn, credentials.AuthInfo, error) {
+	return conn, info{credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity}}, nil
+}
+
+func (insecureTC) Info() credentials.ProtocolInfo {
+	return credentials.ProtocolInfo{SecurityProtocol: "insecure"}
+}
+
+func (insecureTC) Clone() credentials.TransportCredentials {
+	return insecureTC{}
+}
+
+func (insecureTC) OverrideServerName(string) error {
+	return nil
+}
+
+// info contains the auth information for an insecure connection.
+// It implements the AuthInfo interface.
+type info struct {
+	credentials.CommonAuthInfo
+}
+
+// AuthType returns the type of info as a string.
+func (info) AuthType() string {
+	return "insecure"
+}
+
+// ValidateAuthority allows any value to be overridden for the :authority
+// header.
+func (info) ValidateAuthority(string) error {
+	return nil
+}
+
+// insecureBundle implements an insecure bundle.
+// An insecure bundle provides a thin wrapper around insecureTC to support
+// the credentials.Bundle interface.
+type insecureBundle struct{}
+
+// NewBundle returns a bundle with disabled transport security and no per rpc credential.
+func NewBundle() credentials.Bundle {
+	return insecureBundle{}
+}
+
+// NewWithMode returns a new insecure Bundle. The mode is ignored.
+func (insecureBundle) NewWithMode(string) (credentials.Bundle, error) {
+	return insecureBundle{}, nil
+}
+
+// PerRPCCredentials returns an nil implementation as insecure
+// bundle does not support a per rpc credential.
+func (insecureBundle) PerRPCCredentials() credentials.PerRPCCredentials {
+	return nil
+}
+
+// TransportCredentials returns the underlying insecure transport credential.
+func (insecureBundle) TransportCredentials() credentials.TransportCredentials {
+	return NewCredentials()
+}

vendor/google.golang.org/grpc/credentials/tls.go

@@ -0,0 +1,320 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+	"os"
+
+	"google.golang.org/grpc/grpclog"
+	credinternal "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/grpc/internal/envconfig"
+)
+
+const alpnFailureHelpMessage = "If you upgraded from a grpc-go version earlier than 1.67, your TLS connections may have stopped working due to ALPN enforcement. For more details, see: https://github.com/grpc/grpc-go/issues/434"
+
+var logger = grpclog.Component("credentials")
+
+// TLSInfo contains the auth information for a TLS authenticated connection.
+// It implements the AuthInfo interface.
+type TLSInfo struct {
+	State tls.ConnectionState
+	CommonAuthInfo
+	// This API is experimental.
+	SPIFFEID *url.URL
+}
+
+// AuthType returns the type of TLSInfo as a string.
+func (t TLSInfo) AuthType() string {
+	return "tls"
+}
+
+// ValidateAuthority validates the provided authority being used to override the
+// :authority header by verifying it against the peer certificates. It returns a
+// non-nil error if the validation fails.
+func (t TLSInfo) ValidateAuthority(authority string) error {
+	var errs []error
+	for _, cert := range t.State.PeerCertificates {
+		var err error
+		if err = cert.VerifyHostname(authority); err == nil {
+			return nil
+		}
+		errs = append(errs, err)
+	}
+	return fmt.Errorf("credentials: invalid authority %q: %v", authority, errors.Join(errs...))
+}
+
+// cipherSuiteLookup returns the string version of a TLS cipher suite ID.
+func cipherSuiteLookup(cipherSuiteID uint16) string {
+	for _, s := range tls.CipherSuites() {
+		if s.ID == cipherSuiteID {
+			return s.Name
+		}
+	}
+	for _, s := range tls.InsecureCipherSuites() {
+		if s.ID == cipherSuiteID {
+			return s.Name
+		}
+	}
+	return fmt.Sprintf("unknown ID: %v", cipherSuiteID)
+}
+
+// GetSecurityValue returns security info requested by channelz.
+func (t TLSInfo) GetSecurityValue() ChannelzSecurityValue {
+	v := &TLSChannelzSecurityValue{
+		StandardName: cipherSuiteLookup(t.State.CipherSuite),
+	}
+	// Currently there's no way to get LocalCertificate info from tls package.
+	if len(t.State.PeerCertificates) > 0 {
+		v.RemoteCertificate = t.State.PeerCertificates[0].Raw
+	}
+	return v
+}
+
+// tlsCreds is the credentials required for authenticating a connection using TLS.
+type tlsCreds struct {
+	// TLS configuration
+	config *tls.Config
+}
+
+func (c tlsCreds) Info() ProtocolInfo {
+	return ProtocolInfo{
+		SecurityProtocol: "tls",
+		SecurityVersion:  "1.2",
+		ServerName:       c.config.ServerName,
+	}
+}
+
+func (c *tlsCreds) ClientHandshake(ctx context.Context, authority string, rawConn net.Conn) (_ net.Conn, _ AuthInfo, err error) {
+	// use local cfg to avoid clobbering ServerName if using multiple endpoints
+	cfg := credinternal.CloneTLSConfig(c.config)
+
+	serverName, _, err := net.SplitHostPort(authority)
+	if err != nil {
+		// If the authority had no host port or if the authority cannot be parsed, use it as-is.
+		serverName = authority
+	}
+	cfg.ServerName = serverName
+
+	conn := tls.Client(rawConn, cfg)
+	errChannel := make(chan error, 1)
+	go func() {
+		errChannel <- conn.Handshake()
+		close(errChannel)
+	}()
+	select {
+	case err := <-errChannel:
+		if err != nil {
+			conn.Close()
+			return nil, nil, err
+		}
+	case <-ctx.Done():
+		conn.Close()
+		return nil, nil, ctx.Err()
+	}
+
+	// The negotiated protocol can be either of the following:
+	// 1. h2: When the server supports ALPN. Only HTTP/2 can be negotiated since
+	//    it is the only protocol advertised by the client during the handshake.
+	//    The tls library ensures that the server chooses a protocol advertised
+	//    by the client.
+	// 2. "" (empty string): If the server doesn't support ALPN. ALPN is a requirement
+	//    for using HTTP/2 over TLS. We can terminate the connection immediately.
+	np := conn.ConnectionState().NegotiatedProtocol
+	if np == "" {
+		if envconfig.EnforceALPNEnabled {
+			conn.Close()
+			return nil, nil, fmt.Errorf("credentials: cannot check peer: missing selected ALPN property. %s", alpnFailureHelpMessage)
+		}
+		logger.Warningf("Allowing TLS connection to server %q with ALPN disabled. TLS connections to servers with ALPN disabled will be disallowed in future grpc-go releases", cfg.ServerName)
+	}
+	tlsInfo := TLSInfo{
+		State: conn.ConnectionState(),
+		CommonAuthInfo: CommonAuthInfo{
+			SecurityLevel: PrivacyAndIntegrity,
+		},
+	}
+	id := credinternal.SPIFFEIDFromState(conn.ConnectionState())
+	if id != nil {
+		tlsInfo.SPIFFEID = id
+	}
+	return credinternal.WrapSyscallConn(rawConn, conn), tlsInfo, nil
+}
+
+func (c *tlsCreds) ServerHandshake(rawConn net.Conn) (net.Conn, AuthInfo, error) {
+	conn := tls.Server(rawConn, c.config)
+	if err := conn.Handshake(); err != nil {
+		conn.Close()
+		return nil, nil, err
+	}
+	cs := conn.ConnectionState()
+	// The negotiated application protocol can be empty only if the client doesn't
+	// support ALPN. In such cases, we can close the connection since ALPN is required
+	// for using HTTP/2 over TLS.
+	if cs.NegotiatedProtocol == "" {
+		if envconfig.EnforceALPNEnabled {
+			conn.Close()
+			return nil, nil, fmt.Errorf("credentials: cannot check peer: missing selected ALPN property. %s", alpnFailureHelpMessage)
+		} else if logger.V(2) {
+			logger.Info("Allowing TLS connection from client with ALPN disabled. TLS connections with ALPN disabled will be disallowed in future grpc-go releases")
+		}
+	}
+	tlsInfo := TLSInfo{
+		State: cs,
+		CommonAuthInfo: CommonAuthInfo{
+			SecurityLevel: PrivacyAndIntegrity,
+		},
+	}
+	id := credinternal.SPIFFEIDFromState(conn.ConnectionState())
+	if id != nil {
+		tlsInfo.SPIFFEID = id
+	}
+	return credinternal.WrapSyscallConn(rawConn, conn), tlsInfo, nil
+}
+
+func (c *tlsCreds) Clone() TransportCredentials {
+	return NewTLS(c.config)
+}
+
+func (c *tlsCreds) OverrideServerName(serverNameOverride string) error {
+	c.config.ServerName = serverNameOverride
+	return nil
+}
+
+// The following cipher suites are forbidden for use with HTTP/2 by
+// https://datatracker.ietf.org/doc/html/rfc7540#appendix-A
+var tls12ForbiddenCipherSuites = map[uint16]struct{}{
+	tls.TLS_RSA_WITH_AES_128_CBC_SHA:         {},
+	tls.TLS_RSA_WITH_AES_256_CBC_SHA:         {},
+	tls.TLS_RSA_WITH_AES_128_GCM_SHA256:      {},
+	tls.TLS_RSA_WITH_AES_256_GCM_SHA384:      {},
+	tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA: {},
+	tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA: {},
+	tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:   {},
+	tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:   {},
+}
+
+// NewTLS uses c to construct a TransportCredentials based on TLS.
+func NewTLS(c *tls.Config) TransportCredentials {
+	config := applyDefaults(c)
+	if config.GetConfigForClient != nil {
+		oldFn := config.GetConfigForClient
+		config.GetConfigForClient = func(hello *tls.ClientHelloInfo) (*tls.Config, error) {
+			cfgForClient, err := oldFn(hello)
+			if err != nil || cfgForClient == nil {
+				return cfgForClient, err
+			}
+			return applyDefaults(cfgForClient), nil
+		}
+	}
+	return &tlsCreds{config: config}
+}
+
+func applyDefaults(c *tls.Config) *tls.Config {
+	config := credinternal.CloneTLSConfig(c)
+	config.NextProtos = credinternal.AppendH2ToNextProtos(config.NextProtos)
+	// If the user did not configure a MinVersion and did not configure a
+	// MaxVersion < 1.2, use MinVersion=1.2, which is required by
+	// https://datatracker.ietf.org/doc/html/rfc7540#section-9.2
+	if config.MinVersion == 0 && (config.MaxVersion == 0 || config.MaxVersion >= tls.VersionTLS12) {
+		config.MinVersion = tls.VersionTLS12
+	}
+	// If the user did not configure CipherSuites, use all "secure" cipher
+	// suites reported by the TLS package, but remove some explicitly forbidden
+	// by https://datatracker.ietf.org/doc/html/rfc7540#appendix-A
+	if config.CipherSuites == nil {
+		for _, cs := range tls.CipherSuites() {
+			if _, ok := tls12ForbiddenCipherSuites[cs.ID]; !ok {
+				config.CipherSuites = append(config.CipherSuites, cs.ID)
+			}
+		}
+	}
+	return config
+}
+
+// NewClientTLSFromCert constructs TLS credentials from the provided root
+// certificate authority certificate(s) to validate server connections. If
+// certificates to establish the identity of the client need to be included in
+// the credentials (eg: for mTLS), use NewTLS instead, where a complete
+// tls.Config can be specified.
+//
+// serverNameOverride is for testing only. If set to a non empty string, it will
+// override the virtual host name of authority (e.g. :authority header field) in
+// requests.  Users should use grpc.WithAuthority passed to grpc.NewClient to
+// override the authority of the client instead.
+func NewClientTLSFromCert(cp *x509.CertPool, serverNameOverride string) TransportCredentials {
+	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp})
+}
+
+// NewClientTLSFromFile constructs TLS credentials from the provided root
+// certificate authority certificate file(s) to validate server connections. If
+// certificates to establish the identity of the client need to be included in
+// the credentials (eg: for mTLS), use NewTLS instead, where a complete
+// tls.Config can be specified.
+//
+// serverNameOverride is for testing only. If set to a non empty string, it will
+// override the virtual host name of authority (e.g. :authority header field) in
+// requests.  Users should use grpc.WithAuthority passed to grpc.NewClient to
+// override the authority of the client instead.
+func NewClientTLSFromFile(certFile, serverNameOverride string) (TransportCredentials, error) {
+	b, err := os.ReadFile(certFile)
+	if err != nil {
+		return nil, err
+	}
+	cp := x509.NewCertPool()
+	if !cp.AppendCertsFromPEM(b) {
+		return nil, fmt.Errorf("credentials: failed to append certificates")
+	}
+	return NewTLS(&tls.Config{ServerName: serverNameOverride, RootCAs: cp}), nil
+}
+
+// NewServerTLSFromCert constructs TLS credentials from the input certificate for server.
+func NewServerTLSFromCert(cert *tls.Certificate) TransportCredentials {
+	return NewTLS(&tls.Config{Certificates: []tls.Certificate{*cert}})
+}
+
+// NewServerTLSFromFile constructs TLS credentials from the input certificate file and key
+// file for server.
+func NewServerTLSFromFile(certFile, keyFile string) (TransportCredentials, error) {
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		return nil, err
+	}
+	return NewTLS(&tls.Config{Certificates: []tls.Certificate{cert}}), nil
+}
+
+// TLSChannelzSecurityValue defines the struct that TLS protocol should return
+// from GetSecurityValue(), containing security info like cipher and certificate used.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type TLSChannelzSecurityValue struct {
+	ChannelzSecurityValue
+	StandardName      string
+	LocalCertificate  []byte
+	RemoteCertificate []byte
+}

vendor/google.golang.org/grpc/dialoptions.go

@@ -0,0 +1,797 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"context"
+	"net"
+	"net/url"
+	"time"
+
+	"google.golang.org/grpc/backoff"
+	"google.golang.org/grpc/channelz"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/internal"
+	internalbackoff "google.golang.org/grpc/internal/backoff"
+	"google.golang.org/grpc/internal/binarylog"
+	"google.golang.org/grpc/internal/transport"
+	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/mem"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/stats"
+)
+
+const (
+	// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#limits-on-retries-and-hedges
+	defaultMaxCallAttempts = 5
+)
+
+func init() {
+	internal.AddGlobalDialOptions = func(opt ...DialOption) {
+		globalDialOptions = append(globalDialOptions, opt...)
+	}
+	internal.ClearGlobalDialOptions = func() {
+		globalDialOptions = nil
+	}
+	internal.AddGlobalPerTargetDialOptions = func(opt any) {
+		if ptdo, ok := opt.(perTargetDialOption); ok {
+			globalPerTargetDialOptions = append(globalPerTargetDialOptions, ptdo)
+		}
+	}
+	internal.ClearGlobalPerTargetDialOptions = func() {
+		globalPerTargetDialOptions = nil
+	}
+	internal.WithBinaryLogger = withBinaryLogger
+	internal.JoinDialOptions = newJoinDialOption
+	internal.DisableGlobalDialOptions = newDisableGlobalDialOptions
+	internal.WithBufferPool = withBufferPool
+}
+
+// dialOptions configure a Dial call. dialOptions are set by the DialOption
+// values passed to Dial.
+type dialOptions struct {
+	unaryInt  UnaryClientInterceptor
+	streamInt StreamClientInterceptor
+
+	chainUnaryInts  []UnaryClientInterceptor
+	chainStreamInts []StreamClientInterceptor
+
+	compressorV0                Compressor
+	dc                          Decompressor
+	bs                          internalbackoff.Strategy
+	block                       bool
+	returnLastError             bool
+	timeout                     time.Duration
+	authority                   string
+	binaryLogger                binarylog.Logger
+	copts                       transport.ConnectOptions
+	callOptions                 []CallOption
+	channelzParent              channelz.Identifier
+	disableServiceConfig        bool
+	disableRetry                bool
+	disableHealthCheck          bool
+	minConnectTimeout           func() time.Duration
+	defaultServiceConfig        *ServiceConfig // defaultServiceConfig is parsed from defaultServiceConfigRawJSON.
+	defaultServiceConfigRawJSON *string
+	resolvers                   []resolver.Builder
+	idleTimeout                 time.Duration
+	defaultScheme               string
+	maxCallAttempts             int
+	enableLocalDNSResolution    bool // Specifies if target hostnames should be resolved when proxying is enabled.
+	useProxy                    bool // Specifies if a server should be connected via proxy.
+}
+
+// DialOption configures how we set up the connection.
+type DialOption interface {
+	apply(*dialOptions)
+}
+
+var globalDialOptions []DialOption
+
+// perTargetDialOption takes a parsed target and returns a dial option to apply.
+//
+// This gets called after NewClient() parses the target, and allows per target
+// configuration set through a returned DialOption. The DialOption will not take
+// effect if specifies a resolver builder, as that Dial Option is factored in
+// while parsing target.
+type perTargetDialOption interface {
+	// DialOption returns a Dial Option to apply.
+	DialOptionForTarget(parsedTarget url.URL) DialOption
+}
+
+var globalPerTargetDialOptions []perTargetDialOption
+
+// EmptyDialOption does not alter the dial configuration. It can be embedded in
+// another structure to build custom dial options.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type EmptyDialOption struct{}
+
+func (EmptyDialOption) apply(*dialOptions) {}
+
+type disableGlobalDialOptions struct{}
+
+func (disableGlobalDialOptions) apply(*dialOptions) {}
+
+// newDisableGlobalDialOptions returns a DialOption that prevents the ClientConn
+// from applying the global DialOptions (set via AddGlobalDialOptions).
+func newDisableGlobalDialOptions() DialOption {
+	return &disableGlobalDialOptions{}
+}
+
+// funcDialOption wraps a function that modifies dialOptions into an
+// implementation of the DialOption interface.
+type funcDialOption struct {
+	f func(*dialOptions)
+}
+
+func (fdo *funcDialOption) apply(do *dialOptions) {
+	fdo.f(do)
+}
+
+func newFuncDialOption(f func(*dialOptions)) *funcDialOption {
+	return &funcDialOption{
+		f: f,
+	}
+}
+
+type joinDialOption struct {
+	opts []DialOption
+}
+
+func (jdo *joinDialOption) apply(do *dialOptions) {
+	for _, opt := range jdo.opts {
+		opt.apply(do)
+	}
+}
+
+func newJoinDialOption(opts ...DialOption) DialOption {
+	return &joinDialOption{opts: opts}
+}
+
+// WithSharedWriteBuffer allows reusing per-connection transport write buffer.
+// If this option is set to true every connection will release the buffer after
+// flushing the data on the wire.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithSharedWriteBuffer(val bool) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.SharedWriteBuffer = val
+	})
+}
+
+// WithWriteBufferSize determines how much data can be batched before doing a
+// write on the wire. The default value for this buffer is 32KB.
+//
+// Zero or negative values will disable the write buffer such that each write
+// will be on underlying connection. Note: A Send call may not directly
+// translate to a write.
+func WithWriteBufferSize(s int) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.WriteBufferSize = s
+	})
+}
+
+// WithReadBufferSize lets you set the size of read buffer, this determines how
+// much data can be read at most for each read syscall.
+//
+// The default value for this buffer is 32KB. Zero or negative values will
+// disable read buffer for a connection so data framer can access the
+// underlying conn directly.
+func WithReadBufferSize(s int) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.ReadBufferSize = s
+	})
+}
+
+// WithInitialWindowSize returns a DialOption which sets the value for initial
+// window size on a stream. The lower bound for window size is 64K and any value
+// smaller than that will be ignored.
+func WithInitialWindowSize(s int32) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.InitialWindowSize = s
+		o.copts.StaticWindowSize = true
+	})
+}
+
+// WithInitialConnWindowSize returns a DialOption which sets the value for
+// initial window size on a connection. The lower bound for window size is 64K
+// and any value smaller than that will be ignored.
+func WithInitialConnWindowSize(s int32) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.InitialConnWindowSize = s
+		o.copts.StaticWindowSize = true
+	})
+}
+
+// WithStaticStreamWindowSize returns a DialOption which sets the initial
+// stream window size to the value provided and disables dynamic flow control.
+func WithStaticStreamWindowSize(s int32) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.InitialWindowSize = s
+		o.copts.StaticWindowSize = true
+	})
+}
+
+// WithStaticConnWindowSize returns a DialOption which sets the initial
+// connection window size to the value provided and disables dynamic flow
+// control.
+func WithStaticConnWindowSize(s int32) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.InitialConnWindowSize = s
+		o.copts.StaticWindowSize = true
+	})
+}
+
+// WithMaxMsgSize returns a DialOption which sets the maximum message size the
+// client can receive.
+//
+// Deprecated: use WithDefaultCallOptions(MaxCallRecvMsgSize(s)) instead.  Will
+// be supported throughout 1.x.
+func WithMaxMsgSize(s int) DialOption {
+	return WithDefaultCallOptions(MaxCallRecvMsgSize(s))
+}
+
+// WithDefaultCallOptions returns a DialOption which sets the default
+// CallOptions for calls over the connection.
+func WithDefaultCallOptions(cos ...CallOption) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.callOptions = append(o.callOptions, cos...)
+	})
+}
+
+// WithCodec returns a DialOption which sets a codec for message marshaling and
+// unmarshaling.
+//
+// Deprecated: use WithDefaultCallOptions(ForceCodec(_)) instead.  Will be
+// supported throughout 1.x.
+func WithCodec(c Codec) DialOption {
+	return WithDefaultCallOptions(CallCustomCodec(c))
+}
+
+// WithCompressor returns a DialOption which sets a Compressor to use for
+// message compression. It has lower priority than the compressor set by the
+// UseCompressor CallOption.
+//
+// Deprecated: use UseCompressor instead.  Will be supported throughout 1.x.
+func WithCompressor(cp Compressor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.compressorV0 = cp
+	})
+}
+
+// WithDecompressor returns a DialOption which sets a Decompressor to use for
+// incoming message decompression.  If incoming response messages are encoded
+// using the decompressor's Type(), it will be used.  Otherwise, the message
+// encoding will be used to look up the compressor registered via
+// encoding.RegisterCompressor, which will then be used to decompress the
+// message.  If no compressor is registered for the encoding, an Unimplemented
+// status error will be returned.
+//
+// Deprecated: use encoding.RegisterCompressor instead.  Will be supported
+// throughout 1.x.
+func WithDecompressor(dc Decompressor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.dc = dc
+	})
+}
+
+// WithConnectParams configures the ClientConn to use the provided ConnectParams
+// for creating and maintaining connections to servers.
+//
+// The backoff configuration specified as part of the ConnectParams overrides
+// all defaults specified in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. Consider
+// using the backoff.DefaultConfig as a base, in cases where you want to
+// override only a subset of the backoff configuration.
+func WithConnectParams(p ConnectParams) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.bs = internalbackoff.Exponential{Config: p.Backoff}
+		o.minConnectTimeout = func() time.Duration {
+			return p.MinConnectTimeout
+		}
+	})
+}
+
+// WithBackoffMaxDelay configures the dialer to use the provided maximum delay
+// when backing off after failed connection attempts.
+//
+// Deprecated: use WithConnectParams instead. Will be supported throughout 1.x.
+func WithBackoffMaxDelay(md time.Duration) DialOption {
+	return WithBackoffConfig(BackoffConfig{MaxDelay: md})
+}
+
+// WithBackoffConfig configures the dialer to use the provided backoff
+// parameters after connection failures.
+//
+// Deprecated: use WithConnectParams instead. Will be supported throughout 1.x.
+func WithBackoffConfig(b BackoffConfig) DialOption {
+	bc := backoff.DefaultConfig
+	bc.MaxDelay = b.MaxDelay
+	return withBackoff(internalbackoff.Exponential{Config: bc})
+}
+
+// withBackoff sets the backoff strategy used for connectRetryNum after a failed
+// connection attempt.
+//
+// This can be exported if arbitrary backoff strategies are allowed by gRPC.
+func withBackoff(bs internalbackoff.Strategy) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.bs = bs
+	})
+}
+
+// WithBlock returns a DialOption which makes callers of Dial block until the
+// underlying connection is up. Without this, Dial returns immediately and
+// connecting the server happens in background.
+//
+// Use of this feature is not recommended.  For more information, please see:
+// https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
+//
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
+func WithBlock() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.block = true
+	})
+}
+
+// WithReturnConnectionError returns a DialOption which makes the client connection
+// return a string containing both the last connection error that occurred and
+// the context.DeadlineExceeded error.
+// Implies WithBlock()
+//
+// Use of this feature is not recommended.  For more information, please see:
+// https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
+//
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
+func WithReturnConnectionError() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.block = true
+		o.returnLastError = true
+	})
+}
+
+// WithInsecure returns a DialOption which disables transport security for this
+// ClientConn. Under the hood, it uses insecure.NewCredentials().
+//
+// Note that using this DialOption with per-RPC credentials (through
+// WithCredentialsBundle or WithPerRPCCredentials) which require transport
+// security is incompatible and will cause RPCs to fail.
+//
+// Deprecated: use WithTransportCredentials and insecure.NewCredentials()
+// instead. Will be supported throughout 1.x.
+func WithInsecure() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.TransportCredentials = insecure.NewCredentials()
+	})
+}
+
+// WithNoProxy returns a DialOption which disables the use of proxies for this
+// ClientConn. This is ignored if WithDialer or WithContextDialer are used.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithNoProxy() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.useProxy = false
+	})
+}
+
+// WithLocalDNSResolution forces local DNS name resolution even when a proxy is
+// specified in the environment.  By default, the server name is provided
+// directly to the proxy as part of the CONNECT handshake. This is ignored if
+// WithNoProxy is used.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithLocalDNSResolution() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.enableLocalDNSResolution = true
+	})
+}
+
+// WithTransportCredentials returns a DialOption which configures a connection
+// level security credentials (e.g., TLS/SSL). This should not be used together
+// with WithCredentialsBundle.
+func WithTransportCredentials(creds credentials.TransportCredentials) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.TransportCredentials = creds
+	})
+}
+
+// WithPerRPCCredentials returns a DialOption which sets credentials and places
+// auth state on each outbound RPC.
+func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.PerRPCCredentials = append(o.copts.PerRPCCredentials, creds)
+	})
+}
+
+// WithCredentialsBundle returns a DialOption to set a credentials bundle for
+// the ClientConn.WithCreds. This should not be used together with
+// WithTransportCredentials.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithCredentialsBundle(b credentials.Bundle) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.CredsBundle = b
+	})
+}
+
+// WithTimeout returns a DialOption that configures a timeout for dialing a
+// ClientConn initially. This is valid if and only if WithBlock() is present.
+//
+// Deprecated: this DialOption is not supported by NewClient.
+// Will be supported throughout 1.x.
+func WithTimeout(d time.Duration) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.timeout = d
+	})
+}
+
+// WithContextDialer returns a DialOption that sets a dialer to create
+// connections. If FailOnNonTempDialError() is set to true, and an error is
+// returned by f, gRPC checks the error's Temporary() method to decide if it
+// should try to reconnect to the network address.
+//
+// Note that gRPC by default performs name resolution on the target passed to
+// NewClient. To bypass name resolution and cause the target string to be
+// passed directly to the dialer here instead, use the "passthrough" resolver
+// by specifying it in the target string, e.g. "passthrough:target".
+//
+// Note: All supported releases of Go (as of December 2023) override the OS
+// defaults for TCP keepalive time and interval to 15s. To enable TCP keepalive
+// with OS defaults for keepalive time and interval, use a net.Dialer that sets
+// the KeepAlive field to a negative value, and sets the SO_KEEPALIVE socket
+// option to true from the Control field. For a concrete example of how to do
+// this, see internal.NetDialerWithTCPKeepalive().
+//
+// For more information, please see [issue 23459] in the Go GitHub repo.
+//
+// [issue 23459]: https://github.com/golang/go/issues/23459
+func WithContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.Dialer = f
+	})
+}
+
+// WithDialer returns a DialOption that specifies a function to use for dialing
+// network addresses. If FailOnNonTempDialError() is set to true, and an error
+// is returned by f, gRPC checks the error's Temporary() method to decide if it
+// should try to reconnect to the network address.
+//
+// Deprecated: use WithContextDialer instead.  Will be supported throughout
+// 1.x.
+func WithDialer(f func(string, time.Duration) (net.Conn, error)) DialOption {
+	return WithContextDialer(
+		func(ctx context.Context, addr string) (net.Conn, error) {
+			if deadline, ok := ctx.Deadline(); ok {
+				return f(addr, time.Until(deadline))
+			}
+			return f(addr, 0)
+		})
+}
+
+// WithStatsHandler returns a DialOption that specifies the stats handler for
+// all the RPCs and underlying network connections in this ClientConn.
+func WithStatsHandler(h stats.Handler) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		if h == nil {
+			logger.Error("ignoring nil parameter in grpc.WithStatsHandler ClientOption")
+			// Do not allow a nil stats handler, which would otherwise cause
+			// panics.
+			return
+		}
+		o.copts.StatsHandlers = append(o.copts.StatsHandlers, h)
+	})
+}
+
+// withBinaryLogger returns a DialOption that specifies the binary logger for
+// this ClientConn.
+func withBinaryLogger(bl binarylog.Logger) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.binaryLogger = bl
+	})
+}
+
+// FailOnNonTempDialError returns a DialOption that specifies if gRPC fails on
+// non-temporary dial errors. If f is true, and dialer returns a non-temporary
+// error, gRPC will fail the connection to the network address and won't try to
+// reconnect. The default value of FailOnNonTempDialError is false.
+//
+// FailOnNonTempDialError only affects the initial dial, and does not do
+// anything useful unless you are also using WithBlock().
+//
+// Use of this feature is not recommended.  For more information, please see:
+// https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md
+//
+// Deprecated: this DialOption is not supported by NewClient.
+// This API may be changed or removed in a
+// later release.
+func FailOnNonTempDialError(f bool) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.FailOnNonTempDialError = f
+	})
+}
+
+// WithUserAgent returns a DialOption that specifies a user agent string for all
+// the RPCs.
+func WithUserAgent(s string) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.UserAgent = s + " " + grpcUA
+	})
+}
+
+// WithKeepaliveParams returns a DialOption that specifies keepalive parameters
+// for the client transport.
+//
+// Keepalive is disabled by default.
+func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption {
+	if kp.Time < internal.KeepaliveMinPingTime {
+		logger.Warningf("Adjusting keepalive ping interval to minimum period of %v", internal.KeepaliveMinPingTime)
+		kp.Time = internal.KeepaliveMinPingTime
+	}
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.KeepaliveParams = kp
+	})
+}
+
+// WithUnaryInterceptor returns a DialOption that specifies the interceptor for
+// unary RPCs.
+func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.unaryInt = f
+	})
+}
+
+// WithChainUnaryInterceptor returns a DialOption that specifies the chained
+// interceptor for unary RPCs. The first interceptor will be the outer most,
+// while the last interceptor will be the inner most wrapper around the real call.
+// All interceptors added by this method will be chained, and the interceptor
+// defined by WithUnaryInterceptor will always be prepended to the chain.
+func WithChainUnaryInterceptor(interceptors ...UnaryClientInterceptor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.chainUnaryInts = append(o.chainUnaryInts, interceptors...)
+	})
+}
+
+// WithStreamInterceptor returns a DialOption that specifies the interceptor for
+// streaming RPCs.
+func WithStreamInterceptor(f StreamClientInterceptor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.streamInt = f
+	})
+}
+
+// WithChainStreamInterceptor returns a DialOption that specifies the chained
+// interceptor for streaming RPCs. The first interceptor will be the outer most,
+// while the last interceptor will be the inner most wrapper around the real call.
+// All interceptors added by this method will be chained, and the interceptor
+// defined by WithStreamInterceptor will always be prepended to the chain.
+func WithChainStreamInterceptor(interceptors ...StreamClientInterceptor) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.chainStreamInts = append(o.chainStreamInts, interceptors...)
+	})
+}
+
+// WithAuthority returns a DialOption that specifies the value to be used as the
+// :authority pseudo-header and as the server name in authentication handshake.
+// This overrides all other ways of setting authority on the channel, but can be
+// overridden per-call by using grpc.CallAuthority.
+func WithAuthority(a string) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.authority = a
+	})
+}
+
+// WithChannelzParentID returns a DialOption that specifies the channelz ID of
+// current ClientConn's parent. This function is used in nested channel creation
+// (e.g. grpclb dial).
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithChannelzParentID(c channelz.Identifier) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.channelzParent = c
+	})
+}
+
+// WithDisableServiceConfig returns a DialOption that causes gRPC to ignore any
+// service config provided by the resolver and provides a hint to the resolver
+// to not fetch service configs.
+//
+// Note that this dial option only disables service config from resolver. If
+// default service config is provided, gRPC will use the default service config.
+func WithDisableServiceConfig() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.disableServiceConfig = true
+	})
+}
+
+// WithDefaultServiceConfig returns a DialOption that configures the default
+// service config, which will be used in cases where:
+//
+// 1. WithDisableServiceConfig is also used, or
+//
+// 2. The name resolver does not provide a service config or provides an
+// invalid service config.
+//
+// The parameter s is the JSON representation of the default service config.
+// For more information about service configs, see:
+// https://github.com/grpc/grpc/blob/master/doc/service_config.md
+// For a simple example of usage, see:
+// examples/features/load_balancing/client/main.go
+func WithDefaultServiceConfig(s string) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.defaultServiceConfigRawJSON = &s
+	})
+}
+
+// WithDisableRetry returns a DialOption that disables retries, even if the
+// service config enables them.  This does not impact transparent retries, which
+// will happen automatically if no data is written to the wire or if the RPC is
+// unprocessed by the remote server.
+func WithDisableRetry() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.disableRetry = true
+	})
+}
+
+// MaxHeaderListSizeDialOption is a DialOption that specifies the maximum
+// (uncompressed) size of header list that the client is prepared to accept.
+type MaxHeaderListSizeDialOption struct {
+	MaxHeaderListSize uint32
+}
+
+func (o MaxHeaderListSizeDialOption) apply(do *dialOptions) {
+	do.copts.MaxHeaderListSize = &o.MaxHeaderListSize
+}
+
+// WithMaxHeaderListSize returns a DialOption that specifies the maximum
+// (uncompressed) size of header list that the client is prepared to accept.
+func WithMaxHeaderListSize(s uint32) DialOption {
+	return MaxHeaderListSizeDialOption{
+		MaxHeaderListSize: s,
+	}
+}
+
+// WithDisableHealthCheck disables the LB channel health checking for all
+// SubConns of this ClientConn.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithDisableHealthCheck() DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.disableHealthCheck = true
+	})
+}
+
+func defaultDialOptions() dialOptions {
+	return dialOptions{
+		copts: transport.ConnectOptions{
+			ReadBufferSize:  defaultReadBufSize,
+			WriteBufferSize: defaultWriteBufSize,
+			UserAgent:       grpcUA,
+			BufferPool:      mem.DefaultBufferPool(),
+		},
+		bs:                       internalbackoff.DefaultExponential,
+		idleTimeout:              30 * time.Minute,
+		defaultScheme:            "dns",
+		maxCallAttempts:          defaultMaxCallAttempts,
+		useProxy:                 true,
+		enableLocalDNSResolution: false,
+	}
+}
+
+// withMinConnectDeadline specifies the function that clientconn uses to
+// get minConnectDeadline. This can be used to make connection attempts happen
+// faster/slower.
+//
+// For testing purpose only.
+func withMinConnectDeadline(f func() time.Duration) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.minConnectTimeout = f
+	})
+}
+
+// withDefaultScheme is used to allow Dial to use "passthrough" as the default
+// name resolver, while NewClient uses "dns" otherwise.
+func withDefaultScheme(s string) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.defaultScheme = s
+	})
+}
+
+// WithResolvers allows a list of resolver implementations to be registered
+// locally with the ClientConn without needing to be globally registered via
+// resolver.Register.  They will be matched against the scheme used for the
+// current Dial only, and will take precedence over the global registry.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithResolvers(rs ...resolver.Builder) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.resolvers = append(o.resolvers, rs...)
+	})
+}
+
+// WithIdleTimeout returns a DialOption that configures an idle timeout for the
+// channel. If the channel is idle for the configured timeout, i.e there are no
+// ongoing RPCs and no new RPCs are initiated, the channel will enter idle mode
+// and as a result the name resolver and load balancer will be shut down. The
+// channel will exit idle mode when the Connect() method is called or when an
+// RPC is initiated.
+//
+// A default timeout of 30 minutes will be used if this dial option is not set
+// at dial time and idleness can be disabled by passing a timeout of zero.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WithIdleTimeout(d time.Duration) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.idleTimeout = d
+	})
+}
+
+// WithMaxCallAttempts returns a DialOption that configures the maximum number
+// of attempts per call (including retries and hedging) using the channel.
+// Service owners may specify a higher value for these parameters, but higher
+// values will be treated as equal to the maximum value by the client
+// implementation. This mitigates security concerns related to the service
+// config being transferred to the client via DNS.
+//
+// A value of 5 will be used if this dial option is not set or n < 2.
+func WithMaxCallAttempts(n int) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		if n < 2 {
+			n = defaultMaxCallAttempts
+		}
+		o.maxCallAttempts = n
+	})
+}
+
+func withBufferPool(bufferPool mem.BufferPool) DialOption {
+	return newFuncDialOption(func(o *dialOptions) {
+		o.copts.BufferPool = bufferPool
+	})
+}

vendor/google.golang.org/grpc/doc.go

@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+//go:generate ./scripts/regenerate.sh
+
+/*
+Package grpc implements an RPC system called gRPC.
+
+See grpc.io for more information about gRPC.
+*/
+package grpc // import "google.golang.org/grpc"

vendor/google.golang.org/grpc/encoding/encoding.go

@@ -0,0 +1,151 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package encoding defines the interface for the compressor and codec, and
+// functions to register and retrieve compressors and codecs.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package encoding
+
+import (
+	"io"
+	"slices"
+	"strings"
+
+	"google.golang.org/grpc/encoding/internal"
+	"google.golang.org/grpc/internal/grpcutil"
+)
+
+// Identity specifies the optional encoding for uncompressed streams.
+// It is intended for grpc internal use only.
+const Identity = "identity"
+
+func init() {
+	internal.RegisterCompressorForTesting = func(c Compressor) func() {
+		name := c.Name()
+		curCompressor, found := registeredCompressor[name]
+		RegisterCompressor(c)
+		return func() {
+			if found {
+				registeredCompressor[name] = curCompressor
+				return
+			}
+			delete(registeredCompressor, name)
+			grpcutil.RegisteredCompressorNames = slices.DeleteFunc(grpcutil.RegisteredCompressorNames, func(s string) bool {
+				return s == name
+			})
+		}
+	}
+}
+
+// Compressor is used for compressing and decompressing when sending or
+// receiving messages.
+//
+// If a Compressor implements `DecompressedSize(compressedBytes []byte) int`,
+// gRPC will invoke it to determine the size of the buffer allocated for the
+// result of decompression.  A return value of -1 indicates unknown size.
+type Compressor interface {
+	// Compress writes the data written to wc to w after compressing it.  If an
+	// error occurs while initializing the compressor, that error is returned
+	// instead.
+	Compress(w io.Writer) (io.WriteCloser, error)
+	// Decompress reads data from r, decompresses it, and provides the
+	// uncompressed data via the returned io.Reader.  If an error occurs while
+	// initializing the decompressor, that error is returned instead.
+	Decompress(r io.Reader) (io.Reader, error)
+	// Name is the name of the compression codec and is used to set the content
+	// coding header.  The result must be static; the result cannot change
+	// between calls.
+	Name() string
+}
+
+var registeredCompressor = make(map[string]Compressor)
+
+// RegisterCompressor registers the compressor with gRPC by its name.  It can
+// be activated when sending an RPC via grpc.UseCompressor().  It will be
+// automatically accessed when receiving a message based on the content coding
+// header.  Servers also use it to send a response with the same encoding as
+// the request.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe.  If multiple Compressors are
+// registered with the same name, the one registered last will take effect.
+func RegisterCompressor(c Compressor) {
+	registeredCompressor[c.Name()] = c
+	if !grpcutil.IsCompressorNameRegistered(c.Name()) {
+		grpcutil.RegisteredCompressorNames = append(grpcutil.RegisteredCompressorNames, c.Name())
+	}
+}
+
+// GetCompressor returns Compressor for the given compressor name.
+func GetCompressor(name string) Compressor {
+	return registeredCompressor[name]
+}
+
+// Codec defines the interface gRPC uses to encode and decode messages.  Note
+// that implementations of this interface must be thread safe; a Codec's
+// methods can be called from concurrent goroutines.
+type Codec interface {
+	// Marshal returns the wire format of v.
+	Marshal(v any) ([]byte, error)
+	// Unmarshal parses the wire format into v.
+	Unmarshal(data []byte, v any) error
+	// Name returns the name of the Codec implementation. The returned string
+	// will be used as part of content type in transmission.  The result must be
+	// static; the result cannot change between calls.
+	Name() string
+}
+
+var registeredCodecs = make(map[string]any)
+
+// RegisterCodec registers the provided Codec for use with all gRPC clients and
+// servers.
+//
+// The Codec will be stored and looked up by result of its Name() method, which
+// should match the content-subtype of the encoding handled by the Codec.  This
+// is case-insensitive, and is stored and looked up as lowercase.  If the
+// result of calling Name() is an empty string, RegisterCodec will panic. See
+// Content-Type on
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe.  If multiple Codecs are
+// registered with the same name, the one registered last will take effect.
+func RegisterCodec(codec Codec) {
+	if codec == nil {
+		panic("cannot register a nil Codec")
+	}
+	if codec.Name() == "" {
+		panic("cannot register Codec with empty string result for Name()")
+	}
+	contentSubtype := strings.ToLower(codec.Name())
+	registeredCodecs[contentSubtype] = codec
+}
+
+// GetCodec gets a registered Codec by content-subtype, or nil if no Codec is
+// registered for the content-subtype.
+//
+// The content-subtype is expected to be lowercase.
+func GetCodec(contentSubtype string) Codec {
+	c, _ := registeredCodecs[contentSubtype].(Codec)
+	return c
+}

vendor/google.golang.org/grpc/encoding/encoding_v2.go

@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package encoding
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/mem"
+)
+
+// CodecV2 defines the interface gRPC uses to encode and decode messages. Note
+// that implementations of this interface must be thread safe; a CodecV2's
+// methods can be called from concurrent goroutines.
+type CodecV2 interface {
+	// Marshal returns the wire format of v. The buffers in the returned
+	// [mem.BufferSlice] must have at least one reference each, which will be freed
+	// by gRPC when they are no longer needed.
+	Marshal(v any) (out mem.BufferSlice, err error)
+	// Unmarshal parses the wire format into v. Note that data will be freed as soon
+	// as this function returns. If the codec wishes to guarantee access to the data
+	// after this function, it must take its own reference that it frees when it is
+	// no longer needed.
+	Unmarshal(data mem.BufferSlice, v any) error
+	// Name returns the name of the Codec implementation. The returned string
+	// will be used as part of content type in transmission.  The result must be
+	// static; the result cannot change between calls.
+	Name() string
+}
+
+// RegisterCodecV2 registers the provided CodecV2 for use with all gRPC clients and
+// servers.
+//
+// The CodecV2 will be stored and looked up by result of its Name() method, which
+// should match the content-subtype of the encoding handled by the CodecV2.  This
+// is case-insensitive, and is stored and looked up as lowercase.  If the
+// result of calling Name() is an empty string, RegisterCodecV2 will panic. See
+// Content-Type on
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+//
+// If both a Codec and CodecV2 are registered with the same name, the CodecV2
+// will be used.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe.  If multiple Codecs are
+// registered with the same name, the one registered last will take effect.
+func RegisterCodecV2(codec CodecV2) {
+	if codec == nil {
+		panic("cannot register a nil CodecV2")
+	}
+	if codec.Name() == "" {
+		panic("cannot register CodecV2 with empty string result for Name()")
+	}
+	contentSubtype := strings.ToLower(codec.Name())
+	registeredCodecs[contentSubtype] = codec
+}
+
+// GetCodecV2 gets a registered CodecV2 by content-subtype, or nil if no CodecV2 is
+// registered for the content-subtype.
+//
+// The content-subtype is expected to be lowercase.
+func GetCodecV2(contentSubtype string) CodecV2 {
+	c, _ := registeredCodecs[contentSubtype].(CodecV2)
+	return c
+}

vendor/google.golang.org/grpc/encoding/internal/internal.go

@@ -0,0 +1,28 @@
+/*
+ *
+ * Copyright 2025 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains code internal to the encoding package.
+package internal
+
+// RegisterCompressorForTesting registers a compressor in the global compressor
+// registry. It returns a cleanup function that should be called at the end
+// of the test to unregister the compressor.
+//
+// This prevents compressors registered in one test from appearing in the
+// encoding headers of subsequent tests.
+var RegisterCompressorForTesting any // func RegisterCompressor(c Compressor) func()

vendor/google.golang.org/grpc/encoding/proto/proto.go

@@ -0,0 +1,112 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package proto defines the protobuf codec. Importing this package will
+// register the codec.
+package proto
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/mem"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/protoadapt"
+)
+
+// Name is the name registered for the proto compressor.
+const Name = "proto"
+
+func init() {
+	encoding.RegisterCodecV2(&codecV2{})
+}
+
+// codec is a CodecV2 implementation with protobuf. It is the default codec for
+// gRPC.
+type codecV2 struct{}
+
+func (c *codecV2) Marshal(v any) (data mem.BufferSlice, err error) {
+	vv := messageV2Of(v)
+	if vv == nil {
+		return nil, fmt.Errorf("proto: failed to marshal, message is %T, want proto.Message", v)
+	}
+
+	// Important: if we remove this Size call then we cannot use
+	// UseCachedSize in MarshalOptions below.
+	size := proto.Size(vv)
+
+	// MarshalOptions with UseCachedSize allows reusing the result from the
+	// previous Size call. This is safe here because:
+	//
+	// 1. We just computed the size.
+	// 2. We assume the message is not being mutated concurrently.
+	//
+	// Important: If the proto.Size call above is removed, using UseCachedSize
+	// becomes unsafe and may lead to incorrect marshaling.
+	//
+	// For more details, see the doc of UseCachedSize:
+	// https://pkg.go.dev/google.golang.org/protobuf/proto#MarshalOptions
+	marshalOptions := proto.MarshalOptions{UseCachedSize: true}
+
+	if mem.IsBelowBufferPoolingThreshold(size) {
+		buf, err := marshalOptions.Marshal(vv)
+		if err != nil {
+			return nil, err
+		}
+		data = append(data, mem.SliceBuffer(buf))
+	} else {
+		pool := mem.DefaultBufferPool()
+		buf := pool.Get(size)
+		if _, err := marshalOptions.MarshalAppend((*buf)[:0], vv); err != nil {
+			pool.Put(buf)
+			return nil, err
+		}
+		data = append(data, mem.NewBuffer(buf, pool))
+	}
+
+	return data, nil
+}
+
+func (c *codecV2) Unmarshal(data mem.BufferSlice, v any) (err error) {
+	vv := messageV2Of(v)
+	if vv == nil {
+		return fmt.Errorf("failed to unmarshal, message is %T, want proto.Message", v)
+	}
+
+	buf := data.MaterializeToBuffer(mem.DefaultBufferPool())
+	defer buf.Free()
+	// TODO: Upgrade proto.Unmarshal to support mem.BufferSlice. Right now, it's not
+	//  really possible without a major overhaul of the proto package, but the
+	//  vtprotobuf library may be able to support this.
+	return proto.Unmarshal(buf.ReadOnlyData(), vv)
+}
+
+func messageV2Of(v any) proto.Message {
+	switch v := v.(type) {
+	case protoadapt.MessageV1:
+		return protoadapt.MessageV2Of(v)
+	case protoadapt.MessageV2:
+		return v
+	}
+
+	return nil
+}
+
+func (c *codecV2) Name() string {
+	return Name
+}

vendor/google.golang.org/grpc/experimental/stats/metricregistry.go

@@ -0,0 +1,342 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package stats
+
+import (
+	"maps"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/stats"
+)
+
+func init() {
+	internal.SnapshotMetricRegistryForTesting = snapshotMetricsRegistryForTesting
+}
+
+var logger = grpclog.Component("metrics-registry")
+
+// DefaultMetrics are the default metrics registered through global metrics
+// registry. This is written to at initialization time only, and is read only
+// after initialization.
+var DefaultMetrics = stats.NewMetricSet()
+
+// MetricDescriptor is the data for a registered metric.
+type MetricDescriptor struct {
+	// The name of this metric. This name must be unique across the whole binary
+	// (including any per call metrics). See
+	// https://github.com/grpc/proposal/blob/master/A79-non-per-call-metrics-architecture.md#metric-instrument-naming-conventions
+	// for metric naming conventions.
+	Name string
+	// The description of this metric.
+	Description string
+	// The unit (e.g. entries, seconds) of this metric.
+	Unit string
+	// The required label keys for this metric. These are intended to
+	// metrics emitted from a stats handler.
+	Labels []string
+	// The optional label keys for this metric. These are intended to attached
+	// to metrics emitted from a stats handler if configured.
+	OptionalLabels []string
+	// Whether this metric is on by default.
+	Default bool
+	// The type of metric. This is set by the metric registry, and not intended
+	// to be set by a component registering a metric.
+	Type MetricType
+	// Bounds are the bounds of this metric. This only applies to histogram
+	// metrics. If unset or set with length 0, stats handlers will fall back to
+	// default bounds.
+	Bounds []float64
+}
+
+// MetricType is the type of metric.
+type MetricType int
+
+// Type of metric supported by this instrument registry.
+const (
+	MetricTypeIntCount MetricType = iota
+	MetricTypeFloatCount
+	MetricTypeIntHisto
+	MetricTypeFloatHisto
+	MetricTypeIntGauge
+	MetricTypeIntUpDownCount
+	MetricTypeIntAsyncGauge
+)
+
+// Int64CountHandle is a typed handle for a int count metric. This handle
+// is passed at the recording point in order to know which metric to record
+// on.
+type Int64CountHandle MetricDescriptor
+
+// Descriptor returns the int64 count handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64CountHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 count value on the metrics recorder provided.
+func (h *Int64CountHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Count(h, incr, labels...)
+}
+
+// Int64UpDownCountHandle is a typed handle for an int up-down counter metric.
+// This handle is passed at the recording point in order to know which metric
+// to record on.
+type Int64UpDownCountHandle MetricDescriptor
+
+// Descriptor returns the int64 up-down counter handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64UpDownCountHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 up-down counter value on the metrics recorder provided.
+// The value 'v' can be positive to increment or negative to decrement.
+func (h *Int64UpDownCountHandle) Record(recorder MetricsRecorder, v int64, labels ...string) {
+	recorder.RecordInt64UpDownCount(h, v, labels...)
+}
+
+// Float64CountHandle is a typed handle for a float count metric. This handle is
+// passed at the recording point in order to know which metric to record on.
+type Float64CountHandle MetricDescriptor
+
+// Descriptor returns the float64 count handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Float64CountHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the float64 count value on the metrics recorder provided.
+func (h *Float64CountHandle) Record(recorder MetricsRecorder, incr float64, labels ...string) {
+	recorder.RecordFloat64Count(h, incr, labels...)
+}
+
+// Int64HistoHandle is a typed handle for an int histogram metric. This handle
+// is passed at the recording point in order to know which metric to record on.
+type Int64HistoHandle MetricDescriptor
+
+// Descriptor returns the int64 histo handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64HistoHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 histo value on the metrics recorder provided.
+func (h *Int64HistoHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Histo(h, incr, labels...)
+}
+
+// Float64HistoHandle is a typed handle for a float histogram metric. This
+// handle is passed at the recording point in order to know which metric to
+// record on.
+type Float64HistoHandle MetricDescriptor
+
+// Descriptor returns the float64 histo handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Float64HistoHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the float64 histo value on the metrics recorder provided.
+func (h *Float64HistoHandle) Record(recorder MetricsRecorder, incr float64, labels ...string) {
+	recorder.RecordFloat64Histo(h, incr, labels...)
+}
+
+// Int64GaugeHandle is a typed handle for an int gauge metric. This handle is
+// passed at the recording point in order to know which metric to record on.
+type Int64GaugeHandle MetricDescriptor
+
+// Descriptor returns the int64 gauge handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64GaugeHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 histo value on the metrics recorder provided.
+func (h *Int64GaugeHandle) Record(recorder MetricsRecorder, incr int64, labels ...string) {
+	recorder.RecordInt64Gauge(h, incr, labels...)
+}
+
+// AsyncMetric is a marker interface for asynchronous metric types.
+type AsyncMetric interface {
+	isAsync()
+	Descriptor() *MetricDescriptor
+}
+
+// Int64AsyncGaugeHandle is a typed handle for an int gauge metric. This handle is
+// passed at the recording point in order to know which metric to record on.
+type Int64AsyncGaugeHandle MetricDescriptor
+
+// isAsync implements the AsyncMetric interface.
+func (h *Int64AsyncGaugeHandle) isAsync() {}
+
+// Descriptor returns the int64 gauge handle typecast to a pointer to a
+// MetricDescriptor.
+func (h *Int64AsyncGaugeHandle) Descriptor() *MetricDescriptor {
+	return (*MetricDescriptor)(h)
+}
+
+// Record records the int64 gauge value on the metrics recorder provided.
+func (h *Int64AsyncGaugeHandle) Record(recorder AsyncMetricsRecorder, value int64, labels ...string) {
+	recorder.RecordInt64AsyncGauge(h, value, labels...)
+}
+
+// registeredMetrics are the registered metric descriptor names.
+var registeredMetrics = make(map[string]bool)
+
+// metricsRegistry contains all of the registered metrics.
+//
+// This is written to only at init time, and read only after that.
+var metricsRegistry = make(map[string]*MetricDescriptor)
+
+// DescriptorForMetric returns the MetricDescriptor from the global registry.
+//
+// Returns nil if MetricDescriptor not present.
+func DescriptorForMetric(metricName string) *MetricDescriptor {
+	return metricsRegistry[metricName]
+}
+
+func registerMetric(metricName string, def bool) {
+	if registeredMetrics[metricName] {
+		logger.Fatalf("metric %v already registered", metricName)
+	}
+	registeredMetrics[metricName] = true
+	if def {
+		DefaultMetrics = DefaultMetrics.Add(metricName)
+	}
+}
+
+// RegisterInt64Count registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Count(descriptor MetricDescriptor) *Int64CountHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntCount
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64CountHandle)(descPtr)
+}
+
+// RegisterFloat64Count registers the metric description onto the global
+// registry. It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterFloat64Count(descriptor MetricDescriptor) *Float64CountHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeFloatCount
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Float64CountHandle)(descPtr)
+}
+
+// RegisterInt64Histo registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Histo(descriptor MetricDescriptor) *Int64HistoHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntHisto
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64HistoHandle)(descPtr)
+}
+
+// RegisterFloat64Histo registers the metric description onto the global
+// registry. It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterFloat64Histo(descriptor MetricDescriptor) *Float64HistoHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeFloatHisto
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Float64HistoHandle)(descPtr)
+}
+
+// RegisterInt64Gauge registers the metric description onto the global registry.
+// It returns a typed handle to use to recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64Gauge(descriptor MetricDescriptor) *Int64GaugeHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntGauge
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64GaugeHandle)(descPtr)
+}
+
+// RegisterInt64UpDownCount registers the metric description onto the global registry.
+// It returns a typed handle to use for recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64UpDownCount(descriptor MetricDescriptor) *Int64UpDownCountHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	// Set the specific metric type for the up-down counter
+	descriptor.Type = MetricTypeIntUpDownCount
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64UpDownCountHandle)(descPtr)
+}
+
+// RegisterInt64AsyncGauge registers the metric description onto the global registry.
+// It returns a typed handle to use for recording data.
+//
+// NOTE: this function must only be called during initialization time (i.e. in
+// an init() function), and is not thread-safe. If multiple metrics are
+// registered with the same name, this function will panic.
+func RegisterInt64AsyncGauge(descriptor MetricDescriptor) *Int64AsyncGaugeHandle {
+	registerMetric(descriptor.Name, descriptor.Default)
+	descriptor.Type = MetricTypeIntAsyncGauge
+	descPtr := &descriptor
+	metricsRegistry[descriptor.Name] = descPtr
+	return (*Int64AsyncGaugeHandle)(descPtr)
+}
+
+// snapshotMetricsRegistryForTesting snapshots the global data of the metrics
+// registry. Returns a cleanup function that sets the metrics registry to its
+// original state.
+func snapshotMetricsRegistryForTesting() func() {
+	oldDefaultMetrics := DefaultMetrics
+	oldRegisteredMetrics := registeredMetrics
+	oldMetricsRegistry := metricsRegistry
+
+	registeredMetrics = make(map[string]bool)
+	metricsRegistry = make(map[string]*MetricDescriptor)
+	maps.Copy(registeredMetrics, registeredMetrics)
+	maps.Copy(metricsRegistry, metricsRegistry)
+
+	return func() {
+		DefaultMetrics = oldDefaultMetrics
+		registeredMetrics = oldRegisteredMetrics
+		metricsRegistry = oldMetricsRegistry
+	}
+}

vendor/google.golang.org/grpc/experimental/stats/metrics.go

@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package stats contains experimental metrics/stats API's.
+package stats
+
+import "google.golang.org/grpc/stats"
+
+// MetricsRecorder records on metrics derived from metric registry.
+type MetricsRecorder interface {
+	// RecordInt64Count records the measurement alongside labels on the int
+	// count associated with the provided handle.
+	RecordInt64Count(handle *Int64CountHandle, incr int64, labels ...string)
+	// RecordFloat64Count records the measurement alongside labels on the float
+	// count associated with the provided handle.
+	RecordFloat64Count(handle *Float64CountHandle, incr float64, labels ...string)
+	// RecordInt64Histo records the measurement alongside labels on the int
+	// histo associated with the provided handle.
+	RecordInt64Histo(handle *Int64HistoHandle, incr int64, labels ...string)
+	// RecordFloat64Histo records the measurement alongside labels on the float
+	// histo associated with the provided handle.
+	RecordFloat64Histo(handle *Float64HistoHandle, incr float64, labels ...string)
+	// RecordInt64Gauge records the measurement alongside labels on the int
+	// gauge associated with the provided handle.
+	RecordInt64Gauge(handle *Int64GaugeHandle, incr int64, labels ...string)
+	// RecordInt64UpDownCounter records the measurement alongside labels on the int
+	// count associated with the provided handle.
+	RecordInt64UpDownCount(handle *Int64UpDownCountHandle, incr int64, labels ...string)
+}
+
+// AsyncMetricsRecorder records on asynchronous metrics derived from metric registry.
+type AsyncMetricsRecorder interface {
+	// RecordInt64AsyncGauge records the measurement alongside labels on the int
+	// count associated with the provided handle asynchronously
+	RecordInt64AsyncGauge(handle *Int64AsyncGaugeHandle, incr int64, labels ...string)
+}
+
+// Metrics is an experimental legacy alias of the now-stable stats.MetricSet.
+// Metrics will be deleted in a future release.
+type Metrics = stats.MetricSet
+
+// Metric was replaced by direct usage of strings.
+type Metric = string
+
+// NewMetrics is an experimental legacy alias of the now-stable
+// stats.NewMetricSet.  NewMetrics will be deleted in a future release.
+func NewMetrics(metrics ...Metric) *Metrics {
+	return stats.NewMetricSet(metrics...)
+}

vendor/google.golang.org/grpc/grpclog/component.go

@@ -0,0 +1,115 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpclog
+
+import (
+	"fmt"
+)
+
+// componentData records the settings for a component.
+type componentData struct {
+	name string
+}
+
+var cache = map[string]*componentData{}
+
+func (c *componentData) InfoDepth(depth int, args ...any) {
+	args = append([]any{"[" + string(c.name) + "]"}, args...)
+	InfoDepth(depth+1, args...)
+}
+
+func (c *componentData) WarningDepth(depth int, args ...any) {
+	args = append([]any{"[" + string(c.name) + "]"}, args...)
+	WarningDepth(depth+1, args...)
+}
+
+func (c *componentData) ErrorDepth(depth int, args ...any) {
+	args = append([]any{"[" + string(c.name) + "]"}, args...)
+	ErrorDepth(depth+1, args...)
+}
+
+func (c *componentData) FatalDepth(depth int, args ...any) {
+	args = append([]any{"[" + string(c.name) + "]"}, args...)
+	FatalDepth(depth+1, args...)
+}
+
+func (c *componentData) Info(args ...any) {
+	c.InfoDepth(1, args...)
+}
+
+func (c *componentData) Warning(args ...any) {
+	c.WarningDepth(1, args...)
+}
+
+func (c *componentData) Error(args ...any) {
+	c.ErrorDepth(1, args...)
+}
+
+func (c *componentData) Fatal(args ...any) {
+	c.FatalDepth(1, args...)
+}
+
+func (c *componentData) Infof(format string, args ...any) {
+	c.InfoDepth(1, fmt.Sprintf(format, args...))
+}
+
+func (c *componentData) Warningf(format string, args ...any) {
+	c.WarningDepth(1, fmt.Sprintf(format, args...))
+}
+
+func (c *componentData) Errorf(format string, args ...any) {
+	c.ErrorDepth(1, fmt.Sprintf(format, args...))
+}
+
+func (c *componentData) Fatalf(format string, args ...any) {
+	c.FatalDepth(1, fmt.Sprintf(format, args...))
+}
+
+func (c *componentData) Infoln(args ...any) {
+	c.InfoDepth(1, args...)
+}
+
+func (c *componentData) Warningln(args ...any) {
+	c.WarningDepth(1, args...)
+}
+
+func (c *componentData) Errorln(args ...any) {
+	c.ErrorDepth(1, args...)
+}
+
+func (c *componentData) Fatalln(args ...any) {
+	c.FatalDepth(1, args...)
+}
+
+func (c *componentData) V(l int) bool {
+	return V(l)
+}
+
+// Component creates a new component and returns it for logging. If a component
+// with the name already exists, nothing will be created and it will be
+// returned. SetLoggerV2 will panic if it is called with a logger created by
+// Component.
+func Component(componentName string) DepthLoggerV2 {
+	if cData, ok := cache[componentName]; ok {
+		return cData
+	}
+	c := &componentData{componentName}
+	cache[componentName] = c
+	return c
+}

vendor/google.golang.org/grpc/grpclog/grpclog.go

@@ -0,0 +1,186 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpclog defines logging for grpc.
+//
+// In the default logger, severity level can be set by environment variable
+// GRPC_GO_LOG_SEVERITY_LEVEL, verbosity level can be set by
+// GRPC_GO_LOG_VERBOSITY_LEVEL.
+package grpclog
+
+import (
+	"os"
+
+	"google.golang.org/grpc/grpclog/internal"
+)
+
+func init() {
+	SetLoggerV2(newLoggerV2())
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func V(l int) bool {
+	return internal.LoggerV2Impl.V(l)
+}
+
+// Info logs to the INFO log.
+func Info(args ...any) {
+	internal.LoggerV2Impl.Info(args...)
+}
+
+// Infof logs to the INFO log. Arguments are handled in the manner of fmt.Printf.
+func Infof(format string, args ...any) {
+	internal.LoggerV2Impl.Infof(format, args...)
+}
+
+// Infoln logs to the INFO log. Arguments are handled in the manner of fmt.Println.
+func Infoln(args ...any) {
+	internal.LoggerV2Impl.Infoln(args...)
+}
+
+// Warning logs to the WARNING log.
+func Warning(args ...any) {
+	internal.LoggerV2Impl.Warning(args...)
+}
+
+// Warningf logs to the WARNING log. Arguments are handled in the manner of fmt.Printf.
+func Warningf(format string, args ...any) {
+	internal.LoggerV2Impl.Warningf(format, args...)
+}
+
+// Warningln logs to the WARNING log. Arguments are handled in the manner of fmt.Println.
+func Warningln(args ...any) {
+	internal.LoggerV2Impl.Warningln(args...)
+}
+
+// Error logs to the ERROR log.
+func Error(args ...any) {
+	internal.LoggerV2Impl.Error(args...)
+}
+
+// Errorf logs to the ERROR log. Arguments are handled in the manner of fmt.Printf.
+func Errorf(format string, args ...any) {
+	internal.LoggerV2Impl.Errorf(format, args...)
+}
+
+// Errorln logs to the ERROR log. Arguments are handled in the manner of fmt.Println.
+func Errorln(args ...any) {
+	internal.LoggerV2Impl.Errorln(args...)
+}
+
+// Fatal logs to the FATAL log. Arguments are handled in the manner of fmt.Print.
+// It calls os.Exit() with exit code 1.
+func Fatal(args ...any) {
+	internal.LoggerV2Impl.Fatal(args...)
+	// Make sure fatal logs will exit.
+	os.Exit(1)
+}
+
+// Fatalf logs to the FATAL log. Arguments are handled in the manner of fmt.Printf.
+// It calls os.Exit() with exit code 1.
+func Fatalf(format string, args ...any) {
+	internal.LoggerV2Impl.Fatalf(format, args...)
+	// Make sure fatal logs will exit.
+	os.Exit(1)
+}
+
+// Fatalln logs to the FATAL log. Arguments are handled in the manner of fmt.Println.
+// It calls os.Exit() with exit code 1.
+func Fatalln(args ...any) {
+	internal.LoggerV2Impl.Fatalln(args...)
+	// Make sure fatal logs will exit.
+	os.Exit(1)
+}
+
+// Print prints to the logger. Arguments are handled in the manner of fmt.Print.
+//
+// Deprecated: use Info.
+func Print(args ...any) {
+	internal.LoggerV2Impl.Info(args...)
+}
+
+// Printf prints to the logger. Arguments are handled in the manner of fmt.Printf.
+//
+// Deprecated: use Infof.
+func Printf(format string, args ...any) {
+	internal.LoggerV2Impl.Infof(format, args...)
+}
+
+// Println prints to the logger. Arguments are handled in the manner of fmt.Println.
+//
+// Deprecated: use Infoln.
+func Println(args ...any) {
+	internal.LoggerV2Impl.Infoln(args...)
+}
+
+// InfoDepth logs to the INFO log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func InfoDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.InfoDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Infoln(args...)
+	}
+}
+
+// WarningDepth logs to the WARNING log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func WarningDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.WarningDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Warningln(args...)
+	}
+}
+
+// ErrorDepth logs to the ERROR log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func ErrorDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.ErrorDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Errorln(args...)
+	}
+}
+
+// FatalDepth logs to the FATAL log at the specified depth.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func FatalDepth(depth int, args ...any) {
+	if internal.DepthLoggerV2Impl != nil {
+		internal.DepthLoggerV2Impl.FatalDepth(depth, args...)
+	} else {
+		internal.LoggerV2Impl.Fatalln(args...)
+	}
+	os.Exit(1)
+}

vendor/google.golang.org/grpc/grpclog/internal/grpclog.go

@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains functionality internal to the grpclog package.
+package internal
+
+// LoggerV2Impl is the logger used for the non-depth log functions.
+var LoggerV2Impl LoggerV2
+
+// DepthLoggerV2Impl is the logger used for the depth log functions.
+var DepthLoggerV2Impl DepthLoggerV2

vendor/google.golang.org/grpc/grpclog/internal/logger.go

@@ -0,0 +1,87 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package internal
+
+// Logger mimics golang's standard Logger as an interface.
+//
+// Deprecated: use LoggerV2.
+type Logger interface {
+	Fatal(args ...any)
+	Fatalf(format string, args ...any)
+	Fatalln(args ...any)
+	Print(args ...any)
+	Printf(format string, args ...any)
+	Println(args ...any)
+}
+
+// LoggerWrapper wraps Logger into a LoggerV2.
+type LoggerWrapper struct {
+	Logger
+}
+
+// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Info(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Infoln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Infof(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Warning(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Warningln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Warningf(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+func (l *LoggerWrapper) Error(args ...any) {
+	l.Logger.Print(args...)
+}
+
+// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+func (l *LoggerWrapper) Errorln(args ...any) {
+	l.Logger.Println(args...)
+}
+
+// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+func (l *LoggerWrapper) Errorf(format string, args ...any) {
+	l.Logger.Printf(format, args...)
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func (*LoggerWrapper) V(int) bool {
+	// Returns true for all verbose level.
+	return true
+}

vendor/google.golang.org/grpc/grpclog/internal/loggerv2.go

@@ -0,0 +1,267 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package internal
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+// LoggerV2 does underlying logging work for grpclog.
+type LoggerV2 interface {
+	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+	Info(args ...any)
+	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+	Infoln(args ...any)
+	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+	Infof(format string, args ...any)
+	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+	Warning(args ...any)
+	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+	Warningln(args ...any)
+	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+	Warningf(format string, args ...any)
+	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	Error(args ...any)
+	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	Errorln(args ...any)
+	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	Errorf(format string, args ...any)
+	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatal(args ...any)
+	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalln(args ...any)
+	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalf(format string, args ...any)
+	// V reports whether verbosity level l is at least the requested verbose level.
+	V(l int) bool
+}
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type DepthLoggerV2 interface {
+	LoggerV2
+	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	InfoDepth(depth int, args ...any)
+	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	WarningDepth(depth int, args ...any)
+	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	ErrorDepth(depth int, args ...any)
+	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	FatalDepth(depth int, args ...any)
+}
+
+const (
+	// infoLog indicates Info severity.
+	infoLog int = iota
+	// warningLog indicates Warning severity.
+	warningLog
+	// errorLog indicates Error severity.
+	errorLog
+	// fatalLog indicates Fatal severity.
+	fatalLog
+)
+
+// severityName contains the string representation of each severity.
+var severityName = []string{
+	infoLog:    "INFO",
+	warningLog: "WARNING",
+	errorLog:   "ERROR",
+	fatalLog:   "FATAL",
+}
+
+// sprintf is fmt.Sprintf.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprintf = fmt.Sprintf
+
+// sprint is fmt.Sprint.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprint = fmt.Sprint
+
+// sprintln is fmt.Sprintln.
+// These vars exist to make it possible to test that expensive format calls aren't made unnecessarily.
+var sprintln = fmt.Sprintln
+
+// exit is os.Exit.
+// This var exists to make it possible to test functions calling os.Exit.
+var exit = os.Exit
+
+// loggerT is the default logger used by grpclog.
+type loggerT struct {
+	m          []*log.Logger
+	v          int
+	jsonFormat bool
+}
+
+func (g *loggerT) output(severity int, s string) {
+	sevStr := severityName[severity]
+	if !g.jsonFormat {
+		g.m[severity].Output(2, sevStr+": "+s)
+		return
+	}
+	// TODO: we can also include the logging component, but that needs more
+	// (API) changes.
+	b, _ := json.Marshal(map[string]string{
+		"severity": sevStr,
+		"message":  s,
+	})
+	g.m[severity].Output(2, string(b))
+}
+
+func (g *loggerT) printf(severity int, format string, args ...any) {
+	// Note the discard check is duplicated in each print func, rather than in
+	// output, to avoid the expensive Sprint calls.
+	// De-duplicating this by moving to output would be a significant performance regression!
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprintf(format, args...))
+}
+
+func (g *loggerT) print(severity int, v ...any) {
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprint(v...))
+}
+
+func (g *loggerT) println(severity int, v ...any) {
+	if lg := g.m[severity]; lg.Writer() == io.Discard {
+		return
+	}
+	g.output(severity, sprintln(v...))
+}
+
+func (g *loggerT) Info(args ...any) {
+	g.print(infoLog, args...)
+}
+
+func (g *loggerT) Infoln(args ...any) {
+	g.println(infoLog, args...)
+}
+
+func (g *loggerT) Infof(format string, args ...any) {
+	g.printf(infoLog, format, args...)
+}
+
+func (g *loggerT) Warning(args ...any) {
+	g.print(warningLog, args...)
+}
+
+func (g *loggerT) Warningln(args ...any) {
+	g.println(warningLog, args...)
+}
+
+func (g *loggerT) Warningf(format string, args ...any) {
+	g.printf(warningLog, format, args...)
+}
+
+func (g *loggerT) Error(args ...any) {
+	g.print(errorLog, args...)
+}
+
+func (g *loggerT) Errorln(args ...any) {
+	g.println(errorLog, args...)
+}
+
+func (g *loggerT) Errorf(format string, args ...any) {
+	g.printf(errorLog, format, args...)
+}
+
+func (g *loggerT) Fatal(args ...any) {
+	g.print(fatalLog, args...)
+	exit(1)
+}
+
+func (g *loggerT) Fatalln(args ...any) {
+	g.println(fatalLog, args...)
+	exit(1)
+}
+
+func (g *loggerT) Fatalf(format string, args ...any) {
+	g.printf(fatalLog, format, args...)
+	exit(1)
+}
+
+func (g *loggerT) V(l int) bool {
+	return l <= g.v
+}
+
+// LoggerV2Config configures the LoggerV2 implementation.
+type LoggerV2Config struct {
+	// Verbosity sets the verbosity level of the logger.
+	Verbosity int
+	// FormatJSON controls whether the logger should output logs in JSON format.
+	FormatJSON bool
+}
+
+// combineLoggers returns a combined logger for both higher & lower severity logs,
+// or only one if the other is io.Discard.
+//
+// This uses io.Discard instead of io.MultiWriter when all loggers
+// are set to io.Discard. Both this package and the standard log package have
+// significant optimizations for io.Discard, which io.MultiWriter lacks (as of
+// this writing).
+func combineLoggers(lower, higher io.Writer) io.Writer {
+	if lower == io.Discard {
+		return higher
+	}
+	if higher == io.Discard {
+		return lower
+	}
+	return io.MultiWriter(lower, higher)
+}
+
+// NewLoggerV2 creates a new LoggerV2 instance with the provided configuration.
+// The infoW, warningW, and errorW writers are used to write log messages of
+// different severity levels.
+func NewLoggerV2(infoW, warningW, errorW io.Writer, c LoggerV2Config) LoggerV2 {
+	flag := log.LstdFlags
+	if c.FormatJSON {
+		flag = 0
+	}
+
+	warningW = combineLoggers(infoW, warningW)
+	errorW = combineLoggers(errorW, warningW)
+
+	fatalW := errorW
+
+	m := []*log.Logger{
+		log.New(infoW, "", flag),
+		log.New(warningW, "", flag),
+		log.New(errorW, "", flag),
+		log.New(fatalW, "", flag),
+	}
+	return &loggerT{m: m, v: c.Verbosity, jsonFormat: c.FormatJSON}
+}

vendor/google.golang.org/grpc/grpclog/logger.go

@@ -0,0 +1,34 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpclog
+
+import "google.golang.org/grpc/grpclog/internal"
+
+// Logger mimics golang's standard Logger as an interface.
+//
+// Deprecated: use LoggerV2.
+type Logger internal.Logger
+
+// SetLogger sets the logger that is used in grpc. Call only from
+// init() functions.
+//
+// Deprecated: use SetLoggerV2.
+func SetLogger(l Logger) {
+	internal.LoggerV2Impl = &internal.LoggerWrapper{Logger: l}
+}

vendor/google.golang.org/grpc/grpclog/loggerv2.go

@@ -0,0 +1,97 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpclog
+
+import (
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"google.golang.org/grpc/grpclog/internal"
+)
+
+// LoggerV2 does underlying logging work for grpclog.
+type LoggerV2 internal.LoggerV2
+
+// SetLoggerV2 sets logger that is used in grpc to a V2 logger.
+// Not mutex-protected, should be called before any gRPC functions.
+func SetLoggerV2(l LoggerV2) {
+	if _, ok := l.(*componentData); ok {
+		panic("cannot use component logger as grpclog logger")
+	}
+	internal.LoggerV2Impl = l
+	internal.DepthLoggerV2Impl, _ = l.(internal.DepthLoggerV2)
+}
+
+// NewLoggerV2 creates a loggerV2 with the provided writers.
+// Fatal logs will be written to errorW, warningW, infoW, followed by exit(1).
+// Error logs will be written to errorW, warningW and infoW.
+// Warning logs will be written to warningW and infoW.
+// Info logs will be written to infoW.
+func NewLoggerV2(infoW, warningW, errorW io.Writer) LoggerV2 {
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{})
+}
+
+// NewLoggerV2WithVerbosity creates a loggerV2 with the provided writers and
+// verbosity level.
+func NewLoggerV2WithVerbosity(infoW, warningW, errorW io.Writer, v int) LoggerV2 {
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{Verbosity: v})
+}
+
+// newLoggerV2 creates a loggerV2 to be used as default logger.
+// All logs are written to stderr.
+func newLoggerV2() LoggerV2 {
+	errorW := io.Discard
+	warningW := io.Discard
+	infoW := io.Discard
+
+	logLevel := os.Getenv("GRPC_GO_LOG_SEVERITY_LEVEL")
+	switch logLevel {
+	case "", "ERROR", "error": // If env is unset, set level to ERROR.
+		errorW = os.Stderr
+	case "WARNING", "warning":
+		warningW = os.Stderr
+	case "INFO", "info":
+		infoW = os.Stderr
+	}
+
+	var v int
+	vLevel := os.Getenv("GRPC_GO_LOG_VERBOSITY_LEVEL")
+	if vl, err := strconv.Atoi(vLevel); err == nil {
+		v = vl
+	}
+
+	jsonFormat := strings.EqualFold(os.Getenv("GRPC_GO_LOG_FORMATTER"), "json")
+
+	return internal.NewLoggerV2(infoW, warningW, errorW, internal.LoggerV2Config{
+		Verbosity:  v,
+		FormatJSON: jsonFormat,
+	})
+}
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type DepthLoggerV2 internal.DepthLoggerV2

vendor/google.golang.org/grpc/interceptor.go

@@ -0,0 +1,104 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"context"
+)
+
+// UnaryInvoker is called by UnaryClientInterceptor to complete RPCs.
+type UnaryInvoker func(ctx context.Context, method string, req, reply any, cc *ClientConn, opts ...CallOption) error
+
+// UnaryClientInterceptor intercepts the execution of a unary RPC on the client.
+// Unary interceptors can be specified as a DialOption, using
+// WithUnaryInterceptor() or WithChainUnaryInterceptor(), when creating a
+// ClientConn. When a unary interceptor(s) is set on a ClientConn, gRPC
+// delegates all unary RPC invocations to the interceptor, and it is the
+// responsibility of the interceptor to call invoker to complete the processing
+// of the RPC.
+//
+// method is the RPC name. req and reply are the corresponding request and
+// response messages. cc is the ClientConn on which the RPC was invoked. invoker
+// is the handler to complete the RPC and it is the responsibility of the
+// interceptor to call it. opts contain all applicable call options, including
+// defaults from the ClientConn as well as per-call options.
+//
+// The returned error must be compatible with the status package.
+type UnaryClientInterceptor func(ctx context.Context, method string, req, reply any, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error
+
+// Streamer is called by StreamClientInterceptor to create a ClientStream.
+type Streamer func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)
+
+// StreamClientInterceptor intercepts the creation of a ClientStream. Stream
+// interceptors can be specified as a DialOption, using WithStreamInterceptor()
+// or WithChainStreamInterceptor(), when creating a ClientConn. When a stream
+// interceptor(s) is set on the ClientConn, gRPC delegates all stream creations
+// to the interceptor, and it is the responsibility of the interceptor to call
+// streamer.
+//
+// desc contains a description of the stream. cc is the ClientConn on which the
+// RPC was invoked. streamer is the handler to create a ClientStream and it is
+// the responsibility of the interceptor to call it. opts contain all applicable
+// call options, including defaults from the ClientConn as well as per-call
+// options.
+//
+// StreamClientInterceptor may return a custom ClientStream to intercept all I/O
+// operations. The returned error must be compatible with the status package.
+type StreamClientInterceptor func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error)
+
+// UnaryServerInfo consists of various information about a unary RPC on
+// server side. All per-rpc information may be mutated by the interceptor.
+type UnaryServerInfo struct {
+	// Server is the service implementation the user provides. This is read-only.
+	Server any
+	// FullMethod is the full RPC method string, i.e., /package.service/method.
+	FullMethod string
+}
+
+// UnaryHandler defines the handler invoked by UnaryServerInterceptor to complete the normal
+// execution of a unary RPC.
+//
+// If a UnaryHandler returns an error, it should either be produced by the
+// status package, or be one of the context errors. Otherwise, gRPC will use
+// codes.Unknown as the status code and err.Error() as the status message of the
+// RPC.
+type UnaryHandler func(ctx context.Context, req any) (any, error)
+
+// UnaryServerInterceptor provides a hook to intercept the execution of a unary RPC on the server. info
+// contains all the information of this RPC the interceptor can operate on. And handler is the wrapper
+// of the service method implementation. It is the responsibility of the interceptor to invoke handler
+// to complete the RPC.
+type UnaryServerInterceptor func(ctx context.Context, req any, info *UnaryServerInfo, handler UnaryHandler) (resp any, err error)
+
+// StreamServerInfo consists of various information about a streaming RPC on
+// server side. All per-rpc information may be mutated by the interceptor.
+type StreamServerInfo struct {
+	// FullMethod is the full RPC method string, i.e., /package.service/method.
+	FullMethod string
+	// IsClientStream indicates whether the RPC is a client streaming RPC.
+	IsClientStream bool
+	// IsServerStream indicates whether the RPC is a server streaming RPC.
+	IsServerStream bool
+}
+
+// StreamServerInterceptor provides a hook to intercept the execution of a streaming RPC on the server.
+// info contains all the information of this RPC the interceptor can operate on. And handler is the
+// service method implementation. It is the responsibility of the interceptor to invoke handler to
+// complete the RPC.
+type StreamServerInterceptor func(srv any, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error

vendor/google.golang.org/grpc/internal/backoff/backoff.go

@@ -0,0 +1,109 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package backoff implement the backoff strategy for gRPC.
+//
+// This is kept in internal until the gRPC project decides whether or not to
+// allow alternative backoff strategies.
+package backoff
+
+import (
+	"context"
+	"errors"
+	rand "math/rand/v2"
+	"time"
+
+	grpcbackoff "google.golang.org/grpc/backoff"
+)
+
+// Strategy defines the methodology for backing off after a grpc connection
+// failure.
+type Strategy interface {
+	// Backoff returns the amount of time to wait before the next retry given
+	// the number of consecutive failures.
+	Backoff(retries int) time.Duration
+}
+
+// DefaultExponential is an exponential backoff implementation using the
+// default values for all the configurable knobs defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+var DefaultExponential = Exponential{Config: grpcbackoff.DefaultConfig}
+
+// Exponential implements exponential backoff algorithm as defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+type Exponential struct {
+	// Config contains all options to configure the backoff algorithm.
+	Config grpcbackoff.Config
+}
+
+// Backoff returns the amount of time to wait before the next retry given the
+// number of retries.
+func (bc Exponential) Backoff(retries int) time.Duration {
+	if retries == 0 {
+		return bc.Config.BaseDelay
+	}
+	backoff, max := float64(bc.Config.BaseDelay), float64(bc.Config.MaxDelay)
+	for backoff < max && retries > 0 {
+		backoff *= bc.Config.Multiplier
+		retries--
+	}
+	if backoff > max {
+		backoff = max
+	}
+	// Randomize backoff delays so that if a cluster of requests start at
+	// the same time, they won't operate in lockstep.
+	backoff *= 1 + bc.Config.Jitter*(rand.Float64()*2-1)
+	if backoff < 0 {
+		return 0
+	}
+	return time.Duration(backoff)
+}
+
+// ErrResetBackoff is the error to be returned by the function executed by RunF,
+// to instruct the latter to reset its backoff state.
+var ErrResetBackoff = errors.New("reset backoff state")
+
+// RunF provides a convenient way to run a function f repeatedly until the
+// context expires or f returns a non-nil error that is not ErrResetBackoff.
+// When f returns ErrResetBackoff, RunF continues to run f, but resets its
+// backoff state before doing so. backoff accepts an integer representing the
+// number of retries, and returns the amount of time to backoff.
+func RunF(ctx context.Context, f func() error, backoff func(int) time.Duration) {
+	attempt := 0
+	timer := time.NewTimer(0)
+	for ctx.Err() == nil {
+		select {
+		case <-timer.C:
+		case <-ctx.Done():
+			timer.Stop()
+			return
+		}
+
+		err := f()
+		if errors.Is(err, ErrResetBackoff) {
+			timer.Reset(0)
+			attempt = 0
+			continue
+		}
+		if err != nil {
+			return
+		}
+		timer.Reset(backoff(attempt))
+		attempt++
+	}
+}

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/config.go

@@ -0,0 +1,84 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package gracefulswitch
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+type lbConfig struct {
+	serviceconfig.LoadBalancingConfig
+
+	childBuilder balancer.Builder
+	childConfig  serviceconfig.LoadBalancingConfig
+}
+
+// ChildName returns the name of the child balancer of the gracefulswitch
+// Balancer.
+func ChildName(l serviceconfig.LoadBalancingConfig) string {
+	return l.(*lbConfig).childBuilder.Name()
+}
+
+// ParseConfig parses a child config list and returns a LB config for the
+// gracefulswitch Balancer.
+//
+// cfg is expected to be a json.RawMessage containing a JSON array of LB policy
+// names + configs as the format of the "loadBalancingConfig" field in
+// ServiceConfig.  It returns a type that should be passed to
+// UpdateClientConnState in the BalancerConfig field.
+func ParseConfig(cfg json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+	var lbCfg []map[string]json.RawMessage
+	if err := json.Unmarshal(cfg, &lbCfg); err != nil {
+		return nil, err
+	}
+	for i, e := range lbCfg {
+		if len(e) != 1 {
+			return nil, fmt.Errorf("expected a JSON struct with one entry; received entry %v at index %d", e, i)
+		}
+
+		var name string
+		var jsonCfg json.RawMessage
+		for name, jsonCfg = range e {
+		}
+
+		builder := balancer.Get(name)
+		if builder == nil {
+			// Skip unregistered balancer names.
+			continue
+		}
+
+		parser, ok := builder.(balancer.ConfigParser)
+		if !ok {
+			// This is a valid child with no config.
+			return &lbConfig{childBuilder: builder}, nil
+		}
+
+		cfg, err := parser.ParseConfig(jsonCfg)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing config for policy %q: %v", name, err)
+		}
+		return &lbConfig{childBuilder: builder, childConfig: cfg}, nil
+	}
+
+	return nil, fmt.Errorf("no supported policies found in config: %v", string(cfg))
+}

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go

@@ -0,0 +1,421 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package gracefulswitch implements a graceful switch load balancer.
+package gracefulswitch
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+var errBalancerClosed = errors.New("gracefulSwitchBalancer is closed")
+var _ balancer.Balancer = (*Balancer)(nil)
+
+// NewBalancer returns a graceful switch Balancer.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions) *Balancer {
+	return &Balancer{
+		cc:    cc,
+		bOpts: opts,
+	}
+}
+
+// Balancer is a utility to gracefully switch from one balancer to
+// a new balancer. It implements the balancer.Balancer interface.
+type Balancer struct {
+	bOpts balancer.BuildOptions
+	cc    balancer.ClientConn
+
+	// mu protects the following fields and all fields within balancerCurrent
+	// and balancerPending. mu does not need to be held when calling into the
+	// child balancers, as all calls into these children happen only as a direct
+	// result of a call into the gracefulSwitchBalancer, which are also
+	// guaranteed to be synchronous. There is one exception: an UpdateState call
+	// from a child balancer when current and pending are populated can lead to
+	// calling Close() on the current. To prevent that racing with an
+	// UpdateSubConnState from the channel, we hold currentMu during Close and
+	// UpdateSubConnState calls.
+	mu              sync.Mutex
+	balancerCurrent *balancerWrapper
+	balancerPending *balancerWrapper
+	closed          bool // set to true when this balancer is closed
+
+	// currentMu must be locked before mu. This mutex guards against this
+	// sequence of events: UpdateSubConnState() called, finds the
+	// balancerCurrent, gives up lock, updateState comes in, causes Close() on
+	// balancerCurrent before the UpdateSubConnState is called on the
+	// balancerCurrent.
+	currentMu sync.Mutex
+
+	// activeGoroutines tracks all the goroutines that this balancer has started
+	// and that should be waited on when the balancer closes.
+	activeGoroutines sync.WaitGroup
+}
+
+// swap swaps out the current lb with the pending lb and updates the ClientConn.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) swap() {
+	gsb.cc.UpdateState(gsb.balancerPending.lastState)
+	cur := gsb.balancerCurrent
+	gsb.balancerCurrent = gsb.balancerPending
+	gsb.balancerPending = nil
+	gsb.activeGoroutines.Add(1)
+	go func() {
+		defer gsb.activeGoroutines.Done()
+		gsb.currentMu.Lock()
+		defer gsb.currentMu.Unlock()
+		cur.Close()
+	}()
+}
+
+// Helper function that checks if the balancer passed in is current or pending.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) balancerCurrentOrPending(bw *balancerWrapper) bool {
+	return bw == gsb.balancerCurrent || bw == gsb.balancerPending
+}
+
+// SwitchTo initializes the graceful switch process, which completes based on
+// connectivity state changes on the current/pending balancer. Thus, the switch
+// process is not complete when this method returns. This method must be called
+// synchronously alongside the rest of the balancer.Balancer methods this
+// Graceful Switch Balancer implements.
+//
+// Deprecated: use ParseConfig and pass a parsed config to UpdateClientConnState
+// to cause the Balancer to automatically change to the new child when necessary.
+func (gsb *Balancer) SwitchTo(builder balancer.Builder) error {
+	_, err := gsb.switchTo(builder)
+	return err
+}
+
+func (gsb *Balancer) switchTo(builder balancer.Builder) (*balancerWrapper, error) {
+	gsb.mu.Lock()
+	if gsb.closed {
+		gsb.mu.Unlock()
+		return nil, errBalancerClosed
+	}
+	bw := &balancerWrapper{
+		ClientConn: gsb.cc,
+		builder:    builder,
+		gsb:        gsb,
+		lastState: balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable),
+		},
+		subconns: make(map[balancer.SubConn]bool),
+	}
+	balToClose := gsb.balancerPending // nil if there is no pending balancer
+	if gsb.balancerCurrent == nil {
+		gsb.balancerCurrent = bw
+	} else {
+		gsb.balancerPending = bw
+	}
+	gsb.mu.Unlock()
+	balToClose.Close()
+	// This function takes a builder instead of a balancer because builder.Build
+	// can call back inline, and this utility needs to handle the callbacks.
+	newBalancer := builder.Build(bw, gsb.bOpts)
+	if newBalancer == nil {
+		// This is illegal and should never happen; we clear the balancerWrapper
+		// we were constructing if it happens to avoid a potential panic.
+		gsb.mu.Lock()
+		if gsb.balancerPending != nil {
+			gsb.balancerPending = nil
+		} else {
+			gsb.balancerCurrent = nil
+		}
+		gsb.mu.Unlock()
+		return nil, balancer.ErrBadResolverState
+	}
+
+	// This write doesn't need to take gsb.mu because this field never gets read
+	// or written to on any calls from the current or pending. Calls from grpc
+	// to this balancer are guaranteed to be called synchronously, so this
+	// bw.Balancer field will never be forwarded to until this SwitchTo()
+	// function returns.
+	bw.Balancer = newBalancer
+	return bw, nil
+}
+
+// Returns nil if the graceful switch balancer is closed.
+func (gsb *Balancer) latestBalancer() *balancerWrapper {
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	if gsb.balancerPending != nil {
+		return gsb.balancerPending
+	}
+	return gsb.balancerCurrent
+}
+
+// UpdateClientConnState forwards the update to the latest balancer created.
+//
+// If the state's BalancerConfig is the config returned by a call to
+// gracefulswitch.ParseConfig, then this function will automatically SwitchTo
+// the balancer indicated by the config before forwarding its config to it, if
+// necessary.
+func (gsb *Balancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	gsbCfg, ok := state.BalancerConfig.(*lbConfig)
+	if ok {
+		// Switch to the child in the config unless it is already active.
+		if balToUpdate == nil || gsbCfg.childBuilder.Name() != balToUpdate.builder.Name() {
+			var err error
+			balToUpdate, err = gsb.switchTo(gsbCfg.childBuilder)
+			if err != nil {
+				return fmt.Errorf("could not switch to new child balancer: %w", err)
+			}
+		}
+		// Unwrap the child balancer's config.
+		state.BalancerConfig = gsbCfg.childConfig
+	}
+
+	if balToUpdate == nil {
+		return errBalancerClosed
+	}
+
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	return balToUpdate.UpdateClientConnState(state)
+}
+
+// ResolverError forwards the error to the latest balancer created.
+func (gsb *Balancer) ResolverError(err error) {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		gsb.cc.UpdateState(balancer.State{
+			ConnectivityState: connectivity.TransientFailure,
+			Picker:            base.NewErrPicker(err),
+		})
+		return
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	balToUpdate.ResolverError(err)
+}
+
+// ExitIdle forwards the call to the latest balancer created.
+//
+// If the latest balancer does not support ExitIdle, the subConns are
+// re-connected to manually.
+func (gsb *Balancer) ExitIdle() {
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	balToUpdate.ExitIdle()
+}
+
+// updateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) updateSubConnState(sc balancer.SubConn, state balancer.SubConnState, cb func(balancer.SubConnState)) {
+	gsb.currentMu.Lock()
+	defer gsb.currentMu.Unlock()
+	gsb.mu.Lock()
+	// Forward update to the appropriate child.  Even if there is a pending
+	// balancer, the current balancer should continue to get SubConn updates to
+	// maintain the proper state while the pending is still connecting.
+	var balToUpdate *balancerWrapper
+	if gsb.balancerCurrent != nil && gsb.balancerCurrent.subconns[sc] {
+		balToUpdate = gsb.balancerCurrent
+	} else if gsb.balancerPending != nil && gsb.balancerPending.subconns[sc] {
+		balToUpdate = gsb.balancerPending
+	}
+	if balToUpdate == nil {
+		// SubConn belonged to a stale lb policy that has not yet fully closed,
+		// or the balancer was already closed.
+		gsb.mu.Unlock()
+		return
+	}
+	if state.ConnectivityState == connectivity.Shutdown {
+		delete(balToUpdate.subconns, sc)
+	}
+	gsb.mu.Unlock()
+	if cb != nil {
+		cb(state)
+	} else {
+		balToUpdate.UpdateSubConnState(sc, state)
+	}
+}
+
+// UpdateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	gsb.updateSubConnState(sc, state, nil)
+}
+
+// Close closes any active child balancers.
+func (gsb *Balancer) Close() {
+	gsb.mu.Lock()
+	gsb.closed = true
+	currentBalancerToClose := gsb.balancerCurrent
+	gsb.balancerCurrent = nil
+	pendingBalancerToClose := gsb.balancerPending
+	gsb.balancerPending = nil
+	gsb.mu.Unlock()
+
+	currentBalancerToClose.Close()
+	pendingBalancerToClose.Close()
+	gsb.activeGoroutines.Wait()
+}
+
+// balancerWrapper wraps a balancer.Balancer, and overrides some Balancer
+// methods to help cleanup SubConns created by the wrapped balancer.
+//
+// It implements the balancer.ClientConn interface and is passed down in that
+// capacity to the wrapped balancer. It maintains a set of subConns created by
+// the wrapped balancer and calls from the latter to create/update/shutdown
+// SubConns update this set before being forwarded to the parent ClientConn.
+// State updates from the wrapped balancer can result in invocation of the
+// graceful switch logic.
+type balancerWrapper struct {
+	balancer.ClientConn
+	balancer.Balancer
+	gsb     *Balancer
+	builder balancer.Builder
+
+	lastState balancer.State
+	subconns  map[balancer.SubConn]bool // subconns created by this balancer
+}
+
+// Close closes the underlying LB policy and shuts down the subconns it
+// created. bw must not be referenced via balancerCurrent or balancerPending in
+// gsb when called. gsb.mu must not be held.  Does not panic with a nil
+// receiver.
+func (bw *balancerWrapper) Close() {
+	// before Close is called.
+	if bw == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as Close() is
+	// impossible to be called concurrently with the write in SwitchTo(). The
+	// callsites of Close() for this balancer in Graceful Switch Balancer will
+	// never be called until SwitchTo() returns.
+	bw.Balancer.Close()
+	bw.gsb.mu.Lock()
+	for sc := range bw.subconns {
+		sc.Shutdown()
+	}
+	bw.gsb.mu.Unlock()
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	// Hold the mutex for this entire call to ensure it cannot occur
+	// concurrently with other updateState() calls. This causes updates to
+	// lastState and calls to cc.UpdateState to happen atomically.
+	bw.gsb.mu.Lock()
+	defer bw.gsb.mu.Unlock()
+	bw.lastState = state
+
+	// If Close() acquires the mutex before UpdateState(), the balancer
+	// will already have been removed from the current or pending state when
+	// reaching this point.
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		// Returning here ensures that (*Balancer).swap() is not invoked after
+		// (*Balancer).Close() and therefore prevents "use after close".
+		return
+	}
+
+	if bw == bw.gsb.balancerCurrent {
+		// In the case that the current balancer exits READY, and there is a pending
+		// balancer, you can forward the pending balancer's cached State up to
+		// ClientConn and swap the pending into the current. This is because there
+		// is no reason to gracefully switch from and keep using the old policy as
+		// the ClientConn is not connected to any backends.
+		if state.ConnectivityState != connectivity.Ready && bw.gsb.balancerPending != nil {
+			bw.gsb.swap()
+			return
+		}
+		// Even if there is a pending balancer waiting to be gracefully switched to,
+		// continue to forward current balancer updates to the Client Conn. Ignoring
+		// state + picker from the current would cause undefined behavior/cause the
+		// system to behave incorrectly from the current LB policies perspective.
+		// Also, the current LB is still being used by grpc to choose SubConns per
+		// RPC, and thus should use the most updated form of the current balancer.
+		bw.gsb.cc.UpdateState(state)
+		return
+	}
+	// This method is now dealing with a state update from the pending balancer.
+	// If the current balancer is currently in a state other than READY, the new
+	// policy can be swapped into place immediately. This is because there is no
+	// reason to gracefully switch from and keep using the old policy as the
+	// ClientConn is not connected to any backends.
+	if state.ConnectivityState != connectivity.Connecting || bw.gsb.balancerCurrent.lastState.ConnectivityState != connectivity.Ready {
+		bw.gsb.swap()
+	}
+}
+
+func (bw *balancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.gsb.mu.Unlock()
+
+	var sc balancer.SubConn
+	oldListener := opts.StateListener
+	opts.StateListener = func(state balancer.SubConnState) { bw.gsb.updateSubConnState(sc, state, oldListener) }
+	sc, err := bw.gsb.cc.NewSubConn(addrs, opts)
+	if err != nil {
+		return nil, err
+	}
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) { // balancer was closed during this call
+		sc.Shutdown()
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.subconns[sc] = true
+	bw.gsb.mu.Unlock()
+	return sc, nil
+}
+
+func (bw *balancerWrapper) ResolveNow(opts resolver.ResolveNowOptions) {
+	// Ignore ResolveNow requests from anything other than the most recent
+	// balancer, because older balancers were already removed from the config.
+	if bw != bw.gsb.latestBalancer() {
+		return
+	}
+	bw.gsb.cc.ResolveNow(opts)
+}
+
+func (bw *balancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+	// Note: existing third party balancers may call this, so it must remain
+	// until RemoveSubConn is fully removed.
+	sc.Shutdown()
+}
+
+func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.UpdateAddresses(sc, addrs)
+}

vendor/google.golang.org/grpc/internal/balancerload/load.go

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Package balancerload defines APIs to parse server loads in trailers. The
+// parsed loads are sent to balancers in DoneInfo.
+package balancerload
+
+import (
+	"google.golang.org/grpc/metadata"
+)
+
+// Parser converts loads from metadata into a concrete type.
+type Parser interface {
+	// Parse parses loads from metadata.
+	Parse(md metadata.MD) any
+}
+
+var parser Parser
+
+// SetParser sets the load parser.
+//
+// Not mutex-protected, should be called before any gRPC functions.
+func SetParser(lr Parser) {
+	parser = lr
+}
+
+// Parse calls parser.Read().
+func Parse(md metadata.MD) any {
+	if parser == nil {
+		return nil
+	}
+	return parser.Parse(md)
+}

vendor/google.golang.org/grpc/internal/binarylog/binarylog.go

@@ -0,0 +1,192 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package binarylog implementation binary logging as defined in
+// https://github.com/grpc/proposal/blob/master/A16-binary-logging.md.
+package binarylog
+
+import (
+	"fmt"
+	"os"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/grpcutil"
+)
+
+var grpclogLogger = grpclog.Component("binarylog")
+
+// Logger specifies MethodLoggers for method names with a Log call that
+// takes a context.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+type Logger interface {
+	GetMethodLogger(methodName string) MethodLogger
+}
+
+// binLogger is the global binary logger for the binary. One of this should be
+// built at init time from the configuration (environment variable or flags).
+//
+// It is used to get a MethodLogger for each individual method.
+var binLogger Logger
+
+// SetLogger sets the binary logger.
+//
+// Only call this at init time.
+func SetLogger(l Logger) {
+	binLogger = l
+}
+
+// GetLogger gets the binary logger.
+//
+// Only call this at init time.
+func GetLogger() Logger {
+	return binLogger
+}
+
+// GetMethodLogger returns the MethodLogger for the given methodName.
+//
+// methodName should be in the format of "/service/method".
+//
+// Each MethodLogger returned by this method is a new instance. This is to
+// generate sequence id within the call.
+func GetMethodLogger(methodName string) MethodLogger {
+	if binLogger == nil {
+		return nil
+	}
+	return binLogger.GetMethodLogger(methodName)
+}
+
+func init() {
+	const envStr = "GRPC_BINARY_LOG_FILTER"
+	configStr := os.Getenv(envStr)
+	binLogger = NewLoggerFromConfigString(configStr)
+}
+
+// MethodLoggerConfig contains the setting for logging behavior of a method
+// logger. Currently, it contains the max length of header and message.
+type MethodLoggerConfig struct {
+	// Max length of header and message.
+	Header, Message uint64
+}
+
+// LoggerConfig contains the config for loggers to create method loggers.
+type LoggerConfig struct {
+	All      *MethodLoggerConfig
+	Services map[string]*MethodLoggerConfig
+	Methods  map[string]*MethodLoggerConfig
+
+	Blacklist map[string]struct{}
+}
+
+type logger struct {
+	config LoggerConfig
+}
+
+// NewLoggerFromConfig builds a logger with the given LoggerConfig.
+func NewLoggerFromConfig(config LoggerConfig) Logger {
+	return &logger{config: config}
+}
+
+// newEmptyLogger creates an empty logger. The map fields need to be filled in
+// using the set* functions.
+func newEmptyLogger() *logger {
+	return &logger{}
+}
+
+// Set method logger for "*".
+func (l *logger) setDefaultMethodLogger(ml *MethodLoggerConfig) error {
+	if l.config.All != nil {
+		return fmt.Errorf("conflicting global rules found")
+	}
+	l.config.All = ml
+	return nil
+}
+
+// Set method logger for "service/*".
+//
+// New MethodLogger with same service overrides the old one.
+func (l *logger) setServiceMethodLogger(service string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Services[service]; ok {
+		return fmt.Errorf("conflicting service rules for service %v found", service)
+	}
+	if l.config.Services == nil {
+		l.config.Services = make(map[string]*MethodLoggerConfig)
+	}
+	l.config.Services[service] = ml
+	return nil
+}
+
+// Set method logger for "service/method".
+//
+// New MethodLogger with same method overrides the old one.
+func (l *logger) setMethodMethodLogger(method string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Blacklist[method]; ok {
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+	}
+	if _, ok := l.config.Methods[method]; ok {
+		return fmt.Errorf("conflicting method rules for method %v found", method)
+	}
+	if l.config.Methods == nil {
+		l.config.Methods = make(map[string]*MethodLoggerConfig)
+	}
+	l.config.Methods[method] = ml
+	return nil
+}
+
+// Set blacklist method for "-service/method".
+func (l *logger) setBlacklist(method string) error {
+	if _, ok := l.config.Blacklist[method]; ok {
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+	}
+	if _, ok := l.config.Methods[method]; ok {
+		return fmt.Errorf("conflicting method rules for method %v found", method)
+	}
+	if l.config.Blacklist == nil {
+		l.config.Blacklist = make(map[string]struct{})
+	}
+	l.config.Blacklist[method] = struct{}{}
+	return nil
+}
+
+// getMethodLogger returns the MethodLogger for the given methodName.
+//
+// methodName should be in the format of "/service/method".
+//
+// Each MethodLogger returned by this method is a new instance. This is to
+// generate sequence id within the call.
+func (l *logger) GetMethodLogger(methodName string) MethodLogger {
+	s, m, err := grpcutil.ParseMethod(methodName)
+	if err != nil {
+		grpclogLogger.Infof("binarylogging: failed to parse %q: %v", methodName, err)
+		return nil
+	}
+	if ml, ok := l.config.Methods[s+"/"+m]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
+	}
+	if _, ok := l.config.Blacklist[s+"/"+m]; ok {
+		return nil
+	}
+	if ml, ok := l.config.Services[s]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
+	}
+	if l.config.All == nil {
+		return nil
+	}
+	return NewTruncatingMethodLogger(l.config.All.Header, l.config.All.Message)
+}

vendor/google.golang.org/grpc/internal/binarylog/binarylog_testutil.go

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// This file contains exported variables/functions that are exported for testing
+// only.
+//
+// An ideal way for this would be to put those in a *_test.go but in binarylog
+// package. But this doesn't work with staticcheck with go module. Error was:
+// "MdToMetadataProto not declared by package binarylog". This could be caused
+// by the way staticcheck looks for files for a certain package, which doesn't
+// support *_test.go files.
+//
+// Move those to binary_test.go when staticcheck is fixed.
+
+package binarylog
+
+var (
+	// AllLogger is a logger that logs all headers/messages for all RPCs. It's
+	// for testing only.
+	AllLogger = NewLoggerFromConfigString("*")
+	// MdToMetadataProto converts metadata to a binary logging proto message.
+	// It's for testing only.
+	MdToMetadataProto = mdToMetadataProto
+	// AddrToProto converts an address to a binary logging proto message. It's
+	// for testing only.
+	AddrToProto = addrToProto
+)

vendor/google.golang.org/grpc/internal/binarylog/env_config.go

@@ -0,0 +1,208 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// NewLoggerFromConfigString reads the string and build a logger. It can be used
+// to build a new logger and assign it to binarylog.Logger.
+//
+// Example filter config strings:
+//   - "" Nothing will be logged
+//   - "*" All headers and messages will be fully logged.
+//   - "*{h}" Only headers will be logged.
+//   - "*{m:256}" Only the first 256 bytes of each message will be logged.
+//   - "Foo/*" Logs every method in service Foo
+//   - "Foo/*,-Foo/Bar" Logs every method in service Foo except method /Foo/Bar
+//   - "Foo/*,Foo/Bar{m:256}" Logs the first 256 bytes of each message in method
+//     /Foo/Bar, logs all headers and messages in every other method in service
+//     Foo.
+//
+// If two configs exist for one certain method or service, the one specified
+// later overrides the previous config.
+func NewLoggerFromConfigString(s string) Logger {
+	if s == "" {
+		return nil
+	}
+	l := newEmptyLogger()
+	methods := strings.Split(s, ",")
+	for _, method := range methods {
+		if err := l.fillMethodLoggerWithConfigString(method); err != nil {
+			grpclogLogger.Warningf("failed to parse binary log config: %v", err)
+			return nil
+		}
+	}
+	return l
+}
+
+// fillMethodLoggerWithConfigString parses config, creates TruncatingMethodLogger and adds
+// it to the right map in the logger.
+func (l *logger) fillMethodLoggerWithConfigString(config string) error {
+	// "" is invalid.
+	if config == "" {
+		return errors.New("empty string is not a valid method binary logging config")
+	}
+
+	// "-service/method", blacklist, no * or {} allowed.
+	if config[0] == '-' {
+		s, m, suffix, err := parseMethodConfigAndSuffix(config[1:])
+		if err != nil {
+			return fmt.Errorf("invalid config: %q, %v", config, err)
+		}
+		if m == "*" {
+			return fmt.Errorf("invalid config: %q, %v", config, "* not allowed in blacklist config")
+		}
+		if suffix != "" {
+			return fmt.Errorf("invalid config: %q, %v", config, "header/message limit not allowed in blacklist config")
+		}
+		if err := l.setBlacklist(s + "/" + m); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+		return nil
+	}
+
+	// "*{h:256;m:256}"
+	if config[0] == '*' {
+		hdr, msg, err := parseHeaderMessageLengthConfig(config[1:])
+		if err != nil {
+			return fmt.Errorf("invalid config: %q, %v", config, err)
+		}
+		if err := l.setDefaultMethodLogger(&MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+		return nil
+	}
+
+	s, m, suffix, err := parseMethodConfigAndSuffix(config)
+	if err != nil {
+		return fmt.Errorf("invalid config: %q, %v", config, err)
+	}
+	hdr, msg, err := parseHeaderMessageLengthConfig(suffix)
+	if err != nil {
+		return fmt.Errorf("invalid header/message length config: %q, %v", suffix, err)
+	}
+	if m == "*" {
+		if err := l.setServiceMethodLogger(s, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+	} else {
+		if err := l.setMethodMethodLogger(s+"/"+m, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+	}
+	return nil
+}
+
+const (
+	// TODO: this const is only used by env_config now. But could be useful for
+	// other config. Move to binarylog.go if necessary.
+	maxUInt = ^uint64(0)
+
+	// For "p.s/m" plus any suffix. Suffix will be parsed again. See test for
+	// expected output.
+	longMethodConfigRegexpStr = `^([\w./]+)/((?:\w+)|[*])(.+)?$`
+
+	// For suffix from above, "{h:123,m:123}". See test for expected output.
+	optionalLengthRegexpStr      = `(?::(\d+))?` // Optional ":123".
+	headerConfigRegexpStr        = `^{h` + optionalLengthRegexpStr + `}$`
+	messageConfigRegexpStr       = `^{m` + optionalLengthRegexpStr + `}$`
+	headerMessageConfigRegexpStr = `^{h` + optionalLengthRegexpStr + `;m` + optionalLengthRegexpStr + `}$`
+)
+
+var (
+	longMethodConfigRegexp    = regexp.MustCompile(longMethodConfigRegexpStr)
+	headerConfigRegexp        = regexp.MustCompile(headerConfigRegexpStr)
+	messageConfigRegexp       = regexp.MustCompile(messageConfigRegexpStr)
+	headerMessageConfigRegexp = regexp.MustCompile(headerMessageConfigRegexpStr)
+)
+
+// Turn "service/method{h;m}" into "service", "method", "{h;m}".
+func parseMethodConfigAndSuffix(c string) (service, method, suffix string, _ error) {
+	// Regexp result:
+	//
+	// in:  "p.s/m{h:123,m:123}",
+	// out: []string{"p.s/m{h:123,m:123}", "p.s", "m", "{h:123,m:123}"},
+	match := longMethodConfigRegexp.FindStringSubmatch(c)
+	if match == nil {
+		return "", "", "", fmt.Errorf("%q contains invalid substring", c)
+	}
+	service = match[1]
+	method = match[2]
+	suffix = match[3]
+	return
+}
+
+// Turn "{h:123;m:345}" into 123, 345.
+//
+// Return maxUInt if length is unspecified.
+func parseHeaderMessageLengthConfig(c string) (hdrLenStr, msgLenStr uint64, err error) {
+	if c == "" {
+		return maxUInt, maxUInt, nil
+	}
+	// Header config only.
+	if match := headerConfigRegexp.FindStringSubmatch(c); match != nil {
+		if s := match[1]; s != "" {
+			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+			return hdrLenStr, 0, nil
+		}
+		return maxUInt, 0, nil
+	}
+
+	// Message config only.
+	if match := messageConfigRegexp.FindStringSubmatch(c); match != nil {
+		if s := match[1]; s != "" {
+			msgLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+			return 0, msgLenStr, nil
+		}
+		return 0, maxUInt, nil
+	}
+
+	// Header and message config both.
+	if match := headerMessageConfigRegexp.FindStringSubmatch(c); match != nil {
+		// Both hdr and msg are specified, but one or two of them might be empty.
+		hdrLenStr = maxUInt
+		msgLenStr = maxUInt
+		if s := match[1]; s != "" {
+			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+		}
+		if s := match[2]; s != "" {
+			msgLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+		}
+		return hdrLenStr, msgLenStr, nil
+	}
+	return 0, 0, fmt.Errorf("%q contains invalid substring", c)
+}

vendor/google.golang.org/grpc/internal/binarylog/method_logger.go

@@ -0,0 +1,446 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"context"
+	"net"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/durationpb"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+type callIDGenerator struct {
+	id uint64
+}
+
+func (g *callIDGenerator) next() uint64 {
+	id := atomic.AddUint64(&g.id, 1)
+	return id
+}
+
+// reset is for testing only, and doesn't need to be thread safe.
+func (g *callIDGenerator) reset() {
+	g.id = 0
+}
+
+var idGen callIDGenerator
+
+// MethodLogger is the sub-logger for each method.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+type MethodLogger interface {
+	Log(context.Context, LogEntryConfig)
+}
+
+// TruncatingMethodLogger is a method logger that truncates headers and messages
+// based on configured fields.
+type TruncatingMethodLogger struct {
+	headerMaxLen, messageMaxLen uint64
+
+	callID          uint64
+	idWithinCallGen *callIDGenerator
+
+	sink Sink // TODO(blog): make this pluggable.
+}
+
+// NewTruncatingMethodLogger returns a new truncating method logger.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
+	return &TruncatingMethodLogger{
+		headerMaxLen:  h,
+		messageMaxLen: m,
+
+		callID:          idGen.next(),
+		idWithinCallGen: &callIDGenerator{},
+
+		sink: DefaultSink, // TODO(blog): make it pluggable.
+	}
+}
+
+// Build is an internal only method for building the proto message out of the
+// input event. It's made public to enable other library to reuse as much logic
+// in TruncatingMethodLogger as possible.
+func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *binlogpb.GrpcLogEntry {
+	m := c.toProto()
+	timestamp := timestamppb.Now()
+	m.Timestamp = timestamp
+	m.CallId = ml.callID
+	m.SequenceIdWithinCall = ml.idWithinCallGen.next()
+
+	switch pay := m.Payload.(type) {
+	case *binlogpb.GrpcLogEntry_ClientHeader:
+		m.PayloadTruncated = ml.truncateMetadata(pay.ClientHeader.GetMetadata())
+	case *binlogpb.GrpcLogEntry_ServerHeader:
+		m.PayloadTruncated = ml.truncateMetadata(pay.ServerHeader.GetMetadata())
+	case *binlogpb.GrpcLogEntry_Message:
+		m.PayloadTruncated = ml.truncateMessage(pay.Message)
+	}
+	return m
+}
+
+// Log creates a proto binary log entry, and logs it to the sink.
+func (ml *TruncatingMethodLogger) Log(_ context.Context, c LogEntryConfig) {
+	ml.sink.Write(ml.Build(c))
+}
+
+func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *binlogpb.Metadata) (truncated bool) {
+	if ml.headerMaxLen == maxUInt {
+		return false
+	}
+	var (
+		bytesLimit = ml.headerMaxLen
+		index      int
+	)
+	// At the end of the loop, index will be the first entry where the total
+	// size is greater than the limit:
+	//
+	// len(entry[:index]) <= ml.hdr && len(entry[:index+1]) > ml.hdr.
+	for ; index < len(mdPb.Entry); index++ {
+		entry := mdPb.Entry[index]
+		if entry.Key == "grpc-trace-bin" {
+			// "grpc-trace-bin" is a special key. It's kept in the log entry,
+			// but not counted towards the size limit.
+			continue
+		}
+		currentEntryLen := uint64(len(entry.GetKey())) + uint64(len(entry.GetValue()))
+		if currentEntryLen > bytesLimit {
+			break
+		}
+		bytesLimit -= currentEntryLen
+	}
+	truncated = index < len(mdPb.Entry)
+	mdPb.Entry = mdPb.Entry[:index]
+	return truncated
+}
+
+func (ml *TruncatingMethodLogger) truncateMessage(msgPb *binlogpb.Message) (truncated bool) {
+	if ml.messageMaxLen == maxUInt {
+		return false
+	}
+	if ml.messageMaxLen >= uint64(len(msgPb.Data)) {
+		return false
+	}
+	msgPb.Data = msgPb.Data[:ml.messageMaxLen]
+	return true
+}
+
+// LogEntryConfig represents the configuration for binary log entry.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
+type LogEntryConfig interface {
+	toProto() *binlogpb.GrpcLogEntry
+}
+
+// ClientHeader configs the binary log entry to be a ClientHeader entry.
+type ClientHeader struct {
+	OnClientSide bool
+	Header       metadata.MD
+	MethodName   string
+	Authority    string
+	Timeout      time.Duration
+	// PeerAddr is required only when it's on server side.
+	PeerAddr net.Addr
+}
+
+func (c *ClientHeader) toProto() *binlogpb.GrpcLogEntry {
+	// This function doesn't need to set all the fields (e.g. seq ID). The Log
+	// function will set the fields when necessary.
+	clientHeader := &binlogpb.ClientHeader{
+		Metadata:   mdToMetadataProto(c.Header),
+		MethodName: c.MethodName,
+		Authority:  c.Authority,
+	}
+	if c.Timeout > 0 {
+		clientHeader.Timeout = durationpb.New(c.Timeout)
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ClientHeader{
+			ClientHeader: clientHeader,
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// ServerHeader configs the binary log entry to be a ServerHeader entry.
+type ServerHeader struct {
+	OnClientSide bool
+	Header       metadata.MD
+	// PeerAddr is required only when it's on client side.
+	PeerAddr net.Addr
+}
+
+func (c *ServerHeader) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ServerHeader{
+			ServerHeader: &binlogpb.ServerHeader{
+				Metadata: mdToMetadataProto(c.Header),
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// ClientMessage configs the binary log entry to be a ClientMessage entry.
+type ClientMessage struct {
+	OnClientSide bool
+	// Message can be a proto.Message or []byte. Other messages formats are not
+	// supported.
+	Message any
+}
+
+func (c *ClientMessage) toProto() *binlogpb.GrpcLogEntry {
+	var (
+		data []byte
+		err  error
+	)
+	if m, ok := c.Message.(proto.Message); ok {
+		data, err = proto.Marshal(m)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal proto message: %v", err)
+		}
+	} else if b, ok := c.Message.([]byte); ok {
+		data = b
+	} else {
+		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
+				Length: uint32(len(data)),
+				Data:   data,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ServerMessage configs the binary log entry to be a ServerMessage entry.
+type ServerMessage struct {
+	OnClientSide bool
+	// Message can be a proto.Message or []byte. Other messages formats are not
+	// supported.
+	Message any
+}
+
+func (c *ServerMessage) toProto() *binlogpb.GrpcLogEntry {
+	var (
+		data []byte
+		err  error
+	)
+	if m, ok := c.Message.(proto.Message); ok {
+		data, err = proto.Marshal(m)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal proto message: %v", err)
+		}
+	} else if b, ok := c.Message.([]byte); ok {
+		data = b
+	} else {
+		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
+				Length: uint32(len(data)),
+				Data:   data,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ClientHalfClose configs the binary log entry to be a ClientHalfClose entry.
+type ClientHalfClose struct {
+	OnClientSide bool
+}
+
+func (c *ClientHalfClose) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
+		Payload: nil, // No payload here.
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ServerTrailer configs the binary log entry to be a ServerTrailer entry.
+type ServerTrailer struct {
+	OnClientSide bool
+	Trailer      metadata.MD
+	// Err is the status error.
+	Err error
+	// PeerAddr is required only when it's on client side and the RPC is trailer
+	// only.
+	PeerAddr net.Addr
+}
+
+func (c *ServerTrailer) toProto() *binlogpb.GrpcLogEntry {
+	st, ok := status.FromError(c.Err)
+	if !ok {
+		grpclogLogger.Info("binarylogging: error in trailer is not a status error")
+	}
+	var (
+		detailsBytes []byte
+		err          error
+	)
+	stProto := st.Proto()
+	if stProto != nil && len(stProto.Details) != 0 {
+		detailsBytes, err = proto.Marshal(stProto)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal status proto: %v", err)
+		}
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
+		Payload: &binlogpb.GrpcLogEntry_Trailer{
+			Trailer: &binlogpb.Trailer{
+				Metadata:      mdToMetadataProto(c.Trailer),
+				StatusCode:    uint32(st.Code()),
+				StatusMessage: st.Message(),
+				StatusDetails: detailsBytes,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// Cancel configs the binary log entry to be a Cancel entry.
+type Cancel struct {
+	OnClientSide bool
+}
+
+func (c *Cancel) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CANCEL,
+		Payload: nil,
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// metadataKeyOmit returns whether the metadata entry with this key should be
+// omitted.
+func metadataKeyOmit(key string) bool {
+	switch key {
+	case "lb-token", ":path", ":authority", "content-encoding", "content-type", "user-agent", "te":
+		return true
+	case "grpc-trace-bin": // grpc-trace-bin is special because it's visible to users.
+		return false
+	}
+	return strings.HasPrefix(key, "grpc-")
+}
+
+func mdToMetadataProto(md metadata.MD) *binlogpb.Metadata {
+	ret := &binlogpb.Metadata{}
+	for k, vv := range md {
+		if metadataKeyOmit(k) {
+			continue
+		}
+		for _, v := range vv {
+			ret.Entry = append(ret.Entry,
+				&binlogpb.MetadataEntry{
+					Key:   k,
+					Value: []byte(v),
+				},
+			)
+		}
+	}
+	return ret
+}
+
+func addrToProto(addr net.Addr) *binlogpb.Address {
+	ret := &binlogpb.Address{}
+	switch a := addr.(type) {
+	case *net.TCPAddr:
+		if a.IP.To4() != nil {
+			ret.Type = binlogpb.Address_TYPE_IPV4
+		} else if a.IP.To16() != nil {
+			ret.Type = binlogpb.Address_TYPE_IPV6
+		} else {
+			ret.Type = binlogpb.Address_TYPE_UNKNOWN
+			// Do not set address and port fields.
+			break
+		}
+		ret.Address = a.IP.String()
+		ret.IpPort = uint32(a.Port)
+	case *net.UnixAddr:
+		ret.Type = binlogpb.Address_TYPE_UNIX
+		ret.Address = a.String()
+	default:
+		ret.Type = binlogpb.Address_TYPE_UNKNOWN
+	}
+	return ret
+}

vendor/google.golang.org/grpc/internal/binarylog/sink.go

@@ -0,0 +1,170 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"bufio"
+	"encoding/binary"
+	"io"
+	"sync"
+	"time"
+
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	"google.golang.org/protobuf/proto"
+)
+
+var (
+	// DefaultSink is the sink where the logs will be written to. It's exported
+	// for the binarylog package to update.
+	DefaultSink Sink = &noopSink{} // TODO(blog): change this default (file in /tmp).
+)
+
+// Sink writes log entry into the binary log sink.
+//
+// sink is a copy of the exported binarylog.Sink, to avoid circular dependency.
+type Sink interface {
+	// Write will be called to write the log entry into the sink.
+	//
+	// It should be thread-safe so it can be called in parallel.
+	Write(*binlogpb.GrpcLogEntry) error
+	// Close will be called when the Sink is replaced by a new Sink.
+	Close() error
+}
+
+type noopSink struct{}
+
+func (ns *noopSink) Write(*binlogpb.GrpcLogEntry) error { return nil }
+func (ns *noopSink) Close() error                       { return nil }
+
+// newWriterSink creates a binary log sink with the given writer.
+//
+// Write() marshals the proto message and writes it to the given writer. Each
+// message is prefixed with a 4 byte big endian unsigned integer as the length.
+//
+// No buffer is done, Close() doesn't try to close the writer.
+func newWriterSink(w io.Writer) Sink {
+	return &writerSink{out: w}
+}
+
+type writerSink struct {
+	out io.Writer
+}
+
+func (ws *writerSink) Write(e *binlogpb.GrpcLogEntry) error {
+	b, err := proto.Marshal(e)
+	if err != nil {
+		grpclogLogger.Errorf("binary logging: failed to marshal proto message: %v", err)
+		return err
+	}
+	hdr := make([]byte, 4)
+	binary.BigEndian.PutUint32(hdr, uint32(len(b)))
+	if _, err := ws.out.Write(hdr); err != nil {
+		return err
+	}
+	if _, err := ws.out.Write(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ws *writerSink) Close() error { return nil }
+
+type bufferedSink struct {
+	mu             sync.Mutex
+	closer         io.Closer
+	out            Sink          // out is built on buf.
+	buf            *bufio.Writer // buf is kept for flush.
+	flusherStarted bool
+
+	writeTicker *time.Ticker
+	done        chan struct{}
+}
+
+func (fs *bufferedSink) Write(e *binlogpb.GrpcLogEntry) error {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+	if !fs.flusherStarted {
+		// Start the write loop when Write is called.
+		fs.startFlushGoroutine()
+		fs.flusherStarted = true
+	}
+	if err := fs.out.Write(e); err != nil {
+		return err
+	}
+	return nil
+}
+
+const (
+	bufFlushDuration = 60 * time.Second
+)
+
+func (fs *bufferedSink) startFlushGoroutine() {
+	fs.writeTicker = time.NewTicker(bufFlushDuration)
+	go func() {
+		for {
+			select {
+			case <-fs.done:
+				return
+			case <-fs.writeTicker.C:
+			}
+			fs.mu.Lock()
+			if err := fs.buf.Flush(); err != nil {
+				grpclogLogger.Warningf("failed to flush to Sink: %v", err)
+			}
+			fs.mu.Unlock()
+		}
+	}()
+}
+
+func (fs *bufferedSink) Close() error {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+	if fs.writeTicker != nil {
+		fs.writeTicker.Stop()
+	}
+	close(fs.done)
+	if err := fs.buf.Flush(); err != nil {
+		grpclogLogger.Warningf("failed to flush to Sink: %v", err)
+	}
+	if err := fs.closer.Close(); err != nil {
+		grpclogLogger.Warningf("failed to close the underlying WriterCloser: %v", err)
+	}
+	if err := fs.out.Close(); err != nil {
+		grpclogLogger.Warningf("failed to close the Sink: %v", err)
+	}
+	return nil
+}
+
+// NewBufferedSink creates a binary log sink with the given WriteCloser.
+//
+// Write() marshals the proto message and writes it to the given writer. Each
+// message is prefixed with a 4 byte big endian unsigned integer as the length.
+//
+// Content is kept in a buffer, and is flushed every 60 seconds.
+//
+// Close closes the WriteCloser.
+func NewBufferedSink(o io.WriteCloser) Sink {
+	bufW := bufio.NewWriter(o)
+	return &bufferedSink{
+		closer: o,
+		out:    newWriterSink(bufW),
+		buf:    bufW,
+		done:   make(chan struct{}),
+	}
+}

vendor/google.golang.org/grpc/internal/buffer/unbounded.go

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package buffer provides an implementation of an unbounded buffer.
+package buffer
+
+import (
+	"errors"
+	"sync"
+)
+
+// Unbounded is an implementation of an unbounded buffer which does not use
+// extra goroutines. This is typically used for passing updates from one entity
+// to another within gRPC.
+//
+// All methods on this type are thread-safe and don't block on anything except
+// the underlying mutex used for synchronization.
+//
+// Unbounded supports values of any type to be stored in it by using a channel
+// of `any`. This means that a call to Put() incurs an extra memory allocation,
+// and also that users need a type assertion while reading. For performance
+// critical code paths, using Unbounded is strongly discouraged and defining a
+// new type specific implementation of this buffer is preferred. See
+// internal/transport/transport.go for an example of this.
+type Unbounded struct {
+	c       chan any
+	closed  bool
+	closing bool
+	mu      sync.Mutex
+	backlog []any
+}
+
+// NewUnbounded returns a new instance of Unbounded.
+func NewUnbounded() *Unbounded {
+	return &Unbounded{c: make(chan any, 1)}
+}
+
+var errBufferClosed = errors.New("Put called on closed buffer.Unbounded")
+
+// Put adds t to the unbounded buffer.
+func (b *Unbounded) Put(t any) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closing {
+		return errBufferClosed
+	}
+	if len(b.backlog) == 0 {
+		select {
+		case b.c <- t:
+			return nil
+		default:
+		}
+	}
+	b.backlog = append(b.backlog, t)
+	return nil
+}
+
+// Load sends the earliest buffered data, if any, onto the read channel returned
+// by Get(). Users are expected to call this every time they successfully read a
+// value from the read channel.
+func (b *Unbounded) Load() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if len(b.backlog) > 0 {
+		select {
+		case b.c <- b.backlog[0]:
+			b.backlog[0] = nil
+			b.backlog = b.backlog[1:]
+		default:
+		}
+	} else if b.closing && !b.closed {
+		b.closed = true
+		close(b.c)
+	}
+}
+
+// Get returns a read channel on which values added to the buffer, via Put(),
+// are sent on.
+//
+// Upon reading a value from this channel, users are expected to call Load() to
+// send the next buffered value onto the channel if there is any.
+//
+// If the unbounded buffer is closed, the read channel returned by this method
+// is closed after all data is drained.
+func (b *Unbounded) Get() <-chan any {
+	return b.c
+}
+
+// Close closes the unbounded buffer. No subsequent data may be Put(), and the
+// channel returned from Get() will be closed after all the data is read and
+// Load() is called for the final time.
+func (b *Unbounded) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closing {
+		return
+	}
+	b.closing = true
+	if len(b.backlog) == 0 {
+		b.closed = true
+		close(b.c)
+	}
+}

vendor/google.golang.org/grpc/internal/channelz/channel.go

@@ -0,0 +1,270 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"sync/atomic"
+
+	"google.golang.org/grpc/connectivity"
+)
+
+// Channel represents a channel within channelz, which includes metrics and
+// internal channelz data, such as channelz id, child list, etc.
+type Channel struct {
+	Entity
+	// ID is the channelz id of this channel.
+	ID int64
+	// RefName is the human readable reference string of this channel.
+	RefName string
+
+	closeCalled bool
+	nestedChans map[int64]string
+	subChans    map[int64]string
+	Parent      *Channel
+	trace       *ChannelTrace
+	// traceRefCount is the number of trace events that reference this channel.
+	// Non-zero traceRefCount means the trace of this channel cannot be deleted.
+	traceRefCount int32
+
+	// ChannelMetrics holds connectivity state, target and call metrics for the
+	// channel within channelz.
+	ChannelMetrics ChannelMetrics
+}
+
+// Implemented to make Channel implement the Identifier interface used for
+// nesting.
+func (c *Channel) channelzIdentifier() {}
+
+// String returns a string representation of the Channel, including its parent
+// entity and ID.
+func (c *Channel) String() string {
+	if c.Parent == nil {
+		return fmt.Sprintf("Channel #%d", c.ID)
+	}
+	return fmt.Sprintf("%s Channel #%d", c.Parent, c.ID)
+}
+
+func (c *Channel) id() int64 {
+	return c.ID
+}
+
+// SubChans returns a copy of the map of sub-channels associated with the
+// Channel.
+func (c *Channel) SubChans() map[int64]string {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return copyMap(c.subChans)
+}
+
+// NestedChans returns a copy of the map of nested channels associated with the
+// Channel.
+func (c *Channel) NestedChans() map[int64]string {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return copyMap(c.nestedChans)
+}
+
+// Trace returns a copy of the Channel's trace data.
+func (c *Channel) Trace() *ChannelTrace {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return c.trace.copy()
+}
+
+// ChannelMetrics holds connectivity state, target and call metrics for the
+// channel within channelz.
+type ChannelMetrics struct {
+	// The current connectivity state of the channel.
+	State atomic.Pointer[connectivity.State]
+	// The target this channel originally tried to connect to.  May be absent
+	Target atomic.Pointer[string]
+	// The number of calls started on the channel.
+	CallsStarted atomic.Int64
+	// The number of calls that have completed with an OK status.
+	CallsSucceeded atomic.Int64
+	// The number of calls that have a completed with a non-OK status.
+	CallsFailed atomic.Int64
+	// The last time a call was started on the channel.
+	LastCallStartedTimestamp atomic.Int64
+}
+
+// CopyFrom copies the metrics in o to c.  For testing only.
+func (c *ChannelMetrics) CopyFrom(o *ChannelMetrics) {
+	c.State.Store(o.State.Load())
+	c.Target.Store(o.Target.Load())
+	c.CallsStarted.Store(o.CallsStarted.Load())
+	c.CallsSucceeded.Store(o.CallsSucceeded.Load())
+	c.CallsFailed.Store(o.CallsFailed.Load())
+	c.LastCallStartedTimestamp.Store(o.LastCallStartedTimestamp.Load())
+}
+
+// Equal returns true iff the metrics of c are the same as the metrics of o.
+// For testing only.
+func (c *ChannelMetrics) Equal(o any) bool {
+	oc, ok := o.(*ChannelMetrics)
+	if !ok {
+		return false
+	}
+	if (c.State.Load() == nil) != (oc.State.Load() == nil) {
+		return false
+	}
+	if c.State.Load() != nil && *c.State.Load() != *oc.State.Load() {
+		return false
+	}
+	if (c.Target.Load() == nil) != (oc.Target.Load() == nil) {
+		return false
+	}
+	if c.Target.Load() != nil && *c.Target.Load() != *oc.Target.Load() {
+		return false
+	}
+	return c.CallsStarted.Load() == oc.CallsStarted.Load() &&
+		c.CallsFailed.Load() == oc.CallsFailed.Load() &&
+		c.CallsSucceeded.Load() == oc.CallsSucceeded.Load() &&
+		c.LastCallStartedTimestamp.Load() == oc.LastCallStartedTimestamp.Load()
+}
+
+func strFromPointer(s *string) string {
+	if s == nil {
+		return ""
+	}
+	return *s
+}
+
+// String returns a string representation of the ChannelMetrics, including its
+// state, target, and call metrics.
+func (c *ChannelMetrics) String() string {
+	return fmt.Sprintf("State: %v, Target: %s, CallsStarted: %v, CallsSucceeded: %v, CallsFailed: %v, LastCallStartedTimestamp: %v",
+		c.State.Load(), strFromPointer(c.Target.Load()), c.CallsStarted.Load(), c.CallsSucceeded.Load(), c.CallsFailed.Load(), c.LastCallStartedTimestamp.Load(),
+	)
+}
+
+// NewChannelMetricForTesting creates a new instance of ChannelMetrics with
+// specified initial values for testing purposes.
+func NewChannelMetricForTesting(state connectivity.State, target string, started, succeeded, failed, timestamp int64) *ChannelMetrics {
+	c := &ChannelMetrics{}
+	c.State.Store(&state)
+	c.Target.Store(&target)
+	c.CallsStarted.Store(started)
+	c.CallsSucceeded.Store(succeeded)
+	c.CallsFailed.Store(failed)
+	c.LastCallStartedTimestamp.Store(timestamp)
+	return c
+}
+
+func (c *Channel) addChild(id int64, e entry) {
+	switch v := e.(type) {
+	case *SubChannel:
+		c.subChans[id] = v.RefName
+	case *Channel:
+		c.nestedChans[id] = v.RefName
+	default:
+		logger.Errorf("cannot add a child (id = %d) of type %T to a channel", id, e)
+	}
+}
+
+func (c *Channel) deleteChild(id int64) {
+	delete(c.subChans, id)
+	delete(c.nestedChans, id)
+	c.deleteSelfIfReady()
+}
+
+func (c *Channel) triggerDelete() {
+	c.closeCalled = true
+	c.deleteSelfIfReady()
+}
+
+func (c *Channel) getParentID() int64 {
+	if c.Parent == nil {
+		return -1
+	}
+	return c.Parent.ID
+}
+
+// deleteSelfFromTree tries to delete the channel from the channelz entry relation tree, which means
+// deleting the channel reference from its parent's child list.
+//
+// In order for a channel to be deleted from the tree, it must meet the criteria that, removal of the
+// corresponding grpc object has been invoked, and the channel does not have any children left.
+//
+// The returned boolean value indicates whether the channel has been successfully deleted from tree.
+func (c *Channel) deleteSelfFromTree() (deleted bool) {
+	if !c.closeCalled || len(c.subChans)+len(c.nestedChans) != 0 {
+		return false
+	}
+	// not top channel
+	if c.Parent != nil {
+		c.Parent.deleteChild(c.ID)
+	}
+	return true
+}
+
+// deleteSelfFromMap checks whether it is valid to delete the channel from the map, which means
+// deleting the channel from channelz's tracking entirely. Users can no longer use id to query the
+// channel, and its memory will be garbage collected.
+//
+// The trace reference count of the channel must be 0 in order to be deleted from the map. This is
+// specified in the channel tracing gRFC that as long as some other trace has reference to an entity,
+// the trace of the referenced entity must not be deleted. In order to release the resource allocated
+// by grpc, the reference to the grpc object is reset to a dummy object.
+//
+// deleteSelfFromMap must be called after deleteSelfFromTree returns true.
+//
+// It returns a bool to indicate whether the channel can be safely deleted from map.
+func (c *Channel) deleteSelfFromMap() (delete bool) {
+	return c.getTraceRefCount() == 0
+}
+
+// deleteSelfIfReady tries to delete the channel itself from the channelz database.
+// The delete process includes two steps:
+//  1. delete the channel from the entry relation tree, i.e. delete the channel reference from its
+//     parent's child list.
+//  2. delete the channel from the map, i.e. delete the channel entirely from channelz. Lookup by id
+//     will return entry not found error.
+func (c *Channel) deleteSelfIfReady() {
+	if !c.deleteSelfFromTree() {
+		return
+	}
+	if !c.deleteSelfFromMap() {
+		return
+	}
+	db.deleteEntry(c.ID)
+	c.trace.clear()
+}
+
+func (c *Channel) getChannelTrace() *ChannelTrace {
+	return c.trace
+}
+
+func (c *Channel) incrTraceRefCount() {
+	atomic.AddInt32(&c.traceRefCount, 1)
+}
+
+func (c *Channel) decrTraceRefCount() {
+	atomic.AddInt32(&c.traceRefCount, -1)
+}
+
+func (c *Channel) getTraceRefCount() int {
+	i := atomic.LoadInt32(&c.traceRefCount)
+	return int(i)
+}
+
+func (c *Channel) getRefName() string {
+	return c.RefName
+}

vendor/google.golang.org/grpc/internal/channelz/channelmap.go

@@ -0,0 +1,395 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"sort"
+	"sync"
+	"time"
+)
+
+// entry represents a node in the channelz database.
+type entry interface {
+	// addChild adds a child e, whose channelz id is id to child list
+	addChild(id int64, e entry)
+	// deleteChild deletes a child with channelz id to be id from child list
+	deleteChild(id int64)
+	// triggerDelete tries to delete self from channelz database. However, if
+	// child list is not empty, then deletion from the database is on hold until
+	// the last child is deleted from database.
+	triggerDelete()
+	// deleteSelfIfReady check whether triggerDelete() has been called before,
+	// and whether child list is now empty. If both conditions are met, then
+	// delete self from database.
+	deleteSelfIfReady()
+	// getParentID returns parent ID of the entry. 0 value parent ID means no parent.
+	getParentID() int64
+	Entity
+}
+
+// channelMap is the storage data structure for channelz.
+//
+// Methods of channelMap can be divided into two categories with respect to
+// locking.
+//
+// 1. Methods acquire the global lock.
+// 2. Methods that can only be called when global lock is held.
+//
+// A second type of method need always to be called inside a first type of method.
+type channelMap struct {
+	mu               sync.RWMutex
+	topLevelChannels map[int64]struct{}
+	channels         map[int64]*Channel
+	subChannels      map[int64]*SubChannel
+	sockets          map[int64]*Socket
+	servers          map[int64]*Server
+}
+
+func newChannelMap() *channelMap {
+	return &channelMap{
+		topLevelChannels: make(map[int64]struct{}),
+		channels:         make(map[int64]*Channel),
+		subChannels:      make(map[int64]*SubChannel),
+		sockets:          make(map[int64]*Socket),
+		servers:          make(map[int64]*Server),
+	}
+}
+
+func (c *channelMap) addServer(id int64, s *Server) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	s.cm = c
+	c.servers[id] = s
+}
+
+func (c *channelMap) addChannel(id int64, cn *Channel, isTopChannel bool, pid int64) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	cn.trace.cm = c
+	c.channels[id] = cn
+	if isTopChannel {
+		c.topLevelChannels[id] = struct{}{}
+	} else if p := c.channels[pid]; p != nil {
+		p.addChild(id, cn)
+	} else {
+		logger.Infof("channel %d references invalid parent ID %d", id, pid)
+	}
+}
+
+func (c *channelMap) addSubChannel(id int64, sc *SubChannel, pid int64) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	sc.trace.cm = c
+	c.subChannels[id] = sc
+	if p := c.channels[pid]; p != nil {
+		p.addChild(id, sc)
+	} else {
+		logger.Infof("subchannel %d references invalid parent ID %d", id, pid)
+	}
+}
+
+func (c *channelMap) addSocket(s *Socket) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	s.cm = c
+	c.sockets[s.ID] = s
+	if s.Parent == nil {
+		logger.Infof("normal socket %d has no parent", s.ID)
+	}
+	s.Parent.(entry).addChild(s.ID, s)
+}
+
+// removeEntry triggers the removal of an entry, which may not indeed delete the
+// entry, if it has to wait on the deletion of its children and until no other
+// entity's channel trace references it.  It may lead to a chain of entry
+// deletion. For example, deleting the last socket of a gracefully shutting down
+// server will lead to the server being also deleted.
+func (c *channelMap) removeEntry(id int64) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.findEntry(id).triggerDelete()
+}
+
+// tracedChannel represents tracing operations which are present on both
+// channels and subChannels.
+type tracedChannel interface {
+	getChannelTrace() *ChannelTrace
+	incrTraceRefCount()
+	decrTraceRefCount()
+	getRefName() string
+}
+
+// c.mu must be held by the caller
+func (c *channelMap) decrTraceRefCount(id int64) {
+	e := c.findEntry(id)
+	if v, ok := e.(tracedChannel); ok {
+		v.decrTraceRefCount()
+		e.deleteSelfIfReady()
+	}
+}
+
+// c.mu must be held by the caller.
+func (c *channelMap) findEntry(id int64) entry {
+	if v, ok := c.channels[id]; ok {
+		return v
+	}
+	if v, ok := c.subChannels[id]; ok {
+		return v
+	}
+	if v, ok := c.servers[id]; ok {
+		return v
+	}
+	if v, ok := c.sockets[id]; ok {
+		return v
+	}
+	return &dummyEntry{idNotFound: id}
+}
+
+// c.mu must be held by the caller
+//
+// deleteEntry deletes an entry from the channelMap. Before calling this method,
+// caller must check this entry is ready to be deleted, i.e removeEntry() has
+// been called on it, and no children still exist.
+func (c *channelMap) deleteEntry(id int64) entry {
+	if v, ok := c.sockets[id]; ok {
+		delete(c.sockets, id)
+		return v
+	}
+	if v, ok := c.subChannels[id]; ok {
+		delete(c.subChannels, id)
+		return v
+	}
+	if v, ok := c.channels[id]; ok {
+		delete(c.channels, id)
+		delete(c.topLevelChannels, id)
+		return v
+	}
+	if v, ok := c.servers[id]; ok {
+		delete(c.servers, id)
+		return v
+	}
+	return &dummyEntry{idNotFound: id}
+}
+
+func (c *channelMap) traceEvent(id int64, desc *TraceEvent) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	child := c.findEntry(id)
+	childTC, ok := child.(tracedChannel)
+	if !ok {
+		return
+	}
+	childTC.getChannelTrace().append(&traceEvent{Desc: desc.Desc, Severity: desc.Severity, Timestamp: time.Now()})
+	if desc.Parent != nil {
+		parent := c.findEntry(child.getParentID())
+		var chanType RefChannelType
+		switch child.(type) {
+		case *Channel:
+			chanType = RefChannel
+		case *SubChannel:
+			chanType = RefSubChannel
+		}
+		if parentTC, ok := parent.(tracedChannel); ok {
+			parentTC.getChannelTrace().append(&traceEvent{
+				Desc:      desc.Parent.Desc,
+				Severity:  desc.Parent.Severity,
+				Timestamp: time.Now(),
+				RefID:     id,
+				RefName:   childTC.getRefName(),
+				RefType:   chanType,
+			})
+			childTC.incrTraceRefCount()
+		}
+	}
+}
+
+type int64Slice []int64
+
+func (s int64Slice) Len() int           { return len(s) }
+func (s int64Slice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s int64Slice) Less(i, j int) bool { return s[i] < s[j] }
+
+func copyMap(m map[int64]string) map[int64]string {
+	n := make(map[int64]string)
+	for k, v := range m {
+		n[k] = v
+	}
+	return n
+}
+
+func (c *channelMap) getTopChannels(id int64, maxResults int) ([]*Channel, bool) {
+	if maxResults <= 0 {
+		maxResults = EntriesPerPage
+	}
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	l := int64(len(c.topLevelChannels))
+	ids := make([]int64, 0, l)
+
+	for k := range c.topLevelChannels {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
+	end := true
+	var t []*Channel
+	for _, v := range ids[idx:] {
+		if len(t) == maxResults {
+			end = false
+			break
+		}
+		if cn, ok := c.channels[v]; ok {
+			t = append(t, cn)
+		}
+	}
+	return t, end
+}
+
+func (c *channelMap) getServers(id int64, maxResults int) ([]*Server, bool) {
+	if maxResults <= 0 {
+		maxResults = EntriesPerPage
+	}
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	ids := make([]int64, 0, len(c.servers))
+	for k := range c.servers {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
+	end := true
+	var s []*Server
+	for _, v := range ids[idx:] {
+		if len(s) == maxResults {
+			end = false
+			break
+		}
+		if svr, ok := c.servers[v]; ok {
+			s = append(s, svr)
+		}
+	}
+	return s, end
+}
+
+func (c *channelMap) getServerSockets(id int64, startID int64, maxResults int) ([]*Socket, bool) {
+	if maxResults <= 0 {
+		maxResults = EntriesPerPage
+	}
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	svr, ok := c.servers[id]
+	if !ok {
+		// server with id doesn't exist.
+		return nil, true
+	}
+	svrskts := svr.sockets
+	ids := make([]int64, 0, len(svrskts))
+	sks := make([]*Socket, 0, min(len(svrskts), maxResults))
+	for k := range svrskts {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= startID })
+	end := true
+	for _, v := range ids[idx:] {
+		if len(sks) == maxResults {
+			end = false
+			break
+		}
+		if ns, ok := c.sockets[v]; ok {
+			sks = append(sks, ns)
+		}
+	}
+	return sks, end
+}
+
+func (c *channelMap) getChannel(id int64) *Channel {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.channels[id]
+}
+
+func (c *channelMap) getSubChannel(id int64) *SubChannel {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.subChannels[id]
+}
+
+func (c *channelMap) getSocket(id int64) *Socket {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.sockets[id]
+}
+
+func (c *channelMap) getServer(id int64) *Server {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.servers[id]
+}
+
+type dummyEntry struct {
+	// dummyEntry is a fake entry to handle entry not found case.
+	idNotFound int64
+	Entity
+}
+
+func (d *dummyEntry) String() string {
+	return fmt.Sprintf("non-existent entity #%d", d.idNotFound)
+}
+
+func (d *dummyEntry) ID() int64 { return d.idNotFound }
+
+func (d *dummyEntry) addChild(id int64, e entry) {
+	// Note: It is possible for a normal program to reach here under race
+	// condition.  For example, there could be a race between ClientConn.Close()
+	// info being propagated to addrConn and http2Client. ClientConn.Close()
+	// cancel the context and result in http2Client to error. The error info is
+	// then caught by transport monitor and before addrConn.tearDown() is called
+	// in side ClientConn.Close(). Therefore, the addrConn will create a new
+	// transport. And when registering the new transport in channelz, its parent
+	// addrConn could have already been torn down and deleted from channelz
+	// tracking, and thus reach the code here.
+	logger.Infof("attempt to add child of type %T with id %d to a parent (id=%d) that doesn't currently exist", e, id, d.idNotFound)
+}
+
+func (d *dummyEntry) deleteChild(id int64) {
+	// It is possible for a normal program to reach here under race condition.
+	// Refer to the example described in addChild().
+	logger.Infof("attempt to delete child with id %d from a parent (id=%d) that doesn't currently exist", id, d.idNotFound)
+}
+
+func (d *dummyEntry) triggerDelete() {
+	logger.Warningf("attempt to delete an entry (id=%d) that doesn't currently exist", d.idNotFound)
+}
+
+func (*dummyEntry) deleteSelfIfReady() {
+	// code should not reach here. deleteSelfIfReady is always called on an existing entry.
+}
+
+func (*dummyEntry) getParentID() int64 {
+	return 0
+}
+
+// Entity is implemented by all channelz types.
+type Entity interface {
+	isEntity()
+	fmt.Stringer
+	id() int64
+}

vendor/google.golang.org/grpc/internal/channelz/funcs.go

@@ -0,0 +1,230 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package channelz defines internal APIs for enabling channelz service, entry
+// registration/deletion, and accessing channelz data. It also defines channelz
+// metric struct formats.
+package channelz
+
+import (
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/internal"
+)
+
+var (
+	// IDGen is the global channelz entity ID generator.  It should not be used
+	// outside this package except by tests.
+	IDGen IDGenerator
+
+	db = newChannelMap()
+	// EntriesPerPage defines the number of channelz entries to be shown on a web page.
+	EntriesPerPage = 50
+	curState       int32
+)
+
+// TurnOn turns on channelz data collection.
+func TurnOn() {
+	atomic.StoreInt32(&curState, 1)
+}
+
+func init() {
+	internal.ChannelzTurnOffForTesting = func() {
+		atomic.StoreInt32(&curState, 0)
+	}
+}
+
+// IsOn returns whether channelz data collection is on.
+func IsOn() bool {
+	return atomic.LoadInt32(&curState) == 1
+}
+
+// GetTopChannels returns a slice of top channel's ChannelMetric, along with a
+// boolean indicating whether there's more top channels to be queried for.
+//
+// The arg id specifies that only top channel with id at or above it will be
+// included in the result. The returned slice is up to a length of the arg
+// maxResults or EntriesPerPage if maxResults is zero, and is sorted in ascending
+// id order.
+func GetTopChannels(id int64, maxResults int) ([]*Channel, bool) {
+	return db.getTopChannels(id, maxResults)
+}
+
+// GetServers returns a slice of server's ServerMetric, along with a
+// boolean indicating whether there's more servers to be queried for.
+//
+// The arg id specifies that only server with id at or above it will be included
+// in the result. The returned slice is up to a length of the arg maxResults or
+// EntriesPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServers(id int64, maxResults int) ([]*Server, bool) {
+	return db.getServers(id, maxResults)
+}
+
+// GetServerSockets returns a slice of server's (identified by id) normal socket's
+// SocketMetrics, along with a boolean indicating whether there's more sockets to
+// be queried for.
+//
+// The arg startID specifies that only sockets with id at or above it will be
+// included in the result. The returned slice is up to a length of the arg maxResults
+// or EntriesPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServerSockets(id int64, startID int64, maxResults int) ([]*Socket, bool) {
+	return db.getServerSockets(id, startID, maxResults)
+}
+
+// GetChannel returns the Channel for the channel (identified by id).
+func GetChannel(id int64) *Channel {
+	return db.getChannel(id)
+}
+
+// GetSubChannel returns the SubChannel for the subchannel (identified by id).
+func GetSubChannel(id int64) *SubChannel {
+	return db.getSubChannel(id)
+}
+
+// GetSocket returns the Socket for the socket (identified by id).
+func GetSocket(id int64) *Socket {
+	return db.getSocket(id)
+}
+
+// GetServer returns the ServerMetric for the server (identified by id).
+func GetServer(id int64) *Server {
+	return db.getServer(id)
+}
+
+// RegisterChannel registers the given channel c in the channelz database with
+// target as its target and reference name, and adds it to the child list of its
+// parent.  parent == nil means no parent.
+//
+// Returns a unique channelz identifier assigned to this channel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterChannel(parent *Channel, target string) *Channel {
+	id := IDGen.genID()
+
+	if !IsOn() {
+		return &Channel{ID: id}
+	}
+
+	isTopChannel := parent == nil
+
+	cn := &Channel{
+		ID:          id,
+		RefName:     target,
+		nestedChans: make(map[int64]string),
+		subChans:    make(map[int64]string),
+		Parent:      parent,
+		trace:       &ChannelTrace{CreationTime: time.Now(), Events: make([]*traceEvent, 0, getMaxTraceEntry())},
+	}
+	cn.ChannelMetrics.Target.Store(&target)
+	db.addChannel(id, cn, isTopChannel, cn.getParentID())
+	return cn
+}
+
+// RegisterSubChannel registers the given subChannel c in the channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by pid).
+//
+// Returns a unique channelz identifier assigned to this subChannel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterSubChannel(parent *Channel, ref string) *SubChannel {
+	id := IDGen.genID()
+	sc := &SubChannel{
+		ID:      id,
+		RefName: ref,
+		parent:  parent,
+	}
+
+	if !IsOn() {
+		return sc
+	}
+
+	sc.sockets = make(map[int64]string)
+	sc.trace = &ChannelTrace{CreationTime: time.Now(), Events: make([]*traceEvent, 0, getMaxTraceEntry())}
+	db.addSubChannel(id, sc, parent.ID)
+	return sc
+}
+
+// RegisterServer registers the given server s in channelz database. It returns
+// the unique channelz tracking id assigned to this server.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterServer(ref string) *Server {
+	id := IDGen.genID()
+	if !IsOn() {
+		return &Server{ID: id}
+	}
+
+	svr := &Server{
+		RefName:       ref,
+		sockets:       make(map[int64]string),
+		listenSockets: make(map[int64]string),
+		ID:            id,
+	}
+	db.addServer(id, svr)
+	return svr
+}
+
+// RegisterSocket registers the given normal socket s in channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by skt.Parent, which must be set). It returns the unique channelz
+// tracking id assigned to this normal socket.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterSocket(skt *Socket) *Socket {
+	skt.ID = IDGen.genID()
+	if IsOn() {
+		db.addSocket(skt)
+	}
+	return skt
+}
+
+// RemoveEntry removes an entry with unique channelz tracking id to be id from
+// channelz database.
+//
+// If channelz is not turned ON, this function is a no-op.
+func RemoveEntry(id int64) {
+	if !IsOn() {
+		return
+	}
+	db.removeEntry(id)
+}
+
+// IDGenerator is an incrementing atomic that tracks IDs for channelz entities.
+type IDGenerator struct {
+	id int64
+}
+
+// Reset resets the generated ID back to zero.  Should only be used at
+// initialization or by tests sensitive to the ID number.
+func (i *IDGenerator) Reset() {
+	atomic.StoreInt64(&i.id, 0)
+}
+
+func (i *IDGenerator) genID() int64 {
+	return atomic.AddInt64(&i.id, 1)
+}
+
+// Identifier is an opaque channelz identifier used to expose channelz symbols
+// outside of grpc.  Currently only implemented by Channel since no other
+// types require exposure outside grpc.
+type Identifier interface {
+	Entity
+	channelzIdentifier()
+}

vendor/google.golang.org/grpc/internal/channelz/logging.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("channelz")
+
+// Info logs and adds a trace event if channelz is on.
+func Info(l grpclog.DepthLoggerV2, e Entity, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtInfo,
+	})
+}
+
+// Infof logs and adds a trace event if channelz is on.
+func Infof(l grpclog.DepthLoggerV2, e Entity, format string, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtInfo,
+	})
+}
+
+// Warning logs and adds a trace event if channelz is on.
+func Warning(l grpclog.DepthLoggerV2, e Entity, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtWarning,
+	})
+}
+
+// Warningf logs and adds a trace event if channelz is on.
+func Warningf(l grpclog.DepthLoggerV2, e Entity, format string, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtWarning,
+	})
+}
+
+// Error logs and adds a trace event if channelz is on.
+func Error(l grpclog.DepthLoggerV2, e Entity, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtError,
+	})
+}
+
+// Errorf logs and adds a trace event if channelz is on.
+func Errorf(l grpclog.DepthLoggerV2, e Entity, format string, args ...any) {
+	AddTraceEvent(l, e, 1, &TraceEvent{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtError,
+	})
+}

vendor/google.golang.org/grpc/internal/channelz/server.go

@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"sync/atomic"
+)
+
+// Server is the channelz representation of a server.
+type Server struct {
+	Entity
+	ID      int64
+	RefName string
+
+	ServerMetrics ServerMetrics
+
+	closeCalled   bool
+	sockets       map[int64]string
+	listenSockets map[int64]string
+	cm            *channelMap
+}
+
+// ServerMetrics defines a struct containing metrics for servers.
+type ServerMetrics struct {
+	// The number of incoming calls started on the server.
+	CallsStarted atomic.Int64
+	// The number of incoming calls that have completed with an OK status.
+	CallsSucceeded atomic.Int64
+	// The number of incoming calls that have a completed with a non-OK status.
+	CallsFailed atomic.Int64
+	// The last time a call was started on the server.
+	LastCallStartedTimestamp atomic.Int64
+}
+
+// NewServerMetricsForTesting returns an initialized ServerMetrics.
+func NewServerMetricsForTesting(started, succeeded, failed, timestamp int64) *ServerMetrics {
+	sm := &ServerMetrics{}
+	sm.CallsStarted.Store(started)
+	sm.CallsSucceeded.Store(succeeded)
+	sm.CallsFailed.Store(failed)
+	sm.LastCallStartedTimestamp.Store(timestamp)
+	return sm
+}
+
+// CopyFrom copies the metrics data from the provided ServerMetrics
+// instance into the current instance.
+func (sm *ServerMetrics) CopyFrom(o *ServerMetrics) {
+	sm.CallsStarted.Store(o.CallsStarted.Load())
+	sm.CallsSucceeded.Store(o.CallsSucceeded.Load())
+	sm.CallsFailed.Store(o.CallsFailed.Load())
+	sm.LastCallStartedTimestamp.Store(o.LastCallStartedTimestamp.Load())
+}
+
+// ListenSockets returns the listening sockets for s.
+func (s *Server) ListenSockets() map[int64]string {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return copyMap(s.listenSockets)
+}
+
+// String returns a printable description of s.
+func (s *Server) String() string {
+	return fmt.Sprintf("Server #%d", s.ID)
+}
+
+func (s *Server) id() int64 {
+	return s.ID
+}
+
+func (s *Server) addChild(id int64, e entry) {
+	switch v := e.(type) {
+	case *Socket:
+		switch v.SocketType {
+		case SocketTypeNormal:
+			s.sockets[id] = v.RefName
+		case SocketTypeListen:
+			s.listenSockets[id] = v.RefName
+		}
+	default:
+		logger.Errorf("cannot add a child (id = %d) of type %T to a server", id, e)
+	}
+}
+
+func (s *Server) deleteChild(id int64) {
+	delete(s.sockets, id)
+	delete(s.listenSockets, id)
+	s.deleteSelfIfReady()
+}
+
+func (s *Server) triggerDelete() {
+	s.closeCalled = true
+	s.deleteSelfIfReady()
+}
+
+func (s *Server) deleteSelfIfReady() {
+	if !s.closeCalled || len(s.sockets)+len(s.listenSockets) != 0 {
+		return
+	}
+	s.cm.deleteEntry(s.ID)
+}
+
+func (s *Server) getParentID() int64 {
+	return 0
+}

vendor/google.golang.org/grpc/internal/channelz/socket.go

@@ -0,0 +1,137 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"net"
+	"sync/atomic"
+
+	"google.golang.org/grpc/credentials"
+)
+
+// SocketMetrics defines the struct that the implementor of Socket interface
+// should return from ChannelzMetric().
+type SocketMetrics struct {
+	// The number of streams that have been started.
+	StreamsStarted atomic.Int64
+	// The number of streams that have ended successfully:
+	// On client side, receiving frame with eos bit set.
+	// On server side, sending frame with eos bit set.
+	StreamsSucceeded atomic.Int64
+	// The number of streams that have ended unsuccessfully:
+	// On client side, termination without receiving frame with eos bit set.
+	// On server side, termination without sending frame with eos bit set.
+	StreamsFailed atomic.Int64
+	// The number of messages successfully sent on this socket.
+	MessagesSent     atomic.Int64
+	MessagesReceived atomic.Int64
+	// The number of keep alives sent.  This is typically implemented with HTTP/2
+	// ping messages.
+	KeepAlivesSent atomic.Int64
+	// The last time a stream was created by this endpoint.  Usually unset for
+	// servers.
+	LastLocalStreamCreatedTimestamp atomic.Int64
+	// The last time a stream was created by the remote endpoint.  Usually unset
+	// for clients.
+	LastRemoteStreamCreatedTimestamp atomic.Int64
+	// The last time a message was sent by this endpoint.
+	LastMessageSentTimestamp atomic.Int64
+	// The last time a message was received by this endpoint.
+	LastMessageReceivedTimestamp atomic.Int64
+}
+
+// EphemeralSocketMetrics are metrics that change rapidly and are tracked
+// outside of channelz.
+type EphemeralSocketMetrics struct {
+	// The amount of window, granted to the local endpoint by the remote endpoint.
+	// This may be slightly out of date due to network latency.  This does NOT
+	// include stream level or TCP level flow control info.
+	LocalFlowControlWindow int64
+	// The amount of window, granted to the remote endpoint by the local endpoint.
+	// This may be slightly out of date due to network latency.  This does NOT
+	// include stream level or TCP level flow control info.
+	RemoteFlowControlWindow int64
+}
+
+// SocketType represents the type of socket.
+type SocketType string
+
+// SocketType can be one of these.
+const (
+	SocketTypeNormal = "NormalSocket"
+	SocketTypeListen = "ListenSocket"
+)
+
+// Socket represents a socket within channelz which includes socket
+// metrics and data related to socket activity and provides methods
+// for managing and interacting with sockets.
+type Socket struct {
+	Entity
+	SocketType       SocketType
+	ID               int64
+	Parent           Entity
+	cm               *channelMap
+	SocketMetrics    SocketMetrics
+	EphemeralMetrics func() *EphemeralSocketMetrics
+
+	RefName string
+	// The locally bound address.  Immutable.
+	LocalAddr net.Addr
+	// The remote bound address.  May be absent.  Immutable.
+	RemoteAddr net.Addr
+	// Optional, represents the name of the remote endpoint, if different than
+	// the original target name.  Immutable.
+	RemoteName string
+	// Immutable.
+	SocketOptions *SocketOptionData
+	// Immutable.
+	Security credentials.ChannelzSecurityValue
+}
+
+// String returns a string representation of the Socket, including its parent
+// entity, socket type, and ID.
+func (ls *Socket) String() string {
+	return fmt.Sprintf("%s %s #%d", ls.Parent, ls.SocketType, ls.ID)
+}
+
+func (ls *Socket) id() int64 {
+	return ls.ID
+}
+
+func (ls *Socket) addChild(id int64, e entry) {
+	logger.Errorf("cannot add a child (id = %d) of type %T to a listen socket", id, e)
+}
+
+func (ls *Socket) deleteChild(id int64) {
+	logger.Errorf("cannot delete a child (id = %d) from a listen socket", id)
+}
+
+func (ls *Socket) triggerDelete() {
+	ls.cm.deleteEntry(ls.ID)
+	ls.Parent.(entry).deleteChild(ls.ID)
+}
+
+func (ls *Socket) deleteSelfIfReady() {
+	logger.Errorf("cannot call deleteSelfIfReady on a listen socket")
+}
+
+func (ls *Socket) getParentID() int64 {
+	return ls.Parent.id()
+}

vendor/google.golang.org/grpc/internal/channelz/subchannel.go

@@ -0,0 +1,153 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"sync/atomic"
+)
+
+// SubChannel is the channelz representation of a subchannel.
+type SubChannel struct {
+	Entity
+	// ID is the channelz id of this subchannel.
+	ID int64
+	// RefName is the human readable reference string of this subchannel.
+	RefName       string
+	closeCalled   bool
+	sockets       map[int64]string
+	parent        *Channel
+	trace         *ChannelTrace
+	traceRefCount int32
+
+	ChannelMetrics ChannelMetrics
+}
+
+func (sc *SubChannel) String() string {
+	return fmt.Sprintf("%s SubChannel #%d", sc.parent, sc.ID)
+}
+
+func (sc *SubChannel) id() int64 {
+	return sc.ID
+}
+
+// Sockets returns a copy of the sockets map associated with the SubChannel.
+func (sc *SubChannel) Sockets() map[int64]string {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return copyMap(sc.sockets)
+}
+
+// Trace returns a copy of the ChannelTrace associated with the SubChannel.
+func (sc *SubChannel) Trace() *ChannelTrace {
+	db.mu.RLock()
+	defer db.mu.RUnlock()
+	return sc.trace.copy()
+}
+
+func (sc *SubChannel) addChild(id int64, e entry) {
+	if v, ok := e.(*Socket); ok && v.SocketType == SocketTypeNormal {
+		sc.sockets[id] = v.RefName
+	} else {
+		logger.Errorf("cannot add a child (id = %d) of type %T to a subChannel", id, e)
+	}
+}
+
+func (sc *SubChannel) deleteChild(id int64) {
+	delete(sc.sockets, id)
+	sc.deleteSelfIfReady()
+}
+
+func (sc *SubChannel) triggerDelete() {
+	sc.closeCalled = true
+	sc.deleteSelfIfReady()
+}
+
+func (sc *SubChannel) getParentID() int64 {
+	return sc.parent.ID
+}
+
+// deleteSelfFromTree tries to delete the subchannel from the channelz entry relation tree, which
+// means deleting the subchannel reference from its parent's child list.
+//
+// In order for a subchannel to be deleted from the tree, it must meet the criteria that, removal of
+// the corresponding grpc object has been invoked, and the subchannel does not have any children left.
+//
+// The returned boolean value indicates whether the channel has been successfully deleted from tree.
+func (sc *SubChannel) deleteSelfFromTree() (deleted bool) {
+	if !sc.closeCalled || len(sc.sockets) != 0 {
+		return false
+	}
+	sc.parent.deleteChild(sc.ID)
+	return true
+}
+
+// deleteSelfFromMap checks whether it is valid to delete the subchannel from the map, which means
+// deleting the subchannel from channelz's tracking entirely. Users can no longer use id to query
+// the subchannel, and its memory will be garbage collected.
+//
+// The trace reference count of the subchannel must be 0 in order to be deleted from the map. This is
+// specified in the channel tracing gRFC that as long as some other trace has reference to an entity,
+// the trace of the referenced entity must not be deleted. In order to release the resource allocated
+// by grpc, the reference to the grpc object is reset to a dummy object.
+//
+// deleteSelfFromMap must be called after deleteSelfFromTree returns true.
+//
+// It returns a bool to indicate whether the channel can be safely deleted from map.
+func (sc *SubChannel) deleteSelfFromMap() (delete bool) {
+	return sc.getTraceRefCount() == 0
+}
+
+// deleteSelfIfReady tries to delete the subchannel itself from the channelz database.
+// The delete process includes two steps:
+//  1. delete the subchannel from the entry relation tree, i.e. delete the subchannel reference from
+//     its parent's child list.
+//  2. delete the subchannel from the map, i.e. delete the subchannel entirely from channelz. Lookup
+//     by id will return entry not found error.
+func (sc *SubChannel) deleteSelfIfReady() {
+	if !sc.deleteSelfFromTree() {
+		return
+	}
+	if !sc.deleteSelfFromMap() {
+		return
+	}
+	db.deleteEntry(sc.ID)
+	sc.trace.clear()
+}
+
+func (sc *SubChannel) getChannelTrace() *ChannelTrace {
+	return sc.trace
+}
+
+func (sc *SubChannel) incrTraceRefCount() {
+	atomic.AddInt32(&sc.traceRefCount, 1)
+}
+
+func (sc *SubChannel) decrTraceRefCount() {
+	atomic.AddInt32(&sc.traceRefCount, -1)
+}
+
+func (sc *SubChannel) getTraceRefCount() int {
+	i := atomic.LoadInt32(&sc.traceRefCount)
+	return int(i)
+}
+
+func (sc *SubChannel) getRefName() string {
+	return sc.RefName
+}

vendor/google.golang.org/grpc/internal/channelz/syscall_linux.go

@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// SocketOptionData defines the struct to hold socket option data, and related
+// getter function to obtain info from fd.
+type SocketOptionData struct {
+	Linger      *unix.Linger
+	RecvTimeout *unix.Timeval
+	SendTimeout *unix.Timeval
+	TCPInfo     *unix.TCPInfo
+}
+
+// Getsockopt defines the function to get socket options requested by channelz.
+// It is to be passed to syscall.RawConn.Control().
+func (s *SocketOptionData) Getsockopt(fd uintptr) {
+	if v, err := unix.GetsockoptLinger(int(fd), syscall.SOL_SOCKET, syscall.SO_LINGER); err == nil {
+		s.Linger = v
+	}
+	if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_RCVTIMEO); err == nil {
+		s.RecvTimeout = v
+	}
+	if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_SNDTIMEO); err == nil {
+		s.SendTimeout = v
+	}
+	if v, err := unix.GetsockoptTCPInfo(int(fd), syscall.SOL_TCP, syscall.TCP_INFO); err == nil {
+		s.TCPInfo = v
+	}
+}
+
+// GetSocketOption gets the socket option info of the conn.
+func GetSocketOption(socket any) *SocketOptionData {
+	c, ok := socket.(syscall.Conn)
+	if !ok {
+		return nil
+	}
+	data := &SocketOptionData{}
+	if rawConn, err := c.SyscallConn(); err == nil {
+		rawConn.Control(data.Getsockopt)
+		return data
+	}
+	return nil
+}

vendor/google.golang.org/grpc/internal/channelz/syscall_nonlinux.go

@@ -0,0 +1,47 @@
+//go:build !linux
+
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"sync"
+)
+
+var once sync.Once
+
+// SocketOptionData defines the struct to hold socket option data, and related
+// getter function to obtain info from fd.
+// Windows OS doesn't support Socket Option
+type SocketOptionData struct {
+}
+
+// Getsockopt defines the function to get socket options requested by channelz.
+// It is to be passed to syscall.RawConn.Control().
+// Windows OS doesn't support Socket Option
+func (s *SocketOptionData) Getsockopt(uintptr) {
+	once.Do(func() {
+		logger.Warning("Channelz: socket options are not supported on non-linux environments")
+	})
+}
+
+// GetSocketOption gets the socket option info of the conn.
+func GetSocketOption(any) *SocketOptionData {
+	return nil
+}

vendor/google.golang.org/grpc/internal/channelz/trace.go

@@ -0,0 +1,213 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+const (
+	defaultMaxTraceEntry int32 = 30
+)
+
+var maxTraceEntry = defaultMaxTraceEntry
+
+// SetMaxTraceEntry sets maximum number of trace entries per entity (i.e.
+// channel/subchannel).  Setting it to 0 will disable channel tracing.
+func SetMaxTraceEntry(i int32) {
+	atomic.StoreInt32(&maxTraceEntry, i)
+}
+
+// ResetMaxTraceEntryToDefault resets the maximum number of trace entries per
+// entity to default.
+func ResetMaxTraceEntryToDefault() {
+	atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
+}
+
+func getMaxTraceEntry() int {
+	i := atomic.LoadInt32(&maxTraceEntry)
+	return int(i)
+}
+
+// traceEvent is an internal representation of a single trace event
+type traceEvent struct {
+	// Desc is a simple description of the trace event.
+	Desc string
+	// Severity states the severity of this trace event.
+	Severity Severity
+	// Timestamp is the event time.
+	Timestamp time.Time
+	// RefID is the id of the entity that gets referenced in the event. RefID is 0 if no other entity is
+	// involved in this event.
+	// e.g. SubChannel (id: 4[]) Created. --> RefID = 4, RefName = "" (inside [])
+	RefID int64
+	// RefName is the reference name for the entity that gets referenced in the event.
+	RefName string
+	// RefType indicates the referenced entity type, i.e Channel or SubChannel.
+	RefType RefChannelType
+}
+
+// TraceEvent is what the caller of AddTraceEvent should provide to describe the
+// event to be added to the channel trace.
+//
+// The Parent field is optional. It is used for an event that will be recorded
+// in the entity's parent trace.
+type TraceEvent struct {
+	Desc     string
+	Severity Severity
+	Parent   *TraceEvent
+}
+
+// ChannelTrace provides tracing information for a channel.
+// It tracks various events and metadata related to the channel's lifecycle
+// and operations.
+type ChannelTrace struct {
+	cm          *channelMap
+	clearCalled bool
+	// The time when the trace was created.
+	CreationTime time.Time
+	// A counter for the number of events recorded in the
+	// trace.
+	EventNum int64
+	mu       sync.Mutex
+	// A slice of traceEvent pointers representing the events recorded for
+	// this channel.
+	Events []*traceEvent
+}
+
+func (c *ChannelTrace) copy() *ChannelTrace {
+	return &ChannelTrace{
+		CreationTime: c.CreationTime,
+		EventNum:     c.EventNum,
+		Events:       append(([]*traceEvent)(nil), c.Events...),
+	}
+}
+
+func (c *ChannelTrace) append(e *traceEvent) {
+	c.mu.Lock()
+	if len(c.Events) == getMaxTraceEntry() {
+		del := c.Events[0]
+		c.Events = c.Events[1:]
+		if del.RefID != 0 {
+			// start recursive cleanup in a goroutine to not block the call originated from grpc.
+			go func() {
+				// need to acquire c.cm.mu lock to call the unlocked attemptCleanup func.
+				c.cm.mu.Lock()
+				c.cm.decrTraceRefCount(del.RefID)
+				c.cm.mu.Unlock()
+			}()
+		}
+	}
+	e.Timestamp = time.Now()
+	c.Events = append(c.Events, e)
+	c.EventNum++
+	c.mu.Unlock()
+}
+
+func (c *ChannelTrace) clear() {
+	if c.clearCalled {
+		return
+	}
+	c.clearCalled = true
+	c.mu.Lock()
+	for _, e := range c.Events {
+		if e.RefID != 0 {
+			// caller should have already held the c.cm.mu lock.
+			c.cm.decrTraceRefCount(e.RefID)
+		}
+	}
+	c.mu.Unlock()
+}
+
+// Severity is the severity level of a trace event.
+// The canonical enumeration of all valid values is here:
+// https://github.com/grpc/grpc-proto/blob/9b13d199cc0d4703c7ea26c9c330ba695866eb23/grpc/channelz/v1/channelz.proto#L126.
+type Severity int
+
+const (
+	// CtUnknown indicates unknown severity of a trace event.
+	CtUnknown Severity = iota
+	// CtInfo indicates info level severity of a trace event.
+	CtInfo
+	// CtWarning indicates warning level severity of a trace event.
+	CtWarning
+	// CtError indicates error level severity of a trace event.
+	CtError
+)
+
+// RefChannelType is the type of the entity being referenced in a trace event.
+type RefChannelType int
+
+const (
+	// RefUnknown indicates an unknown entity type, the zero value for this type.
+	RefUnknown RefChannelType = iota
+	// RefChannel indicates the referenced entity is a Channel.
+	RefChannel
+	// RefSubChannel indicates the referenced entity is a SubChannel.
+	RefSubChannel
+	// RefServer indicates the referenced entity is a Server.
+	RefServer
+	// RefListenSocket indicates the referenced entity is a ListenSocket.
+	RefListenSocket
+	// RefNormalSocket indicates the referenced entity is a NormalSocket.
+	RefNormalSocket
+)
+
+var refChannelTypeToString = map[RefChannelType]string{
+	RefUnknown:      "Unknown",
+	RefChannel:      "Channel",
+	RefSubChannel:   "SubChannel",
+	RefServer:       "Server",
+	RefListenSocket: "ListenSocket",
+	RefNormalSocket: "NormalSocket",
+}
+
+// String returns a string representation of the RefChannelType
+func (r RefChannelType) String() string {
+	return refChannelTypeToString[r]
+}
+
+// AddTraceEvent adds trace related to the entity with specified id, using the
+// provided TraceEventDesc.
+//
+// If channelz is not turned ON, this will simply log the event descriptions.
+func AddTraceEvent(l grpclog.DepthLoggerV2, e Entity, depth int, desc *TraceEvent) {
+	// Log only the trace description associated with the bottom most entity.
+	d := fmt.Sprintf("[%s] %s", e, desc.Desc)
+	switch desc.Severity {
+	case CtUnknown, CtInfo:
+		l.InfoDepth(depth+1, d)
+	case CtWarning:
+		l.WarningDepth(depth+1, d)
+	case CtError:
+		l.ErrorDepth(depth+1, d)
+	}
+
+	if getMaxTraceEntry() == 0 {
+		return
+	}
+	if IsOn() {
+		db.traceEvent(e.id(), desc)
+	}
+}

vendor/google.golang.org/grpc/internal/credentials/credentials.go

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"context"
+)
+
+// clientHandshakeInfoKey is a struct used as the key to store
+// ClientHandshakeInfo in a context.
+type clientHandshakeInfoKey struct{}
+
+// ClientHandshakeInfoFromContext extracts the ClientHandshakeInfo from ctx.
+func ClientHandshakeInfoFromContext(ctx context.Context) any {
+	return ctx.Value(clientHandshakeInfoKey{})
+}
+
+// NewClientHandshakeInfoContext creates a context with chi.
+func NewClientHandshakeInfoContext(ctx context.Context, chi any) context.Context {
+	return context.WithValue(ctx, clientHandshakeInfoKey{}, chi)
+}

vendor/google.golang.org/grpc/internal/credentials/spiffe.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package credentials defines APIs for parsing SPIFFE ID.
+//
+// All APIs in this package are experimental.
+package credentials
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net/url"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("credentials")
+
+// SPIFFEIDFromState parses the SPIFFE ID from State. If the SPIFFE ID format
+// is invalid, return nil with warning.
+func SPIFFEIDFromState(state tls.ConnectionState) *url.URL {
+	if len(state.PeerCertificates) == 0 || len(state.PeerCertificates[0].URIs) == 0 {
+		return nil
+	}
+	return SPIFFEIDFromCert(state.PeerCertificates[0])
+}
+
+// SPIFFEIDFromCert parses the SPIFFE ID from x509.Certificate. If the SPIFFE
+// ID format is invalid, return nil with warning.
+func SPIFFEIDFromCert(cert *x509.Certificate) *url.URL {
+	if cert == nil || cert.URIs == nil {
+		return nil
+	}
+	var spiffeID *url.URL
+	for _, uri := range cert.URIs {
+		if uri == nil || uri.Scheme != "spiffe" || uri.Opaque != "" || (uri.User != nil && uri.User.Username() != "") {
+			continue
+		}
+		// From this point, we assume the uri is intended for a SPIFFE ID.
+		if len(uri.String()) > 2048 {
+			logger.Warning("invalid SPIFFE ID: total ID length larger than 2048 bytes")
+			return nil
+		}
+		if len(uri.Host) == 0 || len(uri.Path) == 0 {
+			logger.Warning("invalid SPIFFE ID: domain or workload ID is empty")
+			return nil
+		}
+		if len(uri.Host) > 255 {
+			logger.Warning("invalid SPIFFE ID: domain length larger than 255 characters")
+			return nil
+		}
+		// A valid SPIFFE certificate can only have exactly one URI SAN field.
+		if len(cert.URIs) > 1 {
+			logger.Warning("invalid SPIFFE ID: multiple URI SANs")
+			return nil
+		}
+		spiffeID = uri
+	}
+	return spiffeID
+}

vendor/google.golang.org/grpc/internal/credentials/syscallconn.go

@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"net"
+	"syscall"
+)
+
+type sysConn = syscall.Conn
+
+// syscallConn keeps reference of rawConn to support syscall.Conn for channelz.
+// SyscallConn() (the method in interface syscall.Conn) is explicitly
+// implemented on this type,
+//
+// Interface syscall.Conn is implemented by most net.Conn implementations (e.g.
+// TCPConn, UnixConn), but is not part of net.Conn interface. So wrapper conns
+// that embed net.Conn don't implement syscall.Conn. (Side note: tls.Conn
+// doesn't embed net.Conn, so even if syscall.Conn is part of net.Conn, it won't
+// help here).
+type syscallConn struct {
+	net.Conn
+	// sysConn is a type alias of syscall.Conn. It's necessary because the name
+	// `Conn` collides with `net.Conn`.
+	sysConn
+}
+
+// WrapSyscallConn tries to wrap rawConn and newConn into a net.Conn that
+// implements syscall.Conn. rawConn will be used to support syscall, and newConn
+// will be used for read/write.
+//
+// This function returns newConn if rawConn doesn't implement syscall.Conn.
+func WrapSyscallConn(rawConn, newConn net.Conn) net.Conn {
+	sysConn, ok := rawConn.(syscall.Conn)
+	if !ok {
+		return newConn
+	}
+	return &syscallConn{
+		Conn:    newConn,
+		sysConn: sysConn,
+	}
+}

vendor/google.golang.org/grpc/internal/credentials/util.go

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"crypto/tls"
+)
+
+const alpnProtoStrH2 = "h2"
+
+// AppendH2ToNextProtos appends h2 to next protos.
+func AppendH2ToNextProtos(ps []string) []string {
+	for _, p := range ps {
+		if p == alpnProtoStrH2 {
+			return ps
+		}
+	}
+	ret := make([]string, 0, len(ps)+1)
+	ret = append(ret, ps...)
+	return append(ret, alpnProtoStrH2)
+}
+
+// CloneTLSConfig returns a shallow clone of the exported
+// fields of cfg, ignoring the unexported sync.Once, which
+// contains a mutex and must not be copied.
+//
+// If cfg is nil, a new zero tls.Config is returned.
+//
+// TODO: inline this function if possible.
+func CloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+
+	return cfg.Clone()
+}

vendor/google.golang.org/grpc/internal/envconfig/envconfig.go

@@ -0,0 +1,108 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package envconfig contains grpc settings configured by environment variables.
+package envconfig
+
+import (
+	"os"
+	"strconv"
+	"strings"
+)
+
+var (
+	// EnableTXTServiceConfig is set if the DNS resolver should perform TXT
+	// lookups for service config ("GRPC_ENABLE_TXT_SERVICE_CONFIG" is not
+	// "false").
+	EnableTXTServiceConfig = boolFromEnv("GRPC_ENABLE_TXT_SERVICE_CONFIG", true)
+
+	// TXTErrIgnore is set if TXT errors should be ignored
+	// ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
+	TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
+
+	// RingHashCap indicates the maximum ring size which defaults to 4096
+	// entries but may be overridden by setting the environment variable
+	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
+	// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
+	RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
+
+	// ALTSMaxConcurrentHandshakes is the maximum number of concurrent ALTS
+	// handshakes that can be performed.
+	ALTSMaxConcurrentHandshakes = uint64FromEnv("GRPC_ALTS_MAX_CONCURRENT_HANDSHAKES", 100, 1, 100)
+
+	// EnforceALPNEnabled is set if TLS connections to servers with ALPN disabled
+	// should be rejected. The HTTP/2 protocol requires ALPN to be enabled, this
+	// option is present for backward compatibility. This option may be overridden
+	// by setting the environment variable "GRPC_ENFORCE_ALPN_ENABLED" to "true"
+	// or "false".
+	EnforceALPNEnabled = boolFromEnv("GRPC_ENFORCE_ALPN_ENABLED", true)
+
+	// XDSEndpointHashKeyBackwardCompat controls the parsing of the endpoint hash
+	// key from EDS LbEndpoint metadata. Endpoint hash keys can be disabled by
+	// setting "GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT" to "true". When the
+	// implementation of A76 is stable, we will flip the default value to false
+	// in a subsequent release. A final release will remove this environment
+	// variable, enabling the new behavior unconditionally.
+	XDSEndpointHashKeyBackwardCompat = boolFromEnv("GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT", true)
+
+	// RingHashSetRequestHashKey is set if the ring hash balancer can get the
+	// request hash header by setting the "requestHashHeader" field, according
+	// to gRFC A76. It can be enabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY" to "true".
+	RingHashSetRequestHashKey = boolFromEnv("GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY", false)
+
+	// ALTSHandshakerKeepaliveParams is set if we should add the
+	// KeepaliveParams when dial the ALTS handshaker service.
+	ALTSHandshakerKeepaliveParams = boolFromEnv("GRPC_EXPERIMENTAL_ALTS_HANDSHAKER_KEEPALIVE_PARAMS", false)
+
+	// EnableDefaultPortForProxyTarget controls whether the resolver adds a default port 443
+	// to a target address that lacks one. This flag only has an effect when all of
+	// the following conditions are met:
+	//   - A connect proxy is being used.
+	//   - Target resolution is disabled.
+	//   - The DNS resolver is being used.
+	EnableDefaultPortForProxyTarget = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_DEFAULT_PORT_FOR_PROXY_TARGET", true)
+
+	// XDSAuthorityRewrite indicates whether xDS authority rewriting is enabled.
+	// This feature is defined in gRFC A81 and is enabled by setting the
+	// environment variable GRPC_EXPERIMENTAL_XDS_AUTHORITY_REWRITE to "true".
+	XDSAuthorityRewrite = boolFromEnv("GRPC_EXPERIMENTAL_XDS_AUTHORITY_REWRITE", false)
+)
+
+func boolFromEnv(envVar string, def bool) bool {
+	if def {
+		// The default is true; return true unless the variable is "false".
+		return !strings.EqualFold(os.Getenv(envVar), "false")
+	}
+	// The default is false; return false unless the variable is "true".
+	return strings.EqualFold(os.Getenv(envVar), "true")
+}
+
+func uint64FromEnv(envVar string, def, min, max uint64) uint64 {
+	v, err := strconv.ParseUint(os.Getenv(envVar), 10, 64)
+	if err != nil {
+		return def
+	}
+	if v < min {
+		return min
+	}
+	if v > max {
+		return max
+	}
+	return v
+}

vendor/google.golang.org/grpc/internal/envconfig/observability.go

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package envconfig
+
+import "os"
+
+const (
+	envObservabilityConfig     = "GRPC_GCP_OBSERVABILITY_CONFIG"
+	envObservabilityConfigFile = "GRPC_GCP_OBSERVABILITY_CONFIG_FILE"
+)
+
+var (
+	// ObservabilityConfig is the json configuration for the gcp/observability
+	// package specified directly in the envObservabilityConfig env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ObservabilityConfig = os.Getenv(envObservabilityConfig)
+	// ObservabilityConfigFile is the json configuration for the
+	// gcp/observability specified in a file with the location specified in
+	// envObservabilityConfigFile env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ObservabilityConfigFile = os.Getenv(envObservabilityConfigFile)
+)

vendor/google.golang.org/grpc/internal/envconfig/xds.go

@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package envconfig
+
+import (
+	"os"
+)
+
+const (
+	// XDSBootstrapFileNameEnv is the env variable to set bootstrap file name.
+	// Do not use this and read from env directly. Its value is read and kept in
+	// variable XDSBootstrapFileName.
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileNameEnv = "GRPC_XDS_BOOTSTRAP"
+	// XDSBootstrapFileContentEnv is the env variable to set bootstrap file
+	// content. Do not use this and read from env directly. Its value is read
+	// and kept in variable XDSBootstrapFileContent.
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileContentEnv = "GRPC_XDS_BOOTSTRAP_CONFIG"
+)
+
+var (
+	// XDSBootstrapFileName holds the name of the file which contains xDS
+	// bootstrap configuration. Users can specify the location of the bootstrap
+	// file by setting the environment variable "GRPC_XDS_BOOTSTRAP".
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileName = os.Getenv(XDSBootstrapFileNameEnv)
+	// XDSBootstrapFileContent holds the content of the xDS bootstrap
+	// configuration. Users can specify the bootstrap config by setting the
+	// environment variable "GRPC_XDS_BOOTSTRAP_CONFIG".
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileContent = os.Getenv(XDSBootstrapFileContentEnv)
+
+	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
+	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+
+	// XDSDualstackEndpointsEnabled is true if gRPC should read the
+	// "additional addresses" in the xDS endpoint resource.
+	XDSDualstackEndpointsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_DUALSTACK_ENDPOINTS", true)
+
+	// XDSSystemRootCertsEnabled is true when xDS enabled gRPC clients can use
+	// the system's default root certificates for TLS certificate validation.
+	// For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A82-xds-system-root-certs.md.
+	XDSSystemRootCertsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_SYSTEM_ROOT_CERTS", false)
+
+	// XDSSPIFFEEnabled controls if SPIFFE Bundle Maps can be used as roots of
+	// trust.  For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A87-mtls-spiffe-support.md
+	XDSSPIFFEEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_MTLS_SPIFFE", false)
+
+	// XDSHTTPConnectEnabled is true if gRPC should parse custom Metadata
+	// configuring use of an HTTP CONNECT proxy via xDS from cluster resources.
+	// For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A86-xds-http-connect.md
+	XDSHTTPConnectEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_HTTP_CONNECT", false)
+
+	// XDSBootstrapCallCredsEnabled controls if call credentials can be used in
+	// xDS bootstrap configuration via the `call_creds` field. For more details,
+	// see: https://github.com/grpc/proposal/blob/master/A97-xds-jwt-call-creds.md
+	XDSBootstrapCallCredsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_BOOTSTRAP_CALL_CREDS", false)
+)

vendor/google.golang.org/grpc/internal/experimental.go

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package internal
+
+var (
+	// WithBufferPool is implemented by the grpc package and returns a dial
+	// option to configure a shared buffer pool for a grpc.ClientConn.
+	WithBufferPool any // func (grpc.SharedBufferPool) grpc.DialOption
+
+	// BufferPool is implemented by the grpc package and returns a server
+	// option to configure a shared buffer pool for a grpc.Server.
+	BufferPool any // func (grpc.SharedBufferPool) grpc.ServerOption
+
+	// AcceptCompressors is implemented by the grpc package and returns
+	// a call option that restricts the grpc-accept-encoding header for a call.
+	AcceptCompressors any // func(...string) grpc.CallOption
+)

vendor/google.golang.org/grpc/internal/grpclog/prefix_logger.go

@@ -0,0 +1,79 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpclog provides logging functionality for internal gRPC packages,
+// outside of the functionality provided by the external `grpclog` package.
+package grpclog
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+// PrefixLogger does logging with a prefix.
+//
+// Logging method on a nil logs without any prefix.
+type PrefixLogger struct {
+	logger grpclog.DepthLoggerV2
+	prefix string
+}
+
+// Infof does info logging.
+func (pl *PrefixLogger) Infof(format string, args ...any) {
+	if pl != nil {
+		// Handle nil, so the tests can pass in a nil logger.
+		format = pl.prefix + format
+		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	grpclog.InfoDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Warningf does warning logging.
+func (pl *PrefixLogger) Warningf(format string, args ...any) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.WarningDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	grpclog.WarningDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Errorf does error logging.
+func (pl *PrefixLogger) Errorf(format string, args ...any) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.ErrorDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	grpclog.ErrorDepth(1, fmt.Sprintf(format, args...))
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func (pl *PrefixLogger) V(l int) bool {
+	if pl != nil {
+		return pl.logger.V(l)
+	}
+	return true
+}
+
+// NewPrefixLogger creates a prefix logger with the given prefix.
+func NewPrefixLogger(logger grpclog.DepthLoggerV2, prefix string) *PrefixLogger {
+	return &PrefixLogger{logger: logger, prefix: prefix}
+}

vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go

@@ -0,0 +1,98 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcsync
+
+import (
+	"context"
+
+	"google.golang.org/grpc/internal/buffer"
+)
+
+// CallbackSerializer provides a mechanism to schedule callbacks in a
+// synchronized manner. It provides a FIFO guarantee on the order of execution
+// of scheduled callbacks. New callbacks can be scheduled by invoking the
+// Schedule() method.
+//
+// This type is safe for concurrent access.
+type CallbackSerializer struct {
+	// done is closed once the serializer is shut down completely, i.e all
+	// scheduled callbacks are executed and the serializer has deallocated all
+	// its resources.
+	done chan struct{}
+
+	callbacks *buffer.Unbounded
+}
+
+// NewCallbackSerializer returns a new CallbackSerializer instance. The provided
+// context will be passed to the scheduled callbacks. Users should cancel the
+// provided context to shutdown the CallbackSerializer. It is guaranteed that no
+// callbacks will be added once this context is canceled, and any pending un-run
+// callbacks will be executed before the serializer is shut down.
+func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
+	cs := &CallbackSerializer{
+		done:      make(chan struct{}),
+		callbacks: buffer.NewUnbounded(),
+	}
+	go cs.run(ctx)
+	return cs
+}
+
+// TrySchedule tries to schedule the provided callback function f to be
+// executed in the order it was added. This is a best-effort operation. If the
+// context passed to NewCallbackSerializer was canceled before this method is
+// called, the callback will not be scheduled.
+//
+// Callbacks are expected to honor the context when performing any blocking
+// operations, and should return early when the context is canceled.
+func (cs *CallbackSerializer) TrySchedule(f func(ctx context.Context)) {
+	cs.callbacks.Put(f)
+}
+
+// ScheduleOr schedules the provided callback function f to be executed in the
+// order it was added. If the context passed to NewCallbackSerializer has been
+// canceled before this method is called, the onFailure callback will be
+// executed inline instead.
+//
+// Callbacks are expected to honor the context when performing any blocking
+// operations, and should return early when the context is canceled.
+func (cs *CallbackSerializer) ScheduleOr(f func(ctx context.Context), onFailure func()) {
+	if cs.callbacks.Put(f) != nil {
+		onFailure()
+	}
+}
+
+func (cs *CallbackSerializer) run(ctx context.Context) {
+	defer close(cs.done)
+
+	// Close the buffer when the context is canceled
+	// to prevent new callbacks from being added.
+	context.AfterFunc(ctx, cs.callbacks.Close)
+
+	// Run all callbacks.
+	for cb := range cs.callbacks.Get() {
+		cs.callbacks.Load()
+		cb.(func(context.Context))(ctx)
+	}
+}
+
+// Done returns a channel that is closed after the context passed to
+// NewCallbackSerializer is canceled and all callbacks have been executed.
+func (cs *CallbackSerializer) Done() <-chan struct{} {
+	return cs.done
+}

vendor/google.golang.org/grpc/internal/grpcsync/event.go

@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpcsync implements additional synchronization primitives built upon
+// the sync package.
+package grpcsync
+
+import (
+	"sync/atomic"
+)
+
+// Event represents a one-time event that may occur in the future.
+type Event struct {
+	fired atomic.Bool
+	c     chan struct{}
+}
+
+// Fire causes e to complete.  It is safe to call multiple times, and
+// concurrently.  It returns true iff this call to Fire caused the signaling
+// channel returned by Done to close. If Fire returns false, it is possible
+// the Done channel has not been closed yet.
+func (e *Event) Fire() bool {
+	if e.fired.CompareAndSwap(false, true) {
+		close(e.c)
+		return true
+	}
+	return false
+}
+
+// Done returns a channel that will be closed when Fire is called.
+func (e *Event) Done() <-chan struct{} {
+	return e.c
+}
+
+// HasFired returns true if Fire has been called.
+func (e *Event) HasFired() bool {
+	return e.fired.Load()
+}
+
+// NewEvent returns a new, ready-to-use Event.
+func NewEvent() *Event {
+	return &Event{c: make(chan struct{})}
+}

vendor/google.golang.org/grpc/internal/grpcsync/pubsub.go

@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcsync
+
+import (
+	"context"
+	"sync"
+)
+
+// Subscriber represents an entity that is subscribed to messages published on
+// a PubSub. It wraps the callback to be invoked by the PubSub when a new
+// message is published.
+type Subscriber interface {
+	// OnMessage is invoked when a new message is published. Implementations
+	// must not block in this method.
+	OnMessage(msg any)
+}
+
+// PubSub is a simple one-to-many publish-subscribe system that supports
+// messages of arbitrary type. It guarantees that messages are delivered in
+// the same order in which they were published.
+//
+// Publisher invokes the Publish() method to publish new messages, while
+// subscribers interested in receiving these messages register a callback
+// via the Subscribe() method.
+//
+// Once a PubSub is stopped, no more messages can be published, but any pending
+// published messages will be delivered to the subscribers.  Done may be used
+// to determine when all published messages have been delivered.
+type PubSub struct {
+	cs *CallbackSerializer
+
+	// Access to the below fields are guarded by this mutex.
+	mu          sync.Mutex
+	msg         any
+	subscribers map[Subscriber]bool
+}
+
+// NewPubSub returns a new PubSub instance.  Users should cancel the
+// provided context to shutdown the PubSub.
+func NewPubSub(ctx context.Context) *PubSub {
+	return &PubSub{
+		cs:          NewCallbackSerializer(ctx),
+		subscribers: map[Subscriber]bool{},
+	}
+}
+
+// Subscribe registers the provided Subscriber to the PubSub.
+//
+// If the PubSub contains a previously published message, the Subscriber's
+// OnMessage() callback will be invoked asynchronously with the existing
+// message to begin with, and subsequently for every newly published message.
+//
+// The caller is responsible for invoking the returned cancel function to
+// unsubscribe itself from the PubSub.
+func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.subscribers[sub] = true
+
+	if ps.msg != nil {
+		msg := ps.msg
+		ps.cs.TrySchedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[sub] {
+				return
+			}
+			sub.OnMessage(msg)
+		})
+	}
+
+	return func() {
+		ps.mu.Lock()
+		defer ps.mu.Unlock()
+		delete(ps.subscribers, sub)
+	}
+}
+
+// Publish publishes the provided message to the PubSub, and invokes
+// callbacks registered by subscribers asynchronously.
+func (ps *PubSub) Publish(msg any) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.msg = msg
+	for sub := range ps.subscribers {
+		s := sub
+		ps.cs.TrySchedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[s] {
+				return
+			}
+			s.OnMessage(msg)
+		})
+	}
+}
+
+// Done returns a channel that is closed after the context passed to NewPubSub
+// is canceled and all updates have been sent to subscribers.
+func (ps *PubSub) Done() <-chan struct{} {
+	return ps.cs.Done()
+}

vendor/google.golang.org/grpc/internal/grpcutil/compressor.go

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"strings"
+)
+
+// RegisteredCompressorNames holds names of the registered compressors.
+var RegisteredCompressorNames []string
+
+// IsCompressorNameRegistered returns true when name is available in registry.
+func IsCompressorNameRegistered(name string) bool {
+	for _, compressor := range RegisteredCompressorNames {
+		if compressor == name {
+			return true
+		}
+	}
+	return false
+}
+
+// RegisteredCompressors returns a string of registered compressor names
+// separated by comma.
+func RegisteredCompressors() string {
+	return strings.Join(RegisteredCompressorNames, ",")
+}

vendor/google.golang.org/grpc/internal/grpcutil/encode_duration.go

@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"strconv"
+	"time"
+)
+
+const maxTimeoutValue int64 = 100000000 - 1
+
+// div does integer division and round-up the result. Note that this is
+// equivalent to (d+r-1)/r but has less chance to overflow.
+func div(d, r time.Duration) int64 {
+	if d%r > 0 {
+		return int64(d/r + 1)
+	}
+	return int64(d / r)
+}
+
+// EncodeDuration encodes the duration to the format grpc-timeout header
+// accepts.
+//
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+func EncodeDuration(t time.Duration) string {
+	// TODO: This is simplistic and not bandwidth efficient. Improve it.
+	if t <= 0 {
+		return "0n"
+	}
+	if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "n"
+	}
+	if d := div(t, time.Microsecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "u"
+	}
+	if d := div(t, time.Millisecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "m"
+	}
+	if d := div(t, time.Second); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "S"
+	}
+	if d := div(t, time.Minute); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "M"
+	}
+	// Note that maxTimeoutValue * time.Hour > MaxInt64.
+	return strconv.FormatInt(div(t, time.Hour), 10) + "H"
+}

vendor/google.golang.org/grpc/internal/grpcutil/grpcutil.go

@@ -0,0 +1,20 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpcutil provides utility functions used across the gRPC codebase.
+package grpcutil

vendor/google.golang.org/grpc/internal/grpcutil/metadata.go

@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"context"
+
+	"google.golang.org/grpc/metadata"
+)
+
+type mdExtraKey struct{}
+
+// WithExtraMetadata creates a new context with incoming md attached.
+func WithExtraMetadata(ctx context.Context, md metadata.MD) context.Context {
+	return context.WithValue(ctx, mdExtraKey{}, md)
+}
+
+// ExtraMetadata returns the incoming metadata in ctx if it exists.  The
+// returned MD should not be modified. Writing to it may cause races.
+// Modification should be made to copies of the returned MD.
+func ExtraMetadata(ctx context.Context) (md metadata.MD, ok bool) {
+	md, ok = ctx.Value(mdExtraKey{}).(metadata.MD)
+	return
+}

vendor/google.golang.org/grpc/internal/grpcutil/method.go

@@ -0,0 +1,88 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"errors"
+	"strings"
+)
+
+// ParseMethod splits service and method from the input. It expects format
+// "/service/method".
+func ParseMethod(methodName string) (service, method string, _ error) {
+	if !strings.HasPrefix(methodName, "/") {
+		return "", "", errors.New("invalid method name: should start with /")
+	}
+	methodName = methodName[1:]
+
+	pos := strings.LastIndex(methodName, "/")
+	if pos < 0 {
+		return "", "", errors.New("invalid method name: suffix /method is missing")
+	}
+	return methodName[:pos], methodName[pos+1:], nil
+}
+
+// baseContentType is the base content-type for gRPC.  This is a valid
+// content-type on its own, but can also include a content-subtype such as
+// "proto" as a suffix after "+" or ";".  See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+// for more details.
+const baseContentType = "application/grpc"
+
+// ContentSubtype returns the content-subtype for the given content-type.  The
+// given content-type must be a valid content-type that starts with
+// "application/grpc". A content-subtype will follow "application/grpc" after a
+// "+" or ";". See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+//
+// If contentType is not a valid content-type for gRPC, the boolean
+// will be false, otherwise true. If content-type == "application/grpc",
+// "application/grpc+", or "application/grpc;", the boolean will be true,
+// but no content-subtype will be returned.
+//
+// contentType is assumed to be lowercase already.
+func ContentSubtype(contentType string) (string, bool) {
+	if contentType == baseContentType {
+		return "", true
+	}
+	if !strings.HasPrefix(contentType, baseContentType) {
+		return "", false
+	}
+	// guaranteed since != baseContentType and has baseContentType prefix
+	switch contentType[len(baseContentType)] {
+	case '+', ';':
+		// this will return true for "application/grpc+" or "application/grpc;"
+		// which the previous validContentType function tested to be valid, so we
+		// just say that no content-subtype is specified in this case
+		return contentType[len(baseContentType)+1:], true
+	default:
+		return "", false
+	}
+}
+
+// ContentType builds full content type with the given sub-type.
+//
+// contentSubtype is assumed to be lowercase
+func ContentType(contentSubtype string) string {
+	if contentSubtype == "" {
+		return baseContentType
+	}
+	return baseContentType + "+" + contentSubtype
+}

vendor/google.golang.org/grpc/internal/grpcutil/regex.go

@@ -0,0 +1,31 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import "regexp"
+
+// FullMatchWithRegex returns whether the full text matches the regex provided.
+func FullMatchWithRegex(re *regexp.Regexp, text string) bool {
+	if len(text) == 0 {
+		return re.MatchString(text)
+	}
+	re.Longest()
+	rem := re.FindString(text)
+	return len(rem) == len(text)
+}

vendor/google.golang.org/grpc/internal/idle/idle.go

@@ -0,0 +1,289 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package idle contains a component for managing idleness (entering and exiting)
+// based on RPC activity.
+package idle
+
+import (
+	"math"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// For overriding in unit tests.
+var timeAfterFunc = func(d time.Duration, f func()) *time.Timer {
+	return time.AfterFunc(d, f)
+}
+
+// ClientConn is the functionality provided by grpc.ClientConn to enter and exit
+// from idle mode.
+type ClientConn interface {
+	ExitIdleMode()
+	EnterIdleMode()
+}
+
+// Manager implements idleness detection and calls the ClientConn to enter/exit
+// idle mode when appropriate. Must be created by NewManager.
+type Manager struct {
+	// State accessed atomically.
+	lastCallEndTime           int64 // Unix timestamp in nanos; time when the most recent RPC completed.
+	activeCallsCount          int32 // Count of active RPCs; -math.MaxInt32 means channel is idle or is trying to get there.
+	activeSinceLastTimerCheck int32 // Boolean; True if there was an RPC since the last timer callback.
+	closed                    int32 // Boolean; True when the manager is closed.
+
+	// Can be accessed without atomics or mutex since these are set at creation
+	// time and read-only after that.
+	cc      ClientConn // Functionality provided by grpc.ClientConn.
+	timeout time.Duration
+
+	// idleMu is used to guarantee mutual exclusion in two scenarios:
+	// - Opposing intentions:
+	//   - a: Idle timeout has fired and handleIdleTimeout() is trying to put
+	//     the channel in idle mode because the channel has been inactive.
+	//   - b: At the same time an RPC is made on the channel, and OnCallBegin()
+	//     is trying to prevent the channel from going idle.
+	// - Competing intentions:
+	//   - The channel is in idle mode and there are multiple RPCs starting at
+	//     the same time, all trying to move the channel out of idle. Only one
+	//     of them should succeed in doing so, while the other RPCs should
+	//     piggyback on the first one and be successfully handled.
+	idleMu       sync.RWMutex
+	actuallyIdle bool
+	timer        *time.Timer
+}
+
+// NewManager creates a new idleness manager implementation for the
+// given idle timeout.  It begins in idle mode.
+func NewManager(cc ClientConn, timeout time.Duration) *Manager {
+	return &Manager{
+		cc:               cc,
+		timeout:          timeout,
+		actuallyIdle:     true,
+		activeCallsCount: -math.MaxInt32,
+	}
+}
+
+// resetIdleTimerLocked resets the idle timer to the given duration.  Called
+// when exiting idle mode or when the timer fires and we need to reset it.
+func (m *Manager) resetIdleTimerLocked(d time.Duration) {
+	if m.isClosed() || m.timeout == 0 || m.actuallyIdle {
+		return
+	}
+
+	// It is safe to ignore the return value from Reset() because this method is
+	// only ever called from the timer callback or when exiting idle mode.
+	if m.timer != nil {
+		m.timer.Stop()
+	}
+	m.timer = timeAfterFunc(d, m.handleIdleTimeout)
+}
+
+func (m *Manager) resetIdleTimer(d time.Duration) {
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+	m.resetIdleTimerLocked(d)
+}
+
+// handleIdleTimeout is the timer callback that is invoked upon expiry of the
+// configured idle timeout. The channel is considered inactive if there are no
+// ongoing calls and no RPC activity since the last time the timer fired.
+func (m *Manager) handleIdleTimeout() {
+	if m.isClosed() {
+		return
+	}
+
+	if atomic.LoadInt32(&m.activeCallsCount) > 0 {
+		m.resetIdleTimer(m.timeout)
+		return
+	}
+
+	// There has been activity on the channel since we last got here. Reset the
+	// timer and return.
+	if atomic.LoadInt32(&m.activeSinceLastTimerCheck) == 1 {
+		// Set the timer to fire after a duration of idle timeout, calculated
+		// from the time the most recent RPC completed.
+		atomic.StoreInt32(&m.activeSinceLastTimerCheck, 0)
+		m.resetIdleTimer(time.Duration(atomic.LoadInt64(&m.lastCallEndTime)-time.Now().UnixNano()) + m.timeout)
+		return
+	}
+
+	// Now that we've checked that there has been no activity, attempt to enter
+	// idle mode, which is very likely to succeed.
+	if m.tryEnterIdleMode(true) {
+		// Successfully entered idle mode. No timer needed until we exit idle.
+		return
+	}
+
+	// Failed to enter idle mode due to a concurrent RPC that kept the channel
+	// active, or because of an error from the channel. Undo the attempt to
+	// enter idle, and reset the timer to try again later.
+	m.resetIdleTimer(m.timeout)
+}
+
+// tryEnterIdleMode instructs the channel to enter idle mode. But before
+// that, it performs a last minute check to ensure that no new RPC has come in,
+// making the channel active.
+//
+// checkActivity controls if a check for RPC activity, since the last time the
+// idle_timeout fired, is made.
+
+// Return value indicates whether or not the channel moved to idle mode.
+//
+// Holds idleMu which ensures mutual exclusion with exitIdleMode.
+func (m *Manager) tryEnterIdleMode(checkActivity bool) bool {
+	// Setting the activeCallsCount to -math.MaxInt32 indicates to OnCallBegin()
+	// that the channel is either in idle mode or is trying to get there.
+	if !atomic.CompareAndSwapInt32(&m.activeCallsCount, 0, -math.MaxInt32) {
+		// This CAS operation can fail if an RPC started after we checked for
+		// activity in the timer handler, or one was ongoing from before the
+		// last time the timer fired, or if a test is attempting to enter idle
+		// mode without checking.  In all cases, abort going into idle mode.
+		return false
+	}
+	// N.B. if we fail to enter idle mode after this, we must re-add
+	// math.MaxInt32 to m.activeCallsCount.
+
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+
+	if atomic.LoadInt32(&m.activeCallsCount) != -math.MaxInt32 {
+		// We raced and lost to a new RPC. Very rare, but stop entering idle.
+		atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+		return false
+	}
+	if checkActivity && atomic.LoadInt32(&m.activeSinceLastTimerCheck) == 1 {
+		// A very short RPC could have come in (and also finished) after we
+		// checked for calls count and activity in handleIdleTimeout(), but
+		// before the CAS operation. So, we need to check for activity again.
+		atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+		return false
+	}
+
+	// No new RPCs have come in since we set the active calls count value to
+	// -math.MaxInt32. And since we have the lock, it is safe to enter idle mode
+	// unconditionally now.
+	m.cc.EnterIdleMode()
+	m.actuallyIdle = true
+	return true
+}
+
+// EnterIdleModeForTesting instructs the channel to enter idle mode.
+func (m *Manager) EnterIdleModeForTesting() {
+	m.tryEnterIdleMode(false)
+}
+
+// OnCallBegin is invoked at the start of every RPC.
+func (m *Manager) OnCallBegin() {
+	if m.isClosed() {
+		return
+	}
+
+	if atomic.AddInt32(&m.activeCallsCount, 1) > 0 {
+		// Channel is not idle now. Set the activity bit and allow the call.
+		atomic.StoreInt32(&m.activeSinceLastTimerCheck, 1)
+		return
+	}
+
+	// Channel is either in idle mode or is in the process of moving to idle
+	// mode. Attempt to exit idle mode to allow this RPC.
+	m.ExitIdleMode()
+	atomic.StoreInt32(&m.activeSinceLastTimerCheck, 1)
+}
+
+// ExitIdleMode instructs m to call the ClientConn's ExitIdleMode and update its
+// internal state.
+func (m *Manager) ExitIdleMode() {
+	// Holds idleMu which ensures mutual exclusion with tryEnterIdleMode.
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+
+	if m.isClosed() || !m.actuallyIdle {
+		// This can happen in three scenarios:
+		// - handleIdleTimeout() set the calls count to -math.MaxInt32 and called
+		//   tryEnterIdleMode(). But before the latter could grab the lock, an RPC
+		//   came in and OnCallBegin() noticed that the calls count is negative.
+		// - Channel is in idle mode, and multiple new RPCs come in at the same
+		//   time, all of them notice a negative calls count in OnCallBegin and get
+		//   here. The first one to get the lock would get the channel to exit idle.
+		// - Channel is not in idle mode, and the user calls Connect which calls
+		//   m.ExitIdleMode.
+		//
+		// In any case, there is nothing to do here.
+		return
+	}
+
+	m.cc.ExitIdleMode()
+
+	// Undo the idle entry process. This also respects any new RPC attempts.
+	atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+	m.actuallyIdle = false
+
+	// Start a new timer to fire after the configured idle timeout.
+	m.resetIdleTimerLocked(m.timeout)
+}
+
+// UnsafeSetNotIdle instructs the Manager to update its internal state to
+// reflect the reality that the channel is no longer in IDLE mode.
+//
+// N.B. This method is intended only for internal use by the gRPC client
+// when it exits IDLE mode **manually** from `Dial`. The callsite must ensure:
+//   - The channel was **actually in IDLE mode** immediately prior to the call.
+//   - There is **no concurrent activity** that could cause the channel to exit
+//     IDLE mode *naturally* at the same time.
+func (m *Manager) UnsafeSetNotIdle() {
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+
+	atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+	m.actuallyIdle = false
+	m.resetIdleTimerLocked(m.timeout)
+}
+
+// OnCallEnd is invoked at the end of every RPC.
+func (m *Manager) OnCallEnd() {
+	if m.isClosed() {
+		return
+	}
+
+	// Record the time at which the most recent call finished.
+	atomic.StoreInt64(&m.lastCallEndTime, time.Now().UnixNano())
+
+	// Decrement the active calls count. This count can temporarily go negative
+	// when the timer callback is in the process of moving the channel to idle
+	// mode, but one or more RPCs come in and complete before the timer callback
+	// can get done with the process of moving to idle mode.
+	atomic.AddInt32(&m.activeCallsCount, -1)
+}
+
+func (m *Manager) isClosed() bool {
+	return atomic.LoadInt32(&m.closed) == 1
+}
+
+// Close stops the timer associated with the Manager, if it exists.
+func (m *Manager) Close() {
+	atomic.StoreInt32(&m.closed, 1)
+
+	m.idleMu.Lock()
+	if m.timer != nil {
+		m.timer.Stop()
+		m.timer = nil
+	}
+	m.idleMu.Unlock()
+}

vendor/google.golang.org/grpc/internal/internal.go

@@ -0,0 +1,297 @@
+/*
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains gRPC-internal code, to avoid polluting
+// the godoc of the top-level grpc package.  It must not import any grpc
+// symbols to avoid circular dependencies.
+package internal
+
+import (
+	"context"
+	"time"
+
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	// HealthCheckFunc is used to provide client-side LB channel health checking
+	HealthCheckFunc HealthChecker
+	// RegisterClientHealthCheckListener is used to provide a listener for
+	// updates from the client-side health checking service. It returns a
+	// function that can be called to stop the health producer.
+	RegisterClientHealthCheckListener any // func(ctx context.Context, sc balancer.SubConn, serviceName string, listener func(balancer.SubConnState)) func()
+	// BalancerUnregister is exported by package balancer to unregister a balancer.
+	BalancerUnregister func(name string)
+	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
+	// default, but tests may wish to set it lower for convenience.
+	KeepaliveMinPingTime = 10 * time.Second
+	// KeepaliveMinServerPingTime is the minimum ping interval for servers.
+	// This must be 1s by default, but tests may wish to set it lower for
+	// convenience.
+	KeepaliveMinServerPingTime = time.Second
+	// ParseServiceConfig parses a JSON representation of the service config.
+	ParseServiceConfig any // func(string) *serviceconfig.ParseResult
+	// EqualServiceConfigForTesting is for testing service config generation and
+	// parsing. Both a and b should be returned by ParseServiceConfig.
+	// This function compares the config without rawJSON stripped, in case the
+	// there's difference in white space.
+	EqualServiceConfigForTesting func(a, b serviceconfig.Config) bool
+	// GetCertificateProviderBuilder returns the registered builder for the
+	// given name. This is set by package certprovider for use from xDS
+	// bootstrap code while parsing certificate provider configs in the
+	// bootstrap file.
+	GetCertificateProviderBuilder any // func(string) certprovider.Builder
+	// GetXDSHandshakeInfoForTesting returns a pointer to the xds.HandshakeInfo
+	// stored in the passed in attributes. This is set by
+	// credentials/xds/xds.go.
+	GetXDSHandshakeInfoForTesting any // func (*attributes.Attributes) *unsafe.Pointer
+	// GetServerCredentials returns the transport credentials configured on a
+	// gRPC server. An xDS-enabled server needs to know what type of credentials
+	// is configured on the underlying gRPC server. This is set by server.go.
+	GetServerCredentials any // func (*grpc.Server) credentials.TransportCredentials
+	// MetricsRecorderForServer returns the MetricsRecorderList derived from a
+	// server's stats handlers.
+	MetricsRecorderForServer any // func (*grpc.Server) estats.MetricsRecorder
+	// CanonicalString returns the canonical string of the code defined here:
+	// https://github.com/grpc/grpc/blob/master/doc/statuscodes.md.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	CanonicalString any // func (codes.Code) string
+	// IsRegisteredMethod returns whether the passed in method is registered as
+	// a method on the server.
+	IsRegisteredMethod any // func(*grpc.Server, string) bool
+	// ServerFromContext returns the server from the context.
+	ServerFromContext any // func(context.Context) *grpc.Server
+	// AddGlobalServerOptions adds an array of ServerOption that will be
+	// effective globally for newly created servers. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalServerOptions any // func(opt ...ServerOption)
+	// ClearGlobalServerOptions clears the array of extra ServerOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalServerOptions func()
+	// AddGlobalDialOptions adds an array of DialOption that will be effective
+	// globally for newly created client channels. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalDialOptions any // func(opt ...DialOption)
+	// DisableGlobalDialOptions returns a DialOption that prevents the
+	// ClientConn from applying the global DialOptions (set via
+	// AddGlobalDialOptions).
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	DisableGlobalDialOptions any // func() grpc.DialOption
+	// ClearGlobalDialOptions clears the array of extra DialOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalDialOptions func()
+
+	// AddGlobalPerTargetDialOptions adds a PerTargetDialOption that will be
+	// configured for newly created ClientConns.
+	AddGlobalPerTargetDialOptions any // func (opt any)
+	// ClearGlobalPerTargetDialOptions clears the slice of global late apply
+	// dial options.
+	ClearGlobalPerTargetDialOptions func()
+
+	// JoinDialOptions combines the dial options passed as arguments into a
+	// single dial option.
+	JoinDialOptions any // func(...grpc.DialOption) grpc.DialOption
+	// JoinServerOptions combines the server options passed as arguments into a
+	// single server option.
+	JoinServerOptions any // func(...grpc.ServerOption) grpc.ServerOption
+
+	// WithBinaryLogger returns a DialOption that specifies the binary logger
+	// for a ClientConn.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	WithBinaryLogger any // func(binarylog.Logger) grpc.DialOption
+	// BinaryLogger returns a ServerOption that can set the binary logger for a
+	// server.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	BinaryLogger any // func(binarylog.Logger) grpc.ServerOption
+
+	// SubscribeToConnectivityStateChanges adds a grpcsync.Subscriber to a
+	// provided grpc.ClientConn.
+	SubscribeToConnectivityStateChanges any // func(*grpc.ClientConn, grpcsync.Subscriber)
+
+	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
+	// the provided xds bootstrap config instead of the global configuration from
+	// the supported environment variables.  The resolver.Builder is meant to be
+	// used in conjunction with the grpc.WithResolvers DialOption.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithConfigForTesting any // func([]byte) (resolver.Builder, error)
+
+	// NewXDSResolverWithPoolForTesting creates a new xDS resolver builder
+	// using the provided xDS pool instead of creating a new one using the
+	// bootstrap configuration specified by the supported environment variables.
+	// The resolver.Builder is meant to be used in conjunction with the
+	// grpc.WithResolvers DialOption. The resolver.Builder does not take
+	// ownership of the provided xDS client and it is the responsibility of the
+	// caller to close the client when no longer required.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithPoolForTesting any // func(*xdsclient.Pool) (resolver.Builder, error)
+
+	// NewXDSResolverWithClientForTesting creates a new xDS resolver builder
+	// using the provided xDS client instead of creating a new one using the
+	// bootstrap configuration specified by the supported environment variables.
+	// The resolver.Builder is meant to be used in conjunction with the
+	// grpc.WithResolvers DialOption. The resolver.Builder does not take
+	// ownership of the provided xDS client and it is the responsibility of the
+	// caller to close the client when no longer required.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithClientForTesting any // func(xdsclient.XDSClient) (resolver.Builder, error)
+
+	// ORCAAllowAnyMinReportingInterval is for examples/orca use ONLY.
+	ORCAAllowAnyMinReportingInterval any // func(so *orca.ServiceOptions)
+
+	// GRPCResolverSchemeExtraMetadata determines when gRPC will add extra
+	// metadata to RPCs.
+	GRPCResolverSchemeExtraMetadata = "xds"
+
+	// EnterIdleModeForTesting gets the ClientConn to enter IDLE mode.
+	EnterIdleModeForTesting any // func(*grpc.ClientConn)
+
+	// ExitIdleModeForTesting gets the ClientConn to exit IDLE mode.
+	ExitIdleModeForTesting any // func(*grpc.ClientConn) error
+
+	// ChannelzTurnOffForTesting disables the Channelz service for testing
+	// purposes.
+	ChannelzTurnOffForTesting func()
+
+	// TriggerXDSResourceNotFoundForTesting causes the provided xDS Client to
+	// invoke resource-not-found error for the given resource type and name.
+	TriggerXDSResourceNotFoundForTesting any // func(xdsclient.XDSClient, xdsresource.Type, string) error
+
+	// FromOutgoingContextRaw returns the un-merged, intermediary contents of
+	// metadata.rawMD.
+	FromOutgoingContextRaw any // func(context.Context) (metadata.MD, [][]string, bool)
+
+	// UserSetDefaultScheme is set to true if the user has overridden the
+	// default resolver scheme.
+	UserSetDefaultScheme = false
+
+	// ConnectedAddress returns the connected address for a SubConnState. The
+	// address is only valid if the state is READY.
+	ConnectedAddress any // func (scs SubConnState) resolver.Address
+
+	// SetConnectedAddress sets the connected address for a SubConnState.
+	SetConnectedAddress any // func(scs *SubConnState, addr resolver.Address)
+
+	// SnapshotMetricRegistryForTesting snapshots the global data of the metric
+	// registry. Returns a cleanup function that sets the metric registry to its
+	// original state. Only called in testing functions.
+	SnapshotMetricRegistryForTesting func() func()
+
+	// SetDefaultBufferPoolForTesting updates the default buffer pool, for
+	// testing purposes.
+	SetDefaultBufferPoolForTesting any // func(mem.BufferPool)
+
+	// SetBufferPoolingThresholdForTesting updates the buffer pooling threshold, for
+	// testing purposes.
+	SetBufferPoolingThresholdForTesting any // func(int)
+
+	// TimeAfterFunc is used to create timers. During tests the function is
+	// replaced to track allocated timers and fail the test if a timer isn't
+	// cancelled.
+	TimeAfterFunc = func(d time.Duration, f func()) Timer {
+		return time.AfterFunc(d, f)
+	}
+
+	// NewStreamWaitingForResolver is a test hook that is triggered when a
+	// new stream blocks while waiting for name resolution. This can be
+	// used in tests to synchronize resolver updates and avoid race conditions.
+	// When set, the function will be called before the stream enters
+	// the blocking state.
+	NewStreamWaitingForResolver = func() {}
+
+	// AddressToTelemetryLabels is an xDS-provided function to extract telemetry
+	// labels from a resolver.Address. Callers must assert its type before calling.
+	AddressToTelemetryLabels any // func(addr resolver.Address) map[string]string
+)
+
+// HealthChecker defines the signature of the client-side LB channel health
+// checking function.
+//
+// The implementation is expected to create a health checking RPC stream by
+// calling newStream(), watch for the health status of serviceName, and report
+// its health back by calling setConnectivityState().
+//
+// The health checking protocol is defined at:
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md
+type HealthChecker func(ctx context.Context, newStream func(string) (any, error), setConnectivityState func(connectivity.State, error), serviceName string) error
+
+const (
+	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.
+	CredsBundleModeFallback = "fallback"
+	// CredsBundleModeBalancer switches GoogleDefaultCreds to grpclb balancer
+	// mode.
+	CredsBundleModeBalancer = "balancer"
+	// CredsBundleModeBackendFromBalancer switches GoogleDefaultCreds to mode
+	// that supports backend returned by grpclb balancer.
+	CredsBundleModeBackendFromBalancer = "backend-from-balancer"
+)
+
+// RLSLoadBalancingPolicyName is the name of the RLS LB policy.
+//
+// It currently has an experimental suffix which would be removed once
+// end-to-end testing of the policy is completed.
+const RLSLoadBalancingPolicyName = "rls_experimental"
+
+// EnforceSubConnEmbedding is used to enforce proper SubConn implementation
+// embedding.
+type EnforceSubConnEmbedding interface {
+	enforceSubConnEmbedding()
+}
+
+// EnforceClientConnEmbedding is used to enforce proper ClientConn implementation
+// embedding.
+type EnforceClientConnEmbedding interface {
+	enforceClientConnEmbedding()
+}
+
+// Timer is an interface to allow injecting different time.Timer implementations
+// during tests.
+type Timer interface {
+	Stop() bool
+}

vendor/google.golang.org/grpc/internal/metadata/metadata.go

@@ -0,0 +1,144 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package metadata contains functions to set and get metadata from addresses.
+//
+// This package is experimental.
+package metadata
+
+import (
+	"fmt"
+	"strings"
+
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+)
+
+type mdKeyType string
+
+const mdKey = mdKeyType("grpc.internal.address.metadata")
+
+type mdValue metadata.MD
+
+func (m mdValue) Equal(o any) bool {
+	om, ok := o.(mdValue)
+	if !ok {
+		return false
+	}
+	if len(m) != len(om) {
+		return false
+	}
+	for k, v := range m {
+		ov := om[k]
+		if len(ov) != len(v) {
+			return false
+		}
+		for i, ve := range v {
+			if ov[i] != ve {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Get returns the metadata of addr.
+func Get(addr resolver.Address) metadata.MD {
+	attrs := addr.Attributes
+	if attrs == nil {
+		return nil
+	}
+	md, _ := attrs.Value(mdKey).(mdValue)
+	return metadata.MD(md)
+}
+
+// Set sets (overrides) the metadata in addr.
+//
+// When a SubConn is created with this address, the RPCs sent on it will all
+// have this metadata.
+func Set(addr resolver.Address, md metadata.MD) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(mdKey, mdValue(md))
+	return addr
+}
+
+// Validate validates every pair in md with ValidatePair.
+func Validate(md metadata.MD) error {
+	for k, vals := range md {
+		if err := ValidatePair(k, vals...); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// hasNotPrintable return true if msg contains any characters which are not in %x20-%x7E
+func hasNotPrintable(msg string) bool {
+	// for i that saving a conversion if not using for range
+	for i := 0; i < len(msg); i++ {
+		if msg[i] < 0x20 || msg[i] > 0x7E {
+			return true
+		}
+	}
+	return false
+}
+
+// ValidateKey validates a key with the following rules (pseudo-headers are
+// skipped):
+// - the key must contain one or more characters.
+// - the characters in the key must be in [0-9 a-z _ - .].
+func ValidateKey(key string) error {
+	// key should not be empty
+	if key == "" {
+		return fmt.Errorf("there is an empty key in the header")
+	}
+	// pseudo-header will be ignored
+	if key[0] == ':' {
+		return nil
+	}
+	// check key, for i that saving a conversion if not using for range
+	for i := 0; i < len(key); i++ {
+		r := key[i]
+		if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+			return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
+		}
+	}
+	return nil
+}
+
+// ValidatePair validates a key-value pair with the following rules
+// (pseudo-header are skipped):
+//   - the key must contain one or more characters.
+//   - the characters in the key must be in [0-9 a-z _ - .].
+//   - if the key ends with a "-bin" suffix, no validation of the corresponding
+//     value is performed.
+//   - the characters in every value must be printable (in [%x20-%x7E]).
+func ValidatePair(key string, vals ...string) error {
+	if err := ValidateKey(key); err != nil {
+		return err
+	}
+	if strings.HasSuffix(key, "-bin") {
+		return nil
+	}
+	// check value
+	for _, val := range vals {
+		if hasNotPrintable(val) {
+			return fmt.Errorf("header key %q contains value with non-printable ASCII characters", key)
+		}
+	}
+	return nil
+}

vendor/google.golang.org/grpc/internal/pretty/pretty.go

@@ -0,0 +1,73 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pretty defines helper functions to pretty-print structs for logging.
+package pretty
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"google.golang.org/protobuf/encoding/protojson"
+	"google.golang.org/protobuf/protoadapt"
+)
+
+const jsonIndent = "  "
+
+// ToJSON marshals the input into a json string.
+//
+// If marshal fails, it falls back to fmt.Sprintf("%+v").
+func ToJSON(e any) string {
+	if ee, ok := e.(protoadapt.MessageV1); ok {
+		e = protoadapt.MessageV2Of(ee)
+	}
+
+	if ee, ok := e.(protoadapt.MessageV2); ok {
+		mm := protojson.MarshalOptions{
+			Indent:    jsonIndent,
+			Multiline: true,
+		}
+		ret, err := mm.Marshal(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	}
+
+	ret, err := json.MarshalIndent(e, "", jsonIndent)
+	if err != nil {
+		return fmt.Sprintf("%+v", e)
+	}
+	return string(ret)
+}
+
+// FormatJSON formats the input json bytes with indentation.
+//
+// If Indent fails, it returns the unchanged input as string.
+func FormatJSON(b []byte) string {
+	var out bytes.Buffer
+	err := json.Indent(&out, b, "", jsonIndent)
+	if err != nil {
+		return string(b)
+	}
+	return out.String()
+}

vendor/google.golang.org/grpc/internal/proxyattributes/proxyattributes.go

@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package proxyattributes contains functions for getting and setting proxy
+// attributes like the CONNECT address and user info.
+package proxyattributes
+
+import (
+	"net/url"
+
+	"google.golang.org/grpc/resolver"
+)
+
+type keyType string
+
+const proxyOptionsKey = keyType("grpc.resolver.delegatingresolver.proxyOptions")
+
+// Options holds the proxy connection details needed during the CONNECT
+// handshake.
+type Options struct {
+	User        *url.Userinfo
+	ConnectAddr string
+}
+
+// Set returns a copy of addr with opts set in its attributes.
+func Set(addr resolver.Address, opts Options) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(proxyOptionsKey, opts)
+	return addr
+}
+
+// Get returns the Options for the proxy [resolver.Address] and a boolean
+// value representing if the attribute is present or not. The returned data
+// should not be mutated.
+func Get(addr resolver.Address) (Options, bool) {
+	if a := addr.Attributes.Value(proxyOptionsKey); a != nil {
+		return a.(Options), true
+	}
+	return Options{}, false
+}

vendor/google.golang.org/grpc/internal/resolver/config_selector.go

@@ -0,0 +1,167 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package resolver provides internal resolver-related functionality.
+package resolver
+
+import (
+	"context"
+	"sync"
+
+	"google.golang.org/grpc/internal/serviceconfig"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+)
+
+// ConfigSelector controls what configuration to use for every RPC.
+type ConfigSelector interface {
+	// Selects the configuration for the RPC, or terminates it using the error.
+	// This error will be converted by the gRPC library to a status error with
+	// code UNKNOWN if it is not returned as a status error.
+	SelectConfig(RPCInfo) (*RPCConfig, error)
+}
+
+// RPCInfo contains RPC information needed by a ConfigSelector.
+type RPCInfo struct {
+	// Context is the user's context for the RPC and contains headers and
+	// application timeout.  It is passed for interception purposes and for
+	// efficiency reasons.  SelectConfig should not be blocking.
+	Context context.Context
+	Method  string // i.e. "/Service/Method"
+}
+
+// RPCConfig describes the configuration to use for each RPC.
+type RPCConfig struct {
+	// The context to use for the remainder of the RPC; can pass info to LB
+	// policy or affect timeout or metadata.
+	Context      context.Context
+	MethodConfig serviceconfig.MethodConfig // configuration to use for this RPC
+	OnCommitted  func()                     // Called when the RPC has been committed (retries no longer possible)
+	Interceptor  ClientInterceptor
+}
+
+// ClientStream is the same as grpc.ClientStream, but defined here for circular
+// dependency reasons.
+type ClientStream interface {
+	// Header returns the header metadata received from the server if there
+	// is any. It blocks if the metadata is not ready to read.
+	Header() (metadata.MD, error)
+	// Trailer returns the trailer metadata from the server, if there is any.
+	// It must only be called after stream.CloseAndRecv has returned, or
+	// stream.Recv has returned a non-nil error (including io.EOF).
+	Trailer() metadata.MD
+	// CloseSend closes the send direction of the stream. It closes the stream
+	// when non-nil error is met. It is also not safe to call CloseSend
+	// concurrently with SendMsg.
+	CloseSend() error
+	// Context returns the context for this stream.
+	//
+	// It should not be called until after Header or RecvMsg has returned. Once
+	// called, subsequent client-side retries are disabled.
+	Context() context.Context
+	// SendMsg is generally called by generated code. On error, SendMsg aborts
+	// the stream. If the error was generated by the client, the status is
+	// returned directly; otherwise, io.EOF is returned and the status of
+	// the stream may be discovered using RecvMsg.
+	//
+	// SendMsg blocks until:
+	//   - There is sufficient flow control to schedule m with the transport, or
+	//   - The stream is done, or
+	//   - The stream breaks.
+	//
+	// SendMsg does not wait until the message is received by the server. An
+	// untimely stream closure may result in lost messages. To ensure delivery,
+	// users should ensure the RPC completed successfully using RecvMsg.
+	//
+	// It is safe to have a goroutine calling SendMsg and another goroutine
+	// calling RecvMsg on the same stream at the same time, but it is not safe
+	// to call SendMsg on the same stream in different goroutines. It is also
+	// not safe to call CloseSend concurrently with SendMsg.
+	SendMsg(m any) error
+	// RecvMsg blocks until it receives a message into m or the stream is
+	// done. It returns io.EOF when the stream completes successfully. On
+	// any other error, the stream is aborted and the error contains the RPC
+	// status.
+	//
+	// It is safe to have a goroutine calling SendMsg and another goroutine
+	// calling RecvMsg on the same stream at the same time, but it is not
+	// safe to call RecvMsg on the same stream in different goroutines.
+	RecvMsg(m any) error
+}
+
+// ClientInterceptor is an interceptor for gRPC client streams.
+type ClientInterceptor interface {
+	// NewStream produces a ClientStream for an RPC which may optionally use
+	// the provided function to produce a stream for delegation.  Note:
+	// RPCInfo.Context should not be used (will be nil).
+	//
+	// done is invoked when the RPC is finished using its connection, or could
+	// not be assigned a connection.  RPC operations may still occur on
+	// ClientStream after done is called, since the interceptor is invoked by
+	// application-layer operations.  done must never be nil when called.
+	NewStream(ctx context.Context, ri RPCInfo, done func(), newStream func(ctx context.Context, done func()) (ClientStream, error)) (ClientStream, error)
+}
+
+// ServerInterceptor is an interceptor for incoming RPC's on gRPC server side.
+type ServerInterceptor interface {
+	// AllowRPC checks if an incoming RPC is allowed to proceed based on
+	// information about connection RPC was received on, and HTTP Headers. This
+	// information will be piped into context.
+	AllowRPC(ctx context.Context) error // TODO: Make this a real interceptor for filters such as rate limiting.
+}
+
+type csKeyType string
+
+const csKey = csKeyType("grpc.internal.resolver.configSelector")
+
+// SetConfigSelector sets the config selector in state and returns the new
+// state.
+func SetConfigSelector(state resolver.State, cs ConfigSelector) resolver.State {
+	state.Attributes = state.Attributes.WithValue(csKey, cs)
+	return state
+}
+
+// GetConfigSelector retrieves the config selector from state, if present, and
+// returns it or nil if absent.
+func GetConfigSelector(state resolver.State) ConfigSelector {
+	cs, _ := state.Attributes.Value(csKey).(ConfigSelector)
+	return cs
+}
+
+// SafeConfigSelector allows for safe switching of ConfigSelector
+// implementations such that previous values are guaranteed to not be in use
+// when UpdateConfigSelector returns.
+type SafeConfigSelector struct {
+	mu sync.RWMutex
+	cs ConfigSelector
+}
+
+// UpdateConfigSelector swaps to the provided ConfigSelector and blocks until
+// all uses of the previous ConfigSelector have completed.
+func (scs *SafeConfigSelector) UpdateConfigSelector(cs ConfigSelector) {
+	scs.mu.Lock()
+	defer scs.mu.Unlock()
+	scs.cs = cs
+}
+
+// SelectConfig defers to the current ConfigSelector in scs.
+func (scs *SafeConfigSelector) SelectConfig(r RPCInfo) (*RPCConfig, error) {
+	scs.mu.RLock()
+	defer scs.mu.RUnlock()
+	return scs.cs.SelectConfig(r)
+}

vendor/google.golang.org/grpc/internal/resolver/delegatingresolver/delegatingresolver.go

@@ -0,0 +1,477 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package delegatingresolver implements a resolver capable of resolving both
+// target URIs and proxy addresses.
+package delegatingresolver
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/proxyattributes"
+	"google.golang.org/grpc/internal/transport"
+	"google.golang.org/grpc/internal/transport/networktype"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	logger = grpclog.Component("delegating-resolver")
+	// HTTPSProxyFromEnvironment will be overwritten in the tests
+	HTTPSProxyFromEnvironment = http.ProxyFromEnvironment
+)
+
+const defaultPort = "443"
+
+// delegatingResolver manages both target URI and proxy address resolution by
+// delegating these tasks to separate child resolvers. Essentially, it acts as
+// an intermediary between the gRPC ClientConn and the child resolvers.
+//
+// It implements the [resolver.Resolver] interface.
+type delegatingResolver struct {
+	target   resolver.Target     // parsed target URI to be resolved
+	cc       resolver.ClientConn // gRPC ClientConn
+	proxyURL *url.URL            // proxy URL, derived from proxy environment and target
+
+	// We do not hold both mu and childMu in the same goroutine. Avoid holding
+	// both locks when calling into the child, as the child resolver may
+	// synchronously callback into the channel.
+	mu                  sync.Mutex         // protects all the fields below
+	targetResolverState *resolver.State    // state of the target resolver
+	proxyAddrs          []resolver.Address // resolved proxy addresses; empty if no proxy is configured
+
+	// childMu serializes calls into child resolvers. It also protects access to
+	// the following fields.
+	childMu        sync.Mutex
+	targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
+	proxyResolver  resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
+}
+
+// nopResolver is a resolver that does nothing.
+type nopResolver struct{}
+
+func (nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (nopResolver) Close() {}
+
+// proxyURLForTarget determines the proxy URL for the given address based on the
+// environment. It can return the following:
+//   - nil URL, nil error: No proxy is configured or the address is excluded
+//     using the `NO_PROXY` environment variable or if req.URL.Host is
+//     "localhost" (with or without // a port number)
+//   - nil URL, non-nil error: An error occurred while retrieving the proxy URL.
+//   - non-nil URL, nil error: A proxy is configured, and the proxy URL was
+//     retrieved successfully without any errors.
+func proxyURLForTarget(address string) (*url.URL, error) {
+	req := &http.Request{URL: &url.URL{
+		Scheme: "https",
+		Host:   address,
+	}}
+	return HTTPSProxyFromEnvironment(req)
+}
+
+// New creates a new delegating resolver that can create up to two child
+// resolvers:
+//   - one to resolve the proxy address specified using the supported
+//     environment variables. This uses the registered resolver for the "dns"
+//     scheme. It is lazily built when a target resolver update contains at least
+//     one TCP address.
+//   - one to resolve the target URI using the resolver specified by the scheme
+//     in the target URI or specified by the user using the WithResolvers dial
+//     option. As a special case, if the target URI's scheme is "dns" and a
+//     proxy is specified using the supported environment variables, the target
+//     URI's path portion is used as the resolved address unless target
+//     resolution is enabled using the dial option.
+func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions, targetResolverBuilder resolver.Builder, targetResolutionEnabled bool) (resolver.Resolver, error) {
+	r := &delegatingResolver{
+		target:         target,
+		cc:             cc,
+		proxyResolver:  nopResolver{},
+		targetResolver: nopResolver{},
+	}
+
+	addr := target.Endpoint()
+	var err error
+	if target.URL.Scheme == "dns" && !targetResolutionEnabled && envconfig.EnableDefaultPortForProxyTarget {
+		addr, err = parseTarget(addr)
+		if err != nil {
+			return nil, fmt.Errorf("delegating_resolver: invalid target address %q: %v", target.Endpoint(), err)
+		}
+	}
+
+	r.proxyURL, err = proxyURLForTarget(addr)
+	if err != nil {
+		return nil, fmt.Errorf("delegating_resolver: failed to determine proxy URL for target %q: %v", target, err)
+	}
+
+	// proxy is not configured or proxy address excluded using `NO_PROXY` env
+	// var, so only target resolver is used.
+	if r.proxyURL == nil {
+		return targetResolverBuilder.Build(target, cc, opts)
+	}
+
+	if logger.V(2) {
+		logger.Infof("Proxy URL detected : %s", r.proxyURL)
+	}
+
+	// Resolver updates from one child may trigger calls into the other. Block
+	// updates until the children are initialized.
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	// When the scheme is 'dns' and target resolution on client is not enabled,
+	// resolution should be handled by the proxy, not the client. Therefore, we
+	// bypass the target resolver and store the unresolved target address.
+	if target.URL.Scheme == "dns" && !targetResolutionEnabled {
+		r.targetResolverState = &resolver.State{
+			Addresses: []resolver.Address{{Addr: addr}},
+			Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: addr}}}},
+		}
+		r.updateTargetResolverState(*r.targetResolverState)
+		return r, nil
+	}
+	wcc := &wrappingClientConn{
+		stateListener: r.updateTargetResolverState,
+		parent:        r,
+	}
+	if r.targetResolver, err = targetResolverBuilder.Build(target, wcc, opts); err != nil {
+		return nil, fmt.Errorf("delegating_resolver: unable to build the resolver for target %s: %v", target, err)
+	}
+	return r, nil
+}
+
+// proxyURIResolver creates a resolver for resolving proxy URIs using the "dns"
+// scheme. It adjusts the proxyURL to conform to the "dns:///" format and builds
+// a resolver with a wrappingClientConn to capture resolved addresses.
+func (r *delegatingResolver) proxyURIResolver(opts resolver.BuildOptions) (resolver.Resolver, error) {
+	proxyBuilder := resolver.Get("dns")
+	if proxyBuilder == nil {
+		panic("delegating_resolver: resolver for proxy not found for scheme dns")
+	}
+	url := *r.proxyURL
+	url.Scheme = "dns"
+	url.Path = "/" + r.proxyURL.Host
+	url.Host = "" // Clear the Host field to conform to the "dns:///" format
+
+	proxyTarget := resolver.Target{URL: url}
+	wcc := &wrappingClientConn{
+		stateListener: r.updateProxyResolverState,
+		parent:        r,
+	}
+	return proxyBuilder.Build(proxyTarget, wcc, opts)
+}
+
+func (r *delegatingResolver) ResolveNow(o resolver.ResolveNowOptions) {
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	r.targetResolver.ResolveNow(o)
+	r.proxyResolver.ResolveNow(o)
+}
+
+func (r *delegatingResolver) Close() {
+	r.childMu.Lock()
+	defer r.childMu.Unlock()
+	r.targetResolver.Close()
+	r.targetResolver = nil
+
+	r.proxyResolver.Close()
+	r.proxyResolver = nil
+}
+
+func needsProxyResolver(state *resolver.State) bool {
+	for _, addr := range state.Addresses {
+		if !skipProxy(addr) {
+			return true
+		}
+	}
+	for _, endpoint := range state.Endpoints {
+		for _, addr := range endpoint.Addresses {
+			if !skipProxy(addr) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// parseTarget takes a target string and ensures it is a valid "host:port" target.
+//
+// It does the following:
+//  1. If the target already has a port (e.g., "host:port", "[ipv6]:port"),
+//     it is returned as is.
+//  2. If the host part is empty (e.g., ":80"), it defaults to "localhost",
+//     returning "localhost:80".
+//  3. If the target is missing a port (e.g., "host", "ipv6"), the defaultPort
+//     is added.
+//
+// An error is returned for empty targets or targets with a trailing colon
+// but no port (e.g., "host:").
+func parseTarget(target string) (string, error) {
+	if target == "" {
+		return "", fmt.Errorf("missing address")
+	}
+
+	host, port, err := net.SplitHostPort(target)
+	if err != nil {
+		// If SplitHostPort fails, it's likely because the port is missing.
+		// We append the default port and return the result.
+		return net.JoinHostPort(target, defaultPort), nil
+	}
+
+	// If SplitHostPort succeeds, we check for edge cases.
+	if port == "" {
+		// A success with an empty port means the target had a trailing colon,
+		// e.g., "host:", which is an error.
+		return "", fmt.Errorf("missing port after port-separator colon")
+	}
+	if host == "" {
+		// A success with an empty host means the target was like ":80".
+		// We default the host to "localhost".
+		host = "localhost"
+	}
+	return net.JoinHostPort(host, port), nil
+}
+
+func skipProxy(address resolver.Address) bool {
+	// Avoid proxy when network is not tcp.
+	networkType, ok := networktype.Get(address)
+	if !ok {
+		networkType, _ = transport.ParseDialTarget(address.Addr)
+	}
+	if networkType != "tcp" {
+		return true
+	}
+
+	req := &http.Request{URL: &url.URL{
+		Scheme: "https",
+		Host:   address.Addr,
+	}}
+	// Avoid proxy when address included in `NO_PROXY` environment variable or
+	// fails to get the proxy address.
+	url, err := HTTPSProxyFromEnvironment(req)
+	if err != nil || url == nil {
+		return true
+	}
+	return false
+}
+
+// updateClientConnStateLocked constructs a combined list of addresses by
+// pairing each proxy address with every target address of type TCP. For each
+// pair, it creates a new [resolver.Address] using the proxy address and
+// attaches the corresponding target address and user info as attributes. Target
+// addresses that are not of type TCP are appended to the list as-is. The
+// function returns nil if either resolver has not yet provided an update, and
+// returns the result of ClientConn.UpdateState once both resolvers have
+// provided at least one update.
+func (r *delegatingResolver) updateClientConnStateLocked() error {
+	if r.targetResolverState == nil || r.proxyAddrs == nil {
+		return nil
+	}
+
+	// If multiple resolved proxy addresses are present, we send only the
+	// unresolved proxy host and let net.Dial handle the proxy host name
+	// resolution when creating the transport. Sending all resolved addresses
+	// would increase the number of addresses passed to the ClientConn and
+	// subsequently to load balancing (LB) policies like Round Robin, leading
+	// to additional TCP connections. However, if there's only one resolved
+	// proxy address, we send it directly, as it doesn't affect the address
+	// count returned by the target resolver and the address count sent to the
+	// ClientConn.
+	var proxyAddr resolver.Address
+	if len(r.proxyAddrs) == 1 {
+		proxyAddr = r.proxyAddrs[0]
+	} else {
+		proxyAddr = resolver.Address{Addr: r.proxyURL.Host}
+	}
+	var addresses []resolver.Address
+	for _, targetAddr := range (*r.targetResolverState).Addresses {
+		if skipProxy(targetAddr) {
+			addresses = append(addresses, targetAddr)
+			continue
+		}
+		addresses = append(addresses, proxyattributes.Set(proxyAddr, proxyattributes.Options{
+			User:        r.proxyURL.User,
+			ConnectAddr: targetAddr.Addr,
+		}))
+	}
+
+	// For each target endpoint, construct a new [resolver.Endpoint] that
+	// includes all addresses from all proxy endpoints and the addresses from
+	// that target endpoint, preserving the number of target endpoints.
+	var endpoints []resolver.Endpoint
+	for _, endpt := range (*r.targetResolverState).Endpoints {
+		var addrs []resolver.Address
+		for _, targetAddr := range endpt.Addresses {
+			// Avoid proxy when network is not tcp.
+			if skipProxy(targetAddr) {
+				addrs = append(addrs, targetAddr)
+				continue
+			}
+			for _, proxyAddr := range r.proxyAddrs {
+				addrs = append(addrs, proxyattributes.Set(proxyAddr, proxyattributes.Options{
+					User:        r.proxyURL.User,
+					ConnectAddr: targetAddr.Addr,
+				}))
+			}
+		}
+		endpoints = append(endpoints, resolver.Endpoint{Addresses: addrs})
+	}
+	// Use the targetResolverState for its service config and attributes
+	// contents. The state update is only sent after both the target and proxy
+	// resolvers have sent their updates, and curState has been updated with the
+	// combined addresses.
+	curState := *r.targetResolverState
+	curState.Addresses = addresses
+	curState.Endpoints = endpoints
+	return r.cc.UpdateState(curState)
+}
+
+// updateProxyResolverState updates the proxy resolver state by storing proxy
+// addresses and endpoints, marking the resolver as ready, and triggering a
+// state update if both proxy and target resolvers are ready. If the ClientConn
+// returns a non-nil error, it calls `ResolveNow()` on the target resolver.  It
+// is a StateListener function of wrappingClientConn passed to the proxy
+// resolver.
+func (r *delegatingResolver) updateProxyResolverState(state resolver.State) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if logger.V(2) {
+		logger.Infof("Addresses received from proxy resolver: %s", state.Addresses)
+	}
+	if len(state.Endpoints) > 0 {
+		// We expect exactly one address per endpoint because the proxy resolver
+		// uses "dns" resolution.
+		r.proxyAddrs = make([]resolver.Address, 0, len(state.Endpoints))
+		for _, endpoint := range state.Endpoints {
+			r.proxyAddrs = append(r.proxyAddrs, endpoint.Addresses...)
+		}
+	} else if state.Addresses != nil {
+		r.proxyAddrs = state.Addresses
+	} else {
+		r.proxyAddrs = []resolver.Address{} // ensure proxyAddrs is non-nil to indicate an update has been received
+	}
+	err := r.updateClientConnStateLocked()
+	// Another possible approach was to block until updates are received from
+	// both resolvers. But this is not used because calling `New()` triggers
+	// `Build()` for the first resolver, which calls `UpdateState()`. And the
+	// second resolver hasn't sent an update yet, so it would cause `New()` to
+	// block indefinitely.
+	if err != nil {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if r.targetResolver != nil {
+				r.targetResolver.ResolveNow(resolver.ResolveNowOptions{})
+			}
+		}()
+	}
+	return err
+}
+
+// updateTargetResolverState is the StateListener function provided to the
+// target resolver via wrappingClientConn. It updates the resolver state and
+// marks the target resolver as ready. If the update includes at least one TCP
+// address and the proxy resolver has not yet been constructed, it initializes
+// the proxy resolver. A combined state update is triggered once both resolvers
+// are ready. If all addresses are non-TCP, it proceeds without waiting for the
+// proxy resolver. If ClientConn.UpdateState returns a non-nil error,
+// ResolveNow() is called on the proxy resolver.
+func (r *delegatingResolver) updateTargetResolverState(state resolver.State) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if logger.V(2) {
+		logger.Infof("Addresses received from target resolver: %v", state.Addresses)
+	}
+	r.targetResolverState = &state
+	// If all addresses returned by the target resolver have a non-TCP network
+	// type, or are listed in the `NO_PROXY` environment variable, do not wait
+	// for proxy update.
+	if !needsProxyResolver(r.targetResolverState) {
+		return r.cc.UpdateState(*r.targetResolverState)
+	}
+
+	// The proxy resolver may be rebuilt multiple times, specifically each time
+	// the target resolver sends an update, even if the target resolver is built
+	// successfully but building the proxy resolver fails.
+	if len(r.proxyAddrs) == 0 {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if _, ok := r.proxyResolver.(nopResolver); !ok {
+				return
+			}
+			proxyResolver, err := r.proxyURIResolver(resolver.BuildOptions{})
+			if err != nil {
+				r.cc.ReportError(fmt.Errorf("delegating_resolver: unable to build the proxy resolver: %v", err))
+				return
+			}
+			r.proxyResolver = proxyResolver
+		}()
+	}
+
+	err := r.updateClientConnStateLocked()
+	if err != nil {
+		go func() {
+			r.childMu.Lock()
+			defer r.childMu.Unlock()
+			if r.proxyResolver != nil {
+				r.proxyResolver.ResolveNow(resolver.ResolveNowOptions{})
+			}
+		}()
+	}
+	return nil
+}
+
+// wrappingClientConn serves as an intermediary between the parent ClientConn
+// and the child resolvers created here. It implements the resolver.ClientConn
+// interface and is passed in that capacity to the child resolvers.
+type wrappingClientConn struct {
+	// Callback to deliver resolver state updates
+	stateListener func(state resolver.State) error
+	parent        *delegatingResolver
+}
+
+// UpdateState receives resolver state updates and forwards them to the
+// appropriate listener function (either for the proxy or target resolver).
+func (wcc *wrappingClientConn) UpdateState(state resolver.State) error {
+	return wcc.stateListener(state)
+}
+
+// ReportError intercepts errors from the child resolvers and passes them to
+// ClientConn.
+func (wcc *wrappingClientConn) ReportError(err error) {
+	wcc.parent.cc.ReportError(err)
+}
+
+// NewAddress intercepts the new resolved address from the child resolvers and
+// passes them to ClientConn.
+func (wcc *wrappingClientConn) NewAddress(addrs []resolver.Address) {
+	wcc.UpdateState(resolver.State{Addresses: addrs})
+}
+
+// ParseServiceConfig parses the provided service config and returns an object
+// that provides the parsed config.
+func (wcc *wrappingClientConn) ParseServiceConfig(serviceConfigJSON string) *serviceconfig.ParseResult {
+	return wcc.parent.cc.ParseServiceConfig(serviceConfigJSON)
+}

vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go

@@ -0,0 +1,461 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package dns implements a dns resolver to be installed as the default resolver
+// in grpc.
+package dns
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	rand "math/rand/v2"
+	"net"
+	"net/netip"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	grpclbstate "google.golang.org/grpc/balancer/grpclb/state"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/backoff"
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/resolver/dns/internal"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
+	// addresses from SRV records.  Must not be changed after init time.
+	EnableSRVLookups = false
+
+	// MinResolutionInterval is the minimum interval at which re-resolutions are
+	// allowed. This helps to prevent excessive re-resolution.
+	MinResolutionInterval = 30 * time.Second
+
+	// ResolvingTimeout specifies the maximum duration for a DNS resolution request.
+	// If the timeout expires before a response is received, the request will be canceled.
+	//
+	// It is recommended to set this value at application startup. Avoid modifying this variable
+	// after initialization as it's not thread-safe for concurrent modification.
+	ResolvingTimeout = 30 * time.Second
+
+	logger = grpclog.Component("dns")
+)
+
+func init() {
+	resolver.Register(NewBuilder())
+	internal.TimeAfterFunc = time.After
+	internal.TimeNowFunc = time.Now
+	internal.TimeUntilFunc = time.Until
+	internal.NewNetResolver = newNetResolver
+	internal.AddressDialer = addressDialer
+}
+
+const (
+	defaultPort       = "443"
+	defaultDNSSvrPort = "53"
+	golang            = "GO"
+	// txtPrefix is the prefix string to be prepended to the host name for txt
+	// record lookup.
+	txtPrefix = "_grpc_config."
+	// In DNS, service config is encoded in a TXT record via the mechanism
+	// described in RFC-1464 using the attribute name grpc_config.
+	txtAttribute = "grpc_config="
+)
+
+var addressDialer = func(address string) func(context.Context, string, string) (net.Conn, error) {
+	return func(ctx context.Context, network, _ string) (net.Conn, error) {
+		var dialer net.Dialer
+		return dialer.DialContext(ctx, network, address)
+	}
+}
+
+var newNetResolver = func(authority string) (internal.NetResolver, error) {
+	if authority == "" {
+		return net.DefaultResolver, nil
+	}
+
+	host, port, err := parseTarget(authority, defaultDNSSvrPort)
+	if err != nil {
+		return nil, err
+	}
+
+	authorityWithPort := net.JoinHostPort(host, port)
+
+	return &net.Resolver{
+		PreferGo: true,
+		Dial:     internal.AddressDialer(authorityWithPort),
+	}, nil
+}
+
+// NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
+func NewBuilder() resolver.Builder {
+	return &dnsBuilder{}
+}
+
+type dnsBuilder struct{}
+
+// Build creates and starts a DNS resolver that watches the name resolution of
+// the target.
+func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	host, port, err := parseTarget(target.Endpoint(), defaultPort)
+	if err != nil {
+		return nil, err
+	}
+
+	// IP address.
+	if ipAddr, err := formatIP(host); err == nil {
+		addr := []resolver.Address{{Addr: ipAddr + ":" + port}}
+		cc.UpdateState(resolver.State{Addresses: addr})
+		return deadResolver{}, nil
+	}
+
+	// DNS address (non-IP).
+	ctx, cancel := context.WithCancel(context.Background())
+	d := &dnsResolver{
+		host:                host,
+		port:                port,
+		ctx:                 ctx,
+		cancel:              cancel,
+		cc:                  cc,
+		rn:                  make(chan struct{}, 1),
+		enableServiceConfig: envconfig.EnableTXTServiceConfig && !opts.DisableServiceConfig,
+	}
+
+	d.resolver, err = internal.NewNetResolver(target.URL.Host)
+	if err != nil {
+		return nil, err
+	}
+
+	d.wg.Add(1)
+	go d.watcher()
+	return d, nil
+}
+
+// Scheme returns the naming scheme of this resolver builder, which is "dns".
+func (b *dnsBuilder) Scheme() string {
+	return "dns"
+}
+
+// deadResolver is a resolver that does nothing.
+type deadResolver struct{}
+
+func (deadResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (deadResolver) Close() {}
+
+// dnsResolver watches for the name resolution update for a non-IP target.
+type dnsResolver struct {
+	host     string
+	port     string
+	resolver internal.NetResolver
+	ctx      context.Context
+	cancel   context.CancelFunc
+	cc       resolver.ClientConn
+	// rn channel is used by ResolveNow() to force an immediate resolution of the
+	// target.
+	rn chan struct{}
+	// wg is used to enforce Close() to return after the watcher() goroutine has
+	// finished. Otherwise, data race will be possible. [Race Example] in
+	// dns_resolver_test we replace the real lookup functions with mocked ones to
+	// facilitate testing. If Close() doesn't wait for watcher() goroutine
+	// finishes, race detector sometimes will warn lookup (READ the lookup
+	// function pointers) inside watcher() goroutine has data race with
+	// replaceNetFunc (WRITE the lookup function pointers).
+	wg                  sync.WaitGroup
+	enableServiceConfig bool
+}
+
+// ResolveNow invoke an immediate resolution of the target that this
+// dnsResolver watches.
+func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
+	select {
+	case d.rn <- struct{}{}:
+	default:
+	}
+}
+
+// Close closes the dnsResolver.
+func (d *dnsResolver) Close() {
+	d.cancel()
+	d.wg.Wait()
+}
+
+func (d *dnsResolver) watcher() {
+	defer d.wg.Done()
+	backoffIndex := 1
+	for {
+		state, err := d.lookup()
+		if err != nil {
+			// Report error to the underlying grpc.ClientConn.
+			d.cc.ReportError(err)
+		} else {
+			err = d.cc.UpdateState(*state)
+		}
+
+		var nextResolutionTime time.Time
+		if err == nil {
+			// Success resolving, wait for the next ResolveNow. However, also wait 30
+			// seconds at the very least to prevent constantly re-resolving.
+			backoffIndex = 1
+			nextResolutionTime = internal.TimeNowFunc().Add(MinResolutionInterval)
+			select {
+			case <-d.ctx.Done():
+				return
+			case <-d.rn:
+			}
+		} else {
+			// Poll on an error found in DNS Resolver or an error received from
+			// ClientConn.
+			nextResolutionTime = internal.TimeNowFunc().Add(backoff.DefaultExponential.Backoff(backoffIndex))
+			backoffIndex++
+		}
+		select {
+		case <-d.ctx.Done():
+			return
+		case <-internal.TimeAfterFunc(internal.TimeUntilFunc(nextResolutionTime)):
+		}
+	}
+}
+
+func (d *dnsResolver) lookupSRV(ctx context.Context) ([]resolver.Address, error) {
+	// Skip this particular host to avoid timeouts with some versions of
+	// systemd-resolved.
+	if !EnableSRVLookups || d.host == "metadata.google.internal." {
+		return nil, nil
+	}
+	var newAddrs []resolver.Address
+	_, srvs, err := d.resolver.LookupSRV(ctx, "grpclb", "tcp", d.host)
+	if err != nil {
+		err = handleDNSError(err, "SRV") // may become nil
+		return nil, err
+	}
+	for _, s := range srvs {
+		lbAddrs, err := d.resolver.LookupHost(ctx, s.Target)
+		if err != nil {
+			err = handleDNSError(err, "A") // may become nil
+			if err == nil {
+				// If there are other SRV records, look them up and ignore this
+				// one that does not exist.
+				continue
+			}
+			return nil, err
+		}
+		for _, a := range lbAddrs {
+			ip, err := formatIP(a)
+			if err != nil {
+				return nil, fmt.Errorf("dns: error parsing A record IP address %v: %v", a, err)
+			}
+			addr := ip + ":" + strconv.Itoa(int(s.Port))
+			newAddrs = append(newAddrs, resolver.Address{Addr: addr, ServerName: s.Target})
+		}
+	}
+	return newAddrs, nil
+}
+
+func handleDNSError(err error, lookupType string) error {
+	dnsErr, ok := err.(*net.DNSError)
+	if ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
+		// Timeouts and temporary errors should be communicated to gRPC to
+		// attempt another DNS query (with backoff).  Other errors should be
+		// suppressed (they may represent the absence of a TXT record).
+		return nil
+	}
+	if err != nil {
+		err = fmt.Errorf("dns: %v record lookup error: %v", lookupType, err)
+		logger.Info(err)
+	}
+	return err
+}
+
+func (d *dnsResolver) lookupTXT(ctx context.Context) *serviceconfig.ParseResult {
+	ss, err := d.resolver.LookupTXT(ctx, txtPrefix+d.host)
+	if err != nil {
+		if envconfig.TXTErrIgnore {
+			return nil
+		}
+		if err = handleDNSError(err, "TXT"); err != nil {
+			return &serviceconfig.ParseResult{Err: err}
+		}
+		return nil
+	}
+	var res string
+	for _, s := range ss {
+		res += s
+	}
+
+	// TXT record must have "grpc_config=" attribute in order to be used as
+	// service config.
+	if !strings.HasPrefix(res, txtAttribute) {
+		logger.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute)
+		// This is not an error; it is the equivalent of not having a service
+		// config.
+		return nil
+	}
+	sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
+	return d.cc.ParseServiceConfig(sc)
+}
+
+func (d *dnsResolver) lookupHost(ctx context.Context) ([]resolver.Address, error) {
+	addrs, err := d.resolver.LookupHost(ctx, d.host)
+	if err != nil {
+		err = handleDNSError(err, "A")
+		return nil, err
+	}
+	newAddrs := make([]resolver.Address, 0, len(addrs))
+	for _, a := range addrs {
+		ip, err := formatIP(a)
+		if err != nil {
+			return nil, fmt.Errorf("dns: error parsing A record IP address %v: %v", a, err)
+		}
+		addr := ip + ":" + d.port
+		newAddrs = append(newAddrs, resolver.Address{Addr: addr})
+	}
+	return newAddrs, nil
+}
+
+func (d *dnsResolver) lookup() (*resolver.State, error) {
+	ctx, cancel := context.WithTimeout(d.ctx, ResolvingTimeout)
+	defer cancel()
+	srv, srvErr := d.lookupSRV(ctx)
+	addrs, hostErr := d.lookupHost(ctx)
+	if hostErr != nil && (srvErr != nil || len(srv) == 0) {
+		return nil, hostErr
+	}
+
+	state := resolver.State{Addresses: addrs}
+	if len(srv) > 0 {
+		state = grpclbstate.Set(state, &grpclbstate.State{BalancerAddresses: srv})
+	}
+	if d.enableServiceConfig {
+		state.ServiceConfig = d.lookupTXT(ctx)
+	}
+	return &state, nil
+}
+
+// formatIP returns an error if addr is not a valid textual representation of
+// an IP address. If addr is an IPv4 address, return the addr and error = nil.
+// If addr is an IPv6 address, return the addr enclosed in square brackets and
+// error = nil.
+func formatIP(addr string) (string, error) {
+	ip, err := netip.ParseAddr(addr)
+	if err != nil {
+		return "", err
+	}
+	if ip.Is4() {
+		return addr, nil
+	}
+	return "[" + addr + "]", nil
+}
+
+// parseTarget takes the user input target string and default port, returns
+// formatted host and port info. If target doesn't specify a port, set the port
+// to be the defaultPort. If target is in IPv6 format and host-name is enclosed
+// in square brackets, brackets are stripped when setting the host.
+// examples:
+// target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
+// target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
+// target: "[ipv6-host]" defaultPort: "443" returns host: "ipv6-host", port: "443"
+// target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
+func parseTarget(target, defaultPort string) (host, port string, err error) {
+	if target == "" {
+		return "", "", internal.ErrMissingAddr
+	}
+	if _, err := netip.ParseAddr(target); err == nil {
+		// target is an IPv4 or IPv6(without brackets) address
+		return target, defaultPort, nil
+	}
+	if host, port, err = net.SplitHostPort(target); err == nil {
+		if port == "" {
+			// If the port field is empty (target ends with colon), e.g. "[::1]:",
+			// this is an error.
+			return "", "", internal.ErrEndsWithColon
+		}
+		// target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
+		if host == "" {
+			// Keep consistent with net.Dial(): If the host is empty, as in ":80",
+			// the local system is assumed.
+			host = "localhost"
+		}
+		return host, port, nil
+	}
+	if host, port, err = net.SplitHostPort(target + ":" + defaultPort); err == nil {
+		// target doesn't have port
+		return host, port, nil
+	}
+	return "", "", fmt.Errorf("invalid target address %v, error info: %v", target, err)
+}
+
+type rawChoice struct {
+	ClientLanguage *[]string        `json:"clientLanguage,omitempty"`
+	Percentage     *int             `json:"percentage,omitempty"`
+	ClientHostName *[]string        `json:"clientHostName,omitempty"`
+	ServiceConfig  *json.RawMessage `json:"serviceConfig,omitempty"`
+}
+
+func containsString(a *[]string, b string) bool {
+	if a == nil {
+		return true
+	}
+	for _, c := range *a {
+		if c == b {
+			return true
+		}
+	}
+	return false
+}
+
+func chosenByPercentage(a *int) bool {
+	if a == nil {
+		return true
+	}
+	return rand.IntN(100)+1 <= *a
+}
+
+func canaryingSC(js string) string {
+	if js == "" {
+		return ""
+	}
+	var rcs []rawChoice
+	err := json.Unmarshal([]byte(js), &rcs)
+	if err != nil {
+		logger.Warningf("dns: error parsing service config json: %v", err)
+		return ""
+	}
+	cliHostname, err := os.Hostname()
+	if err != nil {
+		logger.Warningf("dns: error getting client hostname: %v", err)
+		return ""
+	}
+	var sc string
+	for _, c := range rcs {
+		if !containsString(c.ClientLanguage, golang) ||
+			!chosenByPercentage(c.Percentage) ||
+			!containsString(c.ClientHostName, cliHostname) ||
+			c.ServiceConfig == nil {
+			continue
+		}
+		sc = string(*c.ServiceConfig)
+		break
+	}
+	return sc
+}

vendor/google.golang.org/grpc/internal/resolver/dns/internal/internal.go

@@ -0,0 +1,77 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains functionality internal to the dns resolver package.
+package internal
+
+import (
+	"context"
+	"errors"
+	"net"
+	"time"
+)
+
+// NetResolver groups the methods on net.Resolver that are used by the DNS
+// resolver implementation. This allows the default net.Resolver instance to be
+// overridden from tests.
+type NetResolver interface {
+	LookupHost(ctx context.Context, host string) (addrs []string, err error)
+	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
+	LookupTXT(ctx context.Context, name string) (txts []string, err error)
+}
+
+var (
+	// ErrMissingAddr is the error returned when building a DNS resolver when
+	// the provided target name is empty.
+	ErrMissingAddr = errors.New("dns resolver: missing address")
+
+	// ErrEndsWithColon is the error returned when building a DNS resolver when
+	// the provided target name ends with a colon that is supposed to be the
+	// separator between host and port.  E.g. "::" is a valid address as it is
+	// an IPv6 address (host only) and "[::]:" is invalid as it ends with a
+	// colon as the host and port separator
+	ErrEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
+)
+
+// The following vars are overridden from tests.
+var (
+	// TimeAfterFunc is used by the DNS resolver to wait for the given duration
+	// to elapse. In non-test code, this is implemented by time.After. In test
+	// code, this can be used to control the amount of time the resolver is
+	// blocked waiting for the duration to elapse.
+	TimeAfterFunc func(time.Duration) <-chan time.Time
+
+	// TimeNowFunc is used by the DNS resolver to get the current time.
+	// In non-test code, this is implemented by time.Now. In test code,
+	// this can be used to control the current time for the resolver.
+	TimeNowFunc func() time.Time
+
+	// TimeUntilFunc is used by the DNS resolver to calculate the remaining
+	// wait time for re-resolution. In non-test code, this is implemented by
+	// time.Until. In test code, this can be used to control the remaining
+	// time for resolver to wait for re-resolution.
+	TimeUntilFunc func(time.Time) time.Duration
+
+	// NewNetResolver returns the net.Resolver instance for the given target.
+	NewNetResolver func(string) (NetResolver, error)
+
+	// AddressDialer is the dialer used to dial the DNS server. It accepts the
+	// Host portion of the URL corresponding to the user's dial target and
+	// returns a dial function.
+	AddressDialer func(address string) func(context.Context, string, string) (net.Conn, error)
+)

vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go

@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package passthrough implements a pass-through resolver. It sends the target
+// name without scheme back to gRPC as resolved address.
+package passthrough
+
+import (
+	"errors"
+
+	"google.golang.org/grpc/resolver"
+)
+
+const scheme = "passthrough"
+
+type passthroughBuilder struct{}
+
+func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.Endpoint() == "" && opts.Dialer == nil {
+		return nil, errors.New("passthrough: received empty target in Build()")
+	}
+	r := &passthroughResolver{
+		target: target,
+		cc:     cc,
+	}
+	r.start()
+	return r, nil
+}
+
+func (*passthroughBuilder) Scheme() string {
+	return scheme
+}
+
+type passthroughResolver struct {
+	target resolver.Target
+	cc     resolver.ClientConn
+}
+
+func (r *passthroughResolver) start() {
+	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint()}}})
+}
+
+func (*passthroughResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (*passthroughResolver) Close() {}
+
+func init() {
+	resolver.Register(&passthroughBuilder{})
+}

vendor/google.golang.org/grpc/internal/resolver/unix/unix.go

@@ -0,0 +1,78 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package unix implements a resolver for unix targets.
+package unix
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/internal/transport/networktype"
+	"google.golang.org/grpc/resolver"
+)
+
+const unixScheme = "unix"
+const unixAbstractScheme = "unix-abstract"
+
+type builder struct {
+	scheme string
+}
+
+func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.URL.Host != "" {
+		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
+	}
+
+	// gRPC was parsing the dial target manually before PR #4817, and we
+	// switched to using url.Parse() in that PR. To avoid breaking existing
+	// resolver implementations we ended up stripping the leading "/" from the
+	// endpoint. This obviously does not work for the "unix" scheme. Hence we
+	// end up using the parsed URL instead.
+	endpoint := target.URL.Path
+	if endpoint == "" {
+		endpoint = target.URL.Opaque
+	}
+	addr := resolver.Address{Addr: endpoint}
+	if b.scheme == unixAbstractScheme {
+		// We can not prepend \0 as c++ gRPC does, as in Golang '@' is used to signify we do
+		// not want trailing \0 in address.
+		addr.Addr = "@" + addr.Addr
+	}
+	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
+	return &nopResolver{}, nil
+}
+
+func (b *builder) Scheme() string {
+	return b.scheme
+}
+
+func (b *builder) OverrideAuthority(resolver.Target) string {
+	return "localhost"
+}
+
+type nopResolver struct {
+}
+
+func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (*nopResolver) Close() {}
+
+func init() {
+	resolver.Register(&builder{scheme: unixScheme})
+	resolver.Register(&builder{scheme: unixAbstractScheme})
+}