Force test failure when requested Python protobuf implementations are unavailable Prior to this change, the upb tests could succeed even if the upb backend was failing to import properly. This is because the API switching logic is currently designed to gracefully fall back to pure-Python. This behavior can sometimes be helpful in prod (maybe going more slowly is better than crashing at startup), but is definitely not what we want in tests. This change introduces a PROTOCOL_BUFFERS_PYTHON_INTERNAL_FORCE_IMPLEMENTATION environment variable to prevent falling back to the pure Python implementation when the requested 'cpp' or 'upb' implementation fails to import. The upb/cpp tests are updated to set this variable, ensuring tests fail explicitly if their expected backend is missing. The new variable has "INTERNAL" in the name so that it is not subject to our breaking change policy. I wonder if we should consider changing the PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION variable to have this behavior by default, so that users can be assured that their requested backend will be used, or will fail loudly if it is not available. PiperOrigin-RevId: 976377381
Copyright 2008 Google LLC
Protocol Buffers (a.k.a., protobuf) are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. You can learn more about it in protobuf's documentation.
This README file contains protobuf installation instructions. To install protobuf, you need to install the protocol compiler (used to compile .proto files) and the protobuf runtime for your chosen programming language.
Most users will find working from supported releases to be the easiest path.
If you choose to work from the head revision of the main branch your build will occasionally be broken by source-incompatible changes and insufficiently-tested (and therefore broken) behavior.
If you are using C++ or otherwise need to build protobuf from source as a part of your project, you should pin to a release commit on a release branch.
This is because even release branches can experience some instability in between release commits.
Protobuf supports Bzlmod with Bazel 8 +. Users should specify a dependency on protobuf in their MODULE.bazel file as follows.
bazel_dep(name = "protobuf", version = <VERSION>)
Users can optionally override the repo name, such as for compatibility with WORKSPACE.
bazel_dep(name = "protobuf", version = <VERSION>, repo_name = "com_google_protobuf")
Users can also add the following to their legacy WORKSPACE file.
Note that with the release of 30.x there are a few more load statements to properly set up rules_java and rules_python.
http_archive(
name = "com_google_protobuf",
strip_prefix = "protobuf-VERSION",
sha256 = ...,
url = ...,
)
load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
protobuf_deps()
load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
rules_java_dependencies()
load("@rules_java//java:repositories.bzl", "rules_java_toolchains")
rules_java_toolchains()
load("@rules_python//python:repositories.bzl", "py_repositories")
py_repositories()
The protobuf compiler is written in C++. If you are using C++, please follow the C++ Installation Instructions to install protoc along with the C++ runtime.
For non-C++ users, the simplest way to install the protocol compiler is to download a pre-built binary from our GitHub release page.
In the downloads section of each release, you can find pre-built binaries in zip packages: protoc-$VERSION-$PLATFORM.zip. It contains the protoc binary as well as a set of standard .proto files distributed along with protobuf.
If you are looking for an old version that is not available in the release page, check out the Maven repository.
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If you would like to build protoc binary from source, see the C++ Installation Instructions.
Protobuf supports several different programming languages. For each programming language, you can find instructions in the corresponding source directory about how to install protobuf runtime for that specific language:
| Language | Source |
|---|---|
| C++ (include C++ runtime and protoc) | src |
| Java | java |
| Python | python |
| Objective-C | objectivec |
| C# | csharp |
| Ruby | ruby |
| Go | protocolbuffers/protobuf-go |
| PHP | php |
| Dart | dart-lang/protobuf |
| JavaScript | protocolbuffers/protobuf-javascript |
The best way to learn how to use protobuf is to follow the tutorials in our developer guide.
If you want to learn from code examples, take a look at the examples in the examples directory.
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