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commit975ea595f894ef2a79917101f27e1491a448bf2c[log] [tgz]
authorJoshua Haberman <jhaberman@gmail.com>Wed Sep 15 22:06:52 2021 -0700
committerJoshua Haberman <jhaberman@gmail.com>Wed Sep 15 22:06:52 2021 -0700
treea1547f4a7d481f09d8e26c44cfaa6fb7b1cbe705
parenta52fb799652fa7ac9546779ec1c6eb8f64715a4d [diff]
Fleshed out DESIGN.md a bit more.
2 files changed
tree: a1547f4a7d481f09d8e26c44cfaa6fb7b1cbe705
  1. .bazelci/
  2. .github/
  3. bazel/
  4. benchmarks/
  5. cmake/
  6. python/
  7. tests/
  8. third_party/
  9. upb/
  10. upbc/
  11. .bazelignore
  12. .bazelrc
  13. .gitignore
  14. BUILD
  15. CONTRIBUTING.md
  16. DESIGN.md
  17. LICENSE
  18. README.md
  19. WORKSPACE
README.md

μpb: small, fast C protos

μpb (often written ‘upb’) is a small protobuf implementation written in C.

upb is the core runtime for protobuf languages extensions in Ruby, PHP, and (soon) Python.

While upb offers a C API, the C API & ABI are not stable. For this reason, upb is not generally offered as a C library for direct consumption, and there are no releases.

Features

upb has comparable speed to protobuf C++, but is an order of magnitude smaller in code size.

Like the main protobuf implementation in C++, it supports:

  • a generated API (in C)
  • reflection
  • binary & JSON wire formats
  • text format serialization
  • all standard features of protobufs (oneofs, maps, unknown fields, etc.)
  • full conformance with the protobuf conformance tests

upb also supports some features that C++ does not:

  • optional reflection: generated messages are agnostic to whether reflection will be linked in or not.
  • no global state: no pre-main registration or other global state.
  • fast reflection-based parsing: messages loaded at runtime parse just as fast as compiled-in messages.

However there are some features it does not support:

  • proto2 extensions (coming soon!)
  • text format parsing
  • deep descriptor verification: upb's descriptor validation is not as exhaustive as protoc.

Install

For Ruby, use RubyGems:

$ gem install google-protobuf

For PHP, use PECL:

$ sudo pecl install protobuf

Contributing

Please see CONTRIBUTING.md.