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flutter / third_party / protobuf / df93cf65a2957bd0921462cb9d055c5b82a6d68b
commitdf93cf65a2957bd0921462cb9d055c5b82a6d68b[log] [tgz]
authorJoshua Haberman <haberman@google.com>Mon Apr 10 11:25:06 2023 -0700
committerCopybara-Service <copybara-worker@google.com>Mon Apr 10 11:25:42 2023 -0700
tree4491088b5ab1fc738a24bfc59f138f21a8ddc024
parent9d2b5d1716bf270b42baf251d61ddd63b8bbdd2a [diff]
Hide upb_MiniTableField.submsg_index with new `UPB_PRIVATE()` macro

The fields of upb_MiniTableField are intended to be internal-only, accessed only through public functions like `upb_MiniTable_GetSubMessageTable()`.  But over time, clients have started accessing many of these fields directly.  This is an easy mistake to make, as there is no clear signal that the fields should not be used in applications.  This makes the implementation difficult to change without breaking users.

The new `UPB_PRIVATE()` macro appends an unpredictable string to each private symbol.  This makes it very difficult to accidentally use a private symbol, since users would need to write something like `field->submsg_index_dont_copy_me__upb_internal_use_only`.  This is still possible to do, but it leaves a clear wart in the code showing that an an encapsulation break has occurred.  The `UPB_PRIVATE()` macro itself is defined in `port/def.inc`, which users cannot include directly.

Once we land this, more such CLs will follow for the other fields of `upb_MiniTable*`.  We will add inline functions as needed to provide the semantic functionality needed by users.

PiperOrigin-RevId: 523166901
13 files changed
tree: 4491088b5ab1fc738a24bfc59f138f21a8ddc024
  1. .bazelci/
  2. .github/
  3. bazel/
  4. benchmarks/
  5. cmake/
  6. docs/
  7. lua/
  8. protos/
  9. protos_generator/
  10. python/
  11. third_party/
  12. upb/
  13. upbc/
  14. .bazelignore
  15. .bazelrc
  16. .clang-format
  17. .gitignore
  18. BUILD
  19. CONTRIBUTING.md
  20. DESIGN.md
  21. LICENSE
  22. README.md
  23. 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 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, extensions, 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 a few features it does not support:

  • 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

For Python, use PyPI:

$ sudo pip install protobuf

Alternatively, you can build and install upb using vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install upb

The upb port in vcpkg is kept up to date by microsoft team members and community contributors.

If the version is out of date, please create an issue or pull request on the vcpkg repository.

Contributing

Please see CONTRIBUTING.md.