internal: simplify ExtensionInfo initialization

This CL:
* Make the meaning of impl/ExtensionInfo.goType consistent. Before,
it was sometimes a T and other times a []T depending on the current
state of initialization. Change it so that it is the constructor's
responsibility to pass in a []T if it is repeated.
* Make internal/filetype responsible for constructing a []T for
repeated extension fields.
* Makes filedesc/Extension.Cardinality one of the eagerly initialized
pieces of information since it is useful to internal/filetype.
* Unify ExtensionInfo.desc and ExtensionInfo.tdesc.ExtensionField,
which held the same information.
* Remove the internal implementation for impl.X.ExtensionDescFromType
since we are dropping support for this from v1.

Change-Id: Ie95c4de66cd674c1d886da4f63b133b7d763c7ef
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/195777
Reviewed-by: Damien Neil <dneil@google.com>
9 files changed
tree: 48d654c70d67430f77df1da22ce87cefdd9e7111
  1. benchmarks/
  2. cmd/
  3. compiler/
  4. encoding/
  5. internal/
  6. proto/
  7. reflect/
  8. runtime/
  9. testing/
  10. types/
  11. .gitignore
  12. .travis.yml
  13. AUTHORS
  14. CONTRIBUTING.md
  15. CONTRIBUTORS
  16. go.mod
  17. go.sum
  18. integration_test.go
  19. LICENSE
  20. PATENTS
  21. README.md
  22. regenerate.bash
  23. release.bash
  24. test.bash
README.md

Next Generation Go Protocol Buffers

WARNING: This repository is in active development. There are no guarantees about API stability. Breaking changes will occur until a stable release is made and announced.

This repository is for the development of the next major Go implementation of protocol buffers. This library makes breaking API changes relative to the existing Go protobuf library. Of particular note, this API aims to make protobuf reflection a first-class feature of the API and implements the protobuf ecosystem in terms of reflection.

Design Documents

List of relevant design documents:

Contributing

We appreciate community contributions. See CONTRIBUTING.md.

Reporting Issues

Issues regarding the new API can be filed at github.com/golang/protobuf. Please use a APIv2: prefix in the title to make it clear that the issue is regarding the new API work.