internal/impl: lazy extension decoding

Historically, extensions have been placed in the unknown fields section
of the unmarshaled message and decoded lazily on demand. The current
unmarshal implementation decodes extensions eagerly at unmarshal time,
permitting errors to be immediately reported and correctly detecting
unset required fields in extension values.

Add support for validated lazy extension decoding, where the extension
value is fully validated at initial unmarshal time but the fully
unmarshaled message is only created lazily.

Make this behavior conditional on the protolegacy flag for now.

Change-Id: I9d742496a4bd4dafea83fca8619cd6e8d7e65bc3
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/216764
Reviewed-by: Joe Tsai <joetsai@google.com>
5 files changed
tree: 1c0f6173156ebc1a82be79d309098ec59e2405ad
  1. cmd/
  2. compiler/
  3. encoding/
  4. internal/
  5. proto/
  6. reflect/
  7. runtime/
  8. testing/
  9. types/
  10. .gitignore
  11. .travis.yml
  12. AUTHORS
  13. CONTRIBUTING.md
  14. CONTRIBUTORS
  15. go.mod
  16. go.sum
  17. integration_test.go
  18. LICENSE
  19. PATENTS
  20. README.md
  21. regenerate.bash
  22. release.bash
  23. 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.