commit | b6405bd782c6647995056c9a4864adf8e726a84a | [log] [tgz] |
---|---|---|
author | Joe Tsai <joetsai@digital-static.net> | Thu Nov 15 14:44:37 2018 -0800 |
committer | Joe Tsai <thebrokentoaster@gmail.com> | Wed Dec 05 19:32:12 2018 +0000 |
tree | 38c5c08d23d12e5532ea1dd254bd0074ef75b18d | |
parent | eeca8bb946adf3da3b20fc65f998c7af4772330c [diff] |
cmd/protoc-gen-go: add support for protobuf reflection Implement support in protoc-gen-go for generating messages and enums that satisfy the v2 protobuf reflection interfaces. Specifically, the following are added: * top-level variable representing the file descriptor * ProtoReflect method on enums (to implement protoV2.Enum) * ProtoReflect method on messages (to implement protoV2.Message) The following are not supported yet: * resolving transitive dependencies for file imports * Extension descriptors * Service descriptors The implementation approach creates a single array for all the message and enum declarations and references sections of that array to complete dependencies. Since protobuf declarations can form a graph (a message may depend on itself), it is difficult to construct a graph as a single literal. One way is to use placeholder descriptors, but that is not efficient as it requires encoding the full name of each dependent enum and message and then later resolving it; thus, both expanding the binary size and also increasing initialization cost. Instead, we add a prototype.{Enum,Message}.Reference method to obtain a descriptor reference for the purposes for satisfying dependencies. As such, nested declarations and dependencies are populated in an init function. Other changes to support the implementation: * Added a protoimpl package to expose the MessageType type and also the MessageTypeOf and EnumTypeOf helper functions. * Added a protogen.File.GoIdent field to provide a suggested variable name for the file descriptor. * Added prototype.{Enum,Message}.Reference that provides a descriptor reference for the purposes for satisfying cyclic dependencies. * Added protoreflect.{Syntax,Cardinality,Kind}.GoString to obtain a Go source identifier that represents the given constant. Change-Id: I9455764882dee6ad10f251901e7d419091e8bf1d Reviewed-on: https://go-review.googlesource.com/c/150074 Reviewed-by: Damien Neil <dneil@google.com>
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.
List of relevant design documents:
We appreciate community contributions. See CONTRIBUTING.md.
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.