goprotobuf v1.4.0-rc.2 Release NotesRelease Date: 2020-02-29 // over 1 year ago
- Notable changes
- Upcoming breakage changes
🚀 This release of the
github.com/golang/protobufmodule introduces a number of significant changes relative to the previous minor release. In particular, this module is now implemented in terms of the new
google.golang.org/protobufmodule, which is the next major revision of Go bindings for protocol buffers. From this point onwards, most of the development effort for Go protobufs will be dedicated to the new module, with minimal changes being made to this module.
🚀 See the release notes for the new module for specific implementation details that may affect this release.
🚀 This release maintains backwards compatibility with previous releases of this module. Any observable changes in behavior are to fix bugs, change unspecified behavior, or to make behavior more compliant with the protobuf specification. The compatibility document provides us the freedom to make changes in these areas.
🚀 Wire serialization is now implemented in terms of the new
protopackage by calling out to the relevant functionality in that package (e.g.,
proto.Unmarshal). There should be no observable changes in behavior other what is mentioned elsewhere in the release notes (e.g., behavior around errors or nil values).
JSON and text serialization
🚀 The JSON and text format implementations have been ported to use protobuf reflection under the hood instead of relying on Go reflection. This provides flexibility as they can operate on any concrete message type that properly implements the new
The implementations do not use the new
prototextpackages in order to maintain a higher degree of backwards compatibility. Our analysis unfortunately showed us that too many tests rely on their output being stable by performing byte-for-byte comparisons. Even though the compatibility promise gives us the freedom to change the output, we have chosen not to do so for pragmatic reasons. The implementations are now functionally frozen (bugs and all) and will not receive future improvements. Users are encouraged to migrate to the
🚀 For a period of time, it is expected that the
protoc-gen-goplugin continues to generate code with dependencies on the well-known types in this module. The import paths for the well-known types are determined by the
go_packageoption specified in the
.protofiles. Since these files are managed by the main protocol buffers project, it will require a new release of the protobuf toolchain before the new import paths take effect. Depending on this module’s packages for well-known types is fine since they simply forward over to the new packages.
📦 In order for dynamic usages of protobufs to operate correctly, there must be a unified registry between this module and the new
protoregistrypackage is the primary registry for all protobuf files that are linked into a Go program. The registration functions (e.g.,
proto.RegisterType) in this package forward to the global registries in that module, and the lookup functions (e.g.,
proto.MessageType) in this package source from the global registry in that module.
🚀 Use of the
google.golang.org/protobufmodule for the underlying implementation means that semantics for nil values may have changed. See that module’s release notes for details.
🚀 A consequence of using the
google.golang.org/protobufmodule as the underlying implementation means that the text for some errors may change in trivial ways. This may break brittle tests depending on the error message. See that module’s release notes for details.
protoc-gen-goplugin in this module is now a thin wrapper over the
protoc-gen-goplugin in the
google.golang.org/protobufmodule. As a result, there are many changes to the generated code. See that module’s release notes for details. Users should migrate to use the new
protoc-gen-goplugin instead of the old one. Code generated by either plugin should be compatible with either module.
🚀 For backward compatibility purposes, the
protoc-gen-goplugin in this module continues to support generation of gRPC bindings, while the
protoc-gen-goplugin in the new module does not.
Upcoming breakage changes
Per the compatibility agreement for Go protobufs, we promise to make announcements about deliberate or potentially breaking changes 6 months in advance.
🚀 None of these changes are effective yet in this release.
🗄 Deprecation of
Descriptormethods on generated messages are deprecated and may be removed in the future.
descriptor.Messagetype is deprecated as fewer and fewer message types in the future will implement the
descriptor.Messageinterface. Existing usages should migrate to the new
📦 Removal of
generatorpackage is an internal implementation detail of
protoc-gen-goand existed before the internal package mechanism. It has long been exempt from the compatibility promise. A future release of this module will remove the package. Existing users must migrate to the new
compiler/protogenpackage, which is a stable API for implementing protoc plugins, or fork the existing
🚀 Similarly, the
grpcpackage is also an internal implementation detail of
protoc-gen-goand will also be deleted in a future release of this module.