Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/cloudwan/goten-protobuf

Go Protobuf fork
https://github.com/cloudwan/goten-protobuf

Last synced: 8 days ago
JSON representation

Go Protobuf fork

Awesome Lists containing this project

README 

        
# Go support for Protocol Buffers



[![Go Reference](https://pkg.go.dev/badge/google.golang.org/protobuf.svg)](https://pkg.go.dev/google.golang.org/protobuf)

[![Build Status](https://travis-ci.org/protocolbuffers/protobuf-go.svg?branch=master)](https://travis-ci.org/protocolbuffers/protobuf-go)



This project hosts the Go implementation for

[protocol buffers](https://developers.google.com/protocol-buffers), which is a

language-neutral, platform-neutral, extensible mechanism for serializing

structured data. The protocol buffer language is a language for specifying the

schema for structured data. This schema is compiled into language specific

bindings. This project provides both a tool to generate Go code for the

protocol buffer language, and also the runtime implementation to handle

serialization of messages in Go. See the

[protocol buffer developer guide](https://developers.google.com/protocol-buffers/docs/overview)

for more information about protocol buffers themselves.



This project is comprised of two components:



*   Code generator: The

    [`protoc-gen-go`](https://pkg.go.dev/google.golang.org/protobuf/cmd/protoc-gen-go)

    tool is a compiler plugin to `protoc`, the protocol buffer compiler. It

    augments the `protoc` compiler so that it knows how to

    [generate Go specific code for a given `.proto` file](https://developers.google.com/protocol-buffers/docs/reference/go-generated).



*   Runtime library: The

    [`protobuf`](https://pkg.go.dev/mod/google.golang.org/protobuf) module

    contains a set of Go packages that form the runtime implementation of

    protobufs in Go. This provides the set of interfaces that

    [define what a message is](https://pkg.go.dev/google.golang.org/protobuf/reflect/protoreflect)

    and functionality to serialize message in various formats (e.g.,

    [wire](https://pkg.go.dev/google.golang.org/protobuf/proto),

    [JSON](https://pkg.go.dev/google.golang.org/protobuf/encoding/protojson),

    and

    [text](https://pkg.go.dev/google.golang.org/protobuf/encoding/prototext)).



See the

[developer guide for protocol buffers in Go](https://developers.google.com/protocol-buffers/docs/gotutorial)

for a general guide for how to get started using protobufs in Go.



This project is the second major revision of the Go protocol buffer API

implemented by the

[`google.golang.org/protobuf`](https://pkg.go.dev/mod/google.golang.org/protobuf)

module. The first major version is implemented by the

[`github.com/golang/protobuf`](https://pkg.go.dev/mod/github.com/golang/protobuf)

module.



## Package index



Summary of the packages provided by this module:



*   [`proto`](https://pkg.go.dev/google.golang.org/protobuf/proto): Package

    `proto` provides functions operating on protobuf messages such as cloning,

    merging, and checking equality, as well as binary serialization.

*   [`encoding/protojson`](https://pkg.go.dev/google.golang.org/protobuf/encoding/protojson):

    Package `protojson` serializes protobuf messages as JSON.

*   [`encoding/prototext`](https://pkg.go.dev/google.golang.org/protobuf/encoding/prototext):

    Package `prototext` serializes protobuf messages as the text format.

*   [`encoding/protowire`](https://pkg.go.dev/google.golang.org/protobuf/encoding/protowire):

    Package `protowire` parses and formats the low-level raw wire encoding. Most

    users should use package `proto` to serialize messages in the wire format.

*   [`reflect/protoreflect`](https://pkg.go.dev/google.golang.org/protobuf/reflect/protoreflect):

    Package `protoreflect` provides interfaces to dynamically manipulate

    protobuf messages.

*   [`reflect/protoregistry`](https://pkg.go.dev/google.golang.org/protobuf/reflect/protoregistry):

    Package `protoregistry` provides data structures to register and lookup

    protobuf descriptor types.

*   [`reflect/protodesc`](https://pkg.go.dev/google.golang.org/protobuf/reflect/protodesc):

    Package `protodesc` provides functionality for converting

    `descriptorpb.FileDescriptorProto` messages to/from the reflective

    `protoreflect.FileDescriptor`.

*   [`testing/protocmp`](https://pkg.go.dev/google.golang.org/protobuf/testing/protocmp):

    Package `protocmp` provides protobuf specific options for the `cmp` package.

*   [`testing/protopack`](https://pkg.go.dev/google.golang.org/protobuf/testing/protopack):

    Package `protopack` aids manual encoding and decoding of the wire format.

*   [`testing/prototest`](https://pkg.go.dev/google.golang.org/protobuf/testing/prototest):

    Package `prototest` exercises the protobuf reflection implementation for

    concrete message types.

*   [`types/dynamicpb`](https://pkg.go.dev/google.golang.org/protobuf/types/dynamicpb):

    Package `dynamicpb` creates protobuf messages at runtime from protobuf

    descriptors.

*   [`types/known/anypb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/anypb):

    Package `anypb` is the generated package for `google/protobuf/any.proto`.

*   [`types/known/timestamppb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/timestamppb):

    Package `timestamppb` is the generated package for

    `google/protobuf/timestamp.proto`.

*   [`types/known/durationpb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/durationpb):

    Package `durationpb` is the generated package for

    `google/protobuf/duration.proto`.

*   [`types/known/wrapperspb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/wrapperspb):

    Package `wrapperspb` is the generated package for

    `google/protobuf/wrappers.proto`.

*   [`types/known/structpb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/structpb):

    Package `structpb` is the generated package for

    `google/protobuf/struct.proto`.

*   [`types/known/fieldmaskpb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/fieldmaskpb):

    Package `fieldmaskpb` is the generated package for

    `google/protobuf/field_mask.proto`.

*   [`types/known/apipb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/apipb):

    Package `apipb` is the generated package for

    `google/protobuf/api.proto`.

*   [`types/known/typepb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/typepb):

    Package `typepb` is the generated package for

    `google/protobuf/type.proto`.

*   [`types/known/sourcecontextpb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/sourcecontextpb):

    Package `sourcecontextpb` is the generated package for

    `google/protobuf/source_context.proto`.

*   [`types/known/emptypb`](https://pkg.go.dev/google.golang.org/protobuf/types/known/emptypb):

    Package `emptypb` is the generated package for

    `google/protobuf/empty.proto`.

*   [`types/descriptorpb`](https://pkg.go.dev/google.golang.org/protobuf/types/descriptorpb):

    Package `descriptorpb` is the generated package for

    `google/protobuf/descriptor.proto`.

*   [`types/pluginpb`](https://pkg.go.dev/google.golang.org/protobuf/types/pluginpb):

    Package `pluginpb` is the generated package for

    `google/protobuf/compiler/plugin.proto`.

*   [`compiler/protogen`](https://pkg.go.dev/google.golang.org/protobuf/compiler/protogen):

    Package `protogen` provides support for writing protoc plugins.

*   [`cmd/protoc-gen-go`](https://pkg.go.dev/google.golang.org/protobuf/cmd/protoc-gen-go):

    The `protoc-gen-go` binary is a protoc plugin to generate a Go protocol

    buffer package.



## Reporting issues



The issue tracker for this project is currently located at

[golang/protobuf](https://github.com/golang/protobuf/issues).



Please report any issues there with a sufficient description of the bug or

feature request. Bug reports should ideally be accompanied by a minimal

reproduction of the issue. Irreproducible bugs are difficult to diagnose and fix

(and likely to be closed after some period of time). Bug reports must specify

the version of the

[Go protocol buffer module](https://github.com/protocolbuffers/protobuf-go/releases)

and also the version of the

[protocol buffer toolchain](https://github.com/protocolbuffers/protobuf/releases)

being used.



## Contributing



This project is open-source and accepts contributions. See the

[contribution guide](https://github.com/protocolbuffers/protobuf-go/blob/master/CONTRIBUTING.md)

for more information.



## Compatibility



This module and the generated code are expected to be stable over time. However,

we reserve the right to make breaking changes without notice for the following

reasons:



*   **Security:** A security issue in the specification or implementation may

    come to light whose resolution requires breaking compatibility. We reserve

    the right to address such issues.

*   **Unspecified behavior:** There are some aspects of the protocol buffer

    specification that are undefined. Programs that depend on unspecified

    behavior may break in future releases.

*   **Specification changes:** It may become necessary to address an

    inconsistency, incompleteness, or change in the protocol buffer

    specification, which may affect the behavior of existing programs. We

    reserve the right to address such changes.

*   **Bugs:** If a package has a bug that violates correctness, a program

    depending on the buggy behavior may break if the bug is fixed. We reserve

    the right to fix such bugs.

*   **Generated additions**: We reserve the right to add new declarations to

    generated Go packages of `.proto` files. This includes declared constants,

    variables, functions, types, fields in structs, and methods on types. This

    may break attempts at injecting additional code on top of what is generated

    by `protoc-gen-go`. Such practice is not supported by this project.

*   **Internal changes**: We reserve the right to add, modify, and remove

    internal code, which includes all unexported declarations, the

    [`protoc-gen-go/internal_gengo`](https://pkg.go.dev/google.golang.org/protobuf/cmd/protoc-gen-go/internal_gengo)

    package, the

    [`runtime/protoimpl`](https://pkg.go.dev/google.golang.org/protobuf/runtime/protoimpl?tab=doc)

    package, and all packages under

    [`internal`](https://pkg.go.dev/google.golang.org/protobuf/internal).



Any breaking changes outside of these will be announced 6 months in advance to

[[email protected]](https://groups.google.com/forum/#!forum/protobuf).



Users should use generated code produced by a version of

[`protoc-gen-go`](https://pkg.go.dev/google.golang.org/protobuf/cmd/protoc-gen-go)

that is identical to the runtime version provided by the

[protobuf module](https://pkg.go.dev/mod/google.golang.org/protobuf). This

project promises that the runtime remains compatible with code produced by a

version of the generator that is no older than 1 year from the version of the

runtime used, according to the release dates of the minor version. Generated

code is expected to use a runtime version that is at least as new as the

generator used to produce it. Generated code contains references to

[`protoimpl.EnforceVersion`](https://pkg.go.dev/google.golang.org/protobuf/runtime/protoimpl?tab=doc#EnforceVersion)

to statically ensure that the generated code and runtime do not drift

sufficiently far apart.



## Historical legacy



This project is the second major revision

([released in 2020](https://blog.golang.org/a-new-go-api-for-protocol-buffers))

of the Go protocol buffer API implemented by the

[`google.golang.org/protobuf`](https://pkg.go.dev/mod/google.golang.org/protobuf)

module. The first major version

([released publicly in 2010](https://blog.golang.org/third-party-libraries-goprotobuf-and))

is implemented by the

[`github.com/golang/protobuf`](https://pkg.go.dev/mod/github.com/golang/protobuf)

module.



The first version predates the release of Go 1 by several years. It has a long

history as one of the first core pieces of infrastructure software ever written

in Go. As such, the Go protobuf project was one of many pioneers for determining

what the Go language should even look like and what would eventually be

considered good design patterns and “idiomatic” Go (by simultaneously being

both positive and negative examples of it).



Consider the changing signature of the `proto.Unmarshal` function as an example

of Go language and library evolution throughout the life of this project:



```go

// 2007/09/25 - Conception of Go



// 2008/11/12

export func UnMarshal(r io.Read, pb_e reflect.Empty) *os.Error



// 2008/11/13

export func UnMarshal(buf *[]byte, pb_e reflect.Empty) *os.Error



// 2008/11/24

export func UnMarshal(buf *[]byte, pb_e interface{}) *os.Error



// 2008/12/18

export func UnMarshal(buf []byte, pb_e interface{}) *os.Error



// 2009/01/20

func UnMarshal(buf []byte, pb_e interface{}) *os.Error



// 2009/04/17

func UnMarshal(buf []byte, pb_e interface{}) os.Error



// 2009/05/22

func Unmarshal(buf []byte, pb_e interface{}) os.Error



// 2011/11/03

func Unmarshal(buf []byte, pb_e interface{}) error



// 2012/03/28 - Release of Go 1



// 2012/06/12

func Unmarshal(buf []byte, pb Message) error

```



These changes demonstrate the difficulty of determining what the right API is

for any new technology. It takes time multiplied by many users to determine what

is best; even then, “best” is often still somewhere over the horizon.



The change on June 6th, 2012 added a degree of type-safety to Go protobufs by

declaring a new interface that all protobuf messages were required to implement:



```go

type Message interface {

   Reset()

   String() string

   ProtoMessage()

}

```



This interface reduced the set of types that can be passed to `proto.Unmarshal`

from the universal set of all possible Go types to those with a special

`ProtoMessage` marker method. The intention of this change is to limit the

protobuf API to only operate on protobuf data types (i.e., protobuf messages).

For example, there is no sensible operation if a Go channel were passed to the

protobuf API as a channel cannot be serialized. The restricted interface would

prevent that.



This interface does not behaviorally describe what a protobuf message is, but

acts as a marker with an undocumented expectation that protobuf messages must be

a Go struct with a specific layout of fields with formatted tags. This

expectation is not statically enforced by the Go language, for it is an

implementation detail checked dynamically at runtime using Go reflection. Back

in 2012, the only types with this marker were those generated by

`protoc-gen-go`. Since `protoc-gen-go` would always generate messages with the

proper layout of fields, this was deemed an acceptable and dramatic improvement

over `interface{}`.



Over the next 10 years,

[use of Go would skyrocket](https://blog.golang.org/10years) and use of

protobufs in Go would skyrocket as well. With increased popularity also came

more diverse usages and requirements for Go protobufs and an increased number of

custom `proto.Message` implementations that were not generated by

`protoc-gen-go`.



The increasingly diverse ecosystem of Go types implementing the `proto.Message`

interface led to incompatibilities, which often occurred when:



*   **Passing custom `proto.Message` types to the protobuf APIs**: A concrete

    message implementation might work with some top-level functions (e.g.,

    `proto.Marshal`), but cause others (e.g., `proto.Equal`) to choke and panic.

    This occurs because the type only had partial support for being an actual

    message by only implementing the `proto.Marshaler` interface or having

    malformed struct field tags that happened to work with one function, but not

    another.



*   **Using Go reflection on any `proto.Message` types**: A common desire is to

    write general-purpose code that operates on any protobuf message. For

    example, a microservice might want to populate a `trace_id` field if it is

    present in a message. To accomplish this, one would use Go reflection to

    introspect the message type, and assume it were a pointer to a Go struct

    with a field named `TraceId` (as would be commonly produced by

    `protoc-gen-go`). If the concrete message type did not match this

    expectation, it either failed to work or even resulted in a panic. Such was

    the case for concrete message types that might be backed by a Go map instead

    of a Go struct.



Both of these issues are solved by following the idiom that _interfaces should

describe behavior, not data_. This means that the interface itself should

provide sufficient functionality through its methods that users can introspect

and interact with all aspects of a protobuf message through a principled API.

This feature is called _protobuf reflection_. Just as how Go reflection provides

an API for programmatically interacting with any arbitrary Go value, protobuf

reflection provides an API for programmatically interacting with any arbitrary

protobuf message.



Since an interface cannot be extended in a backwards compatible way, this

suggested the need for a new major version that defines a new `proto.Message`

interface:



```go

type Message interface {

    ProtoReflect() protoreflect.Message

}

```



The new

[`proto.Message`](https://pkg.go.dev/google.golang.org/protobuf/proto?tab=doc#Message)

interface contains a single `ProtoReflect` method that returns a

[`protoreflect.Message`](https://pkg.go.dev/google.golang.org/protobuf/reflect/protoreflect?tab=doc#Message),

which is a reflective view over a protobuf message. In addition to making a

breaking change to the `proto.Message` interface, we took this opportunity to

cleanup the supporting functionality that operate on a `proto.Message`, split up

complicated functionality apart into manageable packages, and to hide

implementation details away from the public API.



The goal for this major revision is to improve upon all the benefits of, while

addressing all the shortcomings of the old API. We hope that it will serve the

Go ecosystem well for the next 10 years and beyond.