+++ /dev/null
-# Go support for Protocol Buffers
-
-[](https://travis-ci.org/golang/protobuf)
-[](https://godoc.org/github.com/golang/protobuf)
-
-Google's data interchange format.
-Copyright 2010 The Go Authors.
-https://github.com/golang/protobuf
-
-This package and the code it generates requires at least Go 1.4.
-
-This software implements Go bindings for protocol buffers. For
-information about protocol buffers themselves, see
- https://developers.google.com/protocol-buffers/
-
-## Installation ##
-
-To use this software, you must:
-- Install the standard C++ implementation of protocol buffers from
- https://developers.google.com/protocol-buffers/
-- Of course, install the Go compiler and tools from
- https://golang.org/
- See
- https://golang.org/doc/install
- for details or, if you are using gccgo, follow the instructions at
- https://golang.org/doc/install/gccgo
-- Grab the code from the repository and install the proto package.
- The simplest way is to run `go get -u github.com/golang/protobuf/protoc-gen-go`.
- The compiler plugin, protoc-gen-go, will be installed in $GOBIN,
- defaulting to $GOPATH/bin. It must be in your $PATH for the protocol
- compiler, protoc, to find it.
-
-This software has two parts: a 'protocol compiler plugin' that
-generates Go source files that, once compiled, can access and manage
-protocol buffers; and a library that implements run-time support for
-encoding (marshaling), decoding (unmarshaling), and accessing protocol
-buffers.
-
-There is support for gRPC in Go using protocol buffers.
-See the note at the bottom of this file for details.
-
-There are no insertion points in the plugin.
-
-
-## Using protocol buffers with Go ##
-
-Once the software is installed, there are two steps to using it.
-First you must compile the protocol buffer definitions and then import
-them, with the support library, into your program.
-
-To compile the protocol buffer definition, run protoc with the --go_out
-parameter set to the directory you want to output the Go code to.
-
- protoc --go_out=. *.proto
-
-The generated files will be suffixed .pb.go. See the Test code below
-for an example using such a file.
-
-
-The package comment for the proto library contains text describing
-the interface provided in Go for protocol buffers. Here is an edited
-version.
-
-==========
-
-The proto package converts data structures to and from the
-wire format of protocol buffers. It works in concert with the
-Go source code generated for .proto files by the protocol compiler.
-
-A summary of the properties of the protocol buffer interface
-for a protocol buffer variable v:
-
- - Names are turned from camel_case to CamelCase for export.
- - There are no methods on v to set fields; just treat
- them as structure fields.
- - There are getters that return a field's value if set,
- and return the field's default value if unset.
- The getters work even if the receiver is a nil message.
- - The zero value for a struct is its correct initialization state.
- All desired fields must be set before marshaling.
- - A Reset() method will restore a protobuf struct to its zero state.
- - Non-repeated fields are pointers to the values; nil means unset.
- That is, optional or required field int32 f becomes F *int32.
- - Repeated fields are slices.
- - Helper functions are available to aid the setting of fields.
- Helpers for getting values are superseded by the
- GetFoo methods and their use is deprecated.
- msg.Foo = proto.String("hello") // set field
- - Constants are defined to hold the default values of all fields that
- have them. They have the form Default_StructName_FieldName.
- Because the getter methods handle defaulted values,
- direct use of these constants should be rare.
- - Enums are given type names and maps from names to values.
- Enum values are prefixed with the enum's type name. Enum types have
- a String method, and a Enum method to assist in message construction.
- - Nested groups and enums have type names prefixed with the name of
- the surrounding message type.
- - Extensions are given descriptor names that start with E_,
- followed by an underscore-delimited list of the nested messages
- that contain it (if any) followed by the CamelCased name of the
- extension field itself. HasExtension, ClearExtension, GetExtension
- and SetExtension are functions for manipulating extensions.
- - Oneof field sets are given a single field in their message,
- with distinguished wrapper types for each possible field value.
- - Marshal and Unmarshal are functions to encode and decode the wire format.
-
-When the .proto file specifies `syntax="proto3"`, there are some differences:
-
- - Non-repeated fields of non-message type are values instead of pointers.
- - Enum types do not get an Enum method.
-
-Consider file test.proto, containing
-
-```proto
- syntax = "proto2";
- package example;
-
- enum FOO { X = 17; };
-
- message Test {
- required string label = 1;
- optional int32 type = 2 [default=77];
- repeated int64 reps = 3;
- optional group OptionalGroup = 4 {
- required string RequiredField = 5;
- }
- }
-```
-
-To create and play with a Test object from the example package,
-
-```go
- package main
-
- import (
- "log"
-
- "github.com/golang/protobuf/proto"
- "path/to/example"
- )
-
- func main() {
- test := &example.Test {
- Label: proto.String("hello"),
- Type: proto.Int32(17),
- Reps: []int64{1, 2, 3},
- Optionalgroup: &example.Test_OptionalGroup {
- RequiredField: proto.String("good bye"),
- },
- }
- data, err := proto.Marshal(test)
- if err != nil {
- log.Fatal("marshaling error: ", err)
- }
- newTest := &example.Test{}
- err = proto.Unmarshal(data, newTest)
- if err != nil {
- log.Fatal("unmarshaling error: ", err)
- }
- // Now test and newTest contain the same data.
- if test.GetLabel() != newTest.GetLabel() {
- log.Fatalf("data mismatch %q != %q", test.GetLabel(), newTest.GetLabel())
- }
- // etc.
- }
-```
-
-## Parameters ##
-
-To pass extra parameters to the plugin, use a comma-separated
-parameter list separated from the output directory by a colon:
-
-
- protoc --go_out=plugins=grpc,import_path=mypackage:. *.proto
-
-
-- `import_prefix=xxx` - a prefix that is added onto the beginning of
- all imports. Useful for things like generating protos in a
- subdirectory, or regenerating vendored protobufs in-place.
-- `import_path=foo/bar` - used as the package if no input files
- declare `go_package`. If it contains slashes, everything up to the
- rightmost slash is ignored.
-- `plugins=plugin1+plugin2` - specifies the list of sub-plugins to
- load. The only plugin in this repo is `grpc`.
-- `Mfoo/bar.proto=quux/shme` - declares that foo/bar.proto is
- associated with Go package quux/shme. This is subject to the
- import_prefix parameter.
-
-## gRPC Support ##
-
-If a proto file specifies RPC services, protoc-gen-go can be instructed to
-generate code compatible with gRPC (http://www.grpc.io/). To do this, pass
-the `plugins` parameter to protoc-gen-go; the usual way is to insert it into
-the --go_out argument to protoc:
-
- protoc --go_out=plugins=grpc:. *.proto
-
-## Compatibility ##
-
-The library 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 security issues.
-- Unspecified behavior. There are some aspects of the Protocol Buffers
- specification that are undefined. Programs that depend on such unspecified
- behavior may break in future releases.
-- Specification errors or changes. If it becomes necessary to address an
- inconsistency, incompleteness, or change in the Protocol Buffers
- specification, resolving the issue could affect the meaning or legality of
- existing programs. We reserve the right to address such issues, including
- updating the implementations.
-- Bugs. If the library has a bug that violates the specification, a program
- that depends on the buggy behavior may break if the bug is fixed. We reserve
- the right to fix such bugs.
-- Adding methods or fields to generated structs. These may conflict with field
- names that already exist in a schema, causing applications to break. When the
- code generator encounters a field in the schema that would collide with a
- generated field or method name, the code generator will append an underscore
- to the generated field or method name.
-- Adding, removing, or changing methods or fields in generated structs that
- start with `XXX`. These parts of the generated code are exported out of
- necessity, but should not be considered part of the public API.
-- Adding, removing, or changing unexported symbols in generated code.
-
-Any breaking changes outside of these will be announced 6 months in advance to
-protobuf@googlegroups.com.
-
-You should, whenever possible, use generated code created by the `protoc-gen-go`
-tool built at the same commit as the `proto` package. The `proto` package
-declares package-level constants in the form `ProtoPackageIsVersionX`.
-Application code and generated code may depend on one of these constants to
-ensure that compilation will fail if the available version of the proto library
-is too old. Whenever we make a change to the generated code that requires newer
-library support, in the same commit we will increment the version number of the
-generated code and declare a new package-level constant whose name incorporates
-the latest version number. Removing a compatibility constant is considered a
-breaking change and would be subject to the announcement policy stated above.
-
-The `protoc-gen-go/generator` package exposes a plugin interface,
-which is used by the gRPC code generation. This interface is not
-supported and is subject to incompatible changes without notice.
OSDN Git Service
