golang Protobuf學習
阿新 • • 發佈：2018-01-26
byte 編輯器 devel ike des 生成 const version pty protobuf是一種高效的數據傳輸格式（Google‘s data interchange format），且與語言無關，protobuf和json是基於http服務中最常見的兩種數據格式。今天來學習基於golang的protobuf相關內容。
google protocol buffer: https://developers.google.com/protocol-buffers/
golang 官方提供的protobuf支持插件:https://github.com/golang/protobuf
要想使用protobuf，需要4步：
- 下載安裝google protocol buffer 編輯器:https://github.com/google/protobuf/releases/tag/v3.5.1
- 下載安裝golang protobuf plugin:https://github.com/golang/protobuf
使用go tools安裝:go get -u github.com/golang/protobuf/protoc-gen-go - 按照protobuf 語法規則編寫.proto文件
- 將proto文件編譯成golang代碼模型
protoc -I=$SRC_DIR --go_out=$DST_DIR $SRC_DIR/addressbook.proto
-IPATH, --proto_path=PATH 指定import路徑
--go_out 指定生成go代碼路徑（同理--java_out是指定java生成路徑）??
下面以一個實際例子來說明：
addressbook.proto
syntax = "proto3"; package test.protobuf.tutorial; message Person{ string name = 1;//姓名 int32 id = 2;//id編號 string email = 3;//郵箱 enum PhoneType { //枚舉類型（電話類型） MOBILE = 0; HOME = 1; WORK = 2; } message PhoneNumber{ string number = 1; PhoneType type = 2; } repeated PhoneNumber phones = 4; //repeated可理解為動態數組 } // Our address book file is just one of these. message AddressBook { repeated Person people = 1; }
編譯生成go文件。protoc會調用protoc-go-gen來生成go文件
.
├── addressbook.proto
└── src
└── addressbook.pb.go
protoc --go_out=./src addressbook.proto
addressbook.pb.go
// Code generated by protoc-gen-go. DO NOT EDIT.
// source: addressbook.proto
/*
Package test_protobuf_tutorial is a generated protocol buffer package.
It is generated from these files:
addressbook.proto
It has these top-level messages:
Person
AddressBook
*/
package test_protobuf_tutorial
import proto "github.com/golang/protobuf/proto"
import fmt "fmt"
import math "math"
// Reference imports to suppress errors if they are not otherwise used.
var _ = proto.Marshal
var _ = fmt.Errorf
var _ = math.Inf
// This is a compile-time assertion to ensure that this generated file
// is compatible with the proto package it is being compiled against.
// A compilation error at this line likely means your copy of the
// proto package needs to be updated.
const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
type Person_PhoneType int32
const (
Person_MOBILE Person_PhoneType = 0
Person_HOME Person_PhoneType = 1
Person_WORK Person_PhoneType = 2
)
var Person_PhoneType_name = map[int32]string{
0: "MOBILE",
1: "HOME",
2: "WORK",
}
var Person_PhoneType_value = map[string]int32{
"MOBILE": 0,
"HOME": 1,
"WORK": 2,
}
func (x Person_PhoneType) String() string {
return proto.EnumName(Person_PhoneType_name, int32(x))
}
func (Person_PhoneType) EnumDescriptor() ([]byte, []int) { return fileDescriptor0, []int{0, 0} }
type Person struct {
Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
Id int32 `protobuf:"varint,2,opt,name=id" json:"id,omitempty"`
Email string `protobuf:"bytes,3,opt,name=email" json:"email,omitempty"`
Phones []*Person_PhoneNumber `protobuf:"bytes,4,rep,name=phones" json:"phones,omitempty"`
}
func (m *Person) Reset() { *m = Person{} }
func (m *Person) String() string { return proto.CompactTextString(m) }
func (*Person) ProtoMessage() {}
func (*Person) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
func (m *Person) GetName() string {
if m != nil {
return m.Name
}
return ""
}
func (m *Person) GetId() int32 {
if m != nil {
return m.Id
}
return 0
}
func (m *Person) GetEmail() string {
if m != nil {
return m.Email
}
return ""
}
func (m *Person) GetPhones() []*Person_PhoneNumber {
if m != nil {
return m.Phones
}
return nil
}
type Person_PhoneNumber struct {
Number string `protobuf:"bytes,1,opt,name=number" json:"number,omitempty"`
Type Person_PhoneType `protobuf:"varint,2,opt,name=type,enum=test.protobuf.tutorial.Person_PhoneType" json:"type,omitempty"`
}
func (m *Person_PhoneNumber) Reset() { *m = Person_PhoneNumber{} }
func (m *Person_PhoneNumber) String() string { return proto.CompactTextString(m) }
func (*Person_PhoneNumber) ProtoMessage() {}
func (*Person_PhoneNumber) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0, 0} }
func (m *Person_PhoneNumber) GetNumber() string {
if m != nil {
return m.Number
}
return ""
}
func (m *Person_PhoneNumber) GetType() Person_PhoneType {
if m != nil {
return m.Type
}
return Person_MOBILE
}
// Our address book file is just one of these.
type AddressBook struct {
People []*Person `protobuf:"bytes,1,rep,name=people" json:"people,omitempty"`
}
func (m *AddressBook) Reset() { *m = AddressBook{} }
func (m *AddressBook) String() string { return proto.CompactTextString(m) }
func (*AddressBook) ProtoMessage() {}
func (*AddressBook) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
func (m *AddressBook) GetPeople() []*Person {
if m != nil {
return m.People
}
return nil
}
func init() {
proto.RegisterType((*Person)(nil), "test.protobuf.tutorial.Person")
proto.RegisterType((*Person_PhoneNumber)(nil), "test.protobuf.tutorial.Person.PhoneNumber")
proto.RegisterType((*AddressBook)(nil), "test.protobuf.tutorial.AddressBook")
proto.RegisterEnum("test.protobuf.tutorial.Person_PhoneType", Person_PhoneType_name, Person_PhoneType_value)
}
func init() { proto.RegisterFile("addressbook.proto", fileDescriptor0) }
var fileDescriptor0 = []byte{
// 265 bytes of a gzipped FileDescriptorProto
0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x90, 0xc1, 0x4b, 0xbc, 0x50,
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0x81, 0x87, 0x0d, 0x3a, 0x75, 0x49, 0x10, 0x8a, 0xda, 0x5c, 0x1e, 0x41, 0x67, 0xcd, 0x89, 0x64,
0xd5, 0x79, 0xe8, 0xf3, 0xb0, 0xff, 0x49, 0x7f, 0x6e, 0xf8, 0x94, 0xe8, 0x10, 0xd1, 0xed, 0x3b,
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0xfc, 0xb0, 0x41, 0xec, 0xa9, 0xeb, 0xb9, 0x45, 0x04, 0xa7, 0xcd, 0x1b, 0xf2, 0xad, 0xc0, 0x8a,
0x56, 0xd2, 0x64, 0x5c, 0x83, 0x5d, 0x95, 0xbe, 0x1d, 0x58, 0xd1, 0x52, 0xda, 0x55, 0x89, 0xa7,
0xb0, 0xa4, 0x26, 0xaf, 0x6a, 0x7f, 0x61, 0xa0, 0xa9, 0xc0, 0x04, 0x84, 0x7a, 0xe7, 0x96, 0x7a,
0xdf, 0x09, 0x16, 0x91, 0xbb, 0xbd, 0x88, 0x7f, 0xb6, 0xc5, 0x93, 0x29, 0xde, 0x8f, 0xf0, 0xd3,
0xd0, 0x14, 0xd4, 0xc9, 0x79, 0xf2, 0xec, 0x15, 0xdc, 0x6f, 0x6d, 0xdc, 0x80, 0x68, 0x4d, 0x9a,
0xd7, 0x99, 0x2b, 0xbc, 0x01, 0x47, 0x1f, 0x15, 0x99, 0x95, 0xd6, 0xdb, 0xe8, 0x2f, 0xa2, 0xe7,
0xa3, 0x22, 0x69, 0xa6, 0xc2, 0x4b, 0x58, 0x7d, 0xb5, 0x10, 0x40, 0xec, 0xb2, 0xe4, 0xfe, 0x31,
0xf5, 0xfe, 0xe1, 0x7f, 0x70, 0xee, 0xb2, 0x5d, 0xea, 0x59, 0x63, 0x7a, 0xc9, 0xe4, 0x83, 0x67,
0x87, 0x29, 0xb8, 0xb7, 0xd3, 0x1f, 0x13, 0xe6, 0x03, 0x5e, 0x83, 0x50, 0xc4, 0xaa, 0x1e, 0x1f,
0x34, 0x1e, 0x79, 0xfe, 0xbb, 0x5b, 0xce, 0x74, 0x21, 0x0c, 0x71, 0xf5, 0x19, 0x00, 0x00, 0xff,
0xff, 0x38, 0xba, 0x26, 0x8c, 0x95, 0x01, 0x00, 0x00,
} ok,生成模型代碼後，我們就可以使用protobuf協議來對數據進行編解碼了
//將數據編碼成protobuf 二進制格式--Writing a Message
func EncodeAddressBook (book *pb.AddressBook)(out []byte, err error) {
// Write the new address book back to disk.
out, err = proto.Marshal(book)
if err != nil {
log.Println("Failed to encode address book:", err)
return nil,err
}
if err := ioutil.WriteFile("addressbook_proto.data", out, 0644); err != nil {
log.Fatalln("Failed to write address book:", err)
return nil,err
}
fmt.Println("[Debug]: ", out)
return
} //將二進制數據解碼為golang 數據結構 --Reading a Message
func DecodeAddressBook(in []byte) (book *pb.AddressBook, err error){
// Read the existing address book.
book = &pb.AddressBook{}
if err := proto.Unmarshal(in, book); err != nil {
log.Println("Failed to parse address book:", err)
return nil,err
}
return
}
proto buffer 3 指南:https://developers.google.com/protocol-buffers/docs/proto3
Go Generated Code Guide:https://developers.google.com/protocol-buffers/docs/reference/go-generated
golang Protobuf學習