golang基础protobuf使用

前些日子了解过python中protobuf，今天主要是来学习下如何使用golang来使用protobuf

python基础–protobuf的使用(一)
python基础—protobuf的使用(还未完成)


参考资料：
https://github.com/google/protobuf

以下的需要VPN翻墙

pythontutorial
https://developers.google.com/protocol-buffers/docs/pythontutorial

python-generated
https://developers.google.com/protocol-buffers/docs/reference/python-generated#extension

语言指南
https://developers.google.com/protocol-buffers/docs/proto3

API文档
https://developers.google.com/protocol-buffers/docs/reference/python/?hl=zh-cn

Mac安装

Protobuf是Protocol Buffers的简称，它是Google公司开发的一种数据描述语言，并于2008年对外开源。Protobuf刚开源时的定位类似于XML、JSON等数据描述语言，通过附带工具生成代码并实现将结构化数据序列化的功能。但是我们更关注的是Protobuf作为接口规范的描述语言，可以作为设计安全的跨语言PRC接口的基础工具。

Protobuf核心的工具集是C++语言开发的，在官方的protoc编译器中并不支持Go语言。要想基于上面的hello.proto文件生成相应的Go代码，需要安装相应的插件。首先是安装官方的protoc工具

Mac通过brew install protobuf安装即可

然后是安装针对Go语言的代码生成插件，可以通过go get github.com/golang/protobuf/protoc-gen-go命令安装

然后通过以下命令生成相应的Go代码：protoc ./hello.proto --go_out=./

摘自谷歌protobuf官网案例

参考链接https://github.com/iyongfei/protobuf/tree/master/examples

链接包含java、python、go等多种语言来实现的protobuf的例子，我今天就把go语言中的例子摘出来

首先看我的项目目录结构：

首先看下dressbook.proto

syntax = "proto3";
package go_protoc;
message Person {
string name = 1;
int32 id = 2;
string email = 3;
enum PhoneType {
MOBILE = 0;
HOME = 1;
WORK = 2;
}
message PhoneNumber {
string number = 1;
PhoneType type = 2;
}
repeated PhoneNumber phOnes= 4;
}
message AddressBook {
repeated Person people = 1;
}


然后通过 protoc ./dressbook.proto --go_out=./ 进行编译

zhiliaodeMBP:go_protoc zhiliao$ protoc ./dressbook.proto --go_out=./
zhiliaodeMBP:go_protoc zhiliao$ pwd
/Users/zhiliao/zhiliao/go/src/go_protoc
zhiliaodeMBP:go_protoc zhiliao$

我们来看下添加的功能add_person.go

package main
import (
"bufio"
"fmt"
"go_protoc"
"io"
"io/ioutil"
"log"
"os"
"strings"
"github.com/golang/protobuf/proto"
)
func promptForAddress(r io.Reader) (*go_protoc.Person, error) {
p := &go_protoc.Person{}
rd := bufio.NewReader(r)
fmt.Print("Enter person ID number: ")
if _, err := fmt.Fscanf(rd, "%dn", &p.Id); err != nil {
return p, err
}
fmt.Print("Enter name: ")
name, err := rd.ReadString('n')
if err != nil {
return p, err
}
p.Name = strings.TrimSpace(name)
fmt.Print("Enter email address (blank for none): ")
email, err := rd.ReadString('n')
if err != nil {
return p, err
}
p.Email = strings.TrimSpace(email)
for {
fmt.Print("Enter a phone number (or leave blank to finish): ")
phone, err := rd.ReadString('n')
if err != nil {
return p, err
}
phOne= strings.TrimSpace(phone)
if phOne== "" {
break
}
pn := &go_protoc.Person_PhoneNumber{
Number: phone,
}
fmt.Print("Is this a mobile, home, or work phone? ")
ptype, err := rd.ReadString('n')
if err != nil {
return p, err
}
ptype = strings.TrimSpace(ptype)
switch ptype {
case "mobile":
pn.Type = go_protoc.Person_MOBILE
case "home":
pn.Type = go_protoc.Person_HOME
case "work":
pn.Type = go_protoc.Person_WORK
default:
fmt.Printf("Unknown phone type %q. Using default.n", ptype)
}
p.Phones = append(p.Phones, pn)
}
return p, nil
}
func main() {
if len(os.Args) != 2 {
log.Fatalf("Usage: %s ADDRESS_BOOK_FILEn", os.Args[0])
}
fname := os.Args[1]
fmt.Println("osArgs-->>",os.Args[0],"-->>",os.Args[1])
in, err := ioutil.ReadFile(fname)
if err != nil {
if os.IsNotExist(err) {
fmt.Printf("%s: File not found. Creating new file.n", fname)
} else {
log.Fatalln("Error reading file:", err)
}
}
fmt.Println("osArgs after-->>")
book := &go_protoc.AddressBook{}
if err := proto.Unmarshal(in, book); err != nil {
log.Fatalln("Failed to parse address book:", err)
}
addr, err := promptForAddress(os.Stdin)
if err != nil {
log.Fatalln("Error with address:", err)
}
book.People = append(book.People, addr)
out, err := proto.Marshal(book)
if err != nil {
log.Fatalln("Failed to encode address book:", err)
}
if err := ioutil.WriteFile(fname, out, 0644); err != nil {
log.Fatalln("Failed to write address book:", err)
}
}

接下来通过命令行进行增加操作：

zhiliaodeMBP:src zhiliao$ ls
github.com go_demo go_protoc other
zhiliaodeMBP:src zhiliao$ cd go_demo/
zhiliaodeMBP:go_demo zhiliao$ go run add_person.go txt
osArgs-->> /var/folders/6x/58xzg4n5681_429nfm1d7c0h0000gn/T/go-build149370200/b001/exe/add_person -->> txt
txt: File not found. Creating new file.
osArgs after-->>
Enter person ID number: 111
Enter name: wyf
Enter email address (blank for none): 1@qq.com
Enter a phone number (or leave blank to finish): 123456
Is this a mobile, home, or work phone? mobile
Enter a phone number (or leave blank to finish):
zhiliaodeMBP:go_demo zhiliao$

然后会序列化到txt文件中

我们来看下列出的功能list_people.go

package main
import (
"fmt"
"go_protoc"
"io"
"io/ioutil"
"log"
"os"
"github.com/golang/protobuf/proto"
)
func writePerson(w io.Writer, p *go_protoc.Person) {
fmt.Fprintln(w, "Person ID:", p.Id)
fmt.Fprintln(w, " Name:", p.Name)
if p.Email != "" {
fmt.Fprintln(w, " E-mail address:", p.Email)
}
for _, pn := range p.Phones {
switch pn.Type {
case go_protoc.Person_MOBILE:
fmt.Fprint(w, " Mobile phone #: ")
case go_protoc.Person_HOME:
fmt.Fprint(w, " Home phone #: ")
case go_protoc.Person_WORK:
fmt.Fprint(w, " Work phone #: ")
}
fmt.Fprintln(w, pn.Number)
}
}
func listPeople(w io.Writer, book *go_protoc.AddressBook) {
for _, p := range book.People {
writePerson(w, p)
}
}
func main() {
if len(os.Args) != 2 {
log.Fatalf("Usage: %s ADDRESS_BOOK_FILEn", os.Args[0])
}
fname := os.Args[1]
in, err := ioutil.ReadFile(fname)
if err != nil {
log.Fatalln("Error reading file:", err)
}
book := &go_protoc.AddressBook{}
if err := proto.Unmarshal(in, book); err != nil {
log.Fatalln("Failed to parse address book:", err)
}
listPeople(os.Stdout, book)
}

依然通过控制台进行输出查看txt的信息

zhiliaodeMBP:go_demo zhiliao$
zhiliaodeMBP:go_demo zhiliao$ ls
add_person.go list_people.go txt
zhiliaodeMBP:go_demo zhiliao$ go run list_people.go txt
Person ID: 111
Name: wyf
E-mail address: 1@qq.com
Mobile phone #: 123456
zhiliaodeMBP:go_demo zhiliao$

go语言中的另一个练习protobuf的例子

接下来我们通过一个例子来了解下在go中是如何使用protobuf的数据格式的

以下是这个demo的项目结构

首先看下hello.proto

syntax = "proto3";
//包名，通过protoc生成时go文件时
package go_protoc;
//手机类型
//枚举类型第一个字段必须为0
enum PhoneType {
HOME = 0;
WORK = 1;
}
//手机
message Phone {
PhoneType type = 1;
string number = 2;
}
//人
message Person {
//后面的数字表示标识号
int32 id = 1;
string name = 2;
//repeated表示可重复
//可以有多个手机
repeated Phone phOnes= 3;
}
//联系簿
message ContactBook {
repeated Person persOns= 1;
}

然后从hello.proto编译为hello.pb.go

zhiliaodeMBP:go_protoc zhiliao$ protoc ./hello.proto --go_out=./
zhiliaodeMBP:go_protoc zhiliao$ pwd
/Users/zhiliao/zhiliao/go/src/go_protoc
zhiliaodeMBP:go_protoc zhiliao$ ls
hello.pb.go hello.proto
zhiliaodeMBP:go_protoc zhiliao$

然后看下go语言的代码safly.go

package main;
import (
"github.com/golang/protobuf/proto"
"go_protoc"
"io/ioutil"
"os"
"fmt"
)
func write() {
p1 := &go_protoc.Person{
Id: 1,
Name: "小张",
Phones: []*go_protoc.Phone{
{Type:go_protoc.PhoneType_HOME, Number:"111111111"},
{Type:go_protoc.PhoneType_WORK, Number:"222222222"},
},
};
p2 := &go_protoc.Person{
Id: 2,
Name: "小王",
Phones: []*go_protoc.Phone{
{Type:go_protoc.PhoneType_HOME, Number:"333333333"},
{Type:go_protoc.PhoneType_WORK, Number:"444444444"},
},
};
//创建地址簿
book := &go_protoc.ContactBook{};
book.Persons = append(book.Persons, p1);
book.Persons = append(book.Persons, p2);
//编码数据
data, _ := proto.Marshal(book);
//把数据写入文件
ioutil.WriteFile("./txt", data, os.ModePerm);
}
func read() {
//读取文件数据
data, _ := ioutil.ReadFile("./txt");
book := &go_protoc.ContactBook{};
//解码数据
proto.Unmarshal(data , book);
for _, v := range book.Persons {
fmt.Println(v.Id, v.Name);
for _, vv := range v.Phones {
fmt.Println(vv.Type, vv.Number);
}
}
}
func main() {
write();
read();
}

结果输出如下：

1 小张
HOME 111111111
WORK 222222222
2 小王
HOME 333333333
WORK 444444444


保存至文件内容如下：


&小张 111111111
222222222
&小王 333333333
444444444

最后看下编译生成的hello.pb.go的代码

// Code generated by protoc-gen-go. DO NOT EDIT.
// source: hello.proto
package go_protoc
/*
包名，通过protoc生成时go文件时
*/
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
// 手机类型
// 枚举类型第一个字段必须为0
type PhoneType int32
const (
PhoneType_HOME PhOneType= 0
PhoneType_WORK PhOneType= 1
)
var PhoneType_name = map[int32]string{
0: "HOME",
1: "WORK",
}
var PhoneType_value = map[string]int32{
"HOME": 0,
"WORK": 1,
}
func (x PhoneType) String() string {
return proto.EnumName(PhoneType_name, int32(x))
}
func (PhoneType) EnumDescriptor() ([]byte, []int) {
return fileDescriptor_61ef911816e0a8ce, []int{0}
}
// 手机
type Phone struct {
Type PhoneType `protobuf:"varint,1,opt,name=type,proto3,enum=go_protoc.PhoneType" json:"type,omitempty"`
Number string `protobuf:"bytes,2,opt,name=number,proto3" json:"number,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}
func (m *Phone) Reset() { *m = Phone{} }
func (m *Phone) String() string { return proto.CompactTextString(m) }
func (*Phone) ProtoMessage() {}
func (*Phone) Descriptor() ([]byte, []int) {
return fileDescriptor_61ef911816e0a8ce, []int{0}
}
func (m *Phone) XXX_Unmarshal(b []byte) error {
return xxx_messageInfo_Phone.Unmarshal(m, b)
}
func (m *Phone) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
return xxx_messageInfo_Phone.Marshal(b, m, deterministic)
}
func (dst *Phone) XXX_Merge(src proto.Message) {
xxx_messageInfo_Phone.Merge(dst, src)
}
func (m *Phone) XXX_Size() int {
return xxx_messageInfo_Phone.Size(m)
}
func (m *Phone) XXX_DiscardUnknown() {
xxx_messageInfo_Phone.DiscardUnknown(m)
}
var xxx_messageInfo_Phone proto.InternalMessageInfo
func (m *Phone) GetType() PhoneType {
if m != nil {
return m.Type
}
return PhoneType_HOME
}
func (m *Phone) GetNumber() string {
if m != nil {
return m.Number
}
return ""
}
// 人
type Person struct {
// 后面的数字表示标识号
Id int32 `protobuf:"varint,1,opt,name=id,proto3" json:"id,omitempty"`
Name string `protobuf:"bytes,2,opt,name=name,proto3" json:"name,omitempty"`
// repeated表示可重复
// 可以有多个手机
Phones []*Phone `protobuf:"bytes,3,rep,name=phones,proto3" json:"phones,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}
func (m *Person) Reset() { *m = Person{} }
func (m *Person) String() string { return proto.CompactTextString(m) }
func (*Person) ProtoMessage() {}
func (*Person) Descriptor() ([]byte, []int) {
return fileDescriptor_61ef911816e0a8ce, []int{1}
}
func (m *Person) XXX_Unmarshal(b []byte) error {
return xxx_messageInfo_Person.Unmarshal(m, b)
}
func (m *Person) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
return xxx_messageInfo_Person.Marshal(b, m, deterministic)
}
func (dst *Person) XXX_Merge(src proto.Message) {
xxx_messageInfo_Person.Merge(dst, src)
}
func (m *Person) XXX_Size() int {
return xxx_messageInfo_Person.Size(m)
}
func (m *Person) XXX_DiscardUnknown() {
xxx_messageInfo_Person.DiscardUnknown(m)
}
var xxx_messageInfo_Person proto.InternalMessageInfo
func (m *Person) GetId() int32 {
if m != nil {
return m.Id
}
return 0
}
func (m *Person) GetName() string {
if m != nil {
return m.Name
}
return ""
}
func (m *Person) GetPhones() []*Phone {
if m != nil {
return m.Phones
}
return nil
}
// 联系簿
type ContactBook struct {
Persons []*Person `protobuf:"bytes,1,rep,name=persons,proto3" json:"persons,omitempty"`
XXX_NoUnkeyedLiteral struct{} `json:"-"`
XXX_unrecognized []byte `json:"-"`
XXX_sizecache int32 `json:"-"`
}
func (m *ContactBook) Reset() { *m = ContactBook{} }
func (m *ContactBook) String() string { return proto.CompactTextString(m) }
func (*ContactBook) ProtoMessage() {}
func (*ContactBook) Descriptor() ([]byte, []int) {
return fileDescriptor_61ef911816e0a8ce, []int{2}
}
func (m *ContactBook) XXX_Unmarshal(b []byte) error {
return xxx_messageInfo_ContactBook.Unmarshal(m, b)
}
func (m *ContactBook) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
return xxx_messageInfo_ContactBook.Marshal(b, m, deterministic)
}
func (dst *ContactBook) XXX_Merge(src proto.Message) {
xxx_messageInfo_ContactBook.Merge(dst, src)
}
func (m *ContactBook) XXX_Size() int {
return xxx_messageInfo_ContactBook.Size(m)
}
func (m *ContactBook) XXX_DiscardUnknown() {
xxx_messageInfo_ContactBook.DiscardUnknown(m)
}
var xxx_messageInfo_ContactBook proto.InternalMessageInfo
func (m *ContactBook) GetPersons() []*Person {
if m != nil {
return m.Persons
}
return nil
}
func init() {
proto.RegisterType((*Phone)(nil), "go_protoc.Phone")
proto.RegisterType((*Person)(nil), "go_protoc.Person")
proto.RegisterType((*ContactBook)(nil), "go_protoc.ContactBook")
proto.RegisterEnum("go_protoc.PhoneType", PhoneType_name, PhoneType_value)
}
func init() { proto.RegisterFile("hello.proto", fileDescriptor_61ef911816e0a8ce) }
var fileDescriptor_61ef911816e0a8ce = []byte{
// 221 bytes of a gzipped FileDescriptorProto
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