03.gRPC
# 01.gRPC介绍
# 1.1 安装gRPC
go get -u -v google.golang.org/grpc # u(update) v(显示详情)
go mod tidy # 也可以导入后运行此命令
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# 1.2 gRPC 是什么?
- 在 gRPC 里客户端应用可以像调用本地对象一样直接调用另一台不同的机器上服务端应用的方法
- 使得您能够更容易地创建分布式应用和服务。
- 与许多 RPC 系统类似,gRPC 也是基于以下理念:定义一个服务,指定其能够被远程调用的方法(包含参数和返回类型)。
- 在服务端实现这个接口,并运行一个 gRPC 服务器来处理客户端调用。在客户端拥有一个存根能够像服务端一样的方法。
# 1.3 使用 protobuf
- gRPC 默认使用 protocol buffers,这是 Google 开源的一套成熟的结构数据序列化机制(当然也可以使用其他数据格式如 JSON)。
- 正如你将在下方例子里所看到的,你用 proto files 创建 gRPC 服务,用 protocol buffers 消息类型来定义方法参数和返回类型。
- 你可以在 [Protocol Buffers 文档](http://doc.oschina.net/ https://developers.google.com/protocol-buffers/docs/overview)找到更多关于 Protocol Buffers 的资料。
# 02.gRPC基本使用
# 2.1 pb/person.proto
默认,protobuf,编译期间,不编译服,要想使之编译,需要使用 gRPC。
使用的编译指令为:
protoc --go_out=plugins=grpc:./ *.proto
syntax = "proto3";
option go_package ="./person";
package pb;
// 消息体 --- 一个package 中,不允许定义同名的消息体
message Teacher {
int32 age = 1;
string name = 2;
}
// 定义 服务(参数和返回都是“消息体”)
service SayName {
rpc SayHello (Teacher) returns (Teacher);
}
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# 2.2 grpc-server.go
package main
import (
"context" // 上下文. --- goroutine (go程) 之间用来进行数据传递 API 包
"demo/pb/person"
"fmt"
"google.golang.org/grpc"
"net"
)
// 定义类
type Children struct {
}
// 按接口绑定类方法
func (this *Children) SayHello(ctx context.Context, t *person.Teacher) (*person.Teacher, error) {
t.Name += " is Sleeping"
return t, nil
}
func main() {
//1. 初始一个 grpc 对象
grpcServer := grpc.NewServer()
//2. 注册服务
person.RegisterSayNameServer(grpcServer, new(Children))
//3. 设置监听, 指定 IP、port
listener, err := net.Listen("tcp", "127.0.0.1:8800")
if err != nil {
fmt.Println("Listen err:", err)
return
}
defer listener.Close()
//4. 启动服务。---- serve()
grpcServer.Serve(listener)
}
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# 2.3 grpc-client.go
package main
import (
"context"
"demo/pb/person"
"fmt"
"google.golang.org/grpc"
)
func main() {
//1. 连接 grpc 服务
grpcConn, err := grpc.Dial("127.0.0.1:8800", grpc.WithInsecure())
if err != nil {
fmt.Println("grpc.Dial err:", err)
return
}
defer grpcConn.Close()
//2. 初始化 grpc 客户端
grpcClient := person.NewSayNameClient(grpcConn)
// 创建并初始化Teacher 对象
var teacher person.Teacher
teacher.Name = "itcast"
teacher.Age = 18
//3. 调用远程服务, context.TODO 表示一个站位的空对象
t, err := grpcClient.SayHello(context.TODO(), &teacher)
fmt.Println(t, err)
}
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# 2.4 pb/person/person.pb.go
- 运行命令自动生成的文件
// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
// protoc-gen-go v1.26.0
// protoc v3.19.1
// source: person.proto
package person
import (
context "context"
grpc "google.golang.org/grpc"
codes "google.golang.org/grpc/codes"
status "google.golang.org/grpc/status"
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
reflect "reflect"
sync "sync"
)
const (
// Verify that this generated code is sufficiently up-to-date.
_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
// Verify that runtime/protoimpl is sufficiently up-to-date.
_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)
// 消息体 --- 一个package 中,不允许定义同名的消息体
type Teacher struct {
state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
Age int32 `protobuf:"varint,1,opt,name=age,proto3" json:"age,omitempty"`
Name string `protobuf:"bytes,2,opt,name=name,proto3" json:"name,omitempty"`
}
func (x *Teacher) Reset() {
*x = Teacher{}
if protoimpl.UnsafeEnabled {
mi := &file_person_proto_msgTypes[0]
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
ms.StoreMessageInfo(mi)
}
}
func (x *Teacher) String() string {
return protoimpl.X.MessageStringOf(x)
}
func (*Teacher) ProtoMessage() {}
func (x *Teacher) ProtoReflect() protoreflect.Message {
mi := &file_person_proto_msgTypes[0]
if protoimpl.UnsafeEnabled && x != nil {
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
if ms.LoadMessageInfo() == nil {
ms.StoreMessageInfo(mi)
}
return ms
}
return mi.MessageOf(x)
}
// Deprecated: Use Teacher.ProtoReflect.Descriptor instead.
func (*Teacher) Descriptor() ([]byte, []int) {
return file_person_proto_rawDescGZIP(), []int{0}
}
func (x *Teacher) GetAge() int32 {
if x != nil {
return x.Age
}
return 0
}
func (x *Teacher) GetName() string {
if x != nil {
return x.Name
}
return ""
}
var File_person_proto protoreflect.FileDescriptor
var file_person_proto_rawDesc = []byte{
0x0a, 0x0c, 0x70, 0x65, 0x72, 0x73, 0x6f, 0x6e, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x02,
0x70, 0x62, 0x22, 0x2f, 0x0a, 0x07, 0x54, 0x65, 0x61, 0x63, 0x68, 0x65, 0x72, 0x12, 0x10, 0x0a,
0x03, 0x61, 0x67, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x05, 0x52, 0x03, 0x61, 0x67, 0x65, 0x12,
0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x04, 0x6e,
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0x54, 0x65, 0x61, 0x63, 0x68, 0x65, 0x72, 0x1a, 0x0b, 0x2e, 0x70, 0x62, 0x2e, 0x54, 0x65, 0x61,
0x63, 0x68, 0x65, 0x72, 0x42, 0x0a, 0x5a, 0x08, 0x2e, 0x2f, 0x70, 0x65, 0x72, 0x73, 0x6f, 0x6e,
0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}
var (
file_person_proto_rawDescOnce sync.Once
file_person_proto_rawDescData = file_person_proto_rawDesc
)
func file_person_proto_rawDescGZIP() []byte {
file_person_proto_rawDescOnce.Do(func() {
file_person_proto_rawDescData = protoimpl.X.CompressGZIP(file_person_proto_rawDescData)
})
return file_person_proto_rawDescData
}
var file_person_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
var file_person_proto_goTypes = []interface{}{
(*Teacher)(nil), // 0: pb.Teacher
}
var file_person_proto_depIdxs = []int32{
0, // 0: pb.SayName.SayHello:input_type -> pb.Teacher
0, // 1: pb.SayName.SayHello:output_type -> pb.Teacher
1, // [1:2] is the sub-list for method output_type
0, // [0:1] is the sub-list for method input_type
0, // [0:0] is the sub-list for extension type_name
0, // [0:0] is the sub-list for extension extendee
0, // [0:0] is the sub-list for field type_name
}
func init() { file_person_proto_init() }
func file_person_proto_init() {
if File_person_proto != nil {
return
}
if !protoimpl.UnsafeEnabled {
file_person_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
switch v := v.(*Teacher); i {
case 0:
return &v.state
case 1:
return &v.sizeCache
case 2:
return &v.unknownFields
default:
return nil
}
}
}
type x struct{}
out := protoimpl.TypeBuilder{
File: protoimpl.DescBuilder{
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
RawDescriptor: file_person_proto_rawDesc,
NumEnums: 0,
NumMessages: 1,
NumExtensions: 0,
NumServices: 1,
},
GoTypes: file_person_proto_goTypes,
DependencyIndexes: file_person_proto_depIdxs,
MessageInfos: file_person_proto_msgTypes,
}.Build()
File_person_proto = out.File
file_person_proto_rawDesc = nil
file_person_proto_goTypes = nil
file_person_proto_depIdxs = nil
}
// Reference imports to suppress errors if they are not otherwise used.
var _ context.Context
var _ grpc.ClientConnInterface
// This is a compile-time assertion to ensure that this generated file
// is compatible with the grpc package it is being compiled against.
const _ = grpc.SupportPackageIsVersion6
// SayNameClient is the client API for SayName service.
//
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
type SayNameClient interface {
SayHello(ctx context.Context, in *Teacher, opts ...grpc.CallOption) (*Teacher, error)
}
type sayNameClient struct {
cc grpc.ClientConnInterface
}
func NewSayNameClient(cc grpc.ClientConnInterface) SayNameClient {
return &sayNameClient{cc}
}
func (c *sayNameClient) SayHello(ctx context.Context, in *Teacher, opts ...grpc.CallOption) (*Teacher, error) {
out := new(Teacher)
err := c.cc.Invoke(ctx, "/pb.SayName/SayHello", in, out, opts...)
if err != nil {
return nil, err
}
return out, nil
}
// SayNameServer is the server API for SayName service.
type SayNameServer interface {
SayHello(context.Context, *Teacher) (*Teacher, error)
}
// UnimplementedSayNameServer can be embedded to have forward compatible implementations.
type UnimplementedSayNameServer struct {
}
func (*UnimplementedSayNameServer) SayHello(context.Context, *Teacher) (*Teacher, error) {
return nil, status.Errorf(codes.Unimplemented, "method SayHello not implemented")
}
func RegisterSayNameServer(s *grpc.Server, srv SayNameServer) {
s.RegisterService(&_SayName_serviceDesc, srv)
}
func _SayName_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
in := new(Teacher)
if err := dec(in); err != nil {
return nil, err
}
if interceptor == nil {
return srv.(SayNameServer).SayHello(ctx, in)
}
info := &grpc.UnaryServerInfo{
Server: srv,
FullMethod: "/pb.SayName/SayHello",
}
handler := func(ctx context.Context, req interface{}) (interface{}, error) {
return srv.(SayNameServer).SayHello(ctx, req.(*Teacher))
}
return interceptor(ctx, in, info, handler)
}
var _SayName_serviceDesc = grpc.ServiceDesc{
ServiceName: "pb.SayName",
HandlerType: (*SayNameServer)(nil),
Methods: []grpc.MethodDesc{
{
MethodName: "SayHello",
Handler: _SayName_SayHello_Handler,
},
},
Streams: []grpc.StreamDesc{},
Metadata: "person.proto",
}
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上次更新: 2024/3/13 15:35:10