Protocol Buffer

trip.proto 文件:

syntax = "proto3";
package coolcar;
option go_package="server/proto/gen/go;trippb";

message Trip{
    string start = 1;   // 第一个字段是 start
    string end = 2;     // 第二个字段是 end
    int64 duration_sec = 3; // duration in second
    int64 fee_cent = 4;
}

protoc -I=. --go_out=path=source_relative:gen/go

protoc -I=E:\Projects\GolandProjects\go-camp\mooc\code\coolcar\server\proto --go_out=paths=source_relative:gen/go trip.proto

终于生成出来了

// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
//     protoc-gen-go v1.27.1
//     protoc        v3.13.0
// source: trip.proto

package trippb

import (
    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)
)

type Trip struct {
    // 小写的不用管它
    state         protoimpl.MessageState
    sizeCache     protoimpl.SizeCache
    unknownFields protoimpl.UnknownFields

    // go 会自动把 _ 分隔 转成 驼峰吗命名
    Start       string `protobuf:"bytes,1,opt,name=start,proto3" json:"start,omitempty"`                                 // 第一个字段是 start
    End         string `protobuf:"bytes,2,opt,name=end,proto3" json:"end,omitempty"`                                     // 第二个字段是 end
    DurationSec int64  `protobuf:"varint,3,opt,name=duration_sec,json=durationSec,proto3" json:"duration_sec,omitempty"` // duration in second
    FeeCent     int64  `protobuf:"varint,4,opt,name=fee_cent,json=feeCent,proto3" json:"fee_cent,omitempty"`
}

func (x *Trip) Reset() {
    *x = Trip{}
    if protoimpl.UnsafeEnabled {
        mi := &file_trip_proto_msgTypes[0]
        ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
        ms.StoreMessageInfo(mi)
    }
}

func (x *Trip) String() string {
    return protoimpl.X.MessageStringOf(x)
}

func (*Trip) ProtoMessage() {}

func (x *Trip) ProtoReflect() protoreflect.Message {
    mi := &file_trip_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 Trip.ProtoReflect.Descriptor instead.
func (*Trip) Descriptor() ([]byte, []int) {
    return file_trip_proto_rawDescGZIP(), []int{0}
}

func (x *Trip) GetStart() string {
    if x != nil {
        return x.Start
    }
    return ""
}

func (x *Trip) GetEnd() string {
    if x != nil {
        return x.End
    }
    return ""
}

func (x *Trip) GetDurationSec() int64 {
    if x != nil {
        return x.DurationSec
    }
    return 0
}

func (x *Trip) GetFeeCent() int64 {
    if x != nil {
        return x.FeeCent
    }
    return 0
}

var File_trip_proto protoreflect.FileDescriptor

var file_trip_proto_rawDesc = []byte{
    0x0a, 0x0a, 0x74, 0x72, 0x69, 0x70, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x07, 0x63, 0x6f,
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    0x6e, 0x5f, 0x73, 0x65, 0x63, 0x18, 0x03, 0x20, 0x01, 0x28, 0x03, 0x52, 0x0b, 0x64, 0x75, 0x72,
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    0x65, 0x6e, 0x74, 0x42, 0x1c, 0x5a, 0x1a, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x2f, 0x70, 0x72,
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    0x62, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}

var (
    file_trip_proto_rawDescOnce sync.Once
    file_trip_proto_rawDescData = file_trip_proto_rawDesc
)

func file_trip_proto_rawDescGZIP() []byte {
    file_trip_proto_rawDescOnce.Do(func() {
        file_trip_proto_rawDescData = protoimpl.X.CompressGZIP(file_trip_proto_rawDescData)
    })
    return file_trip_proto_rawDescData
}

var file_trip_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
var file_trip_proto_goTypes = []interface{}{
    (*Trip)(nil), // 0: coolcar.Trip
}
var file_trip_proto_depIdxs = []int32{
    0, // [0:0] is the sub-list for method output_type
    0, // [0:0] 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_trip_proto_init() }
func file_trip_proto_init() {
    if File_trip_proto != nil {
        return
    }
    if !protoimpl.UnsafeEnabled {
        file_trip_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
            switch v := v.(*Trip); 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_trip_proto_rawDesc,
            NumEnums:      0,
            NumMessages:   1,
            NumExtensions: 0,
            NumServices:   0,
        },
        GoTypes:           file_trip_proto_goTypes,
        DependencyIndexes: file_trip_proto_depIdxs,
        MessageInfos:      file_trip_proto_msgTypes,
    }.Build()
    File_trip_proto = out.File
    file_trip_proto_rawDesc = nil
    file_trip_proto_goTypes = nil
    file_trip_proto_depIdxs = nil
}

protobuf 的所有字段 都是可选的

go中的零值

omit empty

动态增加字段,新老系统同时可用

默认字段不填,填的是零值

grpc

protoc -I=E:\Projects\GolandProjects\go-camp\mooc\code\coolcar\server\proto --go_out=plugins=grpc,paths=source_relative:gen/go trip.proto

server

package main

import (
    trippb "coolcar/proto/gen/go"
    trip "coolcar/tripservice"
    "google.golang.org/grpc"
    "log"
    "net"
)

func main() {
    lis, err := net.Listen("tcp", ":8081")
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }

    s := grpc.NewServer()
    trippb.RegisterTripServiceServer(s, &trip.Service{})
    log.Fatal(s.Serve(lis))


}

client

package main

import (
    "context"
    trippb "coolcar/proto/gen/go"
    "fmt"
    "google.golang.org/grpc"
    "log"
)

func main() {
    log.SetFlags(log.Lshortfile)
    conn, err := grpc.Dial("localhost:8081",grpc.WithInsecure())
    if err != nil {
        log.Fatalf("cannot connect server: %v", err)

    }

    tsClient := trippb.NewTripServiceClient(conn)
    r, err := tsClient.GetTrip(context.Background(), &trippb.GetTripRequest{
        Id: "tr35653",
    })
    if err != nil {
        log.Fatalf("can not call GetTrip : %v", err)
    }

    fmt.Println(r)
}

/**
id:"tr35653"  trip:{start:"abc"  start_pos:{latitude:30  longitude:120}  end_pos:{latitude:30  longitude:120}  path_locaitons:{latitude:31  longitude:118}  path_locaitons:{latitude:37  longitude:125}  status:IN_PROGRESS  end:"def"  duration_sec:36000  fee_cent:13000}

Process finished with the exit code 0
 */