gRPC的Golang簡單應用
首先我們需要知道gRPC是一種用來通訊的框架，傳輸資料走的是二進位制流，資料結構使用protoBuf定義的
我們直接來看一個例子吧！
假如我們需要一個行程的資料：
statar: //起點
statar_pos: //起點位置
path_locations: //中途位置
end: //終點
end_pos //終點位置
duration_sec: //時間
fee_cent: //費用
status: //行程狀態
首先我們需要一個x.proto檔案如下：
syntax = "proto3"; //語法使用proto3
package coolcar; //包名
option go_package = "coolcar/proto/gen/go/;trippb"; //路徑；包名
//使用message來定義結構體
message Location{
double latitude = 1;
double longitude = 2;
}
enum TripStatus{ //列舉型別
TS_NOT_SPECIFID = 0;
NOT_STARTED = 1;
IN_PROGRESS = 2;
FINISHED = 3;
PAID = 4;
}
message Trip{
string statar = 1; //數字表示標記碼，不是賦值
Location statar_pos = 5;
repeated Location path_locations = 7;
string end = 2;
Location end_pos = 6;
int64 duration_sec = 3;
int64 fee_cent = 4;
TripStatus status = 8;
}輸入命令：
protoc -I=. --go_out=paths=source_relative:gen/go trip.proto
編譯出下面程式碼：
編譯後主要部分是：
- 行程結構體序列化及反序列化方法
- 位置結構體序列化及反序列化方法
- 列舉型別的等資料和方法
// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
// protoc-gen-go v1.26.0
// 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 TripStatus int32
const (
TripStatus_TS_NOT_SPECIFID TripStatus = 0
TripStatus_NOT_STARTED TripStatus = 1
TripStatus_IN_PROGRESS TripStatus = 2
TripStatus_FINISHED TripStatus = 3
TripStatus_PAID TripStatus = 4
)
// Enum value maps for TripStatus.
var (
TripStatus_name = map[int32]string{
0: "TS_NOT_SPECIFID",
1: "NOT_STARTED",
2: "IN_PROGRESS",
3: "FINISHED",
4: "PAID",
}
TripStatus_value = map[string]int32{
"TS_NOT_SPECIFID": 0,
"NOT_STARTED": 1,
"IN_PROGRESS": 2,
"FINISHED": 3,
"PAID": 4,
}
)
func (x TripStatus) Enum() *TripStatus {
p := new(TripStatus)
*p = x
return p
}
func (x TripStatus) String() string {
return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
}
func (TripStatus) Descriptor() protoreflect.EnumDescriptor {
return file_trip_proto_enumTypes[0].Descriptor()
}
func (TripStatus) Type() protoreflect.EnumType {
return &file_trip_proto_enumTypes[0]
}
func (x TripStatus) Number() protoreflect.EnumNumber {
return protoreflect.EnumNumber(x)
}
// Deprecated: Use TripStatus.Descriptor instead.
func (TripStatus) EnumDescriptor() ([]byte, []int) {
return file_trip_proto_rawDescGZIP(), []int{0}
}
type Location struct {
state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
Latitude float64 `protobuf:"fixed64,1,opt,name=latitude,proto3" json:"latitude,omitempty"`
Longitude float64 `protobuf:"fixed64,2,opt,name=longitude,proto3" json:"longitude,omitempty"`
}
func (x *Location) Reset() {
*x = Location{}
if protoimpl.UnsafeEnabled {
mi := &file_trip_proto_msgTypes[0]
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
ms.StoreMessageInfo(mi)
}
}
func (x *Location) String() string {
return protoimpl.X.MessageStringOf(x)
}
func (*Location) ProtoMessage() {}
func (x *Location) 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 Location.ProtoReflect.Descriptor instead.
func (*Location) Descriptor() ([]byte, []int) {
return file_trip_proto_rawDescGZIP(), []int{0}
}
func (x *Location) GetLatitude() float64 {
if x != nil {
return x.Latitude
}
return 0
}
func (x *Location) GetLongitude() float64 {
if x != nil {
return x.Longitude
}
return 0
}
type Trip struct {
state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
Statar string `protobuf:"bytes,1,opt,name=statar,proto3" json:"statar,omitempty"` //數字表示標記碼，不是賦值
StatarPos *Location `protobuf:"bytes,5,opt,name=statar_pos,json=statarPos,proto3" json:"statar_pos,omitempty"`
PathLocations []*Location `protobuf:"bytes,7,rep,name=path_locations,json=pathLocations,proto3" json:"path_locations,omitempty"`
End string `protobuf:"bytes,2,opt,name=end,proto3" json:"end,omitempty"`
EndPos *Location `protobuf:"bytes,6,opt,name=end_pos,json=endPos,proto3" json:"end_pos,omitempty"`
DurationSec int64 `protobuf:"varint,3,opt,name=duration_sec,json=durationSec,proto3" json:"duration_sec,omitempty"`
FeeCent int64 `protobuf:"varint,4,opt,name=fee_cent,json=feeCent,proto3" json:"fee_cent,omitempty"`
Status TripStatus `protobuf:"varint,8,opt,name=status,proto3,enum=coolcar.TripStatus" json:"status,omitempty"`
}
func (x *Trip) Reset() {
*x = Trip{}
if protoimpl.UnsafeEnabled {
mi := &file_trip_proto_msgTypes[1]
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[1]
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{1}
}
func (x *Trip) GetStatar() string {
if x != nil {
return x.Statar
}
return ""
}
func (x *Trip) GetStatarPos() *Location {
if x != nil {
return x.StatarPos
}
return nil
}
func (x *Trip) GetPathLocations() []*Location {
if x != nil {
return x.PathLocations
}
return nil
}
func (x *Trip) GetEnd() string {
if x != nil {
return x.End
}
return ""
}
func (x *Trip) GetEndPos() *Location {
if x != nil {
return x.EndPos
}
return nil
}
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
}
func (x *Trip) GetStatus() TripStatus {
if x != nil {
return x.Status
}
return TripStatus_TS_NOT_SPECIFID
}
var File_trip_proto protoreflect.FileDescriptor
var file_trip_proto_rawDesc = []byte{
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}
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_enumTypes = make([]protoimpl.EnumInfo, 1)
var file_trip_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
var file_trip_proto_goTypes = []interface{}{
(TripStatus)(0), // 0: coolcar.TripStatus
(*Location)(nil), // 1: coolcar.Location
(*Trip)(nil), // 2: coolcar.Trip
}
var file_trip_proto_depIdxs = []int32{
1, // 0: coolcar.Trip.statar_pos:type_name -> coolcar.Location
1, // 1: coolcar.Trip.path_locations:type_name -> coolcar.Location
1, // 2: coolcar.Trip.end_pos:type_name -> coolcar.Location
0, // 3: coolcar.Trip.status:type_name -> coolcar.TripStatus
4, // [4:4] is the sub-list for method output_type
4, // [4:4] is the sub-list for method input_type
4, // [4:4] is the sub-list for extension type_name
4, // [4:4] is the sub-list for extension extendee
0, // [0:4] 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.(*Location); i {
case 0:
return &v.state
case 1:
return &v.sizeCache
case 2:
return &v.unknownFields
default:
return nil
}
}
file_trip_proto_msgTypes[1].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: 1,
NumMessages: 2,
NumExtensions: 0,
NumServices: 0,
},
GoTypes: file_trip_proto_goTypes,
DependencyIndexes: file_trip_proto_depIdxs,
EnumInfos: file_trip_proto_enumTypes,
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
}現在我們就可以在main中使用了
package main
import (
trippb "coolcar/proto/gen/go" //包名：路徑
"encoding/json"
"fmt"
"google.golang.org/protobuf/proto"
)
func main() {
trips := trippb.Trip{
Statar: "北京",
End: "南京",
DurationSec: 3600,
FeeCent: 1000,
StatarPos: &trippb.Location{
Latitude: 30,
Longitude: 120,
},
EndPos: &trippb.Location{
Latitude: 125,
Longitude: 35,
},
PathLocations: []*trippb.Location{
{
Latitude: 31,
Longitude: 121,
},
{
Latitude: 33,
Longitude: 122,
},
{
Latitude: 34,
Longitude: 124,
},
},
Status: trippb.TripStatus_FINISHED,
}
fmt.Println(&trips)
//模擬兩端互動
p, err := proto.Marshal(&trips) //將資料轉為二進位制流
if err != nil {
panic(err)
}
fmt.Printf("%X\n", p)
var trips2 trippb.Trip
err = proto.Unmarshal(p, &trips2) //將二進位制流解碼
if err != nil {
panic(err)
}
fmt.Println(&trips2)
b, err := json.Marshal(&trips2) //將二進位制流轉為json格式
if err != nil {
panic(err)
}
fmt.Printf("%s\n", b)
//微服務透過二進位制流進行資訊交流
}輸出：
statar:"北京" statar_pos:{latitude:30 longitude:120} path_locations:{latitude:31 longitude:121} path_locations:{latitude:33 longitude:122} path_locations:{latitude:34 longitude:124} end:"南京" end_pos:{latitude:125 longitude:35} duration_sec:3600 fee_cent:1000 status:FINISHED
0A06E58C97E4BAAC1206E58D97E4BAAC18901C20E8072A12090000000000003E40110000000000005E403212090000000000405F401100000000008041403A12090000000000003F40110000000000405E403A12090000000000804040110000000000805E403A12090000000000004140110000000000005F404003
statar:"北京" statar_pos:{latitude:30 longitude:120} path_locations:{latitude:31 longitude:121} path_locations:{latitude:33 longitude:122} path_locations:{latitude:34 longitude:124} end:"南京" end_pos:{latitude:125 longitude:35} duration_sec:3600 fee_cent:1000 status:FINISHED
{"statar":"北京","statar_pos":{"latitude":30,"longitude":120},"path_locations":[{"latitude":31,"longitude":121},{"latitude":33,"longitude":122},{"latitude":34,"longitude":124}],"end":"南京","end_pos":{"latitude":125,"longitude":35},"duration_sec":3600,"fee_cent":1000,"status":3}* 注意： protobuf中每個欄位都是可選的。*
例如：可以避免系統更新時舊系統與新系統之間的通訊，這樣可以避免如果老系統裡面沒有相應欄位，那麼系統將會掛掉，或者新系統刪去原來欄位，客服端通訊也不會因為欄位不存在而掛掉。
本作品採用《CC 協議》，轉載必須註明作者和本文連結