protobuf基本语法
https://developers.google.com/protocol-buffers/docs/proto3#enum
python沟通protobuf时会遇到的问题
若想传一个列表类型，在poroto文件中应使用repeated关键字
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| message HelloRequest {
string name = 1;
repeated int32 id = 2;
}
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此时在python代码中不能对其直接实例化后直接赋值，而是应使用列表的方法（如：extend，append）等去改变它的值
此外，嵌套定义message也不能实例化后直接赋值
go_package详解
设置：
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| option go_package = "common/stream/proto/v1";
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执行：
cd 到目标文件夹
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| protoc --go_out=plugins=grpc:./ ./hello.proto
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即使目标文件夹下不存在common/stream/proto/v1也会生成common/stream/proto/v1/hello.pb.go脚本
或者：
设置：
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| option go_package = "../common/stream/proto/v1";
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执行命令后会在父路径下生成一系列文件夹及文件
protobuf的一点原理
protobuf不是根据名称来对应的，而是根据编号：
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| message HelloRequest {
string name = 1;
repeated int32 id = 2;
}
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假设对方proto文件为：
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| message HelloRequest {
string name = 2;
repeated int32 id = 1;
}
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此时会将name映射到id，id映射到name
一个proto文件中引入其它proto文件
应用场景：有一些常用的service与message可能很多proto文件都要用到，这时不妨将这些service与message放到一个公用的proto文件中，在需要调用时import。
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|
syntax = "proto3";
message Empty{
}
message Pong{
string id = 1;
}
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syntax = "proto3";
import "python_grpc_helloworld/proto/base.proto";
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
rpc Ping (Empty) returns (Pong) {}
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
}
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message对象嵌套
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| syntax = "proto3";
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
message Result {
string name = 1;
string age = 2;
}
repeated Result persons = 2;
}
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python下使用
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| import grpc
from concurrent import futures
from proto import hello_pb2,hello_pb2_grpc
class Greeter(hello_pb2_grpc.GreeterServicer):
def SayHello(self, request, context):
names = ["name1", "name2", "name3"]
results = []
for name in names:
result = hello_pb2.HelloReply.Result(name=name,age="17")
results.append(result)
return hello_pb2.HelloReply(message=f"hello,{request.name}",persons=results)
if __name__ == "__main__":
server = grpc.server(futures.ThreadPoolExecutor(5))
hello_pb2_grpc.add_GreeterServicer_to_server(servicer=Greeter(),server=server)
server.add_insecure_port('127.0.0.1:50000')
server.start()
server.wait_for_termination()
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| import grpc
from python_grpc_helloworld.proto import hello_pb2_grpc,hello_pb2
with grpc.insecure_channel('127.0.0.1:50000') as channel:
stub = hello_pb2_grpc.GreeterStub(channel)
rsp: hello_pb2.HelloReply = stub.SayHello(hello_pb2.HelloRequest(name="lily"))
print(rsp.persons)
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go下使用
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| package main
import (
"context"
"net"
"google.golang.org/grpc"
"awesomeProject/grpc_test/proto"
)
type Server struct{}
func (s *Server) SayHello(ctx context.Context, request *proto.HelloRequest) (*proto.HelloReply,error){
var results []*proto.HelloReply_Result
for i:=0;i<10;i++{
result := proto.HelloReply_Result{
Name: "name",
Age: string(i),
}
results = append(results,&result)
}
return &proto.HelloReply{
Message: "Hello" + request.Name,
Persons: results,
},nil
}
func main(){
server := grpc.NewServer()
proto.RegisterGreeterServer(server,&Server{})
listen,err := net.Listen("tcp","127.0.0.1:50000")
if err != nil{
panic("fail to listen:" + err.Error())
}
err = server.Serve(listen)
if err != nil{
panic("fail to start:" + err.Error())
}
}
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| package main
import (
"awesomeProject/grpc_test/proto"
"context"
"fmt"
"google.golang.org/grpc"
)
func main(){
conn, err := grpc.Dial("127.0.0.1:50000", grpc.WithInsecure())
if err != nil{
panic(err)
}
defer conn.Close()
c := proto.NewGreeterClient(conn)
resp, err := c.SayHello(context.Background(), &proto.HelloRequest{Name:"Lily"})
if err != nil{
panic(err)
}
fmt.Println(resp.Persons)
}
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几种类型
枚举
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| syntax = "proto3";
option go_package = "./;proto";
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
message Result {
string name = 1;
string age = 2;
}
repeated Result persons = 2;
enum Gender{
MALE = 0;
FEMALE = 1;
}
Gender g = 3;
}
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生成的相关代码
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| type HelloReply_Gender int32
const (
HelloReply_MALE HelloReply_Gender = 0
HelloReply_FEMALE HelloReply_Gender = 1
)
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map
不建议使用，message本身很像map
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| syntax = "proto3";
option go_package = "./;proto";
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
message Result {
string name = 1;
string age = 2;
}
repeated Result persons = 2;
enum Gender{
MALE = 0;
FEMALE = 1;
}
Gender g = 3;
map<string ,string >mp = 4;
}
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return &proto.HelloReply{
Message: "Hello" + request.Name,
Persons: results,
G: proto.HelloReply_FEMALE,
Mp: map[string]string{"hhh":"2333","QAQ":"QWQ"},
},nil
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