golang下的grpc

facebook的thrift也是开源rpc库，性能高出grpc一倍以上，grpc发展的较晚，期待以后有长足的进步。简单来说thrift = grpc + protobuf

gRPC基于HTTP/2标准设计，带来诸如双向流控、头部压缩、单TCP连接上的多复用请求等特性。这些特性使得其在移动设备上表现更好，更省电和节省空间占用。

要求：

go version 版本最好1.7以上

protoc --version 版本最好3.1.0以上

go get -v google.golang.org/grpc

如果下载不了设置代理：(go get走的命令行代理，不是http代理！！！所以只开启shadowsocks是没用的)

windows：

set http_proxy=127.0.0.1:1080

set https_proxy=127.0.0.1:1080

linux：

export http_proxy=127.0.0.1:1080

export https_proxy=127.0.0.1:1080

proto文件

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";

package helloworld;

// The greeting service definition.
service Greeter {
　　// Sends a greeting
　　rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
　　string name = 1;
}

// The response message containing the greetings
message HelloReply {
　　string message = 1;
}

protoc   -I   helloworld/    helloworld/helloworld.proto   --go_out=plugins=grpc:helloworld
注意：grpc插件，否则service不能运行，代码如下：

测试demo：

cd $GOPATH/src/google.golang.org/grpc/examples/helloworld

运行：

服务端代码：go run greeter_server/main.go
 
package main
 
import (
    "log"
    "net"
 
    "golang.org/x/net/context"
    "google.golang.org/grpc"
    pb "google.golang.org/grpc/examples/helloworld/helloworld"
    "google.golang.org/grpc/reflection"
)
 
const (
    port = ":50051"
)
 
// server is used to implement helloworld.GreeterServer.
type server struct{}
 
// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    return &pb.HelloReply{Message: "Hello " + in.Name}, nil
}
 
func main() {
    lis, err := net.Listen("tcp", port)
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }
    s := grpc.NewServer()
    pb.RegisterGreeterServer(s, &server{})
    // Register reflection service on gRPC server.
    reflection.Register(s)
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

客户端代码：go run greeter_client/main.go
 
package main
 
import (
    "log"
    "os"
 
    "golang.org/x/net/context"
    "google.golang.org/grpc"
    pb "google.golang.org/grpc/examples/helloworld/helloworld"
)
 
const (
    address     = "localhost:50051"
    defaultName = "world"
)
 
func main() {
    // Set up a connection to the server.
    conn, err := grpc.Dial(address, grpc.WithInsecure())
    if err != nil {
        log.Fatalf("did not connect: %v", err)
    }
    defer conn.Close()
    c := pb.NewGreeterClient(conn)
 
    // Contact the server and print out its response.
    name := defaultName
    if len(os.Args) >  {
        name = os.Args[]
    }
    r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
    if err != nil {
        log.Fatalf("could not greet: %v", err)
    }
    log.Printf("Greeting: %s", r.Message)
}

参考网站：

http://www.grpc.io/docs/quickstart/go.html         上面代码的详细解释1
http://www.jianshu.com/p/774b38306c30           上面代码的详细解释2
http://www.cnblogs.com/YaoDD/p/5504881.html
https://github.com/tenywen/share