Thrift 的Go與C語(yǔ)言實(shí)現(xiàn)

Thrift 是Facebook為了解決各系統(tǒng)間大數(shù)據(jù)量的傳輸通信以及系統(tǒng)之間語(yǔ)言環(huán)境不同而設(shè)計(jì)的一種傳輸框架霉撵。目前來(lái)看常用的主流語(yǔ)言Thrift都已經(jīng)很好地支持严沥，并且github上已經(jīng)有很多實(shí)現(xiàn)绕辖，除了C語(yǔ)言之外哼勇。Thrift傳輸?shù)某绦虻撵o態(tài)數(shù)據(jù)，即數(shù)據(jù)的數(shù)據(jù)結(jié)構(gòu)必須事前固定带猴。
Thrift原理就不介紹了吼畏，理論性東西網(wǎng)上很多督赤，并且都是雷同的。下面通過(guò)實(shí)例介紹Thrift 接口在Go與C語(yǔ)言下的實(shí)現(xiàn)泻蚊，以及如何在C語(yǔ)言中調(diào)用Go所編寫(xiě)的Thrift客戶(hù)端躲舌。

1. thrift 文件編寫(xiě)

#example.thrift

    namespace go thrift.rpc
    struct Response {
    1: required string data;
    }
service RpcService {
    Response Test(1:string input)
}

2. Go與C的thrift代碼

thrift -r --gen go example.thrift
thrift -r --gen c_glib example.thrift

此時(shí)在目錄下會(huì)出現(xiàn)gen-go與gen-c_gib兩個(gè)文件夾，里邊存放著Thrift自動(dòng)生成的數(shù)據(jù)結(jié)構(gòu)體以及函數(shù)的聲明性雄。

3. Go的server端實(shí)現(xiàn)

/* server.go */

package main
import (
    "./gen-go/thrift/rpc"
    "git.apache.org/thrift.git/lib/go/thrift"
    "log"
    "os"
)

const (
    NetworkAddr = "localhost:9090"
)

type RpcServiceImpl struct {
}
func (this *RpcServiceImpl) Test(input string) (r *rpc.Response, err error) {
    //函數(shù)具體實(shí)現(xiàn)
    return
}

func main() {
    transportFactory := thrift.NewTFramedTransportFactory(thrift.NewTTransportFactory())
    
    protocolFactory := thrift.NewTBinaryProtocolFactoryDefault()
    
    serverTransport, err := thrift.NewTServerSocket(NetworkAddr)
    if err != nil {
        log.Println("Error!", err)
        os.Exit(1)
    }

    handler := &RpcServiceImpl{}
    processor := rpc.NewRpcServiceProcessor(handler)


    log.Println("thrift server in", NetworkAddr)
    server.Serve()
}

4. Go的客戶(hù)端實(shí)現(xiàn)

/* client.go */

import (
    "./gen-go/thrift/rpc"
    "fmt"
    "git.apache.org/thrift.git/lib/go/thrift"
    "net"
    "os"
)

func main(){

ip := "127.0.0.1"
port := "9090"
input :=""  

transportFactory := thrift.NewTFramedTransportFactory(thrift.NewTTransportFactory())
    protocolFactory := thrift.NewTBinaryProtocolFactoryDefault()

    tSocket, err := thrift.NewTSocket(net.JoinHostPort(ip, port))
    if err != nil {
        fmt.Fprintln(os.Stderr, "Error resolving address, ", err)
        os.Exit(1)
    }

    tTransport, _ := transportFactory.GetTransport(tSocket)
    
    client := rpc.NewRpcServiceClientFactory(tTransport, protocolFactory)
    if err := tTransport.Open(); err != nil {
        fmt.Fprintln(os.Stderr, (fmt.Errorf("Error opening socket to %s:%s : %v", ip, port, err)))
        os.Exit(1)
    }
    defer tTransport.Close()

    resp, _ := client.Test(input)
}

C的客戶(hù)端實(shí)現(xiàn)

C 的客戶(hù)端實(shí)現(xiàn)目前在github一個(gè)都沒(méi)有没卸，Thrift好像也是最近才支持的。thrift是一種面向?qū)ο蟮目蚣苊胄珻語(yǔ)言面向?qū)ο蟮膶?shí)現(xiàn)必須依賴(lài)于gobject庫(kù)约计，所以這里邊在實(shí)現(xiàn)的過(guò)程中需要注意一點(diǎn)，對(duì)thrift文件中定義的struct迁筛，其他可以直接實(shí)例化為對(duì)象煤蚌，在C中必須使用g_object_new函數(shù)進(jìn)行初始化，要不然改strcut 將無(wú)法實(shí)現(xiàn)瑰煎。在會(huì)一直出現(xiàn)無(wú)法找到對(duì)應(yīng)結(jié)構(gòu)接收server端傳來(lái)的參數(shù)铺然。

/* client.c */

#include <stdio.h>
#include <glib-object.h>
#include <string.h>

#include <thrift/c_glib/protocol/thrift_binary_protocol.h>
#include <thrift/c_glib/transport/thrift_framed_transport.h>
#include <thrift/c_glib/transport/thrift_socket.h>
#include "gen-c_glib/rpc_service.h"


struct thrift_if{  

   ThriftSocket *socket;
   ThriftTransport *transport;
   ThriftProtocol *protocol;
   RpcServiceIf *client;

};

void if_open (struct thrift_if* if_instance, gchar *hostname, gint32 port, GError **error){

#if (!GLIB_CHECK_VERSION (2, 36, 0))
    g_type_init ();
#endif

   if_instance->socket = g_object_new (THRIFT_TYPE_SOCKET,
                            "hostname",  hostname,
                            "port",      port,
                            NULL);

   if_instance->transport = g_object_new (THRIFT_TYPE_FRAMED_TRANSPORT,
                            "transport", if_instance->socket,
                            NULL);
    if_instance->protocol  = g_object_new (THRIFT_TYPE_BINARY_PROTOCOL,
                            "transport", if_instance->transport,
                            NULL);
   
    thrift_transport_open (if_instance->transport, error);

    if(!error){
        return;
    }

    if_instance->client = g_object_new (TYPE_RPC_SERVICE_CLIENT,
                         "input_protocol",  if_instance->protocol,
                         "output_protocol", if_instance->protocol,
                         NULL);
   
}

void if_close (struct thrift_if *if_instance, GError **error){
   
    g_clear_error (error); 
    thrift_transport_close (if_instance->transport, NULL);
    g_object_unref (if_instance->client);
    g_object_unref (if_instance->protocol);
    g_object_unref (if_instance->transport);
    g_object_unref (if_instance->socket);
}

int main(){

    gchar *hostname = "127.0.0.1";
    gint32 port = 9090;
    gchar *input = ""
    
    struct thrift_if if_instance;
    GError *error = NULL; 
    if_open(&if_instance, hostname, port, &error);
    
    gchar *data;
    Response *Res;
    Res = g_object_new(TYPE_RESPONSE,NULL);
    
    if (!error && rpc_service_if_test(if_instance.client,&Res,input,&error)){   
            g_object_get (Res, "data", &data, NULL);
    }

   if_close(&if_instance, &error);

return 0;
} 

編譯：
gcc  client.c gen-c_glib/rpc_service.c gen-c_glib/sven_types.c -o client -lthrift_c_glib -lgobject-2.0

5. C代碼中調(diào)用Go的客戶(hù)端

由于C的客戶(hù)端編譯依賴(lài)于thrift_c_glib與 gobject 動(dòng)態(tài)庫(kù)俗孝，并且thrift_c_glib動(dòng)態(tài)庫(kù)中對(duì)linux的一些系統(tǒng)庫(kù)又進(jìn)行了引用酒甸，所以動(dòng)態(tài)庫(kù)的依賴(lài)關(guān)系復(fù)雜，不利于在客戶(hù)端穩(wěn)定赋铝、無(wú)依賴(lài)的部署插勤。
可以采用使用Go編寫(xiě)客戶(hù)端，然后編譯為.so文件，供C程序調(diào)用农尖。因?yàn)镚o采用靜態(tài)源碼編譯方式析恋，可以無(wú)依賴(lài)的移植到各個(gè)服務(wù)器中，在過(guò)程中需要注意C與Go基本數(shù)據(jù)結(jié)構(gòu)之間的轉(zhuǎn)化盛卡。代碼與go client的實(shí)現(xiàn)基本相同助隧，只是go 與 C直接不允許 struct的傳遞，所以只能傳遞基本數(shù)據(jù)類(lèi)型

/*client.go */
 
 package main

import (
    "./gen-go/thrift/rpc"
    "C"
    "fmt"
    "git.apache.org/thrift.git/lib/go/thrift"
    "net"
    "os"
)

/*  ；住２⒋濉！務(wù)必寫(xiě)上"http://export Test", 這不是注釋  Ｗ壹肌Ａ埂！*/
//export Test
func Test (input string, ip string, port string) *C.char {

    transportFactory := thrift.NewTFramedTransportFactory(thrift.NewTTransportFactory())
    protocolFactory := thrift.NewTBinaryProtocolFactoryDefault()

    tSocket, err := thrift.NewTSocket(net.JoinHostPort(ip, port))
    if err != nil {
        fmt.Fprintln(os.Stderr, "Error resolving address, ", err)
        os.Exit(1)
    }

    tTransport, _ := transportFactory.GetTransport(tSocket)
    client := rpc.NewRpcServiceClientFactory(tTransport, protocolFactory)
    if err := tTransport.Open(); err != nil {
        fmt.Fprintln(os.Stderr, (fmt.Errorf("Error opening socket to %s:%s : %v", ip, port, err)))
        os.Exit(1)
    }
    defer tTransport.Close()

    resp, _ := client.Test(input)

    return C.CString(resp.Data)
}

編譯為動(dòng)態(tài)庫(kù)令漂，執(zhí)行下面命令會(huì)生成libclient.h 與 libclient.so兩個(gè)文件膝昆。

go build -buildmode=c-shared -o libclient.so client.go

C 語(yǔ)言調(diào)用該 Go生成的動(dòng)態(tài)庫(kù)：

#include <stdio.h>
#include "libclient.h"

int main()
{
    
    GoString input = {(char*)"test", 4};
    GoString ip = {(char*)"127.0.0.1", 9};
    GoString port = {(char*)"9090", 4};

    char *res = NULL;

    res = Test(input, ip, port);

    if (res != NULL)
    {
        printf("%s\n", res);
    }
    
    return 0;
}