ICE入门实例──ping和获取远程时间

虽然使用传统的SOCKET编程，我们可以更为清楚程序的性能，能够更直接的操控SOCKET的设置，比如发送超时时间，接受BUFFER的大小，以及进行自己的协议加密。但是由于其调试成本较高，且不易于分布式部署

ICE 作为一个中间件技术，已经得到越来越广泛的应用。在　ICE3.2 以后，由于采用了epoll 模型，其通信层的性能提升较为明显。而且其相较于SOCKET编程一个很明显的优势是便于调试。这对于程序员来说，无疑是很大的诱惑。

网上介绍ICE原理的文献很多，我就不废话。先从一个简单的实例开始，进行我们的ICE编程入门之旅：

建立一个testice.ice文件　

#ifndef _H_TEST_WG_ICE_H_
#define _H_TEST_WG_ICE_H_

module WG
{
        interface WGTestIce
        {
                int ping();
                int GetTime(out string strTime);
        };
};

#endif

我们需要建立一个客户端和一个服务端。

服务端文件如下：

testiceImpl.h

#include <iostream>
#include <string>
#include “testice.h”
#include <sys/time.h>
using namespace WG;
class CTestIceImpl: public WGTestIce
{
public:
        CTestIceImpl(){}
        ~CTestIceImpl(){}

        int ping(const Ice::Current& = Ice::Current())
        {
                std::cout << “ping successfully.” << std::endl;
                return 0;
        }

        int GetTime(std::string& strTime, const Ice::Current& = Ice::Current())
        {
                time_t tt = time(NULL);
                struct tm tm1;
                struct tm* pNow;

                pNow = localtime_r(&tt,&tm1);
                if (!pNow)
                {
                        strTime = “error”;
                        return -1;
                }
                char buf[32] = {0};
                sprintf(buf,”%04d-%02d-%02d %02d:%02d:%02d”,
                                                        pNow->tm_year+1900,
                                                        pNow->tm_mon+1,
                                                        pNow->tm_mday,
                                                        pNow->tm_hour,
                                                        pNow->tm_min,
                                                        pNow->tm_sec);
                strTime = buf;
                return 0;
        }

};
#endif

上面这个类派生了接口类，用做服务端的实现。

再建立一个主函数文件testServer.cpp’

#include <Ice/Ice.h>
#include “testice.h”
#include “testiceImpl.h”

int createSrv()
try
{
        int tmpargc = 0;
        char** tmpargv = NULL;

        Ice::CommunicatorPtr ic;
        ic = Ice::initialize(tmpargc,tmpargv);

        Ice::ObjectAdapterPtr adapter = ic->createObjectAdapterWithEndpoints(”WGSrv”,”default -p 7788″);
        Ice::ObjectPtr object = new CTestIceImpl();
        adapter->add(object, ic->stringToIdentity(”WGInterfaceAgentId”));

        adapter->activate();

        std::cout << “now server start successfully.” << std::endl;

        ic->waitForShutdown();

        if (ic)
        {
                std::cout << “now ice server exit.” << std::endl;
                ic->destroy();
        }

}
catch(const Ice::Exception& ex)
{
        std::cout << “catch ice exception, ” << ex << std::endl;
        return -1;
}
catch(…)
{
        std::cout << “catch unknown exception.” << std::endl;
        return -1;
}
int main(int argc, char** argv)
{
        std::cout << “before to create Srv” << std::endl;
        return createSrv();

}

接下来我们建立客户端测试文件　testClient.cpp
#include <iostream>
#include <Ice/Ice.h>
#include “testice.h”

Ice::CommunicatorPtr    pCommunicator;
Ice::ObjectPrx          pObject;
WG::WGTestIcePrx        pProxy;

const char* menu =
                “*****************test ice client ***********************\n”
                “\t 1 ping\n”
                “\t 2 getTime\n”
                “\t q quit\n”
                “********************************************************\n”;

void showMenu()
{
        std::cout << menu << std::endl;
        return;
}
int doMenu()
{
        int ret = 0;
        char c;
        std::string strTime;

        showMenu();
        c = getchar();

        while(c != ‘q’)
        {
                switch (c)
                {
                case ‘1′:
                        ret = pProxy->ping();
                        std::cout << “ping ret is ” << ret << std::endl;
                        break;
                case ‘2′:
                        ret = pProxy->GetTime(strTime);
                        std::cout << “GetTime ret is ” << ret << “retTime is ” << strTime << std::endl;
                        break;
                case ‘q’:
                        return 0;
                        break;
                default:
                        break;

                }

                sleep(2);
                showMenu();
                //system(”clear”);
                c = getchar();
        }
        return 0;
}

int main(int argc, char** argv)
try
{
        if (argc < 4)
        {
                std::cout << “argc less than 4. example is : testClient WGInterfaceAgentId 127.0.0.1 7788″ << std::endl;
                return -1;
        }
        char buf[128] = {0};
        snprintf(buf,sizeof(buf)-1,”%s:default -h %s -p %s”,argv[1], argv[2],argv[3]);

        int tmpargc = 0;
        char** tmpargv = NULL;

        pCommunicator = Ice::initialize(tmpargc,tmpargv);
        pObject = pCommunicator->stringToProxy(buf);

        pProxy = WG::WGTestIcePrx::checkedCast(pObject);

        return doMenu();

}
catch(const Ice::Exception& ex)
{
        std::cout << “catch ice exception, ” << ex << std::endl;
        return -1;
}
catch(…)
{
        std::cout << “catch unknown exception. ” << std::endl;
        return -1;
}

然后编译SERVER_OBJS=testice.o\
                testServer.o

CLIENT_OBJS=testice.o\
                testClient.o

就可以测试了。

先启动server,再启动客户端,　效果如下：

*****************test ice client ***********************
         1 ping
         2 getTime
         q quit
********************************************************

2
GetTime ret is 0retTime is 2008-12-29 20:15:30

好，那么入门第一步就完成了。