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。