client.cpp

本程序是网络编程部分

/********************************************************************
	created:	2006/07/28
	filename: 	Client.cpp
	author:		李创
	http://www.cppblog.com/converse/

	purpose:	
*********************************************************************/

#pragma comment(lib, "WS2_32")

#include <WinSock2.h>
#include <stdio.h>
#include <assert.h>

#include "../CommonDef.h"

long	g_lLength = 0;
char*	g_pBuff = NULL;
char	g_szFileName[MAXFILEDIRLENGTH];
char	g_szBuff[MAX_PACKET_SIZE + 1];
SOCKET	g_sClient;

// 初始化socket库
bool InitSocket();
// 关闭socket库
bool CloseSocket();
// 把用户输入的文件路径传送到server端
bool SendFileNameToServer();
// 与server端连接
bool ConectToServer();
// 打开文件失败
bool OpenFileError(CCSDef::TMSG_HEADER *pMsgHeader);
// 分配空间以便写入文件
bool AllocateMemoryForFile(CCSDef::TMSG_HEADER *pMsgHeader);
// 写入文件
bool WriteToFile(CCSDef::TMSG_HEADER *pMsgHeader);
// 处理server端传送过来的消息
bool ProcessMsg();

int main()
{
	InitSocket();
	ConectToServer();

	CloseSocket();

	return 0;
}

// 初始化socket库
bool InitSocket()
{
	// 初始化socket dll
	WSADATA wsaData;
	WORD socketVersion = MAKEWORD(2, 2);
	if (::WSAStartup(socketVersion, &wsaData) != 0)
	{
		printf("Init socket dll error\n");
		exit(-1);
	}

	return true;
}

// 关闭socket库
bool CloseSocket()
{
	// 关闭套接字
	::closesocket(g_sClient);
	// 释放winsock库
	::WSACleanup();

	return true;
}

// 与server端连接进行文件的传输
bool ConectToServer()
{
	// 初始化socket套接字
	if (SOCKET_ERROR == (g_sClient = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)))
	{
		printf("Init Socket Error!\n");
		exit(-1);
	}

	sockaddr_in servAddr;
	servAddr.sin_family = AF_INET;
	servAddr.sin_port	= htons(PORT);
	servAddr.sin_addr.S_un.S_addr = ::inet_addr(SERVER_IP);
	if (INVALID_SOCKET == (::connect(g_sClient, (sockaddr*)&servAddr, sizeof(sockaddr_in))))
	{
		printf("Connect to Server Error!\n");
		exit(-1);
	}

	// 输入文件路径传输到server端
	SendFileNameToServer();

	// 接收server端传过来的信息,直到保存文件成功为止
	while (true == ProcessMsg())
	{
	}

	return true;
}

// 把用户输入的文件路径传送到server端
bool SendFileNameToServer()
{
	char szFileName[MAXFILEDIRLENGTH];
	printf("Input the File Directory: ");

	fgets(szFileName, MAXFILEDIRLENGTH, stdin);

	// 把文件路径发到server端
	CCSDef::TMSG_FILENAME tMsgRequestFileName;
	strcpy(tMsgRequestFileName.szFileName, szFileName);
	if (SOCKET_ERROR == ::send(g_sClient, (char*)(&tMsgRequestFileName), sizeof(CCSDef::TMSG_FILENAME), 0))
	{
		printf("Send File Name Error!\n");
		exit(-1);
	}

	return true;
}

// 处理server端传送过来的消息
bool ProcessMsg()
{
	CCSDef::TMSG_HEADER *pMsgHeader;
	int nRecv = ::recv(g_sClient, g_szBuff, MAX_PACKET_SIZE + 1, 0);
	
	pMsgHeader = (CCSDef::TMSG_HEADER*)g_szBuff;

	switch (pMsgHeader->cMsgID)
	{
	case MSG_OPENFILE_ERROR:		// 打开文件错误
		{
			OpenFileError(pMsgHeader);
		}
		break;
	case MSG_FILELENGTH:			// 文件的长度
		{
			if (0 == g_lLength)
			{
				g_lLength = ((CCSDef::TMSG_FILELENGTH*)pMsgHeader)->lLength;
				printf("File Length: %d\n", g_lLength);
			}
		}
		break;
	case MSG_FILENAME:				// 文件名
		{
			return AllocateMemoryForFile(pMsgHeader);
		}
		break;
	case MSG_FILE:					// 传送文件,写入文件成功之后退出这个函数
		{
			if (WriteToFile(pMsgHeader))
			{
				return false;
			}
		}
		break;
	}

	return true;
}

// 打开文件失败
bool OpenFileError(CCSDef::TMSG_HEADER *pMsgHeader)
{
	if (NULL != g_pBuff)
		return true;
	assert(NULL != pMsgHeader);

	printf("Cannot find file!Please input again!\n");

	// 重新输入文件名称
	SendFileNameToServer();

	return true;
}

// 查找是否已经存在了要保存的文件,同时分配缓冲区保存文件
bool AllocateMemoryForFile(CCSDef::TMSG_HEADER *pMsgHeader)
{
	assert(NULL != pMsgHeader);

	if (NULL != g_pBuff)
	{
		return true;
	}

	CCSDef::TMSG_FILENAME* pRequestFilenameMsg = (CCSDef::TMSG_FILENAME*)pMsgHeader;
	printf("File Name: %s\n", pRequestFilenameMsg->szFileName);

	// 把文件的路径设置为C盘根目录下
	strcpy(g_szFileName, "c:\\");
	strcat(g_szFileName, pRequestFilenameMsg->szFileName);

	// 查找相同文件名的文件是否已经存在,如果存在报错退出
	FILE* pFile;
	if (NULL != (pFile = fopen(g_szFileName, "r")))
	{
		// 文件已经存在,要求重新输入一个文件
		printf("The file already exist!\n");
		CCSDef::TMSG_ERROR_MSG tMsgErrorMsg(MSG_FILEALREADYEXIT_ERROR);
		::send(g_sClient, (char*)(&tMsgErrorMsg), sizeof(CCSDef::TMSG_ERROR_MSG), 0);

		fclose(pFile);
		return false;
	}

	// 分配缓冲区开始接收文件,如果分配成功就给server端发送开始传送文件的要求
	g_pBuff = new char[g_lLength + 1];
	if (NULL != g_pBuff)
	{
		memset(g_pBuff, '\0', g_lLength + 1);
		printf("Now ready to get the file %s!\n", pRequestFilenameMsg->szFileName);
		CCSDef::TMSG_CLIENT_READY tMsgClientReady;

		if (SOCKET_ERROR == ::send(g_sClient, (char*)(&tMsgClientReady), sizeof(CCSDef::TMSG_CLIENT_READY), 0))
		{
			printf("Send Error!\n");
			exit(-1);
		}
	}
	else
	{
		printf("Alloc memory for file error!\n");
		exit(-1);
	}

	return true;
}

// 写入文件
bool WriteToFile(CCSDef::TMSG_HEADER *pMsgHeader)
{
	assert(NULL != pMsgHeader);

	CCSDef::TMSG_FILE* pMsgFile = (CCSDef::TMSG_FILE*)pMsgHeader;

	int nStart = pMsgFile->tFile.nStart;
	int nSize  = pMsgFile->tFile.nSize;
	memcpy(g_pBuff + nStart, pMsgFile->tFile.szBuff, nSize);
	if (0 == nStart)
	{
		printf("Saving file into buffer...\n");
	}

	memcpy(g_pBuff + nStart, pMsgFile->tFile.szBuff, nSize);
	//printf("start = %d, size = %d\n", nStart, nSize);
	
	// 如果已经保存到缓冲区完毕就写入文件
	if (nStart + nSize >= g_lLength)
	{
		printf("Writing to disk....\n");
		// 写入文件
		FILE* pFile;
		pFile = fopen(g_szFileName, "w+b");
		fwrite(g_pBuff, sizeof(char), g_lLength, pFile);

		delete [] g_pBuff;
		g_pBuff = NULL;
		fclose(pFile);

		// 保存文件成功传送消息给server退出server
		CCSDef::TMSG_SENDFILESUCCESS tMsgSendFileSuccess;
		while (SOCKET_ERROR == ::send(g_sClient, (char*)(&tMsgSendFileSuccess), sizeof(CCSDef::TMSG_SENDFILESUCCESS), 0))
		{
		}

		printf("Save the file %s success!\n", g_szFileName);

		return true;
	}
	else
	{
		return false;
	}
}