用 VC+socket 传输大文件

在这个程序中，客户端读取桌面的一个 1.48 GB (1,597,701,030 字节) 的RAR文件发送给服务器。因为这里仅用于学习，所以客户端要连接的目标地址使用127.0.0.1。服务器端接将收的文件文件保存在C盘根目录下。

为保证程序的可靠发送，程序采用TCP协议。经过反复试验得出结论，程序中的重中之重是双方的 ReadFile 和 WriteFile。相反 recv 和 send 不是重要的。为了使代码尽量简化，程序去掉所有错误检查，只让服务器端的accept函数提示一下有人发起连接。双方收发完文件之后直接退出程序。

//服务器端#include<iostream>#include<Windows.h>using namespace std;const int iBufferSize = 1024*1024;char buffer[iBufferSize];void main(){WSAData data;WSAStartup(MAKEWORD(2,2),&data);SOCKET s1 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);SOCKADDR_IN addr;addr.sin_family = AF_INET;addr.sin_port = htons(8888);addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);bind(s1, (SOCKADDR*)&addr, sizeof(addr));listen(s1, 5);int len = sizeof(addr);SOCKET s2 = accept(s1, (SOCKADDR*)&addr, & len);if(s2!=INVALID_SOCKET)cout<<" accept right"<<endl;LARGE_INTEGER i64FileSize, i64FileSizeCopy;recv(s2, (char*)&i64FileSize.QuadPart, sizeof(i64FileSize.QuadPart), 0);i64FileSizeCopy = i64FileSize;HANDLE hFile = CreateFile(L"c:\\a.rar", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_ALWAYS, 0, 0);while( i64FileSize.QuadPart >0 ){ZeroMemory(buffer, iBufferSize);int size;size = recv(s2, buffer, iBufferSize, 0);DWORD dwNumBytes;while( TRUE ){if( i64FileSize.QuadPart < size )size = i64FileSize.QuadPart;WriteFile(hFile, buffer, size, &dwNumBytes, 0);i64FileSize.QuadPart -= dwNumBytes;if( dwNumBytes < size )size -= dwNumBytes;elsebreak;}}}

 

//客户端#include<iostream>#include<Windows.h>using namespace std;const int iBufferSize = 1024*1024;char buffer[iBufferSize];void main(){WSAData data;WSAStartup(MAKEWORD(2,2),&data);SOCKET s1 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);SOCKADDR_IN addr;addr.sin_family = AF_INET;addr.sin_port = htons(8888);addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");connect(s1, (SOCKADDR*)&addr, sizeof(addr));HANDLE hFile = CreateFile(L"C:\\Users\\ys\\Desktop\\Visual C++开发入行真功夫光盘二次.rar",GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_ALWAYS, 0, 0);LARGE_INTEGER i64FileSize, i64FileSizeCopy;GetFileSizeEx(hFile, &i64FileSize);i64FileSizeCopy = i64FileSize;send(s1, (char*)&i64FileSize, sizeof(LARGE_INTEGER),0);while( i64FileSize.QuadPart > 0 ){DWORD dwNumBytes, dwNumberToRead = iBufferSize;while(TRUE){if( i64FileSize.QuadPart <= dwNumberToRead )dwNumberToRead = i64FileSize.QuadPart;ReadFile(hFile, buffer, dwNumberToRead, &dwNumBytes, 0);i64FileSize.QuadPart -= dwNumBytes;if( dwNumBytes < dwNumberToRead )dwNumberToRead -= dwNumBytes;elsebreak;}send(s1, buffer, iBufferSize, 0);cout<<"已发送 "<< (i64FileSizeCopy.QuadPart - i64FileSize.QuadPart)<<"B "<< (i64FileSizeCopy.QuadPart - i64FileSize.QuadPart)/1024<<"K "<< (i64FileSizeCopy.QuadPart - i64FileSize.QuadPart)/1024/1024<<"M "<< (i64FileSizeCopy.QuadPart - i64FileSize.QuadPart)/1024/1024/1024 <<"G"<<endl;}}