一、实验目标
首先将一个图形文件划分成指定大小的数据块。在一台主机下模拟五个应用进程,其中有四个peer,分别为peer1,peer2,peer3,peer4,还有一个tracker。将上述的图片数据块按要求分配到三个节点(peer1,peer2,peer3)上,peer4从tracker上获取三个节点的数据块信息。最后从三个节点(peer1,peer2,peer3)传输图片文件的不同块到peer4上,使得该节点获取完整的图片文件。
二、实验环境
编程测试环境:软件:Dev C++ 语言:标准C语言
实验结构图:
假定peer1上存放数据块1,3,5,7
peer2上存放数据块9,10,11
peer3上存放数据块2,4,6,8
三、方案流程
实验包含以下组件:
Tracker服务器:负责记录哪些节点拥有文件的哪些部分。收到请求即发送相关信息。
节点(Peers):拥有文件的一部分,并与其他节点交换数据。也可以向Tracker服务器请求其他拥有文件部分的节点信息。
1.初始化
选择一个图片文件,并将其分割为11个小块(例如,每个块为256KB)。
设置一个Tracker服务器,并启动它。
2.创建节点(Peers)
启动4个节点,命名为peer1,peer2,peer3,peer4。
将数据块按(4,3,4)分配给Peer1,Peer2,Peer3
3.发送文件
让Peer4请求Tracker获取Peer1,Peer2,Peer3各节点上的数据块情况。从Peer1,Peer2,Peer3获取图片的数据块。得到所有数据块后拼接数据块得到完整的图片。
1 #include <windows.h> 2 #include <iostream> 3 #include <winsock.h> 4 using namespace std; 5 #define NO_FLAGS_SET 0 6 #define FILE_ID_START 1 7 #define FILE_ID_END 4 8 #define FILE_BLOCK_SIZE 409600 9 #define PORT (u_short) 44966 10 #define DEST_IP_ADDR "127.0.0.1" //Server address 11 12 INT main(VOID) 13 { 14 WSADATA Data; 15 SOCKADDR_IN destSockAddr; 16 SOCKET destSocket; 17 unsigned long destAddr; 18 int status; 19 int numsnt; 20 21 /* initialize the Windows Socket DLL */ 22 status=WSAStartup(MAKEWORD(1, 1), &Data); 23 if (status != 0) 24 cerr << "ERROR: WSAStartup unsuccessful" 25 << endl; 26 /* convert IP address into in_addr form */ 27 destAddr=inet_addr(DEST_IP_ADDR); 28 /* copy destAddr into sockaddr_in structure */ 29 memcpy(&destSockAddr.sin_addr, 30 &destAddr, sizeof(destAddr)); 31 /* specify the port portion of the address */ 32 destSockAddr.sin_port=htons(PORT); 33 /* specify the address family as Internet */ 34 destSockAddr.sin_family=AF_INET; 35 36 /* create a socket */ 37 destSocket=socket(AF_INET, SOCK_STREAM, 0); 38 if (destSocket == INVALID_SOCKET) 39 { 40 cerr << "ERROR: socket unsuccessful" << endl; 41 status=WSACleanup(); 42 if (status == SOCKET_ERROR) 43 cerr << "ERROR: WSACleanup unsuccessful" 44 << endl; 45 return(1); 46 } 47 48 cout << "Trying to connect to IP Address: " 49 << DEST_IP_ADDR << endl; 50 51 /* connect to the server */ 52 status=connect(destSocket, 53 (LPSOCKADDR) &destSockAddr, 54 sizeof(destSockAddr)); 55 if (status == SOCKET_ERROR) 56 { 57 cerr << "ERROR: connect unsuccessful" << endl; 58 status=closesocket(destSocket); 59 if (status == SOCKET_ERROR) 60 cerr << "ERROR: closesocket unsuccessful" 61 << endl; 62 status=WSACleanup(); 63 if (status == SOCKET_ERROR) 64 cerr << "ERROR: WSACleanup unsuccessful" 65 << endl; 66 return(1); 67 } 68 69 cout << "Connected..." << endl; 70 71 72 int id = FILE_ID_START; // 文件块编号 73 FILE *fp; // 文件块读取指针 74 char fileName[100]; //文件名 75 char path[100];//路径 76 char buf[FILE_BLOCK_SIZE]; 77 sprintf(fileName, "part_%02d", id); 78 while (id <= FILE_ID_END) { 79 send(destSocket, fileName, strlen(fileName) + 1, 0);// 先发送文件名 80 Sleep(50); 81 sprintf(path, "%s%s", "C:\\Users\\大梦一场\\Desktop\\peer1\\",fileName); 82 fp = fopen(path, "rb+"); 83 int count = fread(buf, 1, FILE_BLOCK_SIZE, fp); // 读取全部元素 84 fclose(fp); 85 send(destSocket, buf, count, 0); // 发送文件块 86 printf("ClientPeer1 sending %s successfully\n", path); 87 Sleep(3000); // 等待 3 s 88 id++; 89 sprintf(fileName, "part_%02d", id); 90 } 91 92 }
peer4
#include <windows.h> #include <iostream> #include <winsock.h> using namespace std; #define NO_FLAGS_SET 0 #define THIS_PORT (u_short) 44967 #define PORT (u_short) 44966 #define DEST_IP_ADDR "127.0.0.1" //Server address #define FILE_BLOCK_SIZE 409600 #define FILE_BLOCK_NUM 11 #define FILE_NAME_LEN 7 #define DEST_PORT (u_short) 44966 #define CLIENT_NUM 3 char dataBuffer[FILE_BLOCK_SIZE]; // 用于存储接收到的数据 char fileName[100]; //文件名 DWORD ThreadProc(LPVOID clientSock) { SOCKET NewConnection = (SOCKET)clientSock; char dataBuffer[FILE_BLOCK_SIZE]; // 用于存储接收到的数据 char fileName[100]; //文件名 int count; FILE *fp = NULL; char path[100];//路径 while ((count = recv(NewConnection, dataBuffer, sizeof(dataBuffer), 0)) > 0) { if (strlen(dataBuffer) == FILE_NAME_LEN) { // 发来的是文件名 strcpy(fileName, dataBuffer); // 记录文件名 printf("receving %s\n", fileName); } else { sprintf(path, "%s%s", "C:\\Users\\大梦一场\\Desktop\\peer4\\",fileName); fp = fopen(path, "wb"); // 创建文件 fwrite(dataBuffer, count, 1, fp); printf("receving data %s\n", fileName); fclose(fp); } } return 0; } int main(void) { int numsnt; char *getInfo="getInfo"; WSADATA Data; SOCKADDR_IN serverSockAddr; SOCKADDR_IN clientSockAddr; SOCKET serverSock; SOCKET clientSock; int addrLen=sizeof(SOCKADDR_IN); int status; int numrcv; char buffer[1024]; /* initialize the Windows Socket DLL */ status=WSAStartup(MAKEWORD(1, 1), &Data); /*初始化Winsock DLL*/ if (status != 0) cerr << "ERROR: WSAStartup unsuccessful" << endl; /* zero the sockaddr_in structure */ memset(&serverSockAddr, 0,sizeof(serverSockAddr)); /* specify the port portion of the address */ serverSockAddr.sin_port=htons(PORT); /* specify the address family as Internet */ serverSockAddr.sin_family=AF_INET; /* specify that the address does not matter */ /*INADDR_ANY 的具体含义是,绑定到0.0.0.0。此时,对所有的地址都将是有效的*/ serverSockAddr.sin_addr.s_addr=htonl(INADDR_ANY); /* create a socket */ serverSock=socket(AF_INET, SOCK_STREAM, 0); if (serverSock == INVALID_SOCKET) cerr << "ERROR: socket unsuccessful" << endl; /* associate the socket with the address */ status=bind(serverSock, (LPSOCKADDR) &serverSockAddr, sizeof(serverSockAddr)); if (status == SOCKET_ERROR) cerr << "ERROR: bind unsuccessful" << endl; /* allow the socket to take connections */ status=listen(serverSock, 1); if (status == SOCKET_ERROR) cerr << "ERROR: listen unsuccessful" << endl; int conn=0; while(1) { int clientAddrLen = sizeof(SOCKADDR); // 求出地址的长度 // 接收请求(链接客户端),第二个参数是客户端的地址 if ((clientSock = accept(serverSock, (LPSOCKADDR)&clientSockAddr, &clientAddrLen)) == INVALID_SOCKET) { printf("accept failed with error %d\n", WSAGetLastError()); closesocket(clientSock); // 释放客户端连接 } // 连接客户端成功,打印客户端的ip地址和端口号 printf("当前已连接:%s:%d\n", inet_ntoa(clientSockAddr.sin_addr), ntohs(clientSockAddr.sin_port)); // 开启线程处理客户端连接 CreateThread(NULL, 0, ThreadProc, (LPVOID)clientSock, 0, NULL); conn++; /* 文件的拼接 */ if (conn == CLIENT_NUM) { // 接收完3个进程发送的文件 Sleep(2000); printf("Succeeded in accepting all file blocks. \n"); int id = 1; // 文件块编号 FILE *fpr; // 文件块读取指针 FILE *fpw = fopen("C:\\Users\\大梦一场\\Desktop\\DarkSoul.jfif", "wb"); char fileName[100]; //文件名 while (id <= FILE_BLOCK_NUM) { sprintf(fileName, "C:\\Users\\大梦一场\\Desktop\\peer4\\part_%02d", id); fpr = fopen(fileName, "rb+"); int count = fread(dataBuffer, 1, FILE_BLOCK_SIZE, fpr); fwrite(dataBuffer, count, 1, fpw); id++; fclose(fpr); } fclose(fpw); Sleep(1000); printf("DarkSoul.jfif combining succeeded!\n"); } } }