最近学习了200行代码实现一个简单的区块链https://github.com/lhartikk/naivechain
初步学习nodejs,实现P2P网络的简单模式,添加了多点信息同步更新。
节点功能实现:
var initHttpServer = () =>{//控制节点的HTTP服务器 类似节点操作 var app = express(); app.use(bodyParser.json()); app.get('/peers', (req, res) => {//获取显示网络中存在的节点, res.send(sockets.map(s => s._socket.remoteAddress + ':' + s._socket.remotePort)); }); app.post('/addPeer', (req, res) => {//请求添加新的节点{"peer" : "ws://localhost:6001"} connectToPeers([req.body.peer]);//添加新节点 res.send([req.body.peer]); }); app.get('/getNum', (req, res) => res.send(num));//显示num值 app.post('/numAdd', (req, res) => {//执行操作num++ num++; broadcast(responseLatestMsg());//广播 console.log('block added: ' + num);//终端实时打印出新增区块 res.send(); }); app.listen(http_port, () => console.log('Listening http on port: ' + http_port));//监听端口 }
P2P网络:
//---建立P2P网络 var initP2PServer = () => {//P2P websocket全双工 服务器 var server = new WebSocket.Server({port: p2p_port}); server.on('connection', ws => initConnection(ws)); console.log('listening websocket p2p port on: ' + p2p_port); }; var initConnection = (ws) => {//初始化连接 sockets.push(ws);//压入已连接的节点堆栈 initMessageHandler(ws);//信息处理 initErrorHandler(ws);//错误状态处理 write(ws,responseLatestMsg());//广播 console.log('new peer:'+ws._socket.remoteAddress + ':' + ws._socket.remotePort) }; var initMessageHandler = (ws) => {//同步信息处理 ws.on('message', (data) => { var message = JSON.parse(data); console.log('Received message' + JSON.stringify(message)); switch (message.type) { case MessageType.QUERY_LATEST: handleNum(message);//写入最新的num break; } }); }; var initErrorHandler = (ws) => {//错误信息处理 var closeConnection = (ws) => { console.log('connection failed to peer: ' + ws.url +" "+ws._socket.remoteAddress + ':' + ws._socket.remotePort); sockets.splice(sockets.indexOf(ws), 1); }; ws.on('close', () => closeConnection(ws)); ws.on('error', () => closeConnection(ws)); }; var handleNum = (message) => {//同步区块链信息 if (num<message.data) { num = message.data; console.log('We got new number ' + message.data); broadcast(responseLatestMsg());//有更新,向临近节点广播 } else { console.log('received num is not max. Do nothing'); } }; var connectToPeers = (newPeers) => {//连接新节点 客户端 newPeers.forEach((peer) => { var ws = new WebSocket(peer); ws.on('open', () => initConnection(ws)); ws.on('error', () => { console.log('connection failed') }); }); };
参考:https://github.com/zfzGit/P2PNodejs