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