让我深信Node强大功能的演示之一是Ryan Dahl在此视频中展示的简单TCP聊天服务器:https://www.youtube.com/watch?v=jo_B4LTHi3I&t=28m23s
这是演示中的代码:
const net = require('net');
const server = net.createServer();
const sockets = [];
server.on('connection', (socket) => {
sockets.push(socket);
socket.on('data', (message) => {
for (const current_socket of sockets) {
if (current_socket !== socket) {
current_socket.write(message);
}
}
});
socket.on('end', () => {
const index = sockets.indexOf(socket);
sockets.splice(index, 1);
});
});
server.listen(8000, () => console.log('tcp server listening on port 8000'));
我在Deno网站上发现的唯一TCP示例是一个如下所示的回显服务器:
const listener = Deno.listen({ port: 8080 });
console.log("listening on 0.0.0.0:8080");
for await (const conn of listener) {
Deno.copy(conn, conn);
}
它既好又紧凑,但是我无法使用Deno.Conn
的{{1}}和read
方法将本示例转换为TCP聊天服务器。任何帮助将非常感激!我还认为添加到网站将是一个有用的示例。
答案 0 :(得分:2)
使用Deno.listen
创建服务器,并使用Deno.connect
连接到该服务器。
tcp
服务器/客户端的简单示例为:
server.js
const encoder = new TextEncoder();
const decoder = new TextDecoder();
const listener = Deno.listen({ port: 8080 });
console.log("listening on 0.0.0.0:8080");
for await (const conn of listener) {
// Read message
const buf = new Uint8Array(1024);
await conn.read(buf);
console.log('Server - received:', decoder.decode(buf))
// Respond
await conn.write(encoder.encode('pong'))
conn.close();
}
client.js
const encoder = new TextEncoder();
const decoder = new TextDecoder();
const conn = await Deno.connect({ hostname: "127.0.0.1", port: 8080 })
// Write to the server
await conn.write(encoder.encode('ping'));
// Read response
const buf = new Uint8Array(1024);
await conn.read(buf);
console.log('Client - Response:', decoder.decode(buf))
conn.close();
您可以从此处构建。对于聊天服务器,您将保持连接打开状态,并发送多条消息。
答案 1 :(得分:2)
好吧,经过更多玩耍之后,这是我的TCP聊天服务器:
const server = Deno.listen({ port: 8000 });
console.log("tcp server listening on port 8000");
const connections: Deno.Conn[] = [];
for await (const connection of server) {
// new connection
connections.push(connection);
handle_connection(connection);
}
async function handle_connection(connection: Deno.Conn) {
let buffer = new Uint8Array(1024);
while (true) {
const count = await connection.read(buffer);
if (!count) {
// connection closed
const index = connections.indexOf(connection);
connections.splice(index, 1);
break;
} else {
// message received
let message = buffer.subarray(0, count);
for (const current_connection of connections) {
if (current_connection !== connection) {
await current_connection.write(message);
}
}
}
}
}
该代码看起来与Node版本完全不同。就是说,TCP不维护消息边界,而Deno版本通过读取Uint8Array
缓冲区来使消息边界明确。这类似于Rust的std::net
和tokio::net
模块处理TCP的方式。实际上,我不太确定socket.on('data')
事件在Node中代表什么;好像只是来自TCP流的任意长度的数据。