89 lines
2.9 KiB
JavaScript
89 lines
2.9 KiB
JavaScript
// sse-server.js (CommonJS)
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const http = require('http');
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const express = require('express');
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const cors = require('cors');
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function startSSE({
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port = 3312,
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path = '/events',
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corsOrigin = '*', // 也可填 'http://localhost:8080' 或你的前端地址
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heartbeatMs = 15000,
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} = {}) {
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const app = express();
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if (corsOrigin) app.use(cors({ origin: corsOrigin, credentials: true }));
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const clients = new Map(); // id -> res
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app.get(path, (req, res) => {
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res.set({
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'Content-Type': 'text/event-stream; charset=utf-8',
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'Cache-Control': 'no-cache, no-transform',
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'Connection': 'keep-alive',
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'X-Accel-Buffering': 'no'
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});
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if (corsOrigin) res.set('Access-Control-Allow-Origin', corsOrigin);
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res.flushHeaders?.();
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const id = `${Date.now()}-${Math.random().toString(36).slice(2)}`;
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clients.set(id, res);
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// // 初次握手
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// res.write(`event: hello\n`);
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// res.write(`data: ${JSON.stringify({ connected: true, t: Date.now() })}\n\n`);
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console.log("sse连接成功")
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const timer = setInterval(() => {
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if (!res.writableEnded) res.write(`: keep-alive ${Date.now()}\n\n`);
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}, heartbeatMs);
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req.on('close', () => {
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clearInterval(timer);
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clients.delete(id);
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try { res.end(); } catch { }
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});
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});
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// 简单健康检查
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app.get('/health', (_req, res) => res.json({ ok: true, clients: clients.size }));
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const server = http.createServer(app);
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server.listen(port, () => {
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console.log(`[SSE] listening at http://127.0.0.1:${port}${path}`);
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});
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// 广播：event 自定义；data 可传对象/字符串/Buffer
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function broadcast(eventOrData, maybeData) {
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const hasEventName = typeof maybeData !== 'undefined'; // 两种调用方式
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const eventName = hasEventName ? eventOrData : null;
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const data = hasEventName ? maybeData : eventOrData;
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const payload = Buffer.isBuffer(data)
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? data.toString()
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: (typeof data === 'string' ? data : JSON.stringify(data));
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for (const [id, res] of clients.entries()) {
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try {
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if (eventName && eventName !== 'message') {
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res.write(`event: ${eventName}\n`);
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} // 否则省略 event 行 => 触发前端 onmessage
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res.write(`data: ${payload}\n\n`);
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} catch {
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clients.delete(id);
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try { res.end(); } catch { }
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}
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}
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}
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async function close() {
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for (const [, res] of clients.entries()) {
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try { res.end(); } catch { }
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}
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clients.clear();
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await new Promise(r => server.close(r));
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}
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return { app, server, broadcast, close, clientsCount: () => clients.size };
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}
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module.exports = { startSSE };
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