0.2.6-dev: traffic counters — HTTP body bytes by category (assets / audio / code / data) and WebSocket wire / payload bytes since the start at GET /healthz?traffic=1, and the page's own downloads (Resource Timing transferSize) as a traffic line in the 问题反馈 diagnostics (host bandwidth layer 0.4); golden: unchanged

server/http/routes.js

@@ -4,9 +4,11 @@
 //   * a URL longer than 4096 characters → 414; one that does not parse → 400;
 //   * any method but GET / HEAD → 405 with `Allow: GET, HEAD`;
 //   * GET /healthz → JSON status (protocol `version`, release `app`, uptime, the served `build`, sockets, sessions,
-//     rooms, matches), never cached;
+//     rooms, matches), never cached; `?traffic=1` adds the traffic counters (traffic.js: bytes by category since the
+//     start, WebSocket wire and payload bytes);
 //   * everything else → the static files (static.js).
-// A route that throws is logged and answers 500.
+// Every response's body bytes count in the traffic counters (traffic.js meter). A route that throws is logged and
+// answers 500.
 
 import { PROTOCOL_VERSION, APP_VERSION } from '../../shared/constants.js';
 import { buildTag } from './buildTag.js';
@@ -15,20 +17,26 @@ import { setSecurityHeaders, sendError, sendJson, splitUrl } from './common.js';
 const MAX_URL_LENGTH = 4096;
 
 /**
- * The GET /healthz body.
+ * The GET /healthz body (`withTraffic`: plus the traffic counters, `?traffic=1`).
  * @param {{ startedAt: number, network: import('../net.js').Network, registry: import('../net.js').SessionRegistry,
- *           lobby: import('../lobby.js').Lobby }} health
+ *           lobby: import('../lobby.js').Lobby, traffic?: ReturnType<typeof import('./traffic.js').createTrafficCounter> }} health
+ * @param {boolean} [withTraffic]
  */
-export function healthReport({ startedAt, network, registry, lobby }) {
-  return {
+export function healthReport({ startedAt, network, registry, lobby, traffic }, withTraffic = false) {
+  const report = {
     ok: true, version: PROTOCOL_VERSION, app: APP_VERSION, uptimeSec: Math.round((Date.now() - startedAt) / 1000),
     // the runtime the server is serving right now (public/js/ui/buildGuard.js): a page whose own build is
     // older than this reloads itself, so a deploy reaches clients that never reload
     build: buildTag(),
     sockets: network.connectionCount, sessions: registry.size, ...lobby.stats(),
   };
+  if (withTraffic && traffic) report.traffic = traffic.snapshot();
+  return report;
 }
 
+/** Does the query ask for the traffic counters (`traffic`, `traffic=1`, `traffic=true`)? */
+const wantsTraffic = (query) => /(?:^|&)traffic(?:=(?:1|true|yes))?(?:&|$)/i.test(query || '');
+
 /**
  * The request listener for `http.createServer`.
  * @param {{ serveStatic: (req: import('node:http').IncomingMessage, res: import('node:http').ServerResponse,
@@ -48,7 +56,7 @@ export function createRequestHandler({ serveStatic, health, log }) {
       return;
     }
     if (parts.rawPath === '/healthz') {
-      sendJson(req, res, 200, healthReport(health));
+      sendJson(req, res, 200, healthReport(health, wantsTraffic(parts.query)));
       return;
     }
     await serveStatic(req, res, parts.rawPath, parts.query);
@@ -56,6 +64,7 @@ export function createRequestHandler({ serveStatic, health, log }) {
 
   return (req, res) => {
     setSecurityHeaders(res);
+    if (health.traffic) health.traffic.meter(res, splitUrl(req.url || '/')?.rawPath || '/');
     handleRequest(req, res).catch((e) => {
       log.error('[http] request failed', e);
       sendError(req, res, 500, '服务器内部错误 · Internal error');

server/http/traffic.js

@@ -0,0 +1,102 @@
+// server/http/traffic.js — what this server has sent and received since it started (host bandwidth, layer 0):
+//
+//   * HTTP: per category of shared/assetPaths.js trafficCategory (assets / audio / code / data / other) the responses
+//     and the body bytes actually written (after gzip / brotli; headers not counted), and how many were 304s;
+//   * WebSocket: the connections, the bytes on the wire both ways (the sockets' own counters, after permessage-deflate,
+//     frame headers included, the HTTP upgrade not) and the message payloads before compression — their ratio is what
+//     the compression saves.
+//
+// routes.js meters every response (`meter`), websocket.js every socket (`wsOpen` / `wsClose` / `wsSent` / `wsReceived`);
+// `snapshot()` is the `traffic` object of GET /healthz?traffic=1 (docs/DEPLOY.md §5). Nothing is stored or sent
+// anywhere else; the counters start at zero with the process.
+
+import { TRAFFIC_CATEGORIES, trafficCategory } from '../../shared/assetPaths.js';
+
+/** Byte length of a chunk handed to res.write / res.end (a string in `encoding`, utf8 by default). */
+function chunkBytes(chunk, encoding) {
+  if (chunk == null || typeof chunk === 'function') return 0;
+  if (typeof chunk === 'string') return Buffer.byteLength(chunk, typeof encoding === 'string' && Buffer.isEncoding(encoding) ? encoding : 'utf8');
+  return typeof chunk.byteLength === 'number' ? chunk.byteLength : 0;
+}
+
+/** Length of a ws 'message' payload (a Buffer, an ArrayBuffer or, fragmented, a Buffer list). */
+function payloadBytes(data) {
+  if (Array.isArray(data)) return data.reduce((n, b) => n + payloadBytes(b), 0);
+  return data && typeof data.byteLength === 'number' ? data.byteLength : typeof data === 'string' ? Buffer.byteLength(data) : 0;
+}
+
+/**
+ * A traffic counter for one server.
+ * @param {{ now?: () => number }} [opts]
+ */
+export function createTrafficCounter({ now = Date.now } = {}) {
+  const startedAt = now();
+  const http = Object.fromEntries(TRAFFIC_CATEGORIES.map((c) => [c, { requests: 0, bytes: 0, notModified: 0 }]));
+  const ws = { connections: 0, wireOut: 0, wireIn: 0, payloadOut: 0, payloadIn: 0, messagesOut: 0, messagesIn: 0 };
+  /** @type {Map<import('node:net').Socket, { out: number, in: number }>} live sockets and their counters at the upgrade */
+  const live = new Map();
+
+  /** One finished HTTP response. */
+  function record(path, status, bytes) {
+    const c = http[trafficCategory(path)] || http.other;
+    c.requests++;
+    c.bytes += bytes;
+    if (status === 304) c.notModified++;
+  }
+
+  return {
+    /**
+     * Count the body bytes of `res` (every res.write / res.end) under the category of `path`, once the response is
+     * done or its connection gone.
+     * @param {import('node:http').ServerResponse} res
+     * @param {string} path the request's URL path
+     */
+    meter(res, path) {
+      let bytes = 0;
+      const { write, end } = res;
+      res.write = function meteredWrite(chunk, encoding, cb) {
+        bytes += chunkBytes(chunk, encoding);
+        return write.call(this, chunk, encoding, cb);
+      };
+      res.end = function meteredEnd(chunk, encoding, cb) {
+        bytes += chunkBytes(chunk, encoding);
+        return end.call(this, chunk, encoding, cb);
+      };
+      res.once('close', () => record(path, res.statusCode, bytes));
+    },
+    /** A WebSocket connection opened on `socket` (after its upgrade answer was written). */
+    wsOpen(socket) {
+      ws.connections++;
+      if (socket && !live.has(socket)) live.set(socket, { out: socket.bytesWritten || 0, in: socket.bytesRead || 0 });
+    },
+    /** …and closed: its wire bytes move to the totals. */
+    wsClose(socket) {
+      const base = live.get(socket);
+      if (!base) return;
+      live.delete(socket);
+      ws.wireOut += Math.max(0, (socket.bytesWritten || 0) - base.out);
+      ws.wireIn += Math.max(0, (socket.bytesRead || 0) - base.in);
+    },
+    /** A message handed to ws.send (its payload before compression). */
+    wsSent(data) { ws.messagesOut++; ws.payloadOut += payloadBytes(data); },
+    /** A message received (its payload after inflating). */
+    wsReceived(data) { ws.messagesIn++; ws.payloadIn += payloadBytes(data); },
+    /** The counters now (plain JSON). */
+    snapshot() {
+      let wireOut = ws.wireOut;
+      let wireIn = ws.wireIn;
+      for (const [socket, base] of live) {
+        wireOut += Math.max(0, (socket.bytesWritten || 0) - base.out);
+        wireIn += Math.max(0, (socket.bytesRead || 0) - base.in);
+      }
+      const byCat = Object.fromEntries(Object.entries(http).map(([k, v]) => [k, { ...v }]));
+      const total = Object.values(http).reduce((t, v) => ({ requests: t.requests + v.requests, bytes: t.bytes + v.bytes }), { requests: 0, bytes: 0 });
+      return {
+        since: new Date(startedAt).toISOString(),
+        seconds: Math.max(0, Math.round((now() - startedAt) / 1000)),
+        http: { ...byCat, total },
+        ws: { ...ws, open: live.size, wireOut, wireIn },
+      };
+    },
+  };
+}

server/http/websocket.js

@@ -61,15 +61,37 @@ export function createSessionStack(opts, { data, log }) {
   return { registry, lobby, network };
 }
 
+/**
+ * Count a socket in the traffic counters (traffic.js): its wire bytes from now until it closes, the payload of every
+ * message it sends (ws.send wrapped) and receives.
+ * @param {import('ws').WebSocket} ws
+ * @param {import('node:http').IncomingMessage} req
+ * @param {ReturnType<typeof import('./traffic.js').createTrafficCounter>} traffic
+ */
+function meterSocket(ws, req, traffic) {
+  const socket = req.socket;
+  traffic.wsOpen(socket);
+  const send = ws.send;
+  ws.send = function meteredSend(data, ...rest) {
+    traffic.wsSent(data);
+    return send.call(this, data, ...rest);
+  };
+  ws.on('message', (data) => traffic.wsReceived(data));
+  ws.once('close', () => traffic.wsClose(socket));
+}
+
 /**
  * Serve the WebSocket endpoint /ws on `server` (its 'upgrade' event).
  * @param {import('node:http').Server} server
- * @param {{ network: Network, log: object }} deps
+ * @param {{ network: Network, log: object, traffic?: ReturnType<typeof import('./traffic.js').createTrafficCounter> }} deps
  * @returns {WebSocketServer}
  */
-export function attachWebSocket(server, { network, log }) {
+export function attachWebSocket(server, { network, log, traffic = null }) {
   const wss = new WebSocketServer({ noServer: true, maxPayload: WS_MAX_PAYLOAD, perMessageDeflate: { ...WS_DEFLATE }, clientTracking: false });
-  wss.on('connection', (ws, req) => network.handleConnection(ws, req));
+  wss.on('connection', (ws, req) => {
+    if (traffic) meterSocket(ws, req, traffic);
+    network.handleConnection(ws, req);
+  });
   wss.on('error', (e) => log.error('[ws] server error', e));
 
   server.on('upgrade', (req, socket, head) => {