Share upstream event stream hub

2026-04-24 12:30:11 +03:00
parent 8e610ca8b3
commit 7030549d78
12 changed files with 1436 additions and 201 deletions
@@ -0,0 +1,143 @@
+import { createUpstreamSseReader } from './upstream-reader.js';
+
+export const MESSAGE_STREAM_GLOBAL_REPLAY_LIMIT = 512;
+
+export function createGlobalMessageStreamHub({
+  buildOpenCodeUrl,
+  getOpenCodeAuthHeaders,
+  fetchImpl = fetch,
+  upstreamStallTimeoutMs,
+  upstreamReconnectDelayMs,
+  replayLimit = MESSAGE_STREAM_GLOBAL_REPLAY_LIMIT,
+}) {
+  const eventSubscribers = new Set();
+  const statusSubscribers = new Set();
+  const replay = [];
+
+  let controller = null;
+  let reader = null;
+  let connected = false;
+  let everConnected = false;
+  let buildUrlFailed = false;
+
+  const notifyStatus = (status) => {
+    for (const subscriber of Array.from(statusSubscribers)) {
+      subscriber(status);
+    }
+  };
+
+  const normalizeEvent = ({ envelope, payload }) => {
+    const directory =
+      typeof envelope?.directory === 'string' && envelope.directory.length > 0 ? envelope.directory : 'global';
+    const eventId = typeof envelope?.eventId === 'string' && envelope.eventId.length > 0 ? envelope.eventId : undefined;
+    return {
+      envelope,
+      payload,
+      directory,
+      eventId,
+    };
+  };
+
+  const start = () => {
+    if (reader) {
+      return;
+    }
+
+    controller = new AbortController();
+    reader = createUpstreamSseReader({
+      signal: controller.signal,
+      stallTimeoutMs: upstreamStallTimeoutMs,
+      reconnectDelayMs: upstreamReconnectDelayMs,
+      fetchImpl,
+      buildUrl: () => {
+        buildUrlFailed = false;
+        try {
+          return new URL(buildOpenCodeUrl('/global/event', ''));
+        } catch {
+          buildUrlFailed = true;
+          throw new Error('OpenCode service unavailable');
+        }
+      },
+      getHeaders: getOpenCodeAuthHeaders,
+      onConnect() {
+        connected = true;
+        const wasReady = everConnected;
+        everConnected = true;
+        notifyStatus({ type: 'connect', wasReady });
+      },
+      onDisconnect({ reason }) {
+        connected = false;
+        notifyStatus({ type: 'disconnect', reason });
+      },
+      onEvent(event) {
+        const normalized = normalizeEvent(event);
+        if (normalized.eventId) {
+          replay.push(normalized);
+          if (replay.length > replayLimit) {
+            replay.splice(0, replay.length - replayLimit);
+          }
+        }
+
+        for (const subscriber of Array.from(eventSubscribers)) {
+          subscriber(normalized);
+        }
+      },
+      onError(error) {
+        if (controller?.signal.aborted) {
+          return;
+        }
+
+        notifyStatus({
+          type: everConnected ? 'error' : 'initial-error',
+          error,
+          buildUrlFailed,
+        });
+      },
+    });
+
+    void reader.start();
+  };
+
+  const stop = () => {
+    connected = false;
+    reader?.stop();
+    if (controller && !controller.signal.aborted) {
+      controller.abort();
+    }
+    reader = null;
+    controller = null;
+    everConnected = false;
+    buildUrlFailed = false;
+  };
+
+  return {
+    start,
+    stop,
+    isConnected() {
+      return connected;
+    },
+    hasConnected() {
+      return everConnected;
+    },
+    subscribeEvent(subscriber) {
+      eventSubscribers.add(subscriber);
+      return () => {
+        eventSubscribers.delete(subscriber);
+      };
+    },
+    subscribeStatus(subscriber) {
+      statusSubscribers.add(subscriber);
+      return () => {
+        statusSubscribers.delete(subscriber);
+      };
+    },
+    replayAfter(eventId) {
+      if (!eventId) {
+        return [];
+      }
+
+      const index = replay.findIndex((entry) => entry.eventId === eventId);
+      return index === -1 ? [] : replay.slice(index + 1);
+    },
+  };
+}