feat: async task pipeline for media and llm workflows

server/worker.ts

@@ -0,0 +1,47 @@
+import "dotenv/config";
+import { ENV } from "./_core/env";
+import * as db from "./db";
+import { processBackgroundTask } from "./taskWorker";
+
+const workerId = `app-worker-${process.pid}`;
+
+function sleep(ms: number) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function workOnce() {
+  await db.requeueStaleBackgroundTasks(new Date(Date.now() - ENV.backgroundTaskStaleMs));
+
+  const task = await db.claimNextBackgroundTask(workerId);
+  if (!task) {
+    return false;
+  }
+
+  try {
+    const result = await processBackgroundTask(task);
+    if (result !== null) {
+      await db.completeBackgroundTask(task.id, result, "任务执行完成");
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Unknown background task error";
+    await db.failBackgroundTask(task.id, message);
+    console.error(`[worker] task ${task.id} failed:`, error);
+  }
+
+  return true;
+}
+
+async function main() {
+  console.log(`[worker] ${workerId} started`);
+  for (;;) {
+    const hasWorked = await workOnce();
+    if (!hasWorked) {
+      await sleep(ENV.backgroundTaskPollMs);
+    }
+  }
+}
+
+main().catch((error) => {
+  console.error("[worker] fatal error", error);
+  process.exit(1);
+});