feat(jobs): 增加后台任务运行时

apps/server/src/modules/jobs/job-lock.service.ts

@@ -0,0 +1,57 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { BackgroundJobRecord, ClaimJobInput, JOBS_PRISMA } from './jobs.types';
+
+const DEFAULT_LEASE_MS = 60_000;
+
+@Injectable()
+export class JobLockService {
+  constructor(@Inject(JOBS_PRISMA) private readonly prisma: any) {}
+
+  async claimNext(input: ClaimJobInput): Promise<BackgroundJobRecord | null> {
+    const now = input.now ?? new Date();
+    const leaseMs = input.leaseMs ?? DEFAULT_LEASE_MS;
+    const types = input.types?.map((type) => type.trim()).filter(Boolean) ?? [];
+
+    return (this.prisma as any).$transaction(async (tx: any) => {
+      const params: unknown[] = [now];
+      const typeCondition = buildTypeCondition(types, params);
+      const rows = await tx.$queryRawUnsafe(
+        `
+SELECT id
+FROM background_jobs
+WHERE (
+    (status = 'queued' AND available_at <= $1)
+    OR (status = 'running' AND locked_until IS NOT NULL AND locked_until < $1)
+  )
+  ${typeCondition}
+ORDER BY available_at ASC, created_at ASC
+LIMIT 1
+FOR UPDATE SKIP LOCKED
+`,
+        ...params,
+      );
+      const id = rows[0]?.id;
+      if (!id) return null;
+
+      return tx.backgroundJob.update({
+        where: { id },
+        data: {
+          status: 'running',
+          lockedBy: input.workerId,
+          lockedUntil: new Date(now.getTime() + leaseMs),
+          attempts: { increment: 1 },
+          lastError: null,
+        },
+      });
+    });
+  }
+}
+
+function buildTypeCondition(types: string[], params: unknown[]): string {
+  if (types.length === 0) return '';
+  const placeholders = types.map((type) => {
+    params.push(type);
+    return `$${params.length}`;
+  });
+  return `AND type IN (${placeholders.join(', ')})`;
+}