implemented a lot of features

commands/workers/Deferred.ts

@@ -0,0 +1,57 @@
+import { BaseCommand, flags } from '@adonisjs/core/ace'
+import { CommandOptions } from '@adonisjs/core/types/ace'
+import env from '#start/env'
+import Shutdown from '#services/Shutdown'
+import NntpService from '#services/NntpService'
+import QueueService from '#services/QueueService'
+import DeferredService from '#services/DeferredService'
+
+const IDLE_MS = 60_000
+
+/**
+ * Works through `deferred_files` (CONCEPT.md D28): one body per file, and
+ * small files completely. Not started by default (compose profile
+ * `deferred`); run it when there is bandwidth to spare.
+ */
+export default class DeferredWorker extends BaseCommand {
+  public static commandName = 'worker:deferred'
+  public static description = 'Samples deferred files (e.g. ngPost uploads): one article body per file.'
+
+  public static options: CommandOptions = {
+    startApp: true,
+  }
+
+  @flags.number({ description: 'Stop after this many files (default: keep running)' })
+  declare limit?: number
+
+  public async run() {
+    const concurrency = env.get('DEFERRED_CONCURRENCY', 4)
+    this.logger.info(`Deferred worker started (concurrency ${concurrency}).`)
+    const counts: Record<string, number> = {}
+    let done = 0
+    try {
+      while (!Shutdown.requested && (!this.limit || done < this.limit)) {
+        const batch = await DeferredService.claim(Math.min(concurrency * 4, this.limit ? this.limit - done : Infinity))
+        if (batch.length === 0) {
+          if (this.limit) break
+          await Shutdown.sleep(IDLE_MS)
+          continue
+        }
+        let next = 0
+        await Promise.all(
+          Array.from({ length: concurrency }, async () => {
+            while (next < batch.length) {
+              const status = await DeferredService.process(batch[next++])
+              counts[status] = (counts[status] ?? 0) + 1
+            }
+          })
+        )
+        done += batch.length
+        this.logger.info(`${done} deferred files processed: ${Object.entries(counts).map(([k, v]) => `${v} ${k}`).join(', ')}.`)
+      }
+    } finally {
+      await NntpService.shutdown()
+      await QueueService.closeAll()
+    }
+  }
+}