Method drain

src/extraction/parse-pool.ts:394–422

()

  }

  private drain(): void {
    // Grow toward maxSize while queued work outstrips workers that are idle OR
    // already on their way up — throttled so we never cold-start the whole pool
    // at once.
    while (
      this.queue.length > this.idle.length + this.pending.size &&
      this.workers.size < this.maxSize &&
      this.pending.size < MAX_CONCURRENT_SPAWN &&
      !this.destroyed &&
      this.healthy
    ) {
      this.spawnOne();
    }
    // Dispatch queued jobs to idle workers.
    while (this.idle.length && this.queue.length) {
      let job: ParseJob | undefined;
      while (this.queue.length && (job = this.queue.shift()) && job.settled) job = undefined;
      if (!job || job.settled) break;
      const w = this.idle.pop()!;
      this.dispatch(w, job);
    }
    // Hang-prevention: if there's queued work but nothing can ever run it (no
    // idle workers, none spawning, none alive), fail it instead of hanging
    // forever. Reached only when the crash budget is exhausted or after destroy.
    if (this.queue.length && this.idle.length === 0 && this.pending.size === 0 && this.workers.size === 0) {
      const reason = this.destroyed ? 'parse pool destroyed' : 'parse pool exhausted its worker crash budget';
      for (const job of this.queue.splice(0)) this.settle(job, undefined, new Error(reason));
    }
  }

  private settle(job: ParseJob, result?: ExtractionResult, err?: Error): void {
    if (job.settled) return;