Building a Simple Task Queue

When building web applications, you often need to process multiple async operations in a controlled manner. A simple task queue can help manage these operations without overwhelming your system.

Here’s a basic implementation using Promise.all for concurrent processing:

class TaskQueue {
  constructor(concurrency = 3) {
    this.concurrency = concurrency;
    this.running = 0;
    this.queue = [];
  }

  async add(task) {
    if (this.running >= this.concurrency) {
      await new Promise(resolve => this.queue.push(resolve));
    }

    this.running++;
    try {
      return await task();
    } finally {
      this.running--;
      const next = this.queue.shift();
      if (next) next();
    }
  }
}

This approach is particularly useful when you need to limit the number of simultaneous API calls or file operations in your application.