Ratan1729/code-execution

1// ─── Execution Queue ─────────────────────────2// Simple in-memory Promise-based queue3// Optimized for 1GB instance — no Redis needed4 5const config = require("../config");6const logger = require("../utils/logger.util");7 8class QueueService {9  constructor() {10    this.maxConcurrent = config.MAX_CONCURRENT;11    this.running = 0;12    this.waiting = [];13    this.totalProcessed = 0;14    this.totalFailed = 0;15  }16 17  /**18   * Enqueue a task for execution.19   * Returns a Promise that resolves with the task result.20   * If max concurrency is reached, the task waits in queue.21   */22  enqueue(task) {23    return new Promise((resolve, reject) => {24      this.waiting.push({ task, resolve, reject, enqueuedAt: Date.now() });25      logger.debug(26        `📋 Queue: ${this.running} running, ${this.waiting.length} waiting`,27      );28      this._process();29    });30  }31 32  /**33   * Process next task if capacity is available34   */35  async _process() {36    if (this.running >= this.maxConcurrent || this.waiting.length === 0) {37      return;38    }39 40    const { task, resolve, reject, enqueuedAt } = this.waiting.shift();41    const waitTime = Date.now() - enqueuedAt;42    this.running++;43 44    if (waitTime > 100) {45      logger.info(`⏳ Task waited ${waitTime}ms in queue`);46    }47 48    try {49      const result = await task();50      this.totalProcessed++;51      resolve(result);52    } catch (err) {53      this.totalFailed++;54      reject(err);55    } finally {56      this.running--;57      // Schedule next task processing58      setImmediate(() => this._process());59    }60  }61 62  /**63   * Get current queue status64   */65  getStatus() {66    return {67      running: this.running,68      waiting: this.waiting.length,69      maxConcurrent: this.maxConcurrent,70      totalProcessed: this.totalProcessed,71      totalFailed: this.totalFailed,72    };73  }74}75 76module.exports = new QueueService();77