batcher.js

"use strict";

class Batcher {
  constructor(size = 10, callback = () => {}) {
    this.size = size;
    this.queue = [];
    this.callback = callback;
  }

  static create(size = 10, callback = () => {}) {
    return new Batcher(size, callback);
  }

  async add(item) {
    this.queue.push(item);

    if (this.queue.length >= this.size) {
      await this._process();
    }
  }

  async finish() {
    if (this.queue.length) {
      await this._process();
    }
  }

  async _process() {
    const items = [];
    while (this.queue.length) {
      const item = this.queue.shift();
      items.push(item);
    }
    if (items.length) {
      await this.callback(items);
    }
  }
}

module.exports = Batcher;