QueuedRequest

QueuedRequest.js

var request = require('request'),
  Promise = require('promise'),
  extend = require('extend');

module.exports = QueuedRequest;

function QueuedRequest(interval) {
  this.interval = interval;
  this.queue = [];
  this.loop = loop.bind(this);
}

QueuedRequest.prototype = {
  start: function() {
    this.timerId = setTimeout(this.loop, this.interval);
  },
  stop: function() {
    clearTimeout(this.timerId);
    delete this.timerId;
  },
  isRunning: function() {
    return !!this.timerId;
  },
  get: function(url, query) {
    var queue = this.queue;

    return new Promise(function(resolve, reject) {
      queue.push({
        url: url,
        query: query,
        resolve: resolve,
        reject: reject
      });
      console.log(queue);
    });
  }
};

function loop() {
  // リクエストキューから取り出し、なければ何もしない
  var queued = this.queue.shift();
  if (!queued) return this.start();

  var self = this;

  // リクエストを実行して結果を返す
  requestPromise(queued.url, queued.query).then(function(result) {
    queued.resolve(result);
    self.start();
  }, function(err) {
    queued.reject(err);
    self.start();
  });
}

function requestPromise(url, query) {
  return new Promise(function(resolve, reject) {
    request(url, {
      qs: query
    }, function(err, response, data) {
      if (err)
        reject(err);
      else
        resolve(data);
    });
  });
};