esnext-async/lib/promise_queue.js

Patterns for asynchronous computation in ES.next

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = undefined;

var _promise = require('babel-runtime/core-js/promise');

var _promise2 = _interopRequireDefault(_promise);

var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');

var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);

var _createClass2 = require('babel-runtime/helpers/createClass');

var _createClass3 = _interopRequireDefault(_createClass2);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var _default = function () {
  function _default() {
    (0, _classCallCheck3.default)(this, _default);
    this.requests = [];
    this.values = [];
  }

  (0, _createClass3.default)(_default, [{
    key: 'publish',
    value: function publish(value) {
      if (this.requests.length > 0) {
        this.requests.shift().resolve(value);
      } else {
        this.values.push({ value: value });
      }
    }
  }, {
    key: 'throw',
    value: function _throw(error) {
      if (this.requests.length > 0) {
        this.requests.shift().reject(error);
      } else {
        this.values.push({ error: error });
      }
    }
  }, {
    key: 'consume',
    value: function consume() {
      var _this = this;

      return new _promise2.default(function (resolve, reject) {
        if (_this.values.length === 0) {
          _this.requests.push({ resolve: resolve, reject: reject });
        } else {
          var item = _this.values.shift();
          if ('error' in item) {
            reject(item.error);
          } else {
            resolve(item.value);
          }
        }
      });
    }
  }]);
  return _default;
}();

exports.default = _default;