thinknode/lib/Util/Await.js

A fast, flexible and all-in-one web framework for node.js.

"use strict";

exports.__esModule = true;

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

var _promise2 = _interopRequireDefault(_promise);

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

var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);

var _possibleConstructorReturn2 = require("babel-runtime/helpers/possibleConstructorReturn");

var _possibleConstructorReturn3 = _interopRequireDefault(_possibleConstructorReturn2);

var _inherits2 = require("babel-runtime/helpers/inherits");

var _inherits3 = _interopRequireDefault(_inherits2);

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

/**
 * 执行等待,避免一个耗时的操作多次被执行
 * callback需要返回一个Promise
 * 常用于避免并发多次执行某个事务的场景
 * @author     richen
 * @copyright  Copyright (c) 2016 - <richenlin(at)gmail.com>
 * @license    MIT
 * @version    16/7/14
 */
var _class = function (_THINK$Base) {
    (0, _inherits3.default)(_class, _THINK$Base);

    function _class() {
        (0, _classCallCheck3.default)(this, _class);
        return (0, _possibleConstructorReturn3.default)(this, _THINK$Base.apply(this, arguments));
    }

    _class.prototype.init = function init() {
        this.queue = {};
    };

    _class.prototype.run = function run(key, fn) {
        var _this2 = this;

        if (!(key in this.queue)) {
            this.queue[key] = [];
            return _promise2.default.resolve(fn()).then(function (data) {
                process.nextTick(function () {
                    _this2.queue[key].forEach(function (deferred) {
                        return deferred.resolve(data);
                    });
                    delete _this2.queue[key];
                });
                return data;
            }).catch(function (err) {
                process.nextTick(function () {
                    _this2.queue[key].forEach(function (deferred) {
                        return deferred.reject(err);
                    });
                    delete _this2.queue[key];
                });
                return THINK.error(err);
            });
        } else {
            var deferred = THINK.getDefer();
            this.queue[key].push(deferred);
            return deferred.promise;
        }
    };

    return _class;
}(THINK.Base);

exports.default = _class;