util-helpers/lib/AsyncMemo.js

一个基于业务场景的工具方法库

'use strict';

var tslib = require('tslib');
var cache2 = require('cache2');
var ut2 = require('ut2');

var AsyncMemo = (function () {
    function AsyncMemo(options, ns) {
        if (ns === void 0) { ns = 'uh_async_memo'; }
        this.promiseCache = {};
        this.cache = new cache2.Cache(ns, options);
    }
    AsyncMemo.prototype.run = function (asyncFn, key, options) {
        var _this = this;
        if (!key || !ut2.isString(key)) {
            return asyncFn();
        }
        var opts = tslib.__assign({ persisted: true }, options);
        if (opts.persisted) {
            var data = this.cache.get(key);
            if (data) {
                return Promise.resolve(data);
            }
        }
        if (!this.promiseCache[key]) {
            this.promiseCache[key] = asyncFn()
                .then(function (res) {
                delete _this.promiseCache[key];
                _this.cache.set(key, res, opts.ttl);
                return res;
            })
                .catch(function (err) {
                delete _this.promiseCache[key];
                return Promise.reject(err);
            });
        }
        return this.promiseCache[key];
    };
    return AsyncMemo;
}());

module.exports = AsyncMemo;