dl/lib/cache/MMemcache.js

DreamLab Libs

var Class = require("core").Class;
var assertions = require("core").common.assertions;
var types = require("core").common.types;
var Memcache = require('./CFMemcache.js').CFMemcache;

var MMemcache = function () {
    this.Extends = Memcache;

    this.initialize = function (options) {
        this.parent(options);
        
        this._storage = {};
        this._expire  = {};
        this._lifetime = 30;
    };

    this.getTimestamp = function () { 
       return (+ new Date()); 
    };

    this.get = function (key, callback) {
        assertions.isString(key, MMemcache.Exception.WRONG_TYPE);
        var that = this;

        if (this._storage.hasOwnProperty(key)) {
            if (this.getTimestamp() >= this._expire[key] ) {
                console.log('       -- CACHE: key: ' + key + ' expired!');
                delete this._expire[ key ];
                delete this._storage[ key ];
                this.parent(key, function (data) {
                    // jezeli nie przyszedl null to zachesuj u mnie na chwile
                    if (data) {
                        console.log(data.length);
                        that._storage[key] = data;
                        that._expire[key]  = that.getTimestamp() + (that._lifetime*1000);
                    }

                    callback(data);
                });
            } else {
                process.nextTick(function () {
                    callback(that._storage[key]);
                });
            }
        } else {
            this.parent(key, function (data) {
                that._storage[key] = data;
                callback(data);
            });
        }
    };

    this.set = function (key, value, callback, lifeTime) {
        assertions.isString(key, MMemcache.Exception.WRONG_TYPE);
        lifeTime = lifeTime || this._lifetime;

        if (Buffer.isBuffer(value)) {
            this._storage[key] = value;
        } else {
            this._storage[key] = new Buffer(value, 'utf8');
        }

        // u siebie zapisuje w ms a nie w sekundach
        this._expire[key] = this.getTimestamp() + (lifeTime * 1000);

        this.parent(key, value, callback, lifeTime);
    };

    this['delete'] = function(key, callback){
        assertions.isString(key, MMemcache.Exception.WRONG_TYPE);
        delete this._storage[key];
        delete this._expire[key];  
    };
};

MMemcache = new Class(new MMemcache());

MMemcache.Exception = {};
MMemcache.Exception.WRONG_KEY_TYPE = "Key has to be a string";
MMemcache.Exception.WRONG_VALUE_TYPE = "Value has to be a string, number or object";
MMemcache.Exception.WRONG_LIFETIME_TYPE = "Lifetime has to be a number";

exports.MMemcache = MMemcache;