betajs/betajs-data

//Stores everything temporarily in the browser's memory

Scoped.define("module:Stores.MemoryStore", [
    "module:Stores.AssocStore",
    //"base:Iterators.ObjectValuesIterator",
    "base:Iterators.FilteredIterator",
    "base:Iterators.ArrayIterator",
    "base:Objs",
    "base:Promise"
], function (AssocStore, FilteredIterator, ArrayIterator, Objs, Promise, scoped) {
    return AssocStore.extend({scoped: scoped}, function (inherited) {            
        return {

            constructor: function (options) {
                inherited.constructor.call(this, options);
                // We reserve index 0.
                this.__dataByIndex = [null];
                this.__indexById = {};
                this.__count = 0;
            },

            _read_key: function (key) {
                var i = this.__indexById[key];
                return i ? this.__dataByIndex[i] : undefined;
            },

            _write_key: function (key, value) {
                var i = this.__indexById[key];
                if (!i) {
                    i = this.__dataByIndex.length;
                    this.__indexById[key] = i;
                    this.__count++;
                }
                this.__dataByIndex[i] = value;
            },

            _remove_key: function (key) {
                var i = this.__indexById[key];
                if (i) {
                    delete this.__indexById[key];
                    delete this.__dataByIndex[i];
                    this.__count--;
                }                
            },

            _iterate: function () {
                var arrIter = new ArrayIterator(this.__dataByIndex);
                return (new FilteredIterator(arrIter, function (item) {
                    return !!item;
                })).auto_destroy(arrIter, true);
                //return new ObjectValuesIterator(this.__data);
            },
            
            _count: function (query) {
                return query ? inherited._count.call(this, query) : Promise.value(this.__count);
            }

        };
    });
});