CacheMap.js

/**
 * Cache for images, audio, or any other kind of resource
 * @param manager
 * @constructor
 */
function CacheMap(manager) {
    this.manager = manager;
    this._inner = {};
    this._lastRemovedEntries = {};
    this.updateTicks = 0;
    this.lastCheckTTL = 0;
    this.delayCheckTTL = 100.0;
    this.updateSeconds = Date.now();
}

/**
 * checks ttl of all elements and removes dead ones
 */
CacheMap.prototype.checkTTL = function () {
    var cache = this._inner;
    var temp = this._lastRemovedEntries;
    if (!temp) {
        temp = [];
        this._lastRemovedEntries = temp;
    }
    for (var key in cache) {
        var entry = cache[key];
        if (!entry.isStillAlive()) {
            temp.push(entry);
        }
    }
    for (var i = 0; i < temp.length; i++) {
        temp[i].free(true);
    }
    temp.length = 0;
};

/**
 * cache item
 * @param key url of cache element
 * @returns {*|null}
 */
CacheMap.prototype.getItem = function (key) {
    var entry = this._inner[key];
    if (entry) {
        return entry.item;
    }
    return null;
};

CacheMap.prototype.clear = function () {
    var keys = Object.keys(this._inner);
    for (var i = 0; i < keys.length; i++) {
        this._inner[keys[i]].free();
    }
};

CacheMap.prototype.setItem = function (key, item) {
    return new CacheEntry(this, key, item).allocate();
};

CacheMap.prototype.update = function(ticks, delta) {
    this.updateTicks += ticks;
    this.updateSeconds += delta;
    if (this.updateSeconds >= this.delayCheckTTL + this.lastCheckTTL) {
        this.lastCheckTTL = this.updateSeconds;
        this.checkTTL();
    }
};