https://www.gipsy.sk/content/plugins/lbg-audio8-html5-radio_ads/audio8_html5/js/lastfm.api.cache.js

1/*
2 *
3 * Copyright (c) 2008-2009, Felix Bruns <[email protected]>
4 *
5 */
6
7/* Set an object on a Storage object. */
8Storage.prototype.setObject = function(key, value){
9	this.setItem(key, JSON.stringify(value));
10}
11
12/* Get an object from a Storage object. */
13Storage.prototype.getObject = function(key){
14	var item = this.getItem(key);
15
16	return JSON.parse(item);
17}
18
19/* Creates a new cache object. */
20function LastFMCache(){
21	/* Expiration times. */
22	var MINUTE =          60;
23	var HOUR   = MINUTE * 60;
24	var DAY    = HOUR   * 24;
25	var WEEK   = DAY    *  7;
26	var MONTH  = WEEK   *  4.34812141;
27	var YEAR   = MONTH  * 12;
28
29	/* Methods with weekly expiration. */
30	var weeklyMethods = [
31		'artist.getSimilar',
32		'tag.getSimilar',
33		'track.getSimilar',
34		'artist.getTopAlbums',
35		'artist.getTopTracks',
36		'geo.getTopArtists',
37		'geo.getTopTracks',
38		'tag.getTopAlbums',
39		'tag.getTopArtists',
40		'tag.getTopTags',
41		'tag.getTopTracks',
42		'user.getTopAlbums',
43		'user.getTopArtists',
44		'user.getTopTags',
45		'user.getTopTracks'
46	];
47
48	/* Name for this cache. */
49	var name = 'lastfm';
50
51	/* Create cache if it doesn't exist yet. */
52	if(localStorage.getObject(name) == null){
53		localStorage.setObject(name, {});
54	}
55
56	/* Get expiration time for given parameters. */
57	this.getExpirationTime = function(params){
58		var method = params.method;
59
60		if((/Weekly/).test(method) && !(/List/).test(method)){
61			if(typeof(params.to) != 'undefined' && typeof(params.from) != 'undefined'){
62				return YEAR;
63			}
64			else{
65				return WEEK;
66			}
67		}
68
69		for(var key in weeklyMethods){
70			if(method == weeklyMethods[key]){
71				return WEEK;
72			}
73		}
74
75		return -1;
76	};
77
78	/* Check if this cache contains specific data. */
79	this.contains = function(hash){
80		return typeof(localStorage.getObject(name)[hash]) != 'undefined' &&
81			typeof(localStorage.getObject(name)[hash].data) != 'undefined';
82	};
83
84	/* Load data from this cache. */
85	this.load = function(hash){
86		return localStorage.getObject(name)[hash].data;
87	};
88
89	/* Remove data from this cache. */
90	this.remove = function(hash){
91		var object = localStorage.getObject(name);
92
93		object[hash] = undefined;
94
95		localStorage.setObject(name, object);
96	};
97
98	/* Store data in this cache with a given expiration time. */
99	this.store = function(hash, data, expiration){
100		var object = localStorage.getObject(name);
101		var time   = Math.round(new Date().getTime() / 1000);
102
103		object[hash] = {
104			data       : data,
105			expiration : time + expiration
106		};
107
108		localStorage.setObject(name, object);
109	};
110
111	/* Check if some specific data expired. */
112	this.isExpired = function(hash){
113		var object = localStorage.getObject(name);
114		var time   = Math.round(new Date().getTime() / 1000);
115
116		if(time > object[hash].expiration){
117			return true;
118		}
119
120		return false;
121	};
122
123	/* Clear this cache. */
124	this.clear = function(){
125		localStorage.setObject(name, {});
126	};
127};