https://bildungskalender.holzbau-schweiz.ch/typo3conf/ext/holzbaus…/simpleStorage.v1-2-0.1784194704.js

1/* jshint browser: true */
2/* global define: false */
3
4// AMD shim
5(function(root, factory) {
6
7    "use strict";
8
9    if (typeof define === 'function' && define.amd) {
10        define(factory);
11    } else {
12        root.simpleStorage = factory();
13    }
14
15}(this, function() {
16
17    "use strict";
18
19    var
20        VERSION = "0.1.2",
21
22        /* This is the object, that holds the cached values */
23        _storage = false,
24
25        /* How much space does the storage take */
26        _storage_size = 0,
27
28        _storage_available = false,
29
30        _ttl_timeout = null;
31
32    // This method might throw as it touches localStorage and doing so
33    // can be prohibited in some environments
34    function _init(){
35
36        // If localStorage does not exist, the following throws
37        // This is intentional
38        window.localStorage.setItem("__simpleStorageInitTest", "tmpval");
39        window.localStorage.removeItem("__simpleStorageInitTest");
40
41        // Load data from storage
42        _load_storage();
43
44        // remove dead keys
45        _handleTTL();
46
47        // start listening for changes
48        _setupUpdateObserver();
49
50        // handle cached navigation
51        if("addEventListener" in window){
52            window.addEventListener("pageshow", function(event){
53                if(event.persisted){
54                    _reloadData();
55                }
56            }, false);
57        }
58
59        _storage_available = true;
60    }
61
62    /**
63     * Sets up a storage change observer
64     */
65    function _setupUpdateObserver(){
66        if("addEventListener" in window){
67            window.addEventListener("storage", _reloadData, false);
68        }else{
69            document.attachEvent("onstorage", _reloadData);
70        }
71    }
72
73    /**
74     * Reload data from storage when needed
75     */
76    function _reloadData(){
77        try{
78            _load_storage();
79        }catch(E){
80            _storage_available = false;
81            return;
82        }
83        _handleTTL();
84    }
85
86    function _load_storage(){
87        var source = localStorage.getItem("simpleStorage");
88
89        try{
90            _storage = JSON.parse(source) || {};
91        }catch(E){
92            _storage = {};
93        }
94
95        _storage_size = _get_storage_size();
96    }
97
98    function _save(){
99        try{
100            localStorage.setItem("simpleStorage", JSON.stringify(_storage));
101            _storage_size = _get_storage_size();
102        }catch(E){
103            return E;
104        }
105        return true;
106    }
107
108    function _get_storage_size() {
109        var source = localStorage.getItem("simpleStorage");
110        return source ? String(source).length : 0;
111    }
112
113    function _handleTTL(){
114        var curtime, i, len, expire, keys, nextExpire = Infinity, expiredKeysCount = 0;
115
116        clearTimeout(_ttl_timeout);
117
118        if(!_storage || !_storage.__simpleStorage_meta || !_storage.__simpleStorage_meta.TTL){
119            return;
120        }
121
122        curtime = +new Date();
123        keys = _storage.__simpleStorage_meta.TTL.keys || [];
124        expire = _storage.__simpleStorage_meta.TTL.expire || {};
125
126        for(i = 0, len = keys.length; i<len; i++){
127            if(expire[keys[i]] <= curtime){
128                expiredKeysCount++;
129                delete _storage[keys[i]];
130                delete expire[keys[i]];
131            }else{
132                if(expire[keys[i]] < nextExpire){
133                    nextExpire = expire[keys[i]];
134                }
135                break;
136            }
137        }
138
139        // set next check
140        if(nextExpire != Infinity){
141            _ttl_timeout = setTimeout(_handleTTL, Math.min(nextExpire - curtime, 0x7FFFFFFF));
142        }
143
144        // remove expired from TTL list and save changes
145        if(expiredKeysCount){
146            keys.splice(0, expiredKeysCount);
147
148            _cleanMetaObject();
149            _save();
150        }
151    }
152
153    function _setTTL(key, ttl){
154        var curtime = +new Date(), i, len, added = false;
155
156        ttl = Number(ttl) || 0;
157
158        // Set TTL value for the key
159        if(ttl !== 0){
160            // If key exists, set TTL
161            if(_storage.hasOwnProperty(key)){
162
163                if(!_storage.__simpleStorage_meta){
164                    _storage.__simpleStorage_meta = {};
165                }
166
167                if(!_storage.__simpleStorage_meta.TTL){
168                    _storage.__simpleStorage_meta.TTL = {expire: {}, keys:[]};
169                }
170
171                _storage.__simpleStorage_meta.TTL.expire[key] = curtime + ttl;
172
173                // remove from keys array
174                if(_storage.__simpleStorage_meta.TTL.expire.hasOwnProperty(key)){
175                    for(i = 0, len = _storage.__simpleStorage_meta.TTL.keys.length; i<len; i++){
176                        if(_storage.__simpleStorage_meta.TTL.keys[i] == key){
177                            _storage.__simpleStorage_meta.TTL.keys.splice(i);
178                        }
179                    }
180                }
181
182                // add to keys array, sorted by ttl
183                for(i = 0, len = _storage.__simpleStorage_meta.TTL.keys.length; i<len; i++){
184                    if(_storage.__simpleStorage_meta.TTL.expire[_storage.__simpleStorage_meta.TTL.keys[i]] > curtime + ttl){
185                        _storage.__simpleStorage_meta.TTL.keys.splice(i, 0, key);
186                    }
187                }
188
189                if(!added){
190                    _storage.__simpleStorage_meta.TTL.keys.push(key);
191                }
192            }else{
193                return false;

194            }
195        }else{
196            // Remove TTL if set
197            if(_storage && _storage.__simpleStorage_meta && _storage.__simpleStorage_meta.TTL){
198
199                if(_storage.__simpleStorage_meta.TTL.expire.hasOwnProperty(key)){
200                    delete _storage.__simpleStorage_meta.TTL.expire[key];
201                    for(i = 0, len = _storage.__simpleStorage_meta.TTL.keys.length; i<len; i++){
202                        if(_storage.__simpleStorage_meta.TTL.keys[i] == key){
203                            _storage.__simpleStorage_meta.TTL.keys.splice(i, 1);
204                            break;
205                        }
206                    }
207                }
208
209                _cleanMetaObject();
210            }
211        }
212
213        // schedule next TTL check
214        clearTimeout(_ttl_timeout);
215        if(_storage && _storage.__simpleStorage_meta && _storage.__simpleStorage_meta.TTL && _storage.__simpleStorage_meta.TTL.keys.length){
216            _ttl_timeout = setTimeout(_handleTTL, Math.min(Math.max(_storage.__simpleStorage_meta.TTL.expire[_storage.__simpleStorage_meta.TTL.keys[0]] - curtime, 0), 0x7FFFFFFF));
217        }
218
219        return true;
220    }
221
222    function _cleanMetaObject(){
223        var updated = false, hasProperties = false, i;
224
225        if(!_storage || !_storage.__simpleStorage_meta){
226            return updated;
227        }
228
229        // If nothing to TTL, remove the object
230        if(_storage.__simpleStorage_meta.TTL && !_storage.__simpleStorage_meta.TTL.keys.length){
231            delete _storage.__simpleStorage_meta.TTL;
232            updated = true;
233        }
234
235        // If meta object is empty, remove it
236        for(i in _storage.__simpleStorage_meta){
237            if(_storage.__simpleStorage_meta.hasOwnProperty(i)){
238                hasProperties = true;
239                break;
240            }
241        }
242
243        if(!hasProperties){
244            delete _storage.__simpleStorage_meta;
245            updated = true;
246        }
247
248        return updated;
249    }
250
251    ////////////////////////// PUBLIC INTERFACE /////////////////////////
252
253    try{
254        _init();
255    }catch(E){}
256
257    return {
258
259        version: VERSION,
260
261        canUse: function(){
262            return !!_storage_available;
263        },
264
265        set: function(key, value, options){
266            if(key == "__simpleStorage_meta"){
267                return false;
268            }
269
270            if(!_storage){
271                return false;
272            }
273
274            // undefined values are deleted automatically
275            if(typeof value == "undefined"){
276                return this.deleteKey(key);
277            }
278
279            options = options || {};
280
281            // Check if the value is JSON compatible (and remove reference to existing objects/arrays)
282            try{
283                value = JSON.parse(JSON.stringify(value));
284            }catch(E){
285                return E;
286            }
287
288            _storage[key] = value;
289
290            _setTTL(key, options.TTL || 0);
291
292            return _save();
293        },
294
295        get: function(key){
296            if(!_storage){
297                return false;
298            }
299
300            if(_storage.hasOwnProperty(key) && key != "__simpleStorage_meta"){
301                // TTL value for an existing key is either a positive number or an Infinity
302                if(this.getTTL(key)){
303                    return _storage[key];
304                }
305            }
306        },
307
308        deleteKey: function(key){
309
310            if(!_storage){
311                return false;
312            }
313
314            if(key in _storage){
315                delete _storage[key];
316
317                _setTTL(key, 0);
318
319                return _save();
320            }
321
322            return false;
323        },
324
325        setTTL: function(key, ttl){
326            if(!_storage){
327                return false;
328            }
329
330            _setTTL(key, ttl);
331
332            return _save();
333        },
334
335        getTTL: function(key){
336            var ttl;
337
338            if(!_storage){
339                return false;
340            }
341
342            if(_storage.hasOwnProperty(key)){
343                if(_storage.__simpleStorage_meta &&
344                    _storage.__simpleStorage_meta.TTL &&
345                    _storage.__simpleStorage_meta.TTL.expire &&
346                    _storage.__simpleStorage_meta.TTL.expire.hasOwnProperty(key)){
347
348                    ttl = Math.max(_storage.__simpleStorage_meta.TTL.expire[key] - (+new Date()) || 0, 0);
349
350                    return ttl || false;
351                }else{
352                    return Infinity;
353                }
354            }
355
356            return false;

357        },
358
359        flush: function(){
360            if(!_storage){
361                return false;
362            }
363
364            _storage = {};
365            try{
366                localStorage.removeItem("simpleStorage");
367                return true;
368            }catch(E){
369                return E;
370            }
371        },
372
373        index: function(){
374            if(!_storage){
375                return false;
376            }
377
378            var index = [], i;
379            for(i in _storage){
380                if(_storage.hasOwnProperty(i) && i != "__simpleStorage_meta"){
381                    index.push(i);
382                }
383            }
384            return index;
385        },
386
387        storageSize: function(){
388            return _storage_size;
389        }
390    };
391
392}));