1: <?php
  2: 
  3: /**
  4:  * This file is part of the Nette Framework (https://nette.org)
  5:  * Copyright (c) 2004 David Grudl (http://davidgrudl.com)
  6:  */
  7: 
  8: namespace Nette\Caching;
  9: 
 10: use Nette;
 11: 
 12: 
 13: /**
 14:  * Implements the cache for a application.
 15:  *
 16:  * @author     David Grudl
 17:  *
 18:  * @property-read IStorage $storage
 19:  * @property-read string $namespace
 20:  */
 21: class Cache extends Nette\Object implements \ArrayAccess
 22: {
 23:     /** dependency */
 24:     const PRIORITY = 'priority',
 25:         EXPIRATION = 'expire',
 26:         EXPIRE = 'expire',
 27:         SLIDING = 'sliding',
 28:         TAGS = 'tags',
 29:         FILES = 'files',
 30:         ITEMS = 'items',
 31:         CONSTS = 'consts',
 32:         CALLBACKS = 'callbacks',
 33:         ALL = 'all';
 34: 
 35:     /** @internal */
 36:     const NAMESPACE_SEPARATOR = "\x00";
 37: 
 38:     /** @var IStorage */
 39:     private $storage;
 40: 
 41:     /** @var string */
 42:     private $namespace;
 43: 
 44:     /** @var string  last query cache used by offsetGet() */
 45:     private $key;
 46: 
 47:     /** @var mixed  last query cache used by offsetGet()  */
 48:     private $data;
 49: 
 50: 
 51:     public function __construct(IStorage $storage, $namespace = NULL)
 52:     {
 53:         $this->storage = $storage;
 54:         $this->namespace = $namespace . self::NAMESPACE_SEPARATOR;
 55:     }
 56: 
 57: 
 58:     /**
 59:      * Returns cache storage.
 60:      * @return IStorage
 61:      */
 62:     public function getStorage()
 63:     {
 64:         return $this->storage;
 65:     }
 66: 
 67: 
 68:     /**
 69:      * Returns cache namespace.
 70:      * @return string
 71:      */
 72:     public function getNamespace()
 73:     {
 74:         return (string) substr($this->namespace, 0, -1);
 75:     }
 76: 
 77: 
 78:     /**
 79:      * Returns new nested cache object.
 80:      * @param  string
 81:      * @return Cache
 82:      */
 83:     public function derive($namespace)
 84:     {
 85:         $derived = new static($this->storage, $this->namespace . $namespace);
 86:         return $derived;
 87:     }
 88: 
 89: 
 90:     /**
 91:      * Reads the specified item from the cache or generate it.
 92:      * @param  mixed key
 93:      * @param  callable
 94:      * @return mixed|NULL
 95:      */
 96:     public function load($key, $fallback = NULL)
 97:     {
 98:         $data = $this->storage->read($this->generateKey($key));
 99:         if ($data === NULL && $fallback) {
100:             return $this->save($key, new Nette\Callback($fallback));
101:         }
102:         return $data;
103:     }
104: 
105: 
106:     /**
107:      * Writes item into the cache.
108:      * Dependencies are:
109:      * - Cache::PRIORITY => (int) priority
110:      * - Cache::EXPIRATION => (timestamp) expiration
111:      * - Cache::SLIDING => (bool) use sliding expiration?
112:      * - Cache::TAGS => (array) tags
113:      * - Cache::FILES => (array|string) file names
114:      * - Cache::ITEMS => (array|string) cache items
115:      * - Cache::CONSTS => (array|string) cache items
116:      *
117:      * @param  mixed  key
118:      * @param  mixed  value
119:      * @param  array  dependencies
120:      * @return mixed  value itself
121:      * @throws Nette\InvalidArgumentException
122:      */
123:     public function save($key, $data, array $dependencies = NULL)
124:     {
125:         $this->release();
126:         $key = $this->generateKey($key);
127: 
128:         if ($data instanceof Nette\Callback || $data instanceof \Closure) {
129:             $this->storage->lock($key);
130:             $data = Nette\Callback::create($data)->invokeArgs(array(& $dependencies));
131:         }
132: 
133:         if ($data === NULL) {
134:             $this->storage->remove($key);
135:         } else {
136:             $this->storage->write($key, $data, $this->completeDependencies($dependencies, $data));
137:             return $data;
138:         }
139:     }
140: 
141: 
142:     private function completeDependencies($dp, $data)
143:     {
144:         if (is_object($data)) {
145:             $dp[self::CALLBACKS][] = array(array(__CLASS__, 'checkSerializationVersion'), get_class($data),
146:                 Nette\Reflection\ClassType::from($data)->getAnnotation('serializationVersion'));
147:         }
148: 
149:         // convert expire into relative amount of seconds
150:         if (isset($dp[Cache::EXPIRATION])) {
151:             $dp[Cache::EXPIRATION] = Nette\DateTime::from($dp[Cache::EXPIRATION])->format('U') - time();
152:         }
153: 
154:         // convert FILES into CALLBACKS
155:         if (isset($dp[self::FILES])) {
156:             foreach (array_unique((array) $dp[self::FILES]) as $item) {
157:                 $dp[self::CALLBACKS][] = array(array(__CLASS__, 'checkFile'), $item, @filemtime($item)); // @ - stat may fail
158:             }
159:             unset($dp[self::FILES]);
160:         }
161: 
162:         // add namespaces to items
163:         if (isset($dp[self::ITEMS])) {
164:             $dp[self::ITEMS] = array_unique(array_map(array($this, 'generateKey'), (array) $dp[self::ITEMS]));
165:         }
166: 
167:         // convert CONSTS into CALLBACKS
168:         if (isset($dp[self::CONSTS])) {
169:             foreach (array_unique((array) $dp[self::CONSTS]) as $item) {
170:                 $dp[self::CALLBACKS][] = array(array(__CLASS__, 'checkConst'), $item, constant($item));
171:             }
172:             unset($dp[self::CONSTS]);
173:         }
174: 
175:         if (!is_array($dp)) {
176:             $dp = array();
177:         }
178:         return $dp;
179:     }
180: 
181: 
182:     /**
183:      * Removes item from the cache.
184:      * @param  mixed  key
185:      * @return void
186:      */
187:     public function remove($key)
188:     {
189:         $this->save($key, NULL);
190:     }
191: 
192: 
193:     /**
194:      * Removes items from the cache by conditions.
195:      * Conditions are:
196:      * - Cache::PRIORITY => (int) priority
197:      * - Cache::TAGS => (array) tags
198:      * - Cache::ALL => TRUE
199:      * @return void
200:      */
201:     public function clean(array $conditions = NULL)
202:     {
203:         $this->release();
204:         $this->storage->clean((array) $conditions);
205:     }
206: 
207: 
208:     /**
209:      * Caches results of function/method calls.
210:      * @param  mixed
211:      * @return mixed
212:      */
213:     public function call($function)
214:     {
215:         $key = func_get_args();
216:         return $this->load($key, function() use ($function, $key) {
217:             return Nette\Callback::create($function)->invokeArgs(array_slice($key, 1));
218:         });
219:     }
220: 
221: 
222:     /**
223:      * Caches results of function/method calls.
224:      * @param  mixed
225:      * @param  array  dependencies
226:      * @return Closure
227:      */
228:     public function wrap($function, array $dependencies = NULL)
229:     {
230:         $cache = $this;
231:         return function() use ($cache, $function, $dependencies) {
232:             $key = array($function, func_get_args());
233:             $data = $cache->load($key);
234:             if ($data === NULL) {
235:                 $data = $cache->save($key, Nette\Callback::create($function)->invokeArgs($key[1]), $dependencies);
236:             }
237:             return $data;
238:         };
239:     }
240: 
241: 
242:     /**
243:      * Starts the output cache.
244:      * @param  mixed  key
245:      * @return OutputHelper|NULL
246:      */
247:     public function start($key)
248:     {
249:         $data = $this->load($key);
250:         if ($data === NULL) {
251:             return new OutputHelper($this, $key);
252:         }
253:         echo $data;
254:     }
255: 
256: 
257:     /**
258:      * Generates internal cache key.
259:      *
260:      * @param  string
261:      * @return string
262:      */
263:     protected function generateKey($key)
264:     {
265:         return $this->namespace . md5(is_scalar($key) ? $key : serialize($key));
266:     }
267: 
268: 
269:     /********************* interface ArrayAccess ****************d*g**/
270: 
271: 
272:     /**
273:      * Inserts (replaces) item into the cache (\ArrayAccess implementation).
274:      * @param  mixed key
275:      * @param  mixed
276:      * @return void
277:      * @throws Nette\InvalidArgumentException
278:      */
279:     public function offsetSet($key, $data)
280:     {
281:         $this->save($key, $data);
282:     }
283: 
284: 
285:     /**
286:      * Retrieves the specified item from the cache or NULL if the key is not found (\ArrayAccess implementation).
287:      * @param  mixed key
288:      * @return mixed|NULL
289:      * @throws Nette\InvalidArgumentException
290:      */
291:     public function offsetGet($key)
292:     {
293:         $key = is_scalar($key) ? (string) $key : serialize($key);
294:         if ($this->key !== $key) {
295:             $this->key = $key;
296:             $this->data = $this->load($key);
297:         }
298:         return $this->data;
299:     }
300: 
301: 
302:     /**
303:      * Exists item in cache? (\ArrayAccess implementation).
304:      * @param  mixed key
305:      * @return bool
306:      * @throws Nette\InvalidArgumentException
307:      */
308:     public function offsetExists($key)
309:     {
310:         $this->release();
311:         return $this->offsetGet($key) !== NULL;
312:     }
313: 
314: 
315:     /**
316:      * Removes the specified item from the cache.
317:      * @param  mixed key
318:      * @return void
319:      * @throws Nette\InvalidArgumentException
320:      */
321:     public function offsetUnset($key)
322:     {
323:         $this->save($key, NULL);
324:     }
325: 
326: 
327:     /**
328:      * Discards the internal cache used by ArrayAccess.
329:      * @return void
330:      */
331:     public function release()
332:     {
333:         $this->key = $this->data = NULL;
334:     }
335: 
336: 
337:     /********************* dependency checkers ****************d*g**/
338: 
339: 
340:     /**
341:      * Checks CALLBACKS dependencies.
342:      * @param  array
343:      * @return bool
344:      */
345:     public static function checkCallbacks($callbacks)
346:     {
347:         foreach ($callbacks as $callback) {
348:             if (!call_user_func_array(array_shift($callback), $callback)) {
349:                 return FALSE;
350:             }
351:         }
352:         return TRUE;
353:     }
354: 
355: 
356:     /**
357:      * Checks CONSTS dependency.
358:      * @param  string
359:      * @param  mixed
360:      * @return bool
361:      */
362:     private static function checkConst($const, $value)
363:     {
364:         return defined($const) && constant($const) === $value;
365:     }
366: 
367: 
368:     /**
369:      * Checks FILES dependency.
370:      * @param  string
371:      * @param  int
372:      * @return bool
373:      */
374:     private static function checkFile($file, $time)
375:     {
376:         return @filemtime($file) == $time; // @ - stat may fail
377:     }
378: 
379: 
380:     /**
381:      * Checks object @serializationVersion label.
382:      * @param  string
383:      * @param  mixed
384:      * @return bool
385:      */
386:     private static function checkSerializationVersion($class, $value)
387:     {
388:         return Nette\Reflection\ClassType::from($class)->getAnnotation('serializationVersion') === $value;
389:     }
390: 
391: }
392: