2 /*********************************************************************************
3 * SugarCRM Community Edition is a customer relationship management program developed by
4 * SugarCRM, Inc. Copyright (C) 2004-2012 SugarCRM Inc.
6 * This program is free software; you can redistribute it and/or modify it under
7 * the terms of the GNU Affero General Public License version 3 as published by the
8 * Free Software Foundation with the addition of the following permission added
9 * to Section 15 as permitted in Section 7(a): FOR ANY PART OF THE COVERED WORK
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15 * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
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19 * this program; if not, see http://www.gnu.org/licenses or write to the Free
20 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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28 * Section 5 of the GNU Affero General Public License version 3.
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35 ********************************************************************************/
39 * Abstract cache class
42 abstract class SugarCacheAbstract
45 * @var set to false if you don't want to use the local store, true by default.
47 public $useLocalStore = true;
50 * @var timeout in seconds used for cache item expiration
52 protected $_expireTimeout = 300;
55 * @var prefix to use for all cache key entries
57 protected $_keyPrefix = 'sugarcrm_';
60 * @var stores locally any cached items so we don't have to hit the external cache as much
62 protected $_localStore = array();
65 * @var records the number of get requests made against the cache
67 protected $_cacheRequests = 0;
70 * @var records the number of hits made against the cache that have been resolved without hitting the
73 protected $_cacheLocalHits = 0;
76 * @var records the number of hits made against the cache that are resolved using the external cache
78 protected $_cacheExternalHits = 0;
81 * @var records the number of get requests that aren't in the cache
83 protected $_cacheMisses = 0;
86 * @var indicates the priority level for using this cache; the lower number indicates the highest
87 * priority ( 1 would be the highest priority, but we should never ship a backend with this number
88 * so we don't bump out custom backends. ) Shipping backends use priorities in the range of 900-999.
90 protected $_priority = 899;
95 public function __construct()
97 if ( isset($GLOBALS['sugar_config']['cache_expire_timeout']) )
98 $this->_expireTimeout = $GLOBALS['sugar_config']['cache_expire_timeout'];
99 if ( isset($GLOBALS['sugar_config']['unique_key']) )
100 $this->_keyPrefix = $GLOBALS['sugar_config']['unique_key'];
106 public function __destruct()
111 * PHP's magic __get() method, used here for getting the current value from the cache.
116 public function __get($key)
118 if ( SugarCache::$isCacheReset )
121 $this->_cacheRequests++;
122 if ( !$this->useLocalStore || !isset($this->_localStore[$key]) ) {
123 $this->_localStore[$key] = $this->_getExternal($this->_keyPrefix.$key);
124 if ( isset($this->_localStore[$key]) ) {
125 $this->_cacheExternalHits++;
128 $this->_cacheMisses++;
131 elseif ( isset($this->_localStore[$key]) ) {
132 $this->_cacheLocalHits++;
135 if ( isset($this->_localStore[$key]) ) {
136 return $this->_localStore[$key];
143 * PHP's magic __set() method, used here for setting a value for a key in the cache.
148 public function __set( $key, $value)
150 $this->set($key, $value);
155 * Set a value for a key in the cache, optionally specify a ttl. A ttl value of zero
156 * will indicate that a value should only be stored per the request.
162 public function set($key, $value, $ttl = null)
164 if ( is_null($value) )
166 $value = SugarCache::EXTERNAL_CACHE_NULL_VALUE;
170 if ( $this->useLocalStore )
172 $this->_localStore[$key] = $value;
177 $this->_setExternal($this->_keyPrefix.$key,$value);
181 //For BC reasons the setExternal signature will remain the same.
182 $previousExpireTimeout = $this->_expireTimeout;
183 $this->_expireTimeout = $ttl;
184 $this->_setExternal($this->_keyPrefix.$key,$value);
185 $this->_expireTimeout = $previousExpireTimeout;
189 * PHP's magic __isset() method, used here for checking for a key in the cache.
194 public function __isset($key)
196 return !is_null($this->__get($key));
200 * PHP's magic __unset() method, used here for clearing a key in the cache.
205 public function __unset($key)
207 unset($this->_localStore[$key]);
208 $this->_clearExternal($this->_keyPrefix.$key);
212 * Reset the cache for this request
214 public function reset()
216 $this->_localStore = array();
217 SugarCache::$isCacheReset = true;
221 * Reset the cache fully
223 public function resetFull()
226 $this->_resetExternal();
230 * Flush the contents of the cache
232 public function flush()
234 $this->_localStore = array();
235 $this->_resetExternal();
239 * Returns the number of cache hits made
241 * @return array assocative array with each key have the value
243 public function getCacheStats()
246 'requests' => $this->_cacheRequests,
247 'externalHits' => $this->_cacheExternalHits,
248 'localHits' => $this->_cacheLocalHits,
249 'misses' => $this->_cacheMisses,
254 * Returns what backend is used for caching, uses normalized class name for lookup
258 public function __toString()
260 return strtolower(str_replace('SugarCache','',get_class($this)));
264 * Hook for the child implementations of the individual backends to provide thier own logic for
265 * setting a value from cache
268 * @param mixed $value
270 abstract protected function _setExternal($key,$value);
273 * Hook for the child implementations of the individual backends to provide thier own logic for
274 * getting a value from cache
277 * @return mixed $value, returns null if the key is not in the cache
279 abstract protected function _getExternal($key);
282 * Hook for the child implementations of the individual backends to provide thier own logic for
283 * clearing a value out of thier cache
287 abstract protected function _clearExternal($key);
290 * Hook for the child implementations of the individual backends to provide thier own logic for
291 * clearing thier cache out fully
293 abstract protected function _resetExternal();
296 * Hook for testing if the backend should be used or not. Typically we'll extend this for backend specific
299 * @return boolean true if we can use the backend, false if not
301 public function useBackend()
303 if ( !empty($GLOBALS['sugar_config']['external_cache_disabled'])
304 && $GLOBALS['sugar_config']['external_cache_disabled'] == true ) {
308 if (defined('SUGARCRM_IS_INSTALLING')) {
312 if ( isset($GLOBALS['sugar_config']['external_cache_force_backend'])
313 && ( $GLOBALS['sugar_config']['external_cache_force_backend'] != (string) $this ) ) {
321 * Returns the priority level for this backend
323 * @see self::$_priority
327 public function getPriority()
329 return $this->_priority;