includes/objectcache/MultiWriteBagOStuff.php

   1 <?php
   2 /**
   3  * Wrapper for object caching in different caches.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Cache
  22  */
  23
  24 /**
  25  * A cache class that replicates all writes to multiple child caches. Reads
  26  * are implemented by reading from the caches in the order they are given in
  27  * the configuration until a cache gives a positive result.
  28  *
  29  * @ingroup Cache
  30  */
  31 class MultiWriteBagOStuff extends BagOStuff {
  32         var $caches;
  33
  34         /**
  35          * Constructor. Parameters are:
  36          *
  37          *   - caches:   This should have a numbered array of cache parameter
  38          *               structures, in the style required by $wgObjectCaches. See
  39          *               the documentation of $wgObjectCaches for more detail.
  40          *
  41          * @param $params array
  42          * @throws MWException
  43          */
  44         public function __construct( $params ) {
  45                 if ( !isset( $params['caches'] ) ) {
  46                         throw new MWException( __METHOD__.': the caches parameter is required' );
  47                 }
  48
  49                 $this->caches = array();
  50                 foreach ( $params['caches'] as $cacheInfo ) {
  51                         $this->caches[] = ObjectCache::newFromParams( $cacheInfo );
  52                 }
  53         }
  54
  55         /**
  56          * @param $debug bool
  57          */
  58         public function setDebug( $debug ) {
  59                 $this->doWrite( 'setDebug', $debug );
  60         }
  61
  62         /**
  63          * @param $key string
  64          * @return bool|mixed
  65          */
  66         public function get( $key ) {
  67                 foreach ( $this->caches as $cache ) {
  68                         $value = $cache->get( $key );
  69                         if ( $value !== false ) {
  70                                 return $value;
  71                         }
  72                 }
  73                 return false;
  74         }
  75
  76         /**
  77          * @param $key string
  78          * @param $value mixed
  79          * @param $exptime int
  80          * @return bool
  81          */
  82         public function set( $key, $value, $exptime = 0 ) {
  83                 return $this->doWrite( 'set', $key, $value, $exptime );
  84         }
  85
  86         /**
  87          * @param $key string
  88          * @param $time int
  89          * @return bool
  90          */
  91         public function delete( $key, $time = 0 ) {
  92                 return $this->doWrite( 'delete', $key, $time );
  93         }
  94
  95         /**
  96          * @param $key string
  97          * @param $value mixed
  98          * @param $exptime int
  99          * @return bool
 100          */
 101         public function add( $key, $value, $exptime = 0 ) {
 102                 return $this->doWrite( 'add', $key, $value, $exptime );
 103         }
 104
 105         /**
 106          * @param $key string
 107          * @param $value mixed
 108          * @param $exptime int
 109          * @return bool
 110          */
 111         public function replace( $key, $value, $exptime = 0 ) {
 112                 return $this->doWrite( 'replace', $key, $value, $exptime );
 113         }
 114
 115         /**
 116          * @param $key string
 117          * @param $value int
 118          * @return bool|null
 119          */
 120         public function incr( $key, $value = 1 ) {
 121                 return $this->doWrite( 'incr', $key, $value );
 122         }
 123
 124         /**
 125          * @param $key string
 126          * @param $value int
 127          * @return bool
 128          */
 129         public function decr( $key, $value = 1 ) {
 130                 return $this->doWrite( 'decr', $key, $value );
 131         }
 132
 133         /**
 134          * @param $key string
 135          * @param $timeout int
 136          * @return bool
 137          */
 138         public function lock( $key, $timeout = 0 ) {
 139                 // Lock only the first cache, to avoid deadlocks
 140                 if ( isset( $this->caches[0] ) ) {
 141                         return $this->caches[0]->lock( $key, $timeout );
 142                 } else {
 143                         return true;
 144                 }
 145         }
 146
 147         /**
 148          * @param $key string
 149          * @return bool
 150          */
 151         public function unlock( $key ) {
 152                 if ( isset( $this->caches[0] ) ) {
 153                         return $this->caches[0]->unlock( $key );
 154                 } else {
 155                         return true;
 156                 }
 157         }
 158
 159         /**
 160          * @param $method string
 161          * @return bool
 162          */
 163         protected function doWrite( $method /*, ... */ ) {
 164                 $ret = true;
 165                 $args = func_get_args();
 166                 array_shift( $args );
 167
 168                 foreach ( $this->caches as $cache ) {
 169                         if ( !call_user_func_array( array( $cache, $method ), $args ) ) {
 170                                 $ret = false;
 171                         }
 172                 }
 173                 return $ret;
 174         }
 175
 176         /**
 177          * Delete objects expiring before a certain date.
 178          *
 179          * Succeed if any of the child caches succeed.
 180          * @param $date string
 181          * @param $progressCallback bool|callback
 182          * @return bool
 183          */
 184         public function deleteObjectsExpiringBefore( $date, $progressCallback = false ) {
 185                 $ret = false;
 186                 foreach ( $this->caches as $cache ) {
 187                         if ( $cache->deleteObjectsExpiringBefore( $date, $progressCallback ) ) {
 188                                 $ret = true;
 189                         }
 190                 }
 191                 return $ret;
 192         }
 193 }