includes/libs/objectcache/CachedBagOStuff.php

   1 <?php
   2 /**
   3  * Wrapper around a BagOStuff that caches data in memory
   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  * Wrapper around a BagOStuff that caches data in memory
  26  *
  27  * The differences between CachedBagOStuff and MultiWriteBagOStuff are:
  28  * * CachedBagOStuff supports only one "backend".
  29  * * There's a flag for writes to only go to the in-memory cache.
  30  * * The in-memory cache is always updated.
  31  * * Locks go to the backend cache (with MultiWriteBagOStuff, it would wind
  32  *   up going to the HashBagOStuff used for the in-memory cache).
  33  *
  34  * @ingroup Cache
  35  */
  36 class CachedBagOStuff extends BagOStuff {
  37         /** @var BagOStuff */
  38         protected $backend;
  39         /** @var HashBagOStuff */
  40         protected $procCache;
  41
  42         /**
  43          * @param BagOStuff $backend Permanent backend to use
  44          * @param array $params Parameters for HashBagOStuff
  45          */
  46         public function __construct( BagOStuff $backend, $params = [] ) {
  47                 parent::__construct( $params );
  48
  49                 $this->backend = $backend;
  50                 $this->procCache = new HashBagOStuff( $params );
  51                 $this->attrMap = $backend->attrMap;
  52         }
  53
  54         public function setDebug( $enabled ) {
  55                 parent::setDebug( $enabled );
  56                 $this->backend->setDebug( $enabled );
  57         }
  58
  59         public function get( $key, $flags = 0 ) {
  60                 $value = $this->procCache->get( $key, $flags );
  61                 if ( $value === false && !$this->procCache->hasKey( $key ) ) {
  62                         $value = $this->backend->get( $key, $flags );
  63                         $this->set( $key, $value, self::TTL_INDEFINITE, self::WRITE_CACHE_ONLY );
  64                 }
  65
  66                 return $value;
  67         }
  68
  69         public function getMulti( array $keys, $flags = 0 ) {
  70                 $valuesByKeyCached = [];
  71
  72                 $keysMissing = [];
  73                 foreach ( $keys as $key ) {
  74                         $value = $this->procCache->get( $key, $flags );
  75                         if ( $value === false && !$this->procCache->hasKey( $key ) ) {
  76                                 $keysMissing[] = $key;
  77                         } else {
  78                                 $valuesByKeyCached[$key] = $value;
  79                         }
  80                 }
  81
  82                 $valuesByKeyFetched = $this->backend->getMulti( $keysMissing, $flags );
  83                 $this->setMulti( $valuesByKeyFetched, self::TTL_INDEFINITE, self::WRITE_CACHE_ONLY );
  84
  85                 return $valuesByKeyCached + $valuesByKeyFetched;
  86         }
  87
  88         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  89                 $this->procCache->set( $key, $value, $exptime, $flags );
  90
  91                 if ( !$this->fieldHasFlags( $flags, self::WRITE_CACHE_ONLY ) ) {
  92                         $this->backend->set( $key, $value, $exptime, $flags );
  93                 }
  94
  95                 return true;
  96         }
  97
  98         public function delete( $key, $flags = 0 ) {
  99                 $this->procCache->delete( $key, $flags );
 100
 101                 if ( !$this->fieldHasFlags( $flags, self::WRITE_CACHE_ONLY ) ) {
 102                         $this->backend->delete( $key, $flags );
 103                 }
 104
 105                 return true;
 106         }
 107
 108         public function add( $key, $value, $exptime = 0, $flags = 0 ) {
 109                 if ( $this->get( $key ) === false ) {
 110                         return $this->set( $key, $value, $exptime, $flags );
 111                 }
 112
 113                 return false; // key already set
 114         }
 115
 116         // These just call the backend (tested elsewhere)
 117         // @codeCoverageIgnoreStart
 118
 119         public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
 120                 $this->procCache->delete( $key );
 121
 122                 return $this->backend->merge( $key, $callback, $exptime, $attempts, $flags );
 123         }
 124
 125         public function changeTTL( $key, $exptime = 0, $flags = 0 ) {
 126                 $this->procCache->delete( $key );
 127
 128                 return $this->backend->changeTTL( $key, $exptime, $flags );
 129         }
 130
 131         public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
 132                 return $this->backend->lock( $key, $timeout, $expiry, $rclass );
 133         }
 134
 135         public function unlock( $key ) {
 136                 return $this->backend->unlock( $key );
 137         }
 138
 139         public function deleteObjectsExpiringBefore(
 140                 $timestamp,
 141                 callable $progress = null,
 142                 $limit = INF
 143         ) {
 144                 $this->procCache->deleteObjectsExpiringBefore( $timestamp, $progress, $limit );
 145
 146                 return $this->backend->deleteObjectsExpiringBefore( $timestamp, $progress, $limit );
 147         }
 148
 149         public function makeKeyInternal( $keyspace, $args ) {
 150                 return $this->backend->makeKeyInternal( $keyspace, $args );
 151         }
 152
 153         public function makeKey( $class, ...$components ) {
 154                 return $this->backend->makeKey( $class, ...$components );
 155         }
 156
 157         public function makeGlobalKey( $class, ...$components ) {
 158                 return $this->backend->makeGlobalKey( $class, ...$components );
 159         }
 160
 161         public function getLastError() {
 162                 return $this->backend->getLastError();
 163         }
 164
 165         public function clearLastError() {
 166                 return $this->backend->clearLastError();
 167         }
 168
 169         public function setMulti( array $data, $exptime = 0, $flags = 0 ) {
 170                 $this->procCache->setMulti( $data, $exptime, $flags );
 171
 172                 if ( !$this->fieldHasFlags( $flags, self::WRITE_CACHE_ONLY ) ) {
 173                         return $this->backend->setMulti( $data, $exptime, $flags );
 174                 }
 175
 176                 return true;
 177         }
 178
 179         public function deleteMulti( array $keys, $flags = 0 ) {
 180                 $this->procCache->deleteMulti( $keys, $flags );
 181
 182                 if ( !$this->fieldHasFlags( $flags, self::WRITE_CACHE_ONLY ) ) {
 183                         return $this->backend->deleteMulti( $keys, $flags );
 184                 }
 185
 186                 return true;
 187         }
 188
 189         public function changeTTLMulti( array $keys, $exptime, $flags = 0 ) {
 190                 $this->procCache->changeTTLMulti( $keys, $exptime, $flags );
 191
 192                 if ( !$this->fieldHasFlags( $flags, self::WRITE_CACHE_ONLY ) ) {
 193                         return $this->backend->changeTTLMulti( $keys, $exptime, $flags );
 194                 }
 195
 196                 return true;
 197         }
 198
 199         public function incr( $key, $value = 1, $flags = 0 ) {
 200                 $this->procCache->delete( $key );
 201
 202                 return $this->backend->incr( $key, $value, $flags );
 203         }
 204
 205         public function decr( $key, $value = 1, $flags = 0 ) {
 206                 $this->procCache->delete( $key );
 207
 208                 return $this->backend->decr( $key, $value, $flags );
 209         }
 210
 211         public function incrWithInit( $key, $exptime, $value = 1, $init = null, $flags = 0 ) {
 212                 $this->procCache->delete( $key );
 213
 214                 return $this->backend->incrWithInit( $key, $exptime, $value, $init, $flags );
 215         }
 216
 217         public function addBusyCallback( callable $workCallback ) {
 218                 $this->backend->addBusyCallback( $workCallback );
 219         }
 220
 221         public function setMockTime( &$time ) {
 222                 parent::setMockTime( $time );
 223                 $this->procCache->setMockTime( $time );
 224                 $this->backend->setMockTime( $time );
 225         }
 226
 227         // @codeCoverageIgnoreEnd
 228 }