includes/libs/objectcache/ReplicatedBagOStuff.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  * @ingroup Cache
  20  * @author Aaron Schulz
  21  */
  22
  23 /**
  24  * A cache class that directs writes to one set of servers and reads to
  25  * another. This assumes that the servers used for reads are setup to slave
  26  * those that writes go to. This can easily be used with redis for example.
  27  *
  28  * In the WAN scenario (e.g. multi-datacenter case), this is useful when
  29  * writes are rare or they usually take place in the primary datacenter.
  30  *
  31  * @ingroup Cache
  32  * @since 1.26
  33  */
  34 class ReplicatedBagOStuff extends BagOStuff {
  35         /** @var BagOStuff */
  36         protected $writeStore;
  37         /** @var BagOStuff */
  38         protected $readStore;
  39
  40         /**
  41          * Constructor. Parameters are:
  42          *   - writeFactory : ObjectFactory::getObjectFromSpec parameters yeilding BagOStuff.
  43          *                    This object will be used for writes (e.g. the master DB).
  44          *   - readFactory  : ObjectFactory::getObjectFromSpec parameters yeilding BagOStuff.
  45          *                    This object will be used for reads (e.g. a slave DB).
  46          *
  47          * @param array $params
  48          * @throws InvalidArgumentException
  49          */
  50         public function __construct( $params ) {
  51                 parent::__construct( $params );
  52
  53                 if ( !isset( $params['writeFactory'] ) ) {
  54                         throw new InvalidArgumentException(
  55                                 __METHOD__ . ': the "writeFactory" parameter is required' );
  56                 }
  57                 if ( !isset( $params['readFactory'] ) ) {
  58                         throw new InvalidArgumentException(
  59                                 __METHOD__ . ': the "readFactory" parameter is required' );
  60                 }
  61
  62                 $this->writeStore = ( $params['writeFactory'] instanceof BagOStuff )
  63                         ? $params['writeFactory']
  64                         : ObjectFactory::getObjectFromSpec( $params['writeFactory'] );
  65                 $this->readStore = ( $params['readFactory'] instanceof BagOStuff )
  66                         ? $params['readFactory']
  67                         : ObjectFactory::getObjectFromSpec( $params['readFactory'] );
  68         }
  69
  70         public function setDebug( $debug ) {
  71                 $this->writeStore->setDebug( $debug );
  72                 $this->readStore->setDebug( $debug );
  73         }
  74
  75         public function get( $key, &$casToken = null, $flags = 0 ) {
  76                 return ( $flags & self::READ_LATEST )
  77                         ? $this->writeStore->get( $key, $casToken, $flags )
  78                         : $this->readStore->get( $key, $casToken, $flags );
  79         }
  80
  81         public function getMulti( array $keys, $flags = 0 ) {
  82                 return ( $flags & self::READ_LATEST )
  83                         ? $this->writeStore->getMulti( $keys, $flags )
  84                         : $this->readStore->getMulti( $keys, $flags );
  85         }
  86
  87         public function set( $key, $value, $exptime = 0 ) {
  88                 return $this->writeStore->set( $key, $value, $exptime );
  89         }
  90
  91         public function delete( $key ) {
  92                 return $this->writeStore->delete( $key );
  93         }
  94
  95         public function add( $key, $value, $exptime = 0 ) {
  96                 return $this->writeStore->add( $key, $value, $exptime );
  97         }
  98
  99         public function incr( $key, $value = 1 ) {
 100                 return $this->writeStore->incr( $key, $value );
 101         }
 102
 103         public function decr( $key, $value = 1 ) {
 104                 return $this->writeStore->decr( $key, $value );
 105         }
 106
 107         public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
 108                 return $this->writeStore->lock( $key, $timeout, $expiry, $rclass );
 109         }
 110
 111         public function unlock( $key ) {
 112                 return $this->writeStore->unlock( $key );
 113         }
 114
 115         public function merge( $key, $callback, $exptime = 0, $attempts = 10 ) {
 116                 return $this->writeStore->merge( $key, $callback, $exptime, $attempts );
 117         }
 118
 119         public function getLastError() {
 120                 return ( $this->writeStore->getLastError() != self::ERR_NONE )
 121                         ? $this->writeStore->getLastError()
 122                         : $this->readStore->getLastError();
 123         }
 124
 125         public function clearLastError() {
 126                 $this->writeStore->clearLastError();
 127                 $this->readStore->clearLastError();
 128         }
 129 }