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  */
  21
  22 /**
  23  * A cache class that directs writes to one set of servers and reads to
  24  * another. This assumes that the servers used for reads are setup to replica DB
  25  * those that writes go to. This can easily be used with redis for example.
  26  *
  27  * In the WAN scenario (e.g. multi-datacenter case), this is useful when
  28  * writes are rare or they usually take place in the primary datacenter.
  29  *
  30  * @ingroup Cache
  31  * @since 1.26
  32  */
  33 class ReplicatedBagOStuff extends BagOStuff {
  34         /** @var BagOStuff */
  35         protected $writeStore;
  36         /** @var BagOStuff */
  37         protected $readStore;
  38
  39         /**
  40          * Constructor. Parameters are:
  41          *   - writeFactory : ObjectFactory::getObjectFromSpec array yeilding BagOStuff.
  42          *                    This object will be used for writes (e.g. the master DB).
  43          *   - readFactory  : ObjectFactory::getObjectFromSpec array yeilding BagOStuff.
  44          *                    This object will be used for reads (e.g. a replica DB).
  45          *
  46          * @param array $params
  47          * @throws InvalidArgumentException
  48          */
  49         public function __construct( $params ) {
  50                 parent::__construct( $params );
  51
  52                 if ( !isset( $params['writeFactory'] ) ) {
  53                         throw new InvalidArgumentException(
  54                                 __METHOD__ . ': the "writeFactory" parameter is required' );
  55                 }
  56                 if ( !isset( $params['readFactory'] ) ) {
  57                         throw new InvalidArgumentException(
  58                                 __METHOD__ . ': the "readFactory" parameter is required' );
  59                 }
  60
  61                 $opts = [ 'reportDupes' => false ]; // redundant
  62                 $this->writeStore = ( $params['writeFactory'] instanceof BagOStuff )
  63                         ? $params['writeFactory']
  64                         : ObjectFactory::getObjectFromSpec( $opts + $params['writeFactory'] );
  65                 $this->readStore = ( $params['readFactory'] instanceof BagOStuff )
  66                         ? $params['readFactory']
  67                         : ObjectFactory::getObjectFromSpec( $opts + $params['readFactory'] );
  68                 $this->attrMap = $this->mergeFlagMaps( [ $this->readStore, $this->writeStore ] );
  69         }
  70
  71         public function setDebug( $debug ) {
  72                 $this->writeStore->setDebug( $debug );
  73                 $this->readStore->setDebug( $debug );
  74         }
  75
  76         protected function doGet( $key, $flags = 0 ) {
  77                 return ( $flags & self::READ_LATEST )
  78                         ? $this->writeStore->get( $key, $flags )
  79                         : $this->readStore->get( $key, $flags );
  80         }
  81
  82         public function getMulti( array $keys, $flags = 0 ) {
  83                 return ( $flags & self::READ_LATEST )
  84                         ? $this->writeStore->getMulti( $keys, $flags )
  85                         : $this->readStore->getMulti( $keys, $flags );
  86         }
  87
  88         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  89                 return $this->writeStore->set( $key, $value, $exptime, $flags );
  90         }
  91
  92         public function delete( $key ) {
  93                 return $this->writeStore->delete( $key );
  94         }
  95
  96         public function add( $key, $value, $exptime = 0 ) {
  97                 return $this->writeStore->add( $key, $value, $exptime );
  98         }
  99
 100         public function incr( $key, $value = 1 ) {
 101                 return $this->writeStore->incr( $key, $value );
 102         }
 103
 104         public function decr( $key, $value = 1 ) {
 105                 return $this->writeStore->decr( $key, $value );
 106         }
 107
 108         public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
 109                 return $this->writeStore->lock( $key, $timeout, $expiry, $rclass );
 110         }
 111
 112         public function unlock( $key ) {
 113                 return $this->writeStore->unlock( $key );
 114         }
 115
 116         public function merge( $key, callable $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
 117                 return $this->writeStore->merge( $key, $callback, $exptime, $attempts, $flags );
 118         }
 119
 120         public function getLastError() {
 121                 return ( $this->writeStore->getLastError() != self::ERR_NONE )
 122                         ? $this->writeStore->getLastError()
 123                         : $this->readStore->getLastError();
 124         }
 125
 126         public function clearLastError() {
 127                 $this->writeStore->clearLastError();
 128                 $this->readStore->clearLastError();
 129         }
 130 }