includes/objectcache/MemcachedPeclBagOStuff.php

   1 <?php
   2 /**
   3  * Object caching using memcached.
   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 wrapper class for the PECL memcached client
  26  *
  27  * @ingroup Cache
  28  */
  29 class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
  30
  31         /**
  32          * Constructor
  33          *
  34          * Available parameters are:
  35          *   - servers:             The list of IP:port combinations holding the memcached servers.
  36          *   - persistent:          Whether to use a persistent connection
  37          *   - compress_threshold:  The minimum size an object must be before it is compressed
  38          *   - timeout:             The read timeout in microseconds
  39          *   - connect_timeout:     The connect timeout in seconds
  40          *   - serializer:          May be either "php" or "igbinary". Igbinary produces more compact
  41          *                          values, but serialization is much slower unless the php.ini option
  42          *                          igbinary.compact_strings is off.
  43          */
  44         function __construct( $params ) {
  45                 $params = $this->applyDefaultParams( $params );
  46
  47                 if ( $params['persistent'] ) {
  48                         $this->client = new Memcached( __CLASS__ );
  49                 } else {
  50                         $this->client = new Memcached;
  51                 }
  52
  53                 if ( !isset( $params['serializer'] ) ) {
  54                         $params['serializer'] = 'php';
  55                 }
  56
  57                 // The compression threshold is an undocumented php.ini option for some
  58                 // reason. There's probably not much harm in setting it globally, for
  59                 // compatibility with the settings for the PHP client.
  60                 ini_set( 'memcached.compression_threshold', $params['compress_threshold'] );
  61
  62                 // Set timeouts
  63                 $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 );
  64                 $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] );
  65                 $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] );
  66                 $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 );
  67
  68                 // Set libketama mode since it's recommended by the documentation and
  69                 // is as good as any. There's no way to configure libmemcached to use
  70                 // hashes identical to the ones currently in use by the PHP client, and
  71                 // even implementing one of the libmemcached hashes in pure PHP for
  72                 // forwards compatibility would require MWMemcached::get_sock() to be
  73                 // rewritten.
  74                 $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true );
  75
  76                 // Set the serializer
  77                 switch ( $params['serializer'] ) {
  78                         case 'php':
  79                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP );
  80                                 break;
  81                         case 'igbinary':
  82                                 if ( !Memcached::HAVE_IGBINARY ) {
  83                                         throw new MWException( __CLASS__.': the igbinary extension is not available ' .
  84                                                 'but igbinary serialization was requested.' );
  85                                 }
  86                                 $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY );
  87                                 break;
  88                         default:
  89                                 throw new MWException( __CLASS__.': invalid value for serializer parameter' );
  90                 }
  91                 foreach ( $params['servers'] as $host ) {
  92                         list( $ip, $port ) = IP::splitHostAndPort( $host );
  93                         $this->client->addServer( $ip, $port );
  94                 }
  95         }
  96
  97         /**
  98          * @param $key string
  99          * @return Mixed
 100          */
 101         public function get( $key ) {
 102                 $this->debugLog( "get($key)" );
 103                 return $this->checkResult( $key, parent::get( $key ) );
 104         }
 105
 106         /**
 107          * @param $key string
 108          * @param $value
 109          * @param $exptime int
 110          * @return bool
 111          */
 112         public function set( $key, $value, $exptime = 0 ) {
 113                 $this->debugLog( "set($key)" );
 114                 return $this->checkResult( $key, parent::set( $key, $value, $exptime ) );
 115         }
 116
 117         /**
 118          * @param $key string
 119          * @param $time int
 120          * @return bool
 121          */
 122         public function delete( $key, $time = 0 ) {
 123                 $this->debugLog( "delete($key)" );
 124                 $result = parent::delete( $key, $time );
 125                 if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) {
 126                         // "Not found" is counted as success in our interface
 127                         return true;
 128                 } else {
 129                         return $this->checkResult( $key, $result );
 130                 }
 131         }
 132
 133         /**
 134          * @param $key string
 135          * @param $value int
 136          * @return Mixed
 137          */
 138         public function add( $key, $value, $exptime = 0 ) {
 139                 $this->debugLog( "add($key)" );
 140                 return $this->checkResult( $key, parent::add( $key, $value, $exptime ) );
 141         }
 142
 143         /**
 144          * @param $key string
 145          * @param $value int
 146          * @param $exptime
 147          * @return Mixed
 148          */
 149         public function replace( $key, $value, $exptime = 0 ) {
 150                 $this->debugLog( "replace($key)" );
 151                 return $this->checkResult( $key, parent::replace( $key, $value, $exptime ) );
 152         }
 153
 154         /**
 155          * @param $key string
 156          * @param $value int
 157          * @return Mixed
 158          */
 159         public function incr( $key, $value = 1 ) {
 160                 $this->debugLog( "incr($key)" );
 161                 $result = $this->client->increment( $key, $value );
 162                 return $this->checkResult( $key, $result );
 163         }
 164
 165         /**
 166          * @param $key string
 167          * @param $value int
 168          * @return Mixed
 169          */
 170         public function decr( $key, $value = 1 ) {
 171                 $this->debugLog( "decr($key)" );
 172                 $result = $this->client->decrement( $key, $value );
 173                 return $this->checkResult( $key, $result );
 174         }
 175
 176         /**
 177          * Check the return value from a client method call and take any necessary
 178          * action. Returns the value that the wrapper function should return. At
 179          * present, the return value is always the same as the return value from
 180          * the client, but some day we might find a case where it should be
 181          * different.
 182          *
 183          * @param $key The key used by the caller, or false if there wasn't one.
 184          * @param $result The return value
 185          */
 186         protected function checkResult( $key, $result ) {
 187                 if ( $result !== false ) {
 188                         return $result;
 189                 }
 190                 switch ( $this->client->getResultCode() ) {
 191                         case Memcached::RES_SUCCESS:
 192                                 break;
 193                         case Memcached::RES_DATA_EXISTS:
 194                         case Memcached::RES_NOTSTORED:
 195                         case Memcached::RES_NOTFOUND:
 196                                 $this->debugLog( "result: " . $this->client->getResultMessage() );
 197                                 break;
 198                         default:
 199                                 $msg = $this->client->getResultMessage();
 200                                 if ( $key !== false ) {
 201                                         $server = $this->client->getServerByKey( $key );
 202                                         $serverName = "{$server['host']}:{$server['port']}";
 203                                         $msg = "Memcached error for key \"$key\" on server \"$serverName\": $msg";
 204                                 } else {
 205                                         $msg = "Memcached error: $msg";
 206                                 }
 207                                 wfDebugLog( 'memcached-serious', $msg );
 208                 }
 209                 return $result;
 210         }
 211
 212         /**
 213          * @param $keys Array
 214          * @return Array
 215          */
 216         public function getMulti( array $keys ) {
 217                 $this->debugLog( 'getMulti(' . implode( ', ', $keys ) . ')' );
 218                 $callback = array( $this, 'encodeKey' );
 219                 $result = $this->client->getMulti( array_map( $callback, $keys ) );
 220                 return $this->checkResult( false, $result );
 221         }
 222
 223         /* NOTE: there is no cas() method here because it is currently not supported
 224          * by the BagOStuff interface and other BagOStuff subclasses, such as
 225          * SqlBagOStuff.
 226          */
 227 }