includes/objectcache/MemcachedBagOStuff.php

   1 <?php
   2 /**
   3  * Base class for memcached clients.
   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  * Base class for memcached clients.
  26  *
  27  * @ingroup Cache
  28  */
  29 class MemcachedBagOStuff extends BagOStuff {
  30         protected $client;
  31
  32         /**
  33          * Fill in the defaults for any parameters missing from $params, using the
  34          * backwards-compatible global variables
  35          * @param array $params
  36          * @return array
  37          */
  38         protected function applyDefaultParams( $params ) {
  39                 if ( !isset( $params['servers'] ) ) {
  40                         $params['servers'] = $GLOBALS['wgMemCachedServers'];
  41                 }
  42                 if ( !isset( $params['debug'] ) ) {
  43                         $params['debug'] = $GLOBALS['wgMemCachedDebug'];
  44                 }
  45                 if ( !isset( $params['persistent'] ) ) {
  46                         $params['persistent'] = $GLOBALS['wgMemCachedPersistent'];
  47                 }
  48                 if ( !isset( $params['compress_threshold'] ) ) {
  49                         $params['compress_threshold'] = 1500;
  50                 }
  51                 if ( !isset( $params['timeout'] ) ) {
  52                         $params['timeout'] = $GLOBALS['wgMemCachedTimeout'];
  53                 }
  54                 if ( !isset( $params['connect_timeout'] ) ) {
  55                         $params['connect_timeout'] = 0.5;
  56                 }
  57                 return $params;
  58         }
  59
  60         public function get( $key, &$casToken = null, $flags = 0 ) {
  61                 return $this->client->get( $this->encodeKey( $key ), $casToken );
  62         }
  63
  64         /**
  65          * @param string $key
  66          * @param mixed $value
  67          * @param int $exptime
  68          * @return bool
  69          */
  70         public function set( $key, $value, $exptime = 0 ) {
  71                 return $this->client->set( $this->encodeKey( $key ), $value,
  72                         $this->fixExpiry( $exptime ) );
  73         }
  74
  75         /**
  76          * @param mixed $casToken
  77          * @param string $key
  78          * @param mixed $value
  79          * @param int $exptime
  80          * @return bool
  81          */
  82         protected function cas( $casToken, $key, $value, $exptime = 0 ) {
  83                 return $this->client->cas( $casToken, $this->encodeKey( $key ),
  84                         $value, $this->fixExpiry( $exptime ) );
  85         }
  86
  87         /**
  88          * @param string $key
  89          * @return bool
  90          */
  91         public function delete( $key ) {
  92                 return $this->client->delete( $this->encodeKey( $key ) );
  93         }
  94
  95         /**
  96          * @param string $key
  97          * @param int $value
  98          * @param int $exptime (default 0)
  99          * @return mixed
 100          */
 101         public function add( $key, $value, $exptime = 0 ) {
 102                 return $this->client->add( $this->encodeKey( $key ), $value,
 103                         $this->fixExpiry( $exptime ) );
 104         }
 105
 106         public function merge( $key, $callback, $exptime = 0, $attempts = 10 ) {
 107                 if ( !is_callable( $callback ) ) {
 108                         throw new Exception( "Got invalid callback." );
 109                 }
 110
 111                 return $this->mergeViaCas( $key, $callback, $exptime, $attempts );
 112         }
 113
 114         /**
 115          * Get the underlying client object. This is provided for debugging
 116          * purposes.
 117          * @return BagOStuff
 118          */
 119         public function getClient() {
 120                 return $this->client;
 121         }
 122
 123         /**
 124          * Encode a key for use on the wire inside the memcached protocol.
 125          *
 126          * We encode spaces and line breaks to avoid protocol errors. We encode
 127          * the other control characters for compatibility with libmemcached
 128          * verify_key. We leave other punctuation alone, to maximise backwards
 129          * compatibility.
 130          * @param string $key
 131          * @return string
 132          */
 133         public function encodeKey( $key ) {
 134                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 135                         array( $this, 'encodeKeyCallback' ), $key );
 136         }
 137
 138         /**
 139          * @param array $m
 140          * @return string
 141          */
 142         protected function encodeKeyCallback( $m ) {
 143                 return rawurlencode( $m[0] );
 144         }
 145
 146         /**
 147          * TTLs higher than 30 days will be detected as absolute TTLs
 148          * (UNIX timestamps), and will result in the cache entry being
 149          * discarded immediately because the expiry is in the past.
 150          * Clamp expires >30d at 30d, unless they're >=1e9 in which
 151          * case they are likely to really be absolute (1e9 = 2011-09-09)
 152          * @param int $expiry
 153          * @return int
 154          */
 155         function fixExpiry( $expiry ) {
 156                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 157                         $expiry = 2592000;
 158                 }
 159                 return (int)$expiry;
 160         }
 161
 162         /**
 163          * Decode a key encoded with encodeKey(). This is provided as a convenience
 164          * function for debugging.
 165          *
 166          * @param string $key
 167          *
 168          * @return string
 169          */
 170         public function decodeKey( $key ) {
 171                 // matches %00-%20, %25, %7F (=decoded alternatives for those encoded in encodeKey)
 172                 return preg_replace_callback( '/%([0-1][0-9]|20|25|7F)/i', function ( $match ) {
 173                         return urldecode( $match[0] );
 174                 }, $key );
 175         }
 176
 177         /**
 178          * Send a debug message to the log
 179          * @param string $text
 180          */
 181         protected function debugLog( $text ) {
 182                 $this->logger->debug( $text );
 183         }
 184
 185         public function modifySimpleRelayEvent( array $event ) {
 186                 if ( array_key_exists( 'val', $event ) ) {
 187                         $event['flg'] = 0; // data is not serialized nor gzipped (for memcached driver)
 188                 }
 189
 190                 return $event;
 191         }
 192 }