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          */
  36         protected function applyDefaultParams( $params ) {
  37                 if ( !isset( $params['servers'] ) ) {
  38                         $params['servers'] = $GLOBALS['wgMemCachedServers'];
  39                 }
  40                 if ( !isset( $params['debug'] ) ) {
  41                         $params['debug'] = $GLOBALS['wgMemCachedDebug'];
  42                 }
  43                 if ( !isset( $params['persistent'] ) ) {
  44                         $params['persistent'] = $GLOBALS['wgMemCachedPersistent'];
  45                 }
  46                 if  ( !isset( $params['compress_threshold'] ) ) {
  47                         $params['compress_threshold'] = 1500;
  48                 }
  49                 if ( !isset( $params['timeout'] ) ) {
  50                         $params['timeout'] = $GLOBALS['wgMemCachedTimeout'];
  51                 }
  52                 if ( !isset( $params['connect_timeout'] ) ) {
  53                         $params['connect_timeout'] = 0.1;
  54                 }
  55                 return $params;
  56         }
  57
  58         /**
  59          * @param $key string
  60          * @return Mixed
  61          */
  62         public function get( $key ) {
  63                 return $this->client->get( $this->encodeKey( $key ) );
  64         }
  65
  66         /**
  67          * @param $key string
  68          * @param $value
  69          * @param $exptime int
  70          * @return bool
  71          */
  72         public function set( $key, $value, $exptime = 0 ) {
  73                 return $this->client->set( $this->encodeKey( $key ), $value,
  74                         $this->fixExpiry( $exptime ) );
  75         }
  76
  77         /**
  78          * @param $key string
  79          * @param $time int
  80          * @return bool
  81          */
  82         public function delete( $key, $time = 0 ) {
  83                 return $this->client->delete( $this->encodeKey( $key ), $time );
  84         }
  85
  86         /**
  87          * @param $key string
  88          * @param $value int
  89          * @param $exptime int (default 0)
  90          * @return Mixed
  91          */
  92         public function add( $key, $value, $exptime = 0 ) {
  93                 return $this->client->add( $this->encodeKey( $key ), $value,
  94                         $this->fixExpiry( $exptime ) );
  95         }
  96
  97         /**
  98          * @param $key string
  99          * @param $value int
 100          * @param $exptime
 101          * @return Mixed
 102          */
 103         public function replace( $key, $value, $exptime = 0 ) {
 104                 return $this->client->replace( $this->encodeKey( $key ), $value,
 105                         $this->fixExpiry( $exptime ) );
 106         }
 107
 108         /**
 109          * Get the underlying client object. This is provided for debugging
 110          * purposes.
 111          */
 112         public function getClient() {
 113                 return $this->client;
 114         }
 115
 116         /**
 117          * Encode a key for use on the wire inside the memcached protocol.
 118          *
 119          * We encode spaces and line breaks to avoid protocol errors. We encode
 120          * the other control characters for compatibility with libmemcached
 121          * verify_key. We leave other punctuation alone, to maximise backwards
 122          * compatibility.
 123          * @param $key string
 124          * @return string
 125          */
 126         public function encodeKey( $key ) {
 127                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 128                         array( $this, 'encodeKeyCallback' ), $key );
 129         }
 130
 131         /**
 132          * @param $m array
 133          * @return string
 134          */
 135         protected function encodeKeyCallback( $m ) {
 136                 return rawurlencode( $m[0] );
 137         }
 138
 139         /**
 140          * TTLs higher than 30 days will be detected as absolute TTLs
 141          * (UNIX timestamps), and will result in the cache entry being
 142          * discarded immediately because the expiry is in the past.
 143          * Clamp expiries >30d at 30d, unless they're >=1e9 in which
 144          * case they are likely to really be absolute (1e9 = 2011-09-09)
 145          */
 146         function fixExpiry( $expiry ) {
 147                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 148                         $expiry = 2592000;
 149                 }
 150                 return $expiry;
 151         }
 152
 153         /**
 154          * Decode a key encoded with encodeKey(). This is provided as a convenience
 155          * function for debugging.
 156          *
 157          * @param $key string
 158          *
 159          * @return string
 160          */
 161         public function decodeKey( $key ) {
 162                 return urldecode( $key );
 163         }
 164
 165         /**
 166          * Send a debug message to the log
 167          */
 168         protected function debugLog( $text ) {
 169                 global $wgDebugLogGroups;
 170                 if( !isset( $wgDebugLogGroups['memcached'] ) ) {
 171                         # Prefix message since it will end up in main debug log file
 172                         $text = "memcached: $text";
 173                 }
 174                 if ( substr( $text, -1 ) !== "\n" ) {
 175                         $text .= "\n";
 176                 }
 177                 wfDebugLog( 'memcached', $text );
 178         }
 179 }
 180