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          * @return Mixed
  90          */
  91         public function add( $key, $value, $exptime = 0 ) {
  92                 return $this->client->add( $this->encodeKey( $key ), $value,
  93                         $this->fixExpiry( $exptime ) );
  94         }
  95
  96         /**
  97          * @param $key string
  98          * @param $value int
  99          * @param $exptime
 100          * @return Mixed
 101          */
 102         public function replace( $key, $value, $exptime = 0 ) {
 103                 return $this->client->replace( $this->encodeKey( $key ), $value,
 104                         $this->fixExpiry( $exptime ) );
 105         }
 106
 107         /**
 108          * Get the underlying client object. This is provided for debugging
 109          * purposes.
 110          */
 111         public function getClient() {
 112                 return $this->client;
 113         }
 114
 115         /**
 116          * Encode a key for use on the wire inside the memcached protocol.
 117          *
 118          * We encode spaces and line breaks to avoid protocol errors. We encode
 119          * the other control characters for compatibility with libmemcached
 120          * verify_key. We leave other punctuation alone, to maximise backwards
 121          * compatibility.
 122          * @param $key string
 123          * @return string
 124          */
 125         public function encodeKey( $key ) {
 126                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 127                         array( $this, 'encodeKeyCallback' ), $key );
 128         }
 129
 130         /**
 131          * @param $m array
 132          * @return string
 133          */
 134         protected function encodeKeyCallback( $m ) {
 135                 return rawurlencode( $m[0] );
 136         }
 137
 138         /**
 139          * TTLs higher than 30 days will be detected as absolute TTLs
 140          * (UNIX timestamps), and will result in the cache entry being
 141          * discarded immediately because the expiry is in the past.
 142          * Clamp expiries >30d at 30d, unless they're >=1e9 in which
 143          * case they are likely to really be absolute (1e9 = 2011-09-09)
 144          */
 145         function fixExpiry( $expiry ) {
 146                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 147                         $expiry = 2592000;
 148                 }
 149                 return $expiry;
 150         }
 151
 152         /**
 153          * Decode a key encoded with encodeKey(). This is provided as a convenience
 154          * function for debugging.
 155          *
 156          * @param $key string
 157          *
 158          * @return string
 159          */
 160         public function decodeKey( $key ) {
 161                 return urldecode( $key );
 162         }
 163
 164         /**
 165          * Send a debug message to the log
 166          */
 167         protected function debugLog( $text ) {
 168                 global $wgDebugLogGroups;
 169                 if( !isset( $wgDebugLogGroups['memcached'] ) ) {
 170                         # Prefix message since it will end up in main debug log file
 171                         $text = "memcached: $text";
 172                 }
 173                 if ( substr( $text, -1 ) !== "\n" ) {
 174                         $text .= "\n";
 175                 }
 176                 wfDebugLog( 'memcached', $text );
 177         }
 178 }
 179