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'] = 0.5;
  54                 }
  55                 return $params;
  56         }
  57
  58         /**
  59          * @param $key string
  60          * @param $casToken[optional] mixed
  61          * @return Mixed
  62          */
  63         public function get( $key, &$casToken = null ) {
  64                 return $this->client->get( $this->encodeKey( $key ), $casToken );
  65         }
  66
  67         /**
  68          * @param $key string
  69          * @param $value
  70          * @param $exptime int
  71          * @return bool
  72          */
  73         public function set( $key, $value, $exptime = 0 ) {
  74                 return $this->client->set( $this->encodeKey( $key ), $value,
  75                         $this->fixExpiry( $exptime ) );
  76         }
  77
  78         /**
  79          * @param $key string
  80          * @param $casToken mixed
  81          * @param $value
  82          * @param $exptime int
  83          * @return bool
  84          */
  85         public function cas( $casToken, $key, $value, $exptime = 0 ) {
  86                 return $this->client->cas( $casToken, $this->encodeKey( $key ),
  87                         $value, $this->fixExpiry( $exptime ) );
  88         }
  89
  90         /**
  91          * @param $key string
  92          * @param $time int
  93          * @return bool
  94          */
  95         public function delete( $key, $time = 0 ) {
  96                 return $this->client->delete( $this->encodeKey( $key ), $time );
  97         }
  98
  99         /**
 100          * @param $key string
 101          * @param $value int
 102          * @param int $exptime (default 0)
 103          * @return Mixed
 104          */
 105         public function add( $key, $value, $exptime = 0 ) {
 106                 return $this->client->add( $this->encodeKey( $key ), $value,
 107                         $this->fixExpiry( $exptime ) );
 108         }
 109
 110         /**
 111          * Get the underlying client object. This is provided for debugging
 112          * purposes.
 113          */
 114         public function getClient() {
 115                 return $this->client;
 116         }
 117
 118         /**
 119          * Encode a key for use on the wire inside the memcached protocol.
 120          *
 121          * We encode spaces and line breaks to avoid protocol errors. We encode
 122          * the other control characters for compatibility with libmemcached
 123          * verify_key. We leave other punctuation alone, to maximise backwards
 124          * compatibility.
 125          * @param $key string
 126          * @return string
 127          */
 128         public function encodeKey( $key ) {
 129                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 130                         array( $this, 'encodeKeyCallback' ), $key );
 131         }
 132
 133         /**
 134          * @param $m array
 135          * @return string
 136          */
 137         protected function encodeKeyCallback( $m ) {
 138                 return rawurlencode( $m[0] );
 139         }
 140
 141         /**
 142          * TTLs higher than 30 days will be detected as absolute TTLs
 143          * (UNIX timestamps), and will result in the cache entry being
 144          * discarded immediately because the expiry is in the past.
 145          * Clamp expiries >30d at 30d, unless they're >=1e9 in which
 146          * case they are likely to really be absolute (1e9 = 2011-09-09)
 147          */
 148         function fixExpiry( $expiry ) {
 149                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 150                         $expiry = 2592000;
 151                 }
 152                 return $expiry;
 153         }
 154
 155         /**
 156          * Decode a key encoded with encodeKey(). This is provided as a convenience
 157          * function for debugging.
 158          *
 159          * @param $key string
 160          *
 161          * @return string
 162          */
 163         public function decodeKey( $key ) {
 164                 return urldecode( $key );
 165         }
 166
 167         /**
 168          * Send a debug message to the log
 169          */
 170         protected function debugLog( $text ) {
 171                 wfDebugLog( 'memcached', $text );
 172         }
 173 }