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