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         protected function doGet( $key, $flags = 0 ) {
  61                 $casToken = null;
  62
  63                 return $this->getWithToken( $key, $casToken, $flags );
  64         }
  65
  66         protected function getWithToken( $key, &$casToken, $flags = 0 ) {
  67                 return $this->client->get( $this->encodeKey( $key ), $casToken );
  68         }
  69
  70         /**
  71          * @param string $key
  72          * @param mixed $value
  73          * @param int $exptime
  74          * @return bool
  75          */
  76         public function set( $key, $value, $exptime = 0 ) {
  77                 return $this->client->set( $this->encodeKey( $key ), $value,
  78                         $this->fixExpiry( $exptime ) );
  79         }
  80
  81         /**
  82          * @param mixed $casToken
  83          * @param string $key
  84          * @param mixed $value
  85          * @param int $exptime
  86          * @return bool
  87          */
  88         protected function cas( $casToken, $key, $value, $exptime = 0 ) {
  89                 return $this->client->cas( $casToken, $this->encodeKey( $key ),
  90                         $value, $this->fixExpiry( $exptime ) );
  91         }
  92
  93         /**
  94          * @param string $key
  95          * @return bool
  96          */
  97         public function delete( $key ) {
  98                 return $this->client->delete( $this->encodeKey( $key ) );
  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         public function merge( $key, $callback, $exptime = 0, $attempts = 10 ) {
 113                 if ( !is_callable( $callback ) ) {
 114                         throw new Exception( "Got invalid callback." );
 115                 }
 116
 117                 return $this->mergeViaCas( $key, $callback, $exptime, $attempts );
 118         }
 119
 120         /**
 121          * Get the underlying client object. This is provided for debugging
 122          * purposes.
 123          * @return BagOStuff
 124          */
 125         public function getClient() {
 126                 return $this->client;
 127         }
 128
 129         /**
 130          * Encode a key for use on the wire inside the memcached protocol.
 131          *
 132          * We encode spaces and line breaks to avoid protocol errors. We encode
 133          * the other control characters for compatibility with libmemcached
 134          * verify_key. We leave other punctuation alone, to maximise backwards
 135          * compatibility.
 136          * @param string $key
 137          * @return string
 138          */
 139         public function encodeKey( $key ) {
 140                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 141                         array( $this, 'encodeKeyCallback' ), $key );
 142         }
 143
 144         /**
 145          * @param array $m
 146          * @return string
 147          */
 148         protected function encodeKeyCallback( $m ) {
 149                 return rawurlencode( $m[0] );
 150         }
 151
 152         /**
 153          * TTLs higher than 30 days will be detected as absolute TTLs
 154          * (UNIX timestamps), and will result in the cache entry being
 155          * discarded immediately because the expiry is in the past.
 156          * Clamp expires >30d at 30d, unless they're >=1e9 in which
 157          * case they are likely to really be absolute (1e9 = 2011-09-09)
 158          * @param int $expiry
 159          * @return int
 160          */
 161         function fixExpiry( $expiry ) {
 162                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 163                         $expiry = 2592000;
 164                 }
 165                 return (int)$expiry;
 166         }
 167
 168         /**
 169          * Decode a key encoded with encodeKey(). This is provided as a convenience
 170          * function for debugging.
 171          *
 172          * @param string $key
 173          *
 174          * @return string
 175          */
 176         public function decodeKey( $key ) {
 177                 // matches %00-%20, %25, %7F (=decoded alternatives for those encoded in encodeKey)
 178                 return preg_replace_callback( '/%([0-1][0-9]|20|25|7F)/i', function ( $match ) {
 179                         return urldecode( $match[0] );
 180                 }, $key );
 181         }
 182
 183         /**
 184          * Send a debug message to the log
 185          * @param string $text
 186          */
 187         protected function debugLog( $text ) {
 188                 $this->logger->debug( $text );
 189         }
 190
 191         public function modifySimpleRelayEvent( array $event ) {
 192                 if ( array_key_exists( 'val', $event ) ) {
 193                         $event['flg'] = 0; // data is not serialized nor gzipped (for memcached driver)
 194                 }
 195
 196                 return $event;
 197         }
 198 }