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         /** @var MWMemcached|Memcached */
  31         protected $client;
  32
  33         /**
  34          * Fill in the defaults for any parameters missing from $params, using the
  35          * backwards-compatible global variables
  36          * @param array $params
  37          * @return array
  38          */
  39         protected function applyDefaultParams( $params ) {
  40                 if ( !isset( $params['servers'] ) ) {
  41                         $params['servers'] = $GLOBALS['wgMemCachedServers'];
  42                 }
  43                 if ( !isset( $params['debug'] ) ) {
  44                         $params['debug'] = $GLOBALS['wgMemCachedDebug'];
  45                 }
  46                 if ( !isset( $params['persistent'] ) ) {
  47                         $params['persistent'] = $GLOBALS['wgMemCachedPersistent'];
  48                 }
  49                 if ( !isset( $params['compress_threshold'] ) ) {
  50                         $params['compress_threshold'] = 1500;
  51                 }
  52                 if ( !isset( $params['timeout'] ) ) {
  53                         $params['timeout'] = $GLOBALS['wgMemCachedTimeout'];
  54                 }
  55                 if ( !isset( $params['connect_timeout'] ) ) {
  56                         $params['connect_timeout'] = 0.5;
  57                 }
  58                 return $params;
  59         }
  60
  61         protected function doGet( $key, $flags = 0 ) {
  62                 $casToken = null;
  63
  64                 return $this->getWithToken( $key, $casToken, $flags );
  65         }
  66
  67         protected function getWithToken( $key, &$casToken, $flags = 0 ) {
  68                 return $this->client->get( $this->encodeKey( $key ), $casToken );
  69         }
  70
  71         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  72                 return $this->client->set( $this->encodeKey( $key ), $value,
  73                         $this->fixExpiry( $exptime ) );
  74         }
  75
  76         protected function cas( $casToken, $key, $value, $exptime = 0 ) {
  77                 return $this->client->cas( $casToken, $this->encodeKey( $key ),
  78                         $value, $this->fixExpiry( $exptime ) );
  79         }
  80
  81         public function delete( $key ) {
  82                 return $this->client->delete( $this->encodeKey( $key ) );
  83         }
  84
  85         public function add( $key, $value, $exptime = 0 ) {
  86                 return $this->client->add( $this->encodeKey( $key ), $value,
  87                         $this->fixExpiry( $exptime ) );
  88         }
  89
  90         public function merge( $key, $callback, $exptime = 0, $attempts = 10, $flags = 0 ) {
  91                 if ( !is_callable( $callback ) ) {
  92                         throw new Exception( "Got invalid callback." );
  93                 }
  94
  95                 return $this->mergeViaCas( $key, $callback, $exptime, $attempts );
  96         }
  97
  98         /**
  99          * Get the underlying client object. This is provided for debugging
 100          * purposes.
 101          * @return BagOStuff
 102          */
 103         public function getClient() {
 104                 return $this->client;
 105         }
 106
 107         /**
 108          * Encode a key for use on the wire inside the memcached protocol.
 109          *
 110          * We encode spaces and line breaks to avoid protocol errors. We encode
 111          * the other control characters for compatibility with libmemcached
 112          * verify_key. We leave other punctuation alone, to maximise backwards
 113          * compatibility.
 114          * @param string $key
 115          * @return string
 116          */
 117         public function encodeKey( $key ) {
 118                 return preg_replace_callback( '/[\x00-\x20\x25\x7f]+/',
 119                         array( $this, 'encodeKeyCallback' ), $key );
 120         }
 121
 122         /**
 123          * @param array $m
 124          * @return string
 125          */
 126         protected function encodeKeyCallback( $m ) {
 127                 return rawurlencode( $m[0] );
 128         }
 129
 130         /**
 131          * TTLs higher than 30 days will be detected as absolute TTLs
 132          * (UNIX timestamps), and will result in the cache entry being
 133          * discarded immediately because the expiry is in the past.
 134          * Clamp expires >30d at 30d, unless they're >=1e9 in which
 135          * case they are likely to really be absolute (1e9 = 2011-09-09)
 136          * @param int $expiry
 137          * @return int
 138          */
 139         function fixExpiry( $expiry ) {
 140                 if ( $expiry > 2592000 && $expiry < 1000000000 ) {
 141                         $expiry = 2592000;
 142                 }
 143                 return (int)$expiry;
 144         }
 145
 146         /**
 147          * Decode a key encoded with encodeKey(). This is provided as a convenience
 148          * function for debugging.
 149          *
 150          * @param string $key
 151          *
 152          * @return string
 153          */
 154         public function decodeKey( $key ) {
 155                 // matches %00-%20, %25, %7F (=decoded alternatives for those encoded in encodeKey)
 156                 return preg_replace_callback( '/%([0-1][0-9]|20|25|7F)/i', function ( $match ) {
 157                         return urldecode( $match[0] );
 158                 }, $key );
 159         }
 160
 161         /**
 162          * Send a debug message to the log
 163          * @param string $text
 164          */
 165         protected function debugLog( $text ) {
 166                 $this->logger->debug( $text );
 167         }
 168
 169         public function modifySimpleRelayEvent( array $event ) {
 170                 if ( array_key_exists( 'val', $event ) ) {
 171                         $event['flg'] = 0; // data is not serialized nor gzipped (for memcached driver)
 172                 }
 173
 174                 return $event;
 175         }
 176 }