includes/MessageCache.php

   1 <?php
   2 /**
   3  *
   4  * @package MediaWiki
   5  */
   6
   7 /**
   8  *
   9  */
  10 define( 'MSG_LOAD_TIMEOUT', 60);
  11 define( 'MSG_LOCK_TIMEOUT', 10);
  12 define( 'MSG_WAIT_TIMEOUT', 10);
  13
  14 /**
  15  * Message cache
  16  * Performs various useful MediaWiki namespace-related functions
  17  *
  18  * @package MediaWiki
  19  */
  20 class MessageCache
  21 {
  22         var $mCache, $mUseCache, $mDisable, $mExpiry;
  23         var $mMemcKey, $mKeys, $mParserOptions, $mParser;
  24         var $mExtensionMessages;
  25         var $mInitialised = false;
  26     var $mLang, $mLangCode;
  27         function initialise( &$memCached, $useDB, $expiry, $memcPrefix, $langobj, $langcode) {
  28                 $fname = 'MessageCache::initialise';
  29                 wfProfileIn( $fname );
  30         $this->mLang = $langobj;
  31         $this->mLangCode = $langcode;
  32                 $this->mUseCache = !is_null( $memCached );
  33                 $this->mMemc = &$memCached;
  34                 $this->mDisable = !$useDB;
  35                 $this->mExpiry = $expiry;
  36                 $this->mDisableTransform = false;
  37                 $this->mMemcKey = $memcPrefix.':messages';
  38                 $this->mKeys = false; # initialised on demand
  39                 $this->mInitialised = true;
  40         if ( isset ( $forContent ) ) $this->mIsForContent = $forContent;
  41                 wfProfileIn( $fname.'-parseropt' );
  42                 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
  43                 wfProfileOut( $fname.'-parseropt' );
  44                 wfProfileIn( $fname.'-parser' );
  45                 $this->mParser = new Parser;
  46                 wfProfileOut( $fname.'-parser' );
  47
  48                 $this->load();
  49                 wfProfileOut( $fname );
  50         }
  51
  52         /**
  53          * Loads messages either from memcached or the database, if not disabled
  54          * On error, quietly switches to a fallback mode
  55          * Returns false for a reportable error, true otherwise
  56          */
  57         function load() {
  58                 global $wgAllMessagesEn;
  59
  60                 if ( $this->mDisable ) {
  61                         wfDebug( "MessageCache::load(): disabled\n" );
  62                         return true;
  63                 }
  64                 $fname = 'MessageCache::load';
  65                 wfProfileIn( $fname );
  66                 $success = true;
  67
  68                 if ( $this->mUseCache ) {
  69                         wfProfileIn( $fname.'-fromcache' );
  70                         $this->mCache = $this->mMemc->get( $this->mMemcKey );
  71                         wfProfileOut( $fname.'-fromcache' );
  72
  73                         # If there's nothing in memcached, load all the messages from the database
  74                         if ( !$this->mCache ) {
  75                                 wfDebug( "MessageCache::load(): loading all messages\n" );
  76                                 $this->lock();
  77                                 # Other threads don't need to load the messages if another thread is doing it.
  78                                 $success = $this->mMemc->set( $this->mMemcKey, "loading", MSG_LOAD_TIMEOUT );
  79                                 if ( $success ) {
  80                                         wfProfileIn( $fname.'-load' );
  81                                         $this->loadFromDB();
  82                                         wfProfileOut( $fname.'-load' );
  83                                         # Save in memcached
  84                                         # Keep trying if it fails, this is kind of important
  85                                         wfProfileIn( $fname.'-save' );
  86                                         for ( $i=0; $i<20 && !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry ); $i++ ) {
  87                                                 usleep(mt_rand(500000,1500000));
  88                                         }
  89                                         wfProfileOut( $fname.'-save' );
  90                                         if ( $i == 20 ) {
  91                                                 $this->mMemc->set( $this->mMemcKey, 'error', 86400 );
  92                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
  93                                         }
  94                                 }
  95                                 $this->unlock();
  96                         }
  97
  98                         if ( !is_array( $this->mCache ) ) {
  99                                 wfMsg( "MessageCache::load(): individual message mode\n" );
 100                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 101                                 # Causing too much DB load, disabling -- TS
 102                                 $this->mDisable = true;
 103                                 /*
 104                                 if ( $this->mCache == "loading" ) {
 105                                         $this->mUseCache = false;
 106                                 } elseif ( $this->mCache == "error" ) {
 107                                         $this->mUseCache = false;
 108                                         $success = false;
 109                                 } else {
 110                                         $this->mDisable = true;
 111                                         $success = false;
 112                                 }*/
 113                                 $this->mCache = false;
 114                         }
 115                 }
 116                 wfProfileOut( $fname );
 117                 return $success;
 118         }
 119
 120         /**
 121          * Loads all cacheable messages from the database
 122          */
 123         function loadFromDB() {
 124                         $fname = 'MessageCache::loadFromDB';
 125                 $dbr =& wfGetDB( DB_SLAVE );
 126                 $res = $dbr->select( 'cur',
 127                         array( 'cur_title', 'cur_text' ),
 128                         array( 'cur_is_redirect' => 0, 'cur_namespace' => NS_MEDIAWIKI ),
 129                         $fname
 130                 );
 131
 132                 $this->mCache = array();
 133                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 134                         $this->mCache[$row->cur_title] = $row->cur_text;
 135                 }
 136
 137                 $dbr->freeResult( $res );
 138         }
 139
 140         /**
 141          * Not really needed anymore
 142          */
 143         function getKeys() {
 144                 global $wgAllMessagesEn;
 145                 if ( !$this->mKeys ) {
 146                         $this->mKeys = array();
 147                         foreach ( $wgAllMessagesEn as $key => $value ) {
 148                                 array_push( $this->mKeys, $this->mLang->ucfirst( $key ) );
 149                         }
 150                 }
 151                 return $this->mKeys;
 152         }
 153
 154         /**
 155          * Obsolete
 156          */
 157         function isCacheable( $key ) {
 158                 return true;
 159                 /*
 160                 global $wgAllMessagesEn, $wgLang;
 161                 return array_key_exists( $wgLang->lcfirst( $key ), $wgAllMessagesEn ) ||
 162                         array_key_exists( $key, $wgAllMessagesEn );
 163                 */
 164         }
 165
 166         function replace( $title, $text ) {
 167                 $this->lock();
 168                 $this->load();
 169                 if ( is_array( $this->mCache ) ) {
 170                         $this->mCache[$title] = $text;
 171                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 172                 }
 173                 $this->unlock();
 174         }
 175
 176         /**
 177          * Returns success
 178          * Represents a write lock on the messages key
 179          */
 180         function lock() {
 181                 if ( !$this->mUseCache ) {
 182                         return true;
 183                 }
 184
 185                 $lockKey = $this->mMemcKey . 'lock';
 186                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 187                         sleep(1);
 188                 }
 189
 190                 return $i >= MSG_WAIT_TIMEOUT;
 191         }
 192
 193         function unlock() {
 194                 if ( !$this->mUseCache ) {
 195                         return;
 196                 }
 197
 198                 $lockKey = $this->mMemcKey . 'lock';
 199                 $this->mMemc->delete( $lockKey );
 200         }
 201
 202         function get( $key, $useDB ) {
 203
 204                 # If uninitialised, someone is trying to call this halfway through Setup.php
 205                 if ( !$this->mInitialised ) {
 206                         return "&lt;$key&gt;";
 207                 }
 208
 209                 $message = false;
 210                 if ( !$this->mDisable && $useDB ) {
 211                         $title = $this->mLang->ucfirst( $key );
 212
 213
 214                         # Try the cache
 215                         if ( $this->mUseCache && $this->mCache && array_key_exists( $title, $this->mCache ) ) {
 216                                 $message = $this->mCache[$title];
 217                         }
 218
 219                         # If it wasn't in the cache, load each message from the DB individually
 220                         if ( !$message ) {
 221                                 $dbr =& wfGetDB( DB_SLAVE );
 222                                 $result = $dbr->getArray( 'cur', array('cur_text'),
 223                                   array( 'cur_namespace' => NS_MEDIAWIKI, 'cur_title' => $title ),
 224                                   'MessageCache::get' );
 225                                 if ( $result ) {
 226                                         $message = $result->cur_text;
 227                                 }
 228                         }
 229                 }
 230                 # Try the extension array
 231                 if ( !$message ) {
 232                         $message = @$this->mExtensionMessages[$key];
 233                 }
 234
 235                 # Try the array in the language object
 236                 if ( !$message ) {
 237                         wfSuppressWarnings();
 238                         $message = $this->mLang->getMessage( $key );
 239                         wfRestoreWarnings();
 240                 }
 241
 242                 # Try the English array
 243                 if ( !$message && $this->mLangCode != 'en' ) {
 244                         wfSuppressWarnings();
 245                         $message = Language::getMessage( $key );
 246                         wfRestoreWarnings();
 247                 }
 248
 249                 # Final fallback
 250                 if ( !$message ) {
 251                         $message = "&lt;$key&gt;";
 252                 }
 253
 254                 # Replace brace tags
 255                 $message = $this->transform( $message );
 256                 return $message;
 257         }
 258
 259         function transform( $message ) {
 260                 if( !$this->mDisableTransform ) {
 261                         if ( strstr( $message, '{{' ) !== false ) {
 262                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 263                         }
 264                 }
 265                 return $message;
 266         }
 267
 268         function disable() { $this->mDisable = true; }
 269         function enable() { $this->mDisable = false; }
 270         function disableTransform() { $this->mDisableTransform = true; }
 271         function enableTransform() { $this->mDisableTransform = false; }
 272
 273         function addMessage( $key, $value ) {
 274                 $this->mExtensionMessages[$key] = $value;
 275         }
 276
 277         function addMessages( $messages ) {
 278                 foreach ( $messages as $key => $value ) {
 279                         $this->mExtensionMessages[$key] = $value;
 280                 }
 281         }
 282
 283         /**
 284          * Clear all stored messages. Mainly used after a mass rebuild.
 285          */
 286         function clear() {
 287                 if( $this->mUseCache ) {
 288                         $this->mMemc->delete( $this->mMemcKey );
 289                 }
 290         }
 291 }
 292 ?>