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 $mInitialised = false;
  26
  27         function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
  28                 $fname = 'MessageCache::initialise';
  29                 wfProfileIn( $fname );
  30
  31                 $this->mUseCache = !is_null( $memCached );
  32                 $this->mMemc = &$memCached;
  33                 $this->mDisable = !$useDB;
  34                 $this->mExpiry = $expiry;
  35                 $this->mDisableTransform = false;
  36                 $this->mMemcKey = $memcPrefix.':messages';
  37                 $this->mKeys = false; # initialised on demand
  38                 $this->mInitialised = true;
  39
  40                 wfProfileIn( $fname.'-parseropt' );
  41                 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
  42                 wfProfileOut( $fname.'-parseropt' );
  43                 wfProfileIn( $fname.'-parser' );
  44                 $this->mParser = new Parser;
  45                 wfProfileOut( $fname.'-parser' );
  46
  47                 $this->load();
  48                 wfProfileOut( $fname );
  49         }
  50
  51         /**
  52          * Loads messages either from memcached or the database, if not disabled
  53          * On error, quietly switches to a fallback mode
  54          * Returns false for a reportable error, true otherwise
  55          */
  56         function load() {
  57                 global $wgAllMessagesEn;
  58
  59                 if ( $this->mDisable ) {
  60                         wfDebug( "MessageCache::load(): disabled\n" );
  61                         return true;
  62                 }
  63                 $fname = 'MessageCache::load';
  64                 wfProfileIn( $fname );
  65                 $success = true;
  66
  67                 if ( $this->mUseCache ) {
  68                         wfProfileIn( $fname.'-fromcache' );
  69                         $this->mCache = $this->mMemc->get( $this->mMemcKey );
  70                         wfProfileOut( $fname.'-fromcache' );
  71
  72                         # If there's nothing in memcached, load all the messages from the database
  73                         if ( !$this->mCache ) {
  74                                 wfDebug( "MessageCache::load(): loading all messages\n" );
  75                                 $this->lock();
  76                                 # Other threads don't need to load the messages if another thread is doing it.
  77                                 $success = $this->mMemc->add( $this->mMemcKey, "loading", MSG_LOAD_TIMEOUT );
  78                                 if ( $success ) {
  79                                         wfProfileIn( $fname.'-load' );
  80                                         $this->loadFromDB();
  81                                         wfProfileOut( $fname.'-load' );
  82                                         # Save in memcached
  83                                         # Keep trying if it fails, this is kind of important
  84                                         wfProfileIn( $fname.'-save' );
  85                                         for ( $i=0; $i<20 && !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry ); $i++ ) {
  86                                                 usleep(mt_rand(500000,1500000));
  87                                         }
  88                                         wfProfileOut( $fname.'-save' );
  89                                         if ( $i == 20 ) {
  90                                                 $this->mMemc->set( $this->mMemcKey, 'error', 86400 );
  91                                                 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
  92                                         }
  93                                 }
  94                                 $this->unlock();
  95                         }
  96
  97                         if ( !is_array( $this->mCache ) ) {
  98                                 wfMsg( "MessageCache::load(): individual message mode\n" );
  99                                 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
 100                                 # Causing too much DB load, disabling -- TS
 101                                 $this->mDisable = true;
 102                                 /*
 103                                 if ( $this->mCache == "loading" ) {
 104                                         $this->mUseCache = false;
 105                                 } elseif ( $this->mCache == "error" ) {
 106                                         $this->mUseCache = false;
 107                                         $success = false;
 108                                 } else {
 109                                         $this->mDisable = true;
 110                                         $success = false;
 111                                 }*/
 112                                 $this->mCache = false;
 113                         }
 114                 }
 115                 wfProfileOut( $fname );
 116                 return $success;
 117         }
 118
 119         /**
 120          * Loads all or main part of cacheable messages from the database
 121          */
 122         function loadFromDB() {
 123                 global $wgPartialMessageCache;
 124                 $fname = 'MessageCache::loadFromDB';
 125                 $dbr =& wfGetDB( DB_SLAVE );
 126                 $conditions = array( 'cur_is_redirect' => 0,
 127                                         'cur_namespace' => NS_MEDIAWIKI);
 128                 if ($wgPartialMessageCache) {
 129                         if (is_array($wgPartialMessageCache)) {
 130                                 $conditions['cur_title']=$wgPartialMessageCache;
 131                         } else {
 132                                 require_once("MessageCacheHints.php");
 133                                 $conditions['cur_title']=MessageCacheHints::get();
 134                         }
 135                 }
 136                 $res = $dbr->select( 'cur',
 137                         array( 'cur_title', 'cur_text' ), $conditions, $fname);
 138
 139                 $this->mCache = array();
 140                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 141                         $this->mCache[$row->cur_title] = $row->cur_text;
 142                 }
 143
 144                 $dbr->freeResult( $res );
 145         }
 146
 147         /**
 148          * Not really needed anymore
 149          */
 150         function getKeys() {
 151                 global $wgAllMessagesEn, $wgContLang;
 152                 if ( !$this->mKeys ) {
 153                         $this->mKeys = array();
 154                         foreach ( $wgAllMessagesEn as $key => $value ) {
 155                                 array_push( $this->mKeys, $wgContLang->ucfirst( $key ) );
 156                         }
 157                 }
 158                 return $this->mKeys;
 159         }
 160
 161         /**
 162          * Obsolete
 163          */
 164         function isCacheable( $key ) {
 165                 return true;
 166                 /*
 167                 global $wgAllMessagesEn, $wgLang;
 168                 return array_key_exists( $wgLang->lcfirst( $key ), $wgAllMessagesEn ) ||
 169                         array_key_exists( $key, $wgAllMessagesEn );
 170                 */
 171         }
 172
 173         function replace( $title, $text ) {
 174                 $this->lock();
 175                 $this->load();
 176                 if ( is_array( $this->mCache ) ) {
 177                         $this->mCache[$title] = $text;
 178                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 179                 }
 180                 $this->unlock();
 181         }
 182
 183         /**
 184          * Returns success
 185          * Represents a write lock on the messages key
 186          */
 187         function lock() {
 188                 if ( !$this->mUseCache ) {
 189                         return true;
 190                 }
 191
 192                 $lockKey = $this->mMemcKey . 'lock';
 193                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 194                         sleep(1);
 195                 }
 196
 197                 return $i >= MSG_WAIT_TIMEOUT;
 198         }
 199
 200         function unlock() {
 201                 if ( !$this->mUseCache ) {
 202                         return;
 203                 }
 204
 205                 $lockKey = $this->mMemcKey . 'lock';
 206                 $this->mMemc->delete( $lockKey );
 207         }
 208
 209         function get( $key, $useDB, $forcontent=true ) {
 210                 global $wgContLanguageCode;
 211                 if( $forcontent ) {
 212                         global $wgContLang;
 213                         $lang =& $wgContLang;
 214                         $langcode = $wgContLanguageCode;
 215                 } else {
 216                         global $wgLang, $wgLanguageCode;
 217                         $lang =& $wgLang;
 218                         $langcode = $wgLanguageCode;
 219                 }
 220                 # If uninitialised, someone is trying to call this halfway through Setup.php
 221                 if( !$this->mInitialised ) {
 222                         return "&lt;$key&gt;";
 223                 }
 224
 225                 $message = false;
 226                 if( !$this->mDisable && $useDB ) {
 227                         $title = $lang->ucfirst( $key );
 228                         if( $langcode != $wgContLanguageCode ) {
 229                                 $title .= '/' . $langcode;
 230                         }
 231
 232                         # Try the cache
 233                         if( $this->mUseCache && $this->mCache && array_key_exists( $title, $this->mCache ) ) {
 234                                 $message = $this->mCache[$title];
 235                         }
 236
 237                         if ( !$message && $this->mUseCache ) {
 238                                 $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
 239                                 if( $message ) {
 240                                         $this->mCache[$title] = $message;
 241                                 }
 242                         }
 243
 244                         # If it wasn't in the cache, load each message from the DB individually
 245                         if ( !$message ) {
 246                                 $dbr =& wfGetDB( DB_SLAVE );
 247                                 $result = $dbr->selectRow( 'cur', array('cur_text'),
 248                                   array( 'cur_namespace' => NS_MEDIAWIKI, 'cur_title' => $title ),
 249                                   'MessageCache::get' );
 250                                 if ( $result ) {
 251                                         $message = $result->cur_text;
 252                                         if( $this->mUseCache ) {
 253                                                 $this->mCache[$title] = $message;
 254                                                 /* individual messages may be often
 255                                                    recached until proper purge code exists
 256                                                 */
 257                                                 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
 258                                         }
 259                                 }
 260                         }
 261                 }
 262                 # Try the extension array
 263                 if( !$message ) {
 264                         $message = @$this->mExtensionMessages[$key];
 265                 }
 266
 267                 # Try the array in the language object
 268                 if( !$message ) {
 269                         wfSuppressWarnings();
 270                         $message = $lang->getMessage( $key );
 271                         wfRestoreWarnings();
 272                 }
 273
 274                 # Try the English array
 275                 if( !$message && $langcode != 'en' ) {
 276                         wfSuppressWarnings();
 277                         $message = Language::getMessage( $key );
 278                         wfRestoreWarnings();
 279                 }
 280
 281                 # Final fallback
 282                 if( !$message ) {
 283                         $message = "&lt;$key&gt;";
 284                 }
 285
 286                 # Replace brace tags
 287                 $message = $this->transform( $message );
 288                 return $message;
 289         }
 290
 291         function transform( $message ) {
 292                 if( !$this->mDisableTransform ) {
 293                         if( strpos( $message, '{{' ) !== false ) {
 294                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 295                         }
 296                 }
 297                 return $message;
 298         }
 299
 300         function disable() { $this->mDisable = true; }
 301         function enable() { $this->mDisable = false; }
 302         function disableTransform() { $this->mDisableTransform = true; }
 303         function enableTransform() { $this->mDisableTransform = false; }
 304
 305         function addMessage( $key, $value ) {
 306                 $this->mExtensionMessages[$key] = $value;
 307         }
 308
 309         function addMessages( $messages ) {
 310                 foreach ( $messages as $key => $value ) {
 311                         $this->mExtensionMessages[$key] = $value;
 312                 }
 313         }
 314
 315         /**
 316          * Clear all stored messages. Mainly used after a mass rebuild.
 317          */
 318         function clear() {
 319                 if( $this->mUseCache ) {
 320                         $this->mMemc->delete( $this->mMemcKey );
 321                 }
 322         }
 323 }
 324 ?>