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->set( $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 cacheable messages from the database
 121          */
 122         function loadFromDB() {
 123                         $fname = 'MessageCache::loadFromDB';
 124                 $dbr =& wfGetDB( DB_SLAVE );
 125                 $res = $dbr->select( 'cur',
 126                         array( 'cur_title', 'cur_text' ),
 127                         array( 'cur_is_redirect' => 0, 'cur_namespace' => NS_MEDIAWIKI ),
 128                         $fname
 129                 );
 130
 131                 $this->mCache = array();
 132                 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
 133                         $this->mCache[$row->cur_title] = $row->cur_text;
 134                 }
 135
 136                 $dbr->freeResult( $res );
 137         }
 138
 139         /**
 140          * Not really needed anymore
 141          */
 142         function getKeys() {
 143                 global $wgAllMessagesEn, $wgContLang;
 144                 if ( !$this->mKeys ) {
 145                         $this->mKeys = array();
 146                         foreach ( $wgAllMessagesEn as $key => $value ) {
 147                                 array_push( $this->mKeys, $wgContLang->ucfirst( $key ) );
 148                         }
 149                 }
 150                 return $this->mKeys;
 151         }
 152
 153         /**
 154          * Obsolete
 155          */
 156         function isCacheable( $key ) {
 157                 return true;
 158                 /*
 159                 global $wgAllMessagesEn, $wgLang;
 160                 return array_key_exists( $wgLang->lcfirst( $key ), $wgAllMessagesEn ) ||
 161                         array_key_exists( $key, $wgAllMessagesEn );
 162                 */
 163         }
 164
 165         function replace( $title, $text ) {
 166                 $this->lock();
 167                 $this->load();
 168                 if ( is_array( $this->mCache ) ) {
 169                         $this->mCache[$title] = $text;
 170                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 171                 }
 172                 $this->unlock();
 173         }
 174
 175         /**
 176          * Returns success
 177          * Represents a write lock on the messages key
 178          */
 179         function lock() {
 180                 if ( !$this->mUseCache ) {
 181                         return true;
 182                 }
 183
 184                 $lockKey = $this->mMemcKey . 'lock';
 185                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 186                         sleep(1);
 187                 }
 188
 189                 return $i >= MSG_WAIT_TIMEOUT;
 190         }
 191
 192         function unlock() {
 193                 if ( !$this->mUseCache ) {
 194                         return;
 195                 }
 196
 197                 $lockKey = $this->mMemcKey . 'lock';
 198                 $this->mMemc->delete( $lockKey );
 199         }
 200
 201         function get( $key, $useDB, $forcontent=true ) {
 202                 if($forcontent) {
 203                         global $wgContLang, $wgContLanguageCode;
 204                         $lang = $wgContLang;
 205                         $langcode = $wgContLanguageCode;
 206                 }
 207                 else {
 208                         global $wgLang, $wgLanguageCode;
 209                         $lang = $wgLang;
 210                         $langcode = $wgLanguageCode;
 211                 }
 212                 # If uninitialised, someone is trying to call this halfway through Setup.php
 213                 if ( !$this->mInitialised ) {
 214                         return "&lt;$key&gt;";
 215                 }
 216
 217                 $message = false;
 218                 if ( !$this->mDisable && $useDB ) {
 219                         $title = $lang->ucfirst( $key )."/$langcode";
 220
 221
 222                         # Try the cache
 223                         if ( $this->mUseCache && $this->mCache && array_key_exists( $title, $this->mCache ) ) {
 224                                 $message = $this->mCache[$title];
 225                         }
 226
 227                         # If it wasn't in the cache, load each message from the DB individually
 228                         if ( !$message ) {
 229                                 $dbr =& wfGetDB( DB_SLAVE );
 230                                 $result = $dbr->getArray( 'cur', array('cur_text'),
 231                                   array( 'cur_namespace' => NS_MEDIAWIKI, 'cur_title' => $title ),
 232                                   'MessageCache::get' );
 233                                 if ( $result ) {
 234                                         $message = $result->cur_text;
 235                                 }
 236                         }
 237                 }
 238                 # Try the extension array
 239                 if ( !$message ) {
 240                         $message = @$this->mExtensionMessages[$key];
 241                 }
 242
 243                 # Try the array in the language object
 244                 if ( !$message ) {
 245                         wfSuppressWarnings();
 246                         $message = $lang->getMessage( $key );
 247                         wfRestoreWarnings();
 248                 }
 249
 250                 # Try the English array
 251                 if ( !$message && $langcode != 'en' ) {
 252                         wfSuppressWarnings();
 253                         $message = Language::getMessage( $key );
 254                         wfRestoreWarnings();
 255                 }
 256
 257                 # Final fallback
 258                 if ( !$message ) {
 259                         $message = "&lt;$key&gt;";
 260                 }
 261
 262                 # Replace brace tags
 263                 $message = $this->transform( $message );
 264                 return $message;
 265         }
 266
 267         function transform( $message ) {
 268                 if( !$this->mDisableTransform ) {
 269                         if ( strstr( $message, '{{' ) !== false ) {
 270                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 271                         }
 272                 }
 273                 return $message;
 274         }
 275
 276         function disable() { $this->mDisable = true; }
 277         function enable() { $this->mDisable = false; }
 278         function disableTransform() { $this->mDisableTransform = true; }
 279         function enableTransform() { $this->mDisableTransform = false; }
 280
 281         function addMessage( $key, $value ) {
 282                 $this->mExtensionMessages[$key] = $value;
 283         }
 284
 285         function addMessages( $messages ) {
 286                 foreach ( $messages as $key => $value ) {
 287                         $this->mExtensionMessages[$key] = $value;
 288                 }
 289         }
 290
 291         /**
 292          * Clear all stored messages. Mainly used after a mass rebuild.
 293          */
 294         function clear() {
 295                 if( $this->mUseCache ) {
 296                         $this->mMemc->delete( $this->mMemcKey );
 297                 }
 298         }
 299 }
 300 ?>