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 $mIsForContent; //whether this is for content messages or ui messages
  26         var $mInitialised = false;
  27
  28         function initialise( &$memCached, $useDB, $expiry, $memcPrefix, $forContent=false ) {
  29                 $fname = 'MessageCache::initialise';
  30                 wfProfileIn( $fname );
  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         $this->mIsForContent = $forContent;
  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 $wgAllMessagesEn;
 144         if($this->mIsForContent) {
 145             global $wgContLang;
 146             $langobj = $wgContLang;
 147         }
 148         else {
 149             global $wgLang;
 150             $langobj = $wgLang;
 151         }
 152
 153                 if ( !$this->mKeys ) {
 154                         $this->mKeys = array();
 155                         foreach ( $wgAllMessagesEn as $key => $value ) {
 156                                 array_push( $this->mKeys, $langobj->ucfirst( $key ) );
 157                         }
 158                 }
 159                 return $this->mKeys;
 160         }
 161
 162         /**
 163          * Obsolete
 164          */
 165         function isCacheable( $key ) {
 166                 return true;
 167                 /*
 168                 global $wgAllMessagesEn, $wgLang;
 169                 return array_key_exists( $wgLang->lcfirst( $key ), $wgAllMessagesEn ) ||
 170                         array_key_exists( $key, $wgAllMessagesEn );
 171                 */
 172         }
 173
 174         function replace( $title, $text ) {
 175                 $this->lock();
 176                 $this->load();
 177                 if ( is_array( $this->mCache ) ) {
 178                         $this->mCache[$title] = $text;
 179                         $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
 180                 }
 181                 $this->unlock();
 182         }
 183
 184         /**
 185          * Returns success
 186          * Represents a write lock on the messages key
 187          */
 188         function lock() {
 189                 if ( !$this->mUseCache ) {
 190                         return true;
 191                 }
 192
 193                 $lockKey = $this->mMemcKey . 'lock';
 194                 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
 195                         sleep(1);
 196                 }
 197
 198                 return $i >= MSG_WAIT_TIMEOUT;
 199         }
 200
 201         function unlock() {
 202                 if ( !$this->mUseCache ) {
 203                         return;
 204                 }
 205
 206                 $lockKey = $this->mMemcKey . 'lock';
 207                 $this->mMemc->delete( $lockKey );
 208         }
 209
 210         function get( $key, $useDB ) {
 211         if($this->mIsForContent) {
 212             global $wgContLang, $wgContLanguageCode;
 213             $langobj = $wgContLang;
 214             $langcode=$wgContLanguageCode;
 215         }
 216         else {
 217             global $wgLang, $wgLanguageCode;
 218             $langobj=$wgLang;
 219             $langcode = $wgLanguageCode;
 220         }
 221
 222                 # If uninitialised, someone is trying to call this halfway through Setup.php
 223                 if ( !$this->mInitialised ) {
 224                         return "&lt;$key&gt;";
 225                 }
 226
 227                 $message = false;
 228                 if ( !$this->mDisable && $useDB ) {
 229                         $title = $langobj->ucfirst( $key );
 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 it wasn't in the cache, load each message from the DB individually
 238                         if ( !$message ) {
 239                                 $dbr =& wfGetDB( DB_SLAVE );
 240                                 $result = $dbr->getArray( 'cur', array('cur_text'),
 241                                   array( 'cur_namespace' => NS_MEDIAWIKI, 'cur_title' => $title ),
 242                                   'MessageCache::get' );
 243                                 if ( $result ) {
 244                                         $message = $result->cur_text;
 245                                 }
 246                         }
 247                 }
 248                 # Try the extension array
 249                 if ( !$message ) {
 250                         $message = @$this->mExtensionMessages[$key];
 251                 }
 252
 253                 # Try the array in $wgLang
 254                 if ( !$message ) {
 255                         wfSuppressWarnings();
 256                         $message = $langobj->getMessage( $key );
 257                         wfRestoreWarnings();
 258                 }
 259
 260                 # Try the English array
 261                 if ( !$message && $langcode != 'en' ) {
 262                         wfSuppressWarnings();
 263                         $message = Language::getMessage( $key );
 264                         wfRestoreWarnings();
 265                 }
 266
 267                 # Final fallback
 268                 if ( !$message ) {
 269                         $message = "&lt;$key&gt;";
 270                 }
 271
 272                 # Replace brace tags
 273                 $message = $this->transform( $message );
 274                 return $message;
 275         }
 276
 277         function transform( $message ) {
 278                 if( !$this->mDisableTransform ) {
 279                         if ( strstr( $message, '{{' ) !== false ) {
 280                                 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
 281                         }
 282                 }
 283                 return $message;
 284         }
 285
 286         function disable() { $this->mDisable = true; }
 287         function enable() { $this->mDisable = false; }
 288         function disableTransform() { $this->mDisableTransform = true; }
 289         function enableTransform() { $this->mDisableTransform = false; }
 290
 291         function addMessage( $key, $value ) {
 292                 $this->mExtensionMessages[$key] = $value;
 293         }
 294
 295         function addMessages( $messages ) {
 296                 foreach ( $messages as $key => $value ) {
 297                         $this->mExtensionMessages[$key] = $value;
 298                 }
 299         }
 300
 301         /**
 302          * Clear all stored messages. Mainly used after a mass rebuild.
 303          */
 304         function clear() {
 305                 if( $this->mUseCache ) {
 306                         $this->mMemc->delete( $this->mMemcKey );
 307                 }
 308         }
 309 }
 310 ?>