* There's no more need for this here than anywhere else..
[mediawiki.git] / includes / MessageCache.php
blob24822b502d125f063d6232ba2445924b5d3df4a5
1 <?php
2 /**
4 * @package MediaWiki
5 * @subpackage Cache
6 */
8 /** */
9 require_once( 'Revision.php' );
11 /**
14 define( 'MSG_LOAD_TIMEOUT', 60);
15 define( 'MSG_LOCK_TIMEOUT', 10);
16 define( 'MSG_WAIT_TIMEOUT', 10);
18 /**
19 * Message cache
20 * Performs various useful MediaWiki namespace-related functions
22 * @package MediaWiki
24 class MessageCache
26 var $mCache, $mUseCache, $mDisable, $mExpiry;
27 var $mMemcKey, $mKeys, $mParserOptions, $mParser;
28 var $mExtensionMessages;
29 var $mInitialised = false;
30 var $mDeferred = true;
32 function initialise( &$memCached, $useDB, $expiry, $memcPrefix) {
33 $fname = 'MessageCache::initialise';
34 wfProfileIn( $fname );
36 $this->mUseCache = !is_null( $memCached );
37 $this->mMemc = &$memCached;
38 $this->mDisable = !$useDB;
39 $this->mExpiry = $expiry;
40 $this->mDisableTransform = false;
41 $this->mMemcKey = $memcPrefix.':messages';
42 $this->mKeys = false; # initialised on demand
43 $this->mInitialised = true;
45 wfProfileIn( $fname.'-parseropt' );
46 $this->mParserOptions = ParserOptions::newFromUser( $u=NULL );
47 wfProfileOut( $fname.'-parseropt' );
48 wfProfileIn( $fname.'-parser' );
49 $this->mParser = new Parser;
50 wfProfileOut( $fname.'-parser' );
52 # When we first get asked for a message,
53 # then we'll fill up the cache. If we
54 # can return a cache hit, this saves
55 # some extra milliseconds
56 $this->mDeferred = true;
58 wfProfileOut( $fname );
61 /**
62 * Loads messages either from memcached or the database, if not disabled
63 * On error, quietly switches to a fallback mode
64 * Returns false for a reportable error, true otherwise
66 function load() {
67 global $wgAllMessagesEn;
69 if ( $this->mDisable ) {
70 static $shownDisabled = false;
71 if ( !$shownDisabled ) {
72 wfDebug( "MessageCache::load(): disabled\n" );
73 $shownDisabled = true;
75 return true;
77 $fname = 'MessageCache::load';
78 wfProfileIn( $fname );
79 $success = true;
81 if ( $this->mUseCache ) {
82 wfProfileIn( $fname.'-fromcache' );
83 $this->mCache = $this->mMemc->get( $this->mMemcKey );
84 wfProfileOut( $fname.'-fromcache' );
86 # If there's nothing in memcached, load all the messages from the database
87 if ( !$this->mCache ) {
88 wfDebug( "MessageCache::load(): loading all messages\n" );
89 $this->lock();
90 # Other threads don't need to load the messages if another thread is doing it.
91 $success = $this->mMemc->add( $this->mMemcKey.'-status', "loading", MSG_LOAD_TIMEOUT );
92 if ( $success ) {
93 wfProfileIn( $fname.'-load' );
94 $this->loadFromDB();
95 wfProfileOut( $fname.'-load' );
96 # Save in memcached
97 # Keep trying if it fails, this is kind of important
98 wfProfileIn( $fname.'-save' );
99 for ($i=0; $i<20 &&
100 !$this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
101 $i++ ) {
102 usleep(mt_rand(500000,1500000));
104 wfProfileOut( $fname.'-save' );
105 if ( $i == 20 ) {
106 $this->mMemc->set( $this->mMemcKey.'-status', 'error', 60*5 );
107 wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
110 $this->unlock();
113 if ( !is_array( $this->mCache ) ) {
114 wfDebug( "MessageCache::load(): individual message mode\n" );
115 # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
116 # Causing too much DB load, disabling -- TS
117 $this->mDisable = true;
119 if ( $this->mCache == "loading" ) {
120 $this->mUseCache = false;
121 } elseif ( $this->mCache == "error" ) {
122 $this->mUseCache = false;
123 $success = false;
124 } else {
125 $this->mDisable = true;
126 $success = false;
128 $this->mCache = false;
131 wfProfileOut( $fname );
132 $this->mDeferred = false;
133 return $success;
137 * Loads all or main part of cacheable messages from the database
139 function loadFromDB() {
140 $fname = 'MessageCache::loadFromDB';
141 $dbr =& wfGetDB( DB_SLAVE );
142 $conditions = array( 'page_is_redirect' => 0,
143 'page_namespace' => NS_MEDIAWIKI);
144 $res = $dbr->select( array( 'page', 'revision', 'text' ),
145 array( 'page_title', 'old_text', 'old_flags' ),
146 'page_is_redirect=0 AND page_namespace='.NS_MEDIAWIKI.' AND page_latest=rev_id AND rev_text_id=old_id',
147 $fname
150 $this->mCache = array();
151 for ( $row = $dbr->fetchObject( $res ); $row; $row = $dbr->fetchObject( $res ) ) {
152 $this->mCache[$row->page_title] = Revision::getRevisionText( $row );
155 $dbr->freeResult( $res );
157 # FIXME: This is too slow currently.
158 # We need to bulk-fetch revisions, but in a portable way...
159 $resultSet = Revision::fetchFromConds( $dbr, array(
160 'page_namespace' => NS_MEDIAWIKI,
161 'page_is_redirect' => 0,
162 'page_id=rev_page' ) );
163 while( $row = $resultSet->fetchObject() ) {
164 $revision = new Revision( $row );
165 $title = $revision->getTitle();
166 $this->mCache[$title->getDBkey()] = $revision->getText();
168 $resultSet->free();
173 * Not really needed anymore
175 function getKeys() {
176 global $wgAllMessagesEn, $wgContLang;
177 if ( !$this->mKeys ) {
178 $this->mKeys = array();
179 foreach ( $wgAllMessagesEn as $key => $value ) {
180 $title = $wgContLang->ucfirst( $key );
181 array_push( $this->mKeys, $title );
184 return $this->mKeys;
188 * @deprecated
190 function isCacheable( $key ) {
191 return true;
194 function replace( $title, $text ) {
195 $this->lock();
196 $this->load();
197 if ( is_array( $this->mCache ) ) {
198 $this->mCache[$title] = $text;
199 $this->mMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
201 $this->unlock();
205 * Returns success
206 * Represents a write lock on the messages key
208 function lock() {
209 if ( !$this->mUseCache ) {
210 return true;
213 $lockKey = $this->mMemcKey . 'lock';
214 for ($i=0; $i < MSG_WAIT_TIMEOUT && !$this->mMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
215 sleep(1);
218 return $i >= MSG_WAIT_TIMEOUT;
221 function unlock() {
222 if ( !$this->mUseCache ) {
223 return;
226 $lockKey = $this->mMemcKey . 'lock';
227 $this->mMemc->delete( $lockKey );
230 function get( $key, $useDB, $forcontent=true, $isfullkey = false ) {
231 global $wgContLanguageCode;
232 if( $forcontent ) {
233 global $wgContLang;
234 $lang =& $wgContLang;
235 $langcode = $wgContLanguageCode;
236 } else {
237 global $wgLang, $wgLanguageCode;
238 $lang =& $wgLang;
239 $langcode = $wgLanguageCode;
241 # If uninitialised, someone is trying to call this halfway through Setup.php
242 if( !$this->mInitialised ) {
243 return '&lt;' . htmlspecialchars($key) . '&gt;';
245 # If cache initialization was deferred, start it now.
246 if( $this->mDeferred ) {
247 $this->load();
250 $message = false;
251 if( !$this->mDisable && $useDB ) {
252 $title = $lang->ucfirst( $key );
253 if(!$isfullkey && ($langcode != $wgContLanguageCode) ) {
254 $title .= '/' . $langcode;
256 $message = $this->getFromCache( $title );
258 # Try the extension array
259 if( !$message ) {
260 $message = @$this->mExtensionMessages[$key];
263 # Try the array in the language object
264 if( !$message ) {
265 wfSuppressWarnings();
266 $message = $lang->getMessage( $key );
267 wfRestoreWarnings();
270 # Try the English array
271 if( !$message && $langcode != 'en' ) {
272 wfSuppressWarnings();
273 $message = Language::getMessage( $key );
274 wfRestoreWarnings();
277 # Is this a custom message? Try the default language in the db...
278 if( !$message &&
279 !$this->mDisable && $useDB &&
280 !$isfullkey && ($langcode != $wgContLanguageCode) ) {
281 $message = $this->getFromCache( $lang->ucfirst( $key ) );
284 # Final fallback
285 if( !$message ) {
286 return '&lt;' . htmlspecialchars($key) . '&gt;';
289 # Replace brace tags
290 $message = $this->transform( $message );
291 return $message;
294 function getFromCache( $title ) {
295 $message = false;
297 # Try the cache
298 if( $this->mUseCache && is_array( $this->mCache ) && array_key_exists( $title, $this->mCache ) ) {
299 $message = $this->mCache[$title];
302 if ( !$message && $this->mUseCache ) {
303 $message = $this->mMemc->get( $this->mMemcKey . ':' . $title );
304 if( $message ) {
305 $this->mCache[$title] = $message;
309 # If it wasn't in the cache, load each message from the DB individually
310 if ( !$message ) {
311 $revision = Revision::newFromTitle( Title::makeTitle( NS_MEDIAWIKI, $title ) );
312 if( $revision ) {
313 $message = $revision->getText();
314 if ($this->mUseCache) {
315 $this->mCache[$title]=$message;
316 /* individual messages may be often
317 recached until proper purge code exists
319 $this->mMemc->set( $this->mMemcKey . ':' . $title, $message, 300 );
324 return $message;
327 function transform( $message ) {
328 if( !$this->mDisableTransform ) {
329 if( strpos( $message, '{{' ) !== false ) {
330 $message = $this->mParser->transformMsg( $message, $this->mParserOptions );
333 return $message;
336 function disable() { $this->mDisable = true; }
337 function enable() { $this->mDisable = false; }
338 function disableTransform() { $this->mDisableTransform = true; }
339 function enableTransform() { $this->mDisableTransform = false; }
342 * Add a message to the cache
344 * @param mixed $key
345 * @param mixed $value
347 function addMessage( $key, $value ) {
348 $this->mExtensionMessages[$key] = $value;
352 * Add an associative array of message to the cache
354 * @param array $messages An associative array of key => values to be added
356 function addMessages( $messages ) {
357 foreach ( $messages as $key => $value ) {
358 $this->mExtensionMessages[$key] = $value;
363 * Clear all stored messages. Mainly used after a mass rebuild.
365 function clear() {
366 if( $this->mUseCache ) {
367 $this->mMemc->delete( $this->mMemcKey );