--- /dev/null
+<?
+
+# Message cache
+# Performs various useful MediaWiki namespace-related functions
+
+define( "MSG_LOAD_TIMEOUT", 60);
+define( "MSG_LOCK_TIMEOUT", 10);
+define( "MSG_WAIT_TIMEOUT", 10);
+
+class MessageCache
+{
+ var $mCache, $mUseCache, $mDisable, $mExpiry;
+ var $mMemcKey, $mKeys;
+
+ function MessageCache( $useMemCached, $useDB, $expiry, $memcPrefix ) {
+ $this->initialise( $useMemCached, $useDB, $expiry, $memcPrefix );
+ }
+
+ function initialise( $useMemCached, $useDB, $expiry, $memcPrefix ) {
+ $this->mUseCache = $useMemCached;
+ $this->mDisable = !$useDB;
+ $this->mExpiry = $expiry;
+ $this->mMemcKey = "$memcPrefix:messages";
+ $this->mKeys = false; # initialised on demand
+
+ $this->load();
+ }
+
+ # Loads messages either from memcached or the database, if not disabled
+ # On error, quietly switches to a fallback mode
+ # Returns false for a reportable error, true otherwise
+ function load() {
+ global $wgAllMessagesEn, $wgMemc;
+
+ if ( $this->mDisable ) {
+ return true;
+ }
+
+ $success = true;
+
+ if ( $this->mUseCache ) {
+ $this->mCache = $wgMemc->get( $this->mMemcKey );
+
+ # If there's nothing in memcached, load all the messages from the database
+ if ( !$this->mCache ) {
+ $this->lock();
+ # Other threads don't need to load the messages if another thread is doing it.
+ $wgMemc->set( $this->mMemcKey, "loading", MSG_LOAD_TIMEOUT );
+ $this->loadFromDB();
+ # Save in memcached
+ if ( !$wgMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry ) ) {
+ # Hack for slabs reassignment problem
+ $wgMemc->set( $this->mMemcKey, "error" );
+ wfDebug( "MemCached set error in MessageCache: restart memcached server!\n" );
+ }
+ $this->unlock();
+ }
+
+ if ( !is_array( $this->mCache ) ) {
+ # If it is 'loading' or 'error', switch to individual message mode, otherwise disable
+ if ( $this->mCache == "loading" ) {
+ $this->mUseCache = false;
+ } elseif ( $this->mCache == "error" ) {
+ $this->mUseCache = false;
+ $success = false;
+ } else {
+ $this->mDisable = true;
+ $success = false;
+ }
+ $this->mCache = false;
+ }
+ }
+ return $success;
+ }
+
+ # Loads all cacheable messages from the database
+ function loadFromDB()
+ {
+ $sql = "SELECT cur_title,cur_text FROM cur WHERE cur_namespace=" . NS_MEDIAWIKI;
+ $sql .= " AND cur_title IN ('";
+ $sql .= implode( "','", $this->getKeys() ) . "')";
+ wfDebug( "$sql\n" );
+
+ $res = wfQuery( $sql, DB_READ, $fname );
+
+ $this->mCache = array();
+ for ( $row = wfFetchObject( $res ); $row; $row = wfFetchObject( $res ) ) {
+ $this->mCache[$row->cur_title] = $row->cur_text;
+ }
+
+ wfDebug( var_export( $this->mCache, true ) );
+
+ wfFreeResult( $res );
+ }
+
+ function getKeys() {
+ global $wgAllMessagesEn;
+ if ( !$this->mKeys ) {
+ $this->mKeys = array_map( 'ucfirst', array_keys( $wgAllMessagesEn ) );
+ }
+ return $this->mKeys;
+ }
+
+ function isCacheable( $key ) {
+ global $wgAllMessagesEn;
+ return array_key_exists( lcfirst( $key ), $wgAllMessagesEn ) ||
+ array_key_exists( $key, $wgAllMessagesEn );
+ }
+
+ function replace( $title, $text ) {
+ global $wgMemc;
+ if ( $this->isCacheable( $title ) ) {
+ $this->lock();
+ $this->load();
+ if ( is_array( $this->mCache ) ) {
+ $this->mCache[$title] = $text;
+ $wgMemc->set( $this->mMemcKey, $this->mCache, $this->mExpiry );
+ }
+ $this->unlock();
+ }
+ }
+
+ # Returns success
+ # Represents a write lock on the messages key
+ function lock() {
+ global $wgMemc;
+
+ if ( !$this->mUseCache ) {
+ return true;
+ }
+
+ $lockKey = $this->mMemcKey . "lock";
+ for ($i=0; $i < MSG_WAIT_TIMEOUT && !$wgMemc->add( $lockKey, 1, MSG_LOCK_TIMEOUT ); $i++ ) {
+ sleep(1);
+ }
+
+ return $i >= MSG_WAIT_TIMEOUT;
+ }
+
+ function unlock() {
+ global $wgMemc;
+
+ if ( !$this->mUseCache ) {
+ return;
+ }
+
+ $lockKey = $this->mMemcKey . "lock";
+ $wgMemc->delete( $lockKey );
+ }
+
+ function get( $key, $useDB ) {
+ global $wgLang, $wgLanguageCode;
+
+ if ( $this->mDisable ) {
+ return $wgLang->getMessage( $key );
+ }
+ $title = ucfirst( $key );
+
+ $message = false;
+
+ # Try the cache
+ if ( $this->mUseCache && $this->mCache ) {
+ $message = $this->mCache[$title];
+ }
+
+ # If it wasn't in the cache, load each message from the DB individually
+ if ( !$message && $useDB) {
+ $sql = "SELECT cur_text FROM cur WHERE cur_namespace=" . NS_MEDIAWIKI .
+ " AND cur_title='$title'";
+ $res = wfQuery( $sql, DB_READ, $fname );
+
+ if ( wfNumRows( $res ) ) {
+ $obj = wfFetchObject( $res );
+ $message = $obj->cur_text;
+ wfFreeResult( $res );
+ }
+ }
+
+ # Try the array in $wgLang
+ if ( !$message ) {
+ $message = $wgLang->getMessage( $key );
+ }
+
+ # Try the English array
+ if ( !$message && $wgLanguageCode != "en" ) {
+ $message = Language::getMessage( $key );
+ }
+
+ # Final fallback
+ if ( !$message ) {
+ $message = "<$key>";
+ }
+ return $message;
+ }
+}
+
+function lcfirst( $s ) {
+ return strtolower( $s{0} ). substr( $s, 1 );
+}
+?>