update to MediaWiki 1.17.0

1 files changed, 370 insertions, 0 deletions

diff --git a/includes/MessageBlobStore.php b/includes/MessageBlobStore.php
new file mode 100644
index 00000000..5e6c8e5e
--- /dev/null
+++ b/includes/MessageBlobStore.php
@@ -0,0 +1,370 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @author Roan Kattouw
+ * @author Trevor Parscal
+ */
+
+/**
+ * This class provides access to the resource message blobs storage used by
+ * the ResourceLoader.
+ *
+ * A message blob is a JSON object containing the interface messages for a
+ * certain resource in a certain language. These message blobs are cached
+ * in the msg_resource table and automatically invalidated when one of their
+ * consistuent messages or the resource itself is changed.
+ */
+class MessageBlobStore {
+
+	/**
+	 * Get the message blobs for a set of modules
+	 *
+	 * @param $resourceLoader ResourceLoader object
+	 * @param $modules array Array of module objects keyed by module name
+	 * @param $lang string Language code
+	 * @return array An array mapping module names to message blobs
+	 */
+	public static function get( ResourceLoader $resourceLoader, $modules, $lang ) {
+		wfProfileIn( __METHOD__ );
+		if ( !count( $modules ) ) {
+			wfProfileOut( __METHOD__ );
+			return array();
+		}
+		// Try getting from the DB first
+		$blobs = self::getFromDB( $resourceLoader, array_keys( $modules ), $lang );
+
+		// Generate blobs for any missing modules and store them in the DB
+		$missing = array_diff( array_keys( $modules ), array_keys( $blobs ) );
+		foreach ( $missing as $name ) {
+			$blob = self::insertMessageBlob( $name, $modules[$name], $lang );
+			if ( $blob ) {
+				$blobs[$name] = $blob;
+			}
+		}
+
+		wfProfileOut( __METHOD__ );
+		return $blobs;
+	}
+
+	/**
+	 * Generate and insert a new message blob. If the blob was already
+	 * present, it is not regenerated; instead, the preexisting blob
+	 * is fetched and returned.
+	 *
+	 * @param $name String: module name
+	 * @param $module ResourceLoaderModule object
+	 * @param $lang String: language code
+	 * @return mixed Message blob or false if the module has no messages
+	 */
+	public static function insertMessageBlob( $name, ResourceLoaderModule $module, $lang ) {
+		$blob = self::generateMessageBlob( $module, $lang );
+
+		if ( !$blob ) {
+			return false;
+		}
+
+		$dbw = wfGetDB( DB_MASTER );
+		$success = $dbw->insert( 'msg_resource', array(
+				'mr_lang' => $lang,
+				'mr_resource' => $name,
+				'mr_blob' => $blob,
+				'mr_timestamp' => $dbw->timestamp()
+			),
+			__METHOD__,
+			array( 'IGNORE' )
+		);
+
+		if ( $success ) {
+			if ( $dbw->affectedRows() == 0 ) {
+				// Blob was already present, fetch it
+				$blob = $dbw->selectField( 'msg_resource', 'mr_blob', array(
+						'mr_resource' => $name,
+						'mr_lang' => $lang,
+					),
+					__METHOD__
+				);
+			} else {
+				// Update msg_resource_links
+				$rows = array();
+
+				foreach ( $module->getMessages() as $key ) {
+					$rows[] = array(
+						'mrl_resource' => $name,
+						'mrl_message' => $key
+					);
+				}
+				$dbw->insert( 'msg_resource_links', $rows,
+					__METHOD__, array( 'IGNORE' )
+				);
+			}
+		}
+
+		return $blob;
+	}
+
+	/**
+	 * Update all message blobs for a given module.
+	 *
+	 * @param $name String: module name
+	 * @param $module ResourceLoaderModule object
+	 * @param $lang String: language code (optional)
+	 * @return Mixed: if $lang is set, the new message blob for that language is 
+	 *    returned if present. Otherwise, null is returned.
+	 */
+	public static function updateModule( $name, ResourceLoaderModule $module, $lang = null ) {
+		$retval = null;
+
+		// Find all existing blobs for this module
+		$dbw = wfGetDB( DB_MASTER );
+		$res = $dbw->select( 'msg_resource',
+			array( 'mr_lang', 'mr_blob' ),
+			array( 'mr_resource' => $name ),
+			__METHOD__
+		);
+
+		// Build the new msg_resource rows
+		$newRows = array();
+		$now = $dbw->timestamp();
+		// Save the last-processed old and new blobs for later
+		$oldBlob = $newBlob = null;
+
+		foreach ( $res as $row ) {
+			$oldBlob = $row->mr_blob;
+			$newBlob = self::generateMessageBlob( $module, $row->mr_lang );
+
+			if ( $row->mr_lang === $lang ) {
+				$retval = $newBlob;
+			}
+			$newRows[] = array(
+				'mr_resource' => $name,
+				'mr_lang' => $row->mr_lang,
+				'mr_blob' => $newBlob,
+				'mr_timestamp' => $now
+			);
+		}
+
+		$dbw->replace( 'msg_resource',
+			array( array( 'mr_resource', 'mr_lang' ) ),
+			$newRows, __METHOD__
+		);
+
+		// Figure out which messages were added and removed
+		$oldMessages = array_keys( FormatJson::decode( $oldBlob, true ) );
+		$newMessages = array_keys( FormatJson::decode( $newBlob, true ) );
+		$added = array_diff( $newMessages, $oldMessages );
+		$removed = array_diff( $oldMessages, $newMessages );
+
+		// Delete removed messages, insert added ones
+		if ( $removed ) {
+			$dbw->delete( 'msg_resource_links', array(
+					'mrl_resource' => $name,
+					'mrl_message' => $removed
+				), __METHOD__
+			);
+		}
+
+		$newLinksRows = array();
+
+		foreach ( $added as $message ) {
+			$newLinksRows[] = array(
+				'mrl_resource' => $name,
+				'mrl_message' => $message
+			);
+		}
+
+		if ( $newLinksRows ) {
+			$dbw->insert( 'msg_resource_links', $newLinksRows, __METHOD__,
+				 array( 'IGNORE' ) // just in case
+			);
+		}
+
+		return $retval;
+	}
+
+	/**
+	 * Update a single message in all message blobs it occurs in.
+	 *
+	 * @param $key String: message key
+	 */
+	public static function updateMessage( $key ) {
+		$dbw = wfGetDB( DB_MASTER );
+
+		// Keep running until the updates queue is empty.
+		// Due to update conflicts, the queue might not be emptied
+		// in one iteration.
+		$updates = null;
+		do {
+			$updates = self::getUpdatesForMessage( $key, $updates );
+
+			foreach ( $updates as $k => $update ) {
+				// Update the row on the condition that it
+				// didn't change since we fetched it by putting
+				// the timestamp in the WHERE clause.
+				$success = $dbw->update( 'msg_resource',
+					array(
+						'mr_blob' => $update['newBlob'],
+						'mr_timestamp' => $dbw->timestamp() ),
+					array(
+						'mr_resource' => $update['resource'],
+						'mr_lang' => $update['lang'],
+						'mr_timestamp' => $update['timestamp'] ),
+					__METHOD__
+				);
+
+				// Only requeue conflicted updates.
+				// If update() returned false, don't retry, for
+				// fear of getting into an infinite loop
+				if ( !( $success && $dbw->affectedRows() == 0 ) ) {
+					// Not conflicted
+					unset( $updates[$k] );
+				}
+			}
+		} while ( count( $updates ) );
+
+		// No need to update msg_resource_links because we didn't add
+		// or remove any messages, we just changed their contents.
+	}
+
+	public static function clear() {
+		// TODO: Give this some more thought
+		// TODO: Is TRUNCATE better?
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->delete( 'msg_resource', '*', __METHOD__ );
+		$dbw->delete( 'msg_resource_links', '*', __METHOD__ );
+	}
+
+	/**
+	 * Create an update queue for updateMessage()
+	 *
+	 * @param $key String: message key
+	 * @param $prevUpdates Array: updates queue to refresh or null to build a fresh update queue
+	 * @return Array: updates queue
+	 */
+	private static function getUpdatesForMessage( $key, $prevUpdates = null ) {
+		$dbw = wfGetDB( DB_MASTER );
+
+		if ( is_null( $prevUpdates ) ) {
+			// Fetch all blobs referencing $key
+			$res = $dbw->select(
+				array( 'msg_resource', 'msg_resource_links' ),
+				array( 'mr_resource', 'mr_lang', 'mr_blob', 'mr_timestamp' ),
+				array( 'mrl_message' => $key, 'mr_resource=mrl_resource' ),
+				__METHOD__
+			);
+		} else {
+			// Refetch the blobs referenced by $prevUpdates
+
+			// Reorganize the (resource, lang) pairs in the format
+			// expected by makeWhereFrom2d()
+			$twoD = array();
+
+			foreach ( $prevUpdates as $update ) {
+				$twoD[$update['resource']][$update['lang']] = true;
+			}
+
+			$res = $dbw->select( 'msg_resource',
+				array( 'mr_resource', 'mr_lang', 'mr_blob', 'mr_timestamp' ),
+				$dbw->makeWhereFrom2d( $twoD, 'mr_resource', 'mr_lang' ),
+				__METHOD__
+			);
+		}
+
+		// Build the new updates queue
+		$updates = array();
+
+		foreach ( $res as $row ) {
+			$updates[] = array(
+				'resource' => $row->mr_resource,
+				'lang' => $row->mr_lang,
+				'timestamp' => $row->mr_timestamp,
+				'newBlob' => self::reencodeBlob( $row->mr_blob, $key, $row->mr_lang )
+			);
+		}
+
+		return $updates;
+	}
+
+	/**
+	 * Reencode a message blob with the updated value for a message
+	 *
+	 * @param $blob String: message blob (JSON object)
+	 * @param $key String: message key
+	 * @param $lang String: language code
+	 * @return Message blob with $key replaced with its new value
+	 */
+	private static function reencodeBlob( $blob, $key, $lang ) {
+		$decoded = FormatJson::decode( $blob, true );
+		$decoded[$key] = wfMsgExt( $key, array( 'language' => $lang ) );
+
+		return FormatJson::encode( (object)$decoded );
+	}
+
+	/**
+	 * Get the message blobs for a set of modules from the database.
+	 * Modules whose blobs are not in the database are silently dropped.
+	 *
+	 * @param $resourceLoader ResourceLoader object
+	 * @param $modules Array of module names
+	 * @param $lang String: language code
+	 * @return array Array mapping module names to blobs
+	 */
+	private static function getFromDB( ResourceLoader $resourceLoader, $modules, $lang ) {
+		global $wgCacheEpoch;
+		$retval = array();
+		$dbr = wfGetDB( DB_SLAVE );
+		$res = $dbr->select( 'msg_resource',
+			array( 'mr_blob', 'mr_resource', 'mr_timestamp' ),
+			array( 'mr_resource' => $modules, 'mr_lang' => $lang ),
+			__METHOD__
+		);
+
+		foreach ( $res as $row ) {
+			$module = $resourceLoader->getModule( $row->mr_resource );
+			if ( !$module ) {
+				// This shouldn't be possible
+				throw new MWException( __METHOD__ . ' passed an invalid module name' );
+			}
+			// Update the module's blobs if the set of messages changed or if the blob is
+			// older than $wgCacheEpoch
+			if ( array_keys( FormatJson::decode( $row->mr_blob, true ) ) !== $module->getMessages() ||
+					wfTimestamp( TS_MW, $row->mr_timestamp ) <= $wgCacheEpoch ) {
+				$retval[$row->mr_resource] = self::updateModule( $row->mr_resource, $module, $lang );
+			} else {
+				$retval[$row->mr_resource] = $row->mr_blob;
+			}
+		}
+
+		return $retval;
+	}
+
+	/**
+	 * Generate the message blob for a given module in a given language.
+	 *
+	 * @param $module ResourceLoaderModule object
+	 * @param $lang String: language code
+	 * @return String: JSON object
+	 */
+	private static function generateMessageBlob( ResourceLoaderModule $module, $lang ) {
+		$messages = array();
+
+		foreach ( $module->getMessages() as $key ) {
+			$messages[$key] = wfMsgExt( $key, array( 'language' => $lang ) );
+		}
+
+		return FormatJson::encode( (object)$messages );
+	}
+}