1 files changed, 240 insertions, 0 deletions
diff --git a/includes/changes/ChangesFeed.php b/includes/changes/ChangesFeed.php
new file mode 100644
index 00000000..2d3b919d
--- /dev/null
+++ b/includes/changes/ChangesFeed.php
@@ -0,0 +1,240 @@
+<?php
+/**
+ * Feed for list of changes.
+ *
+ * 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
+ *
+ * @file
+ */
+
+/**
+ * Feed to Special:RecentChanges and Special:RecentChangesLiked
+ *
+ * @ingroup Feed
+ */
+class ChangesFeed {
+	public $format, $type, $titleMsg, $descMsg;
+
+	/**
+	 * Constructor
+	 *
+	 * @param string $format Feed's format (either 'rss' or 'atom')
+	 * @param string $type Type of feed (for cache keys)
+	 */
+	public function __construct( $format, $type ) {
+		$this->format = $format;
+		$this->type = $type;
+	}
+
+	/**
+	 * Get a ChannelFeed subclass object to use
+	 *
+	 * @param string $title Feed's title
+	 * @param string $description Feed's description
+	 * @param string $url Url of origin page
+	 * @return ChannelFeed|bool ChannelFeed subclass or false on failure
+	 */
+	public function getFeedObject( $title, $description, $url ) {
+		global $wgSitename, $wgLanguageCode, $wgFeedClasses;
+
+		if ( !isset( $wgFeedClasses[$this->format] ) ) {
+			return false;
+		}
+
+		if ( !array_key_exists( $this->format, $wgFeedClasses ) ) {
+			// falling back to atom
+			$this->format = 'atom';
+		}
+
+		$feedTitle = "$wgSitename  - {$title} [$wgLanguageCode]";
+		return new $wgFeedClasses[$this->format](
+			$feedTitle, htmlspecialchars( $description ), $url );
+	}
+
+	/**
+	 * Generates feed's content
+	 *
+	 * @param ChannelFeed $feed ChannelFeed subclass object (generally the one returned
+	 *   by getFeedObject())
+	 * @param ResultWrapper $rows ResultWrapper object with rows in recentchanges table
+	 * @param int $lastmod Timestamp of the last item in the recentchanges table (only
+	 *   used for the cache key)
+	 * @param FormOptions $opts As in SpecialRecentChanges::getDefaultOptions()
+	 * @return null|bool True or null
+	 */
+	public function execute( $feed, $rows, $lastmod, $opts ) {
+		global $wgLang, $wgRenderHashAppend;
+
+		if ( !FeedUtils::checkFeedOutput( $this->format ) ) {
+			return null;
+		}
+
+		$optionsHash = md5( serialize( $opts->getAllValues() ) ) . $wgRenderHashAppend;
+		$timekey = wfMemcKey( $this->type, $this->format, $wgLang->getCode(), $optionsHash, 'timestamp' );
+		$key = wfMemcKey( $this->type, $this->format, $wgLang->getCode(), $optionsHash );
+
+		FeedUtils::checkPurge( $timekey, $key );
+
+		/**
+		 * Bumping around loading up diffs can be pretty slow, so where
+		 * possible we want to cache the feed output so the next visitor
+		 * gets it quick too.
+		 */
+		$cachedFeed = $this->loadFromCache( $lastmod, $timekey, $key );
+		if ( is_string( $cachedFeed ) ) {
+			wfDebug( "RC: Outputting cached feed\n" );
+			$feed->httpHeaders();
+			echo $cachedFeed;
+		} else {
+			wfDebug( "RC: rendering new feed and caching it\n" );
+			ob_start();
+			self::generateFeed( $rows, $feed );
+			$cachedFeed = ob_get_contents();
+			ob_end_flush();
+			$this->saveToCache( $cachedFeed, $timekey, $key );
+		}
+		return true;
+	}
+
+	/**
+	 * Save to feed result to $messageMemc
+	 *
+	 * @param string $feed Feed's content
+	 * @param string $timekey Memcached key of the last modification
+	 * @param string $key Memcached key of the content
+	 */
+	public function saveToCache( $feed, $timekey, $key ) {
+		global $messageMemc;
+		$expire = 3600 * 24; # One day
+		$messageMemc->set( $key, $feed, $expire );
+		$messageMemc->set( $timekey, wfTimestamp( TS_MW ), $expire );
+	}
+
+	/**
+	 * Try to load the feed result from $messageMemc
+	 *
+	 * @param int $lastmod Timestamp of the last item in the recentchanges table
+	 * @param string $timekey Memcached key of the last modification
+	 * @param string $key Memcached key of the content
+	 * @return string|bool Feed's content on cache hit or false on cache miss
+	 */
+	public function loadFromCache( $lastmod, $timekey, $key ) {
+		global $wgFeedCacheTimeout, $wgOut, $messageMemc;
+
+		$feedLastmod = $messageMemc->get( $timekey );
+
+		if ( ( $wgFeedCacheTimeout > 0 ) && $feedLastmod ) {
+			/**
+			 * If the cached feed was rendered very recently, we may
+			 * go ahead and use it even if there have been edits made
+			 * since it was rendered. This keeps a swarm of requests
+			 * from being too bad on a super-frequently edited wiki.
+			 */
+
+			$feedAge = time() - wfTimestamp( TS_UNIX, $feedLastmod );
+			$feedLastmodUnix = wfTimestamp( TS_UNIX, $feedLastmod );
+			$lastmodUnix = wfTimestamp( TS_UNIX, $lastmod );
+
+			if ( $feedAge < $wgFeedCacheTimeout || $feedLastmodUnix > $lastmodUnix ) {
+				wfDebug( "RC: loading feed from cache ($key; $feedLastmod; $lastmod)...\n" );
+				if ( $feedLastmodUnix < $lastmodUnix ) {
+					$wgOut->setLastModified( $feedLastmod ); // bug 21916
+				}
+				return $messageMemc->get( $key );
+			} else {
+				wfDebug( "RC: cached feed timestamp check failed ($feedLastmod; $lastmod)\n" );
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Generate the feed items given a row from the database, printing the feed.
+	 * @param object $rows DatabaseBase resource with recentchanges rows
+	 * @param Feed $feed
+	 */
+	public static function generateFeed( $rows, &$feed ) {
+		wfProfileIn( __METHOD__ );
+		$items = self::buildItems( $rows );
+		$feed->outHeader();
+		foreach ( $items as $item ) {
+			$feed->outItem( $item );
+		}
+		$feed->outFooter();
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Generate the feed items given a row from the database.
+	 * @param object $rows DatabaseBase resource with recentchanges rows
+	 * @return array
+	 */
+	public static function buildItems( $rows ) {
+		wfProfileIn( __METHOD__ );
+		$items = array();
+
+		# Merge adjacent edits by one user
+		$sorted = array();
+		$n = 0;
+		foreach ( $rows as $obj ) {
+			if ( $n > 0 &&
+				$obj->rc_type == RC_EDIT &&
+				$obj->rc_namespace >= 0 &&
+				$obj->rc_cur_id == $sorted[$n - 1]->rc_cur_id &&
+				$obj->rc_user_text == $sorted[$n - 1]->rc_user_text ) {
+				$sorted[$n - 1]->rc_last_oldid = $obj->rc_last_oldid;
+			} else {
+				$sorted[$n] = $obj;
+				$n++;
+			}
+		}
+
+		foreach ( $sorted as $obj ) {
+			$title = Title::makeTitle( $obj->rc_namespace, $obj->rc_title );
+			$talkpage = MWNamespace::canTalk( $obj->rc_namespace )
+				? $title->getTalkPage()->getFullURL()
+				: '';
+
+			// Skip items with deleted content (avoids partially complete/inconsistent output)
+			if ( $obj->rc_deleted ) {
+				continue;
+			}
+
+			if ( $obj->rc_this_oldid ) {
+				$url = $title->getFullURL( array(
+					'diff' => $obj->rc_this_oldid,
+					'oldid' => $obj->rc_last_oldid,
+				) );
+			} else {
+				// log entry or something like that.
+				$url = $title->getFullURL();
+			}
+
+			$items[] = new FeedItem(
+				$title->getPrefixedText(),
+				FeedUtils::formatDiff( $obj ),
+				$url,
+				$obj->rc_timestamp,
+				( $obj->rc_deleted & Revision::DELETED_USER )
+					? wfMessage( 'rev-deleted-user' )->escaped() : $obj->rc_user_text,
+				$talkpage
+			);
+		}
+
+		wfProfileOut( __METHOD__ );
+		return $items;
+	}
+}