includes/ChangesFeed.php

   1 <?php
   2
   3 class ChangesFeed {
   4
   5         public $format, $type, $titleMsg, $descMsg;
   6
   7         public function __construct( $format, $type ) {
   8                 $this->format = $format;
   9                 $this->type = $type;
  10         }
  11
  12         public function getFeedObject( $title, $description ) {
  13                 global $wgSitename, $wgContLanguageCode, $wgFeedClasses, $wgTitle;
  14                 $feedTitle = "$wgSitename  - {$title} [$wgContLanguageCode]";
  15
  16                 return new $wgFeedClasses[$this->format](
  17                         $feedTitle, htmlspecialchars( $description ), $wgTitle->getFullUrl() );
  18         }
  19
  20         public function execute( $feed, $rows, $limit = 0 , $hideminor = false, $lastmod = false ) {
  21                 global $messageMemc, $wgFeedCacheTimeout;
  22                 global $wgFeedClasses, $wgTitle, $wgSitename, $wgContLanguageCode;
  23
  24                 if ( !FeedUtils::checkFeedOutput( $this->format ) ) {
  25                         return;
  26                 }
  27
  28                 $timekey = wfMemcKey( $this->type, $this->format, 'timestamp' );
  29                 $key = wfMemcKey( $this->type, $this->format, 'limit', $limit, 'minor', $hideminor );
  30
  31                 FeedUtils::checkPurge($timekey, $key);
  32
  33                 /*
  34                 * Bumping around loading up diffs can be pretty slow, so where
  35                 * possible we want to cache the feed output so the next visitor
  36                 * gets it quick too.
  37                 */
  38                 $cachedFeed = $this->loadFromCache( $lastmod, $timekey, $key );
  39                 if( is_string( $cachedFeed ) ) {
  40                         wfDebug( "RC: Outputting cached feed\n" );
  41                         $feed->httpHeaders();
  42                         echo $cachedFeed;
  43                 } else {
  44                         wfDebug( "RC: rendering new feed and caching it\n" );
  45                         ob_start();
  46                         self::generateFeed( $rows, $feed );
  47                         $cachedFeed = ob_get_contents();
  48                         ob_end_flush();
  49                         $this->saveToCache( $cachedFeed, $timekey, $key );
  50                 }
  51                 return true;
  52         }
  53
  54         public function saveToCache( $feed, $timekey, $key ) {
  55                 global $messageMemc;
  56                 $expire = 3600 * 24; # One day
  57                 $messageMemc->set( $key, $feed );
  58                 $messageMemc->set( $timekey, wfTimestamp( TS_MW ), $expire );
  59         }
  60
  61         public function loadFromCache( $lastmod, $timekey, $key ) {
  62                 global $wgFeedCacheTimeout, $messageMemc;
  63                 $feedLastmod = $messageMemc->get( $timekey );
  64
  65                 if( ( $wgFeedCacheTimeout > 0 ) && $feedLastmod ) {
  66                         /*
  67                         * If the cached feed was rendered very recently, we may
  68                         * go ahead and use it even if there have been edits made
  69                         * since it was rendered. This keeps a swarm of requests
  70                         * from being too bad on a super-frequently edited wiki.
  71                         */
  72
  73                         $feedAge = time() - wfTimestamp( TS_UNIX, $feedLastmod );
  74                         $feedLastmodUnix = wfTimestamp( TS_UNIX, $feedLastmod );
  75                         $lastmodUnix = wfTimestamp( TS_UNIX, $lastmod );
  76
  77                         if( $feedAge < $wgFeedCacheTimeout || $feedLastmodUnix > $lastmodUnix) {
  78                                 wfDebug( "RC: loading feed from cache ($key; $feedLastmod; $lastmod)...\n" );
  79                                 return $messageMemc->get( $key );
  80                         } else {
  81                                 wfDebug( "RC: cached feed timestamp check failed ($feedLastmod; $lastmod)\n" );
  82                         }
  83                 }
  84                 return false;
  85         }
  86
  87         /**
  88         * @todo document
  89         * @param $rows Database resource with recentchanges rows
  90         * @param $feed Feed object
  91         */
  92         public static function generateFeed( $rows, &$feed ) {
  93                 wfProfileIn( __METHOD__ );
  94
  95                 $feed->outHeader();
  96
  97                 # Merge adjacent edits by one user
  98                 $sorted = array();
  99                 $n = 0;
 100                 foreach( $rows as $obj ) {
 101                         if( $n > 0 &&
 102                                 $obj->rc_namespace >= 0 &&
 103                                 $obj->rc_cur_id == $sorted[$n-1]->rc_cur_id &&
 104                                 $obj->rc_user_text == $sorted[$n-1]->rc_user_text ) {
 105                                 $sorted[$n-1]->rc_last_oldid = $obj->rc_last_oldid;
 106                         } else {
 107                                 $sorted[$n] = $obj;
 108                                 $n++;
 109                         }
 110                 }
 111
 112                 foreach( $sorted as $obj ) {
 113                         $title = Title::makeTitle( $obj->rc_namespace, $obj->rc_title );
 114                         $talkpage = $title->getTalkPage();
 115                         $item = new FeedItem(
 116                                 $title->getPrefixedText(),
 117                                 FeedUtils::formatDiff( $obj ),
 118                                 $title->getFullURL( 'diff=' . $obj->rc_this_oldid . '&oldid=prev' ),
 119                                 $obj->rc_timestamp,
 120                                 ($obj->rc_deleted & Revision::DELETED_USER) ? wfMsgHtml('rev-deleted-user') : $obj->rc_user_text,
 121                                 $talkpage->getFullURL()
 122                                 );
 123                         $feed->outItem( $item );
 124                 }
 125                 $feed->outFooter();
 126                 wfProfileOut( __METHOD__ );
 127         }
 128
 129 }