/**
* Generates feed's content
*
* @param $feed ChannelFeed subclass object (generally the one returned by getFeedObject())
* @param $rows ResultWrapper object with rows in recentchanges table
* @param $lastmod Integer: timestamp of the last item in the recentchanges table (only used for the cache key)
* @param $opts FormOptions as in SpecialRecentChanges::getDefaultOptions()
* @return null or true
*/
public function execute($feed, $rows, $lastmod, $opts)
{
global $messageMemc, $wgFeedCacheTimeout;
global $wgSitename, $wgLang;
if (!FeedUtils::checkFeedOutput($this->format)) {
return;
}
$timekey = wfMemcKey($this->type, $this->format, 'timestamp');
$optionsHash = md5(serialize($opts->getAllValues()));
$key = wfMemcKey($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;
}
/**
* Execute the feed driver, generating the syndication feed and printing
* the results.
*/
public function execute() {
global $wgOut;
if ( !$this->checkFeedOutput() )
return;
$feed = $this->getFeedObject();
if ( !$feed ) {
wfHttpError( 404, "Not found",
"There is no such wikilog feed available from this site." );
return;
}
list( $timekey, $feedkey ) = $this->getCacheKeys();
FeedUtils::checkPurge( $timekey, $feedkey );
if ( $feed->isCacheable() ) {
# Check if client cache is ok.
if ( $wgOut->checkLastModified( $feed->getUpdated() ) ) {
# Client cache is fresh. OutputPage takes care of sending
# the appropriate headers, nothing else to do.
return;
}
# Try to load the feed from our cache.
$cached = $this->loadFromCache( $feed->getUpdated(), $timekey, $feedkey );
if ( is_string( $cached ) ) {
wfDebug( __METHOD__ . ": Outputting cached feed\n" );
$feed->httpHeaders();
echo $cached;
} else {
wfDebug( __METHOD__ . ": rendering new feed and caching it\n" );
ob_start();
$this->printFeed( $feed );
$cached = ob_get_contents();
ob_end_flush();
$this->saveToCache( $cached, $timekey, $feedkey );
}
} else {
# This feed is not cacheable.
$this->printFeed( $feed );
}
}