diff options
Diffstat (limited to 'includes/LinkCache.php')
| -rw-r--r-- | includes/LinkCache.php | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/includes/LinkCache.php b/includes/LinkCache.php new file mode 100644 index 00000000..451b3f0c --- /dev/null +++ b/includes/LinkCache.php @@ -0,0 +1,178 @@ +<?php +/** + * Cache for article titles (prefixed DB keys) and ids linked from one source + * @package MediaWiki + * @subpackage Cache + */ + +/** + * @package MediaWiki + * @subpackage Cache + */ +class LinkCache { + // Increment $mClassVer whenever old serialized versions of this class + // becomes incompatible with the new version. + /* private */ var $mClassVer = 3; + + /* private */ var $mPageLinks; + /* private */ var $mGoodLinks, $mBadLinks; + /* private */ var $mForUpdate; + + /** + * Get an instance of this class + */ + function &singleton() { + static $instance; + if ( !isset( $instance ) ) { + $instance = new LinkCache; + } + return $instance; + } + + function LinkCache() { + $this->mForUpdate = false; + $this->mPageLinks = array(); + $this->mGoodLinks = array(); + $this->mBadLinks = array(); + } + + /* private */ function getKey( $title ) { + global $wgDBname; + return $wgDBname.':lc:title:'.$title; + } + + /** + * General accessor to get/set whether SELECT FOR UPDATE should be used + */ + function forUpdate( $update = NULL ) { + return wfSetVar( $this->mForUpdate, $update ); + } + + function getGoodLinkID( $title ) { + if ( array_key_exists( $title, $this->mGoodLinks ) ) { + return $this->mGoodLinks[$title]; + } else { + return 0; + } + } + + function isBadLink( $title ) { + return array_key_exists( $title, $this->mBadLinks ); + } + + function addGoodLinkObj( $id, $title ) { + $dbkey = $title->getPrefixedDbKey(); + $this->mGoodLinks[$dbkey] = $id; + $this->mPageLinks[$dbkey] = $title; + } + + function addBadLinkObj( $title ) { + $dbkey = $title->getPrefixedDbKey(); + if ( ! $this->isBadLink( $dbkey ) ) { + $this->mBadLinks[$dbkey] = 1; + $this->mPageLinks[$dbkey] = $title; + } + } + + function clearBadLink( $title ) { + unset( $this->mBadLinks[$title] ); + $this->clearLink( $title ); + } + + function clearLink( $title ) { + global $wgMemc, $wgLinkCacheMemcached; + if( $wgLinkCacheMemcached ) + $wgMemc->delete( $this->getKey( $title ) ); + } + + function getPageLinks() { return $this->mPageLinks; } + function getGoodLinks() { return $this->mGoodLinks; } + function getBadLinks() { return array_keys( $this->mBadLinks ); } + + /** + * Add a title to the link cache, return the page_id or zero if non-existent + * @param $title String: title to add + * @return integer + */ + function addLink( $title ) { + $nt = Title::newFromDBkey( $title ); + if( $nt ) { + return $this->addLinkObj( $nt ); + } else { + return 0; + } + } + + /** + * Add a title to the link cache, return the page_id or zero if non-existent + * @param $nt Title to add. + * @return integer + */ + function addLinkObj( &$nt ) { + global $wgMemc, $wgLinkCacheMemcached, $wgAntiLockFlags; + $title = $nt->getPrefixedDBkey(); + if ( $this->isBadLink( $title ) ) { return 0; } + $id = $this->getGoodLinkID( $title ); + if ( 0 != $id ) { return $id; } + + $fname = 'LinkCache::addLinkObj'; + global $wgProfiling, $wgProfiler; + if ( $wgProfiling && isset( $wgProfiler ) ) { + $fname .= ' (' . $wgProfiler->getCurrentSection() . ')'; + } + + wfProfileIn( $fname ); + + $ns = $nt->getNamespace(); + $t = $nt->getDBkey(); + + if ( '' == $title ) { + wfProfileOut( $fname ); + return 0; + } + + $id = NULL; + if( $wgLinkCacheMemcached ) + $id = $wgMemc->get( $key = $this->getKey( $title ) ); + if( ! is_integer( $id ) ) { + if ( $this->mForUpdate ) { + $db =& wfGetDB( DB_MASTER ); + if ( !( $wgAntiLockFlags & ALF_NO_LINK_LOCK ) ) { + $options = array( 'FOR UPDATE' ); + } else { + $options = array(); + } + } else { + $db =& wfGetDB( DB_SLAVE ); + $options = array(); + } + + $id = $db->selectField( 'page', 'page_id', + array( 'page_namespace' => $ns, 'page_title' => $t ), + $fname, $options ); + if ( !$id ) { + $id = 0; + } + if( $wgLinkCacheMemcached ) + $wgMemc->add( $key, $id, 3600*24 ); + } + + if( 0 == $id ) { + $this->addBadLinkObj( $nt ); + } else { + $this->addGoodLinkObj( $id, $nt ); + } + wfProfileOut( $fname ); + return $id; + } + + /** + * Clears cache + */ + function clear() { + $this->mPageLinks = array(); + $this->mGoodLinks = array(); + $this->mBadLinks = array(); + } +} +?> |