diff options
Diffstat (limited to 'includes/cache/LinkCache.php')
| -rw-r--r-- | includes/cache/LinkCache.php | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/includes/cache/LinkCache.php b/includes/cache/LinkCache.php new file mode 100644 index 00000000..aeb10eb0 --- /dev/null +++ b/includes/cache/LinkCache.php @@ -0,0 +1,219 @@ +<?php +/** + * Cache for article titles (prefixed DB keys) and ids linked from one source + * + * @ingroup Cache + */ +class LinkCache { + // Increment $mClassVer whenever old serialized versions of this class + // becomes incompatible with the new version. + private $mClassVer = 4; + + private $mGoodLinks, $mBadLinks; + private $mForUpdate; + + /** + * Get an instance of this class + * + * @return LinkCache + */ + static function &singleton() { + static $instance; + if ( !isset( $instance ) ) { + $instance = new LinkCache; + } + return $instance; + } + + function __construct() { + $this->mForUpdate = false; + $this->mGoodLinks = array(); + $this->mGoodLinkFields = array(); + $this->mBadLinks = array(); + } + + /** + * General accessor to get/set whether SELECT FOR UPDATE should be used + * + * @return bool + */ + public function forUpdate( $update = null ) { + return wfSetVar( $this->mForUpdate, $update ); + } + + /** + * @param $title + * @return array|int + */ + public function getGoodLinkID( $title ) { + if ( array_key_exists( $title, $this->mGoodLinks ) ) { + return $this->mGoodLinks[$title]; + } else { + return 0; + } + } + + /** + * Get a field of a title object from cache. + * If this link is not good, it will return NULL. + * @param $title Title + * @param $field String: ('length','redirect','revision') + * @return mixed + */ + public function getGoodLinkFieldObj( $title, $field ) { + $dbkey = $title->getPrefixedDbKey(); + if ( array_key_exists( $dbkey, $this->mGoodLinkFields ) ) { + return $this->mGoodLinkFields[$dbkey][$field]; + } else { + return null; + } + } + + /** + * @param $title + * @return bool + */ + public function isBadLink( $title ) { + return array_key_exists( $title, $this->mBadLinks ); + } + + /** + * Add a link for the title to the link cache + * + * @param $id Integer: page's ID + * @param $title Title object + * @param $len Integer: text's length + * @param $redir Integer: whether the page is a redirect + * @param $revision Integer: latest revision's ID + */ + public function addGoodLinkObj( $id, $title, $len = -1, $redir = null, $revision = false ) { + $dbkey = $title->getPrefixedDbKey(); + $this->mGoodLinks[$dbkey] = intval( $id ); + $this->mGoodLinkFields[$dbkey] = array( + 'length' => intval( $len ), + 'redirect' => intval( $redir ), + 'revision' => intval( $revision ) ); + } + + /** + * @param $title Title + */ + public function addBadLinkObj( $title ) { + $dbkey = $title->getPrefixedDbKey(); + if ( !$this->isBadLink( $dbkey ) ) { + $this->mBadLinks[$dbkey] = 1; + } + } + + public function clearBadLink( $title ) { + unset( $this->mBadLinks[$title] ); + } + + /** + * @param $title Title + */ + public function clearLink( $title ) { + $dbkey = $title->getPrefixedDbKey(); + if( isset($this->mBadLinks[$dbkey]) ) { + unset($this->mBadLinks[$dbkey]); + } + if( isset($this->mGoodLinks[$dbkey]) ) { + unset($this->mGoodLinks[$dbkey]); + } + if( isset($this->mGoodLinkFields[$dbkey]) ) { + unset($this->mGoodLinkFields[$dbkey]); + } + } + + public function getGoodLinks() { return $this->mGoodLinks; } + public 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 + */ + public 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 object to add + * @return Integer + */ + public function addLinkObj( $nt ) { + global $wgAntiLockFlags; + wfProfileIn( __METHOD__ ); + + $key = $nt->getPrefixedDBkey(); + if ( $this->isBadLink( $key ) || $nt->isExternal() ) { + wfProfileOut( __METHOD__ ); + return 0; + } + $id = $this->getGoodLinkID( $key ); + if ( $id != 0 ) { + wfProfileOut( __METHOD__ ); + return $id; + } + + if ( $key === '' ) { + wfProfileOut( __METHOD__ ); + return 0; + } + + # Some fields heavily used for linking... + 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(); + } + + $s = $db->selectRow( 'page', + array( 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ), + array( 'page_namespace' => $nt->getNamespace(), 'page_title' => $nt->getDBkey() ), + __METHOD__, $options ); + # Set fields... + if ( $s !== false ) { + $id = intval( $s->page_id ); + $len = intval( $s->page_len ); + $redirect = intval( $s->page_is_redirect ); + $revision = intval( $s->page_latest ); + } else { + $id = 0; + $len = -1; + $redirect = 0; + $revision = 0; + } + + if ( $id == 0 ) { + $this->addBadLinkObj( $nt ); + } else { + $this->addGoodLinkObj( $id, $nt, $len, $redirect, $revision ); + } + wfProfileOut( __METHOD__ ); + return $id; + } + + /** + * Clears cache + */ + public function clear() { + $this->mGoodLinks = array(); + $this->mGoodLinkFields = array(); + $this->mBadLinks = array(); + } +} |