-<?
-# Cache for article titles and ids linked from one source
-
-# These are used in incrementalSetup()
-define ('LINKCACHE_GOOD', 0);
-define ('LINKCACHE_BAD', 1);
-define ('LINKCACHE_IMAGE', 2);
-
+<?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 */ var $mClassVer = 4;
+
+ /* private */ var $mGoodLinks, $mBadLinks;
+ /* private */ var $mForUpdate;
+
+ /**
+ * Get an instance of this class
+ */
+ static function &singleton() {
+ static $instance;
+ if ( !isset( $instance ) ) {
+ $instance = new LinkCache;
+ }
+ return $instance;
+ }
- /* private */ var $mGoodLinks, $mBadLinks, $mActive;
- /* private */ var $mImageLinks;
- /* private */ var $mPreFilled, $mOldGoodLinks, $mOldBadLinks;
-
- function LinkCache()
- {
- $this->mActive = true;
- $this->mPreFilled = false;
+ function __construct() {
+ $this->mForUpdate = false;
$this->mGoodLinks = array();
+ $this->mGoodLinkFields = array();
$this->mBadLinks = array();
- $this->mImageLinks = array();
- $this->mOldGoodLinks = array();
- $this->mOldBadLinks = array();
}
- function getGoodLinkID( $title )
- {
+ /**
+ * General accessor to get/set whether SELECT FOR UPDATE should be used
+ */
+ public function forUpdate( $update = NULL ) {
+ return wfSetVar( $this->mForUpdate, $update );
+ }
+
+ public function getGoodLinkID( $title ) {
if ( array_key_exists( $title, $this->mGoodLinks ) ) {
return $this->mGoodLinks[$title];
} else {
}
}
- function isBadLink( $title )
- {
- return in_array( $title, $this->mBadLinks );
- }
-
- function addGoodLink( $id, $title )
- {
- if ( $this->mActive ) {
- $this->mGoodLinks[$title] = $id;
+ /**
+ * Get a field of a title object from cache.
+ * If this link is not good, it will return NULL.
+ * @param Title $title
+ * @param string $field ('length','redirect')
+ * @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;
}
}
- function addBadLink( $title )
- {
- if ( $this->mActive && ( ! $this->isBadLink( $title ) ) ) {
- array_push( $this->mBadLinks, $title );
- }
+ public function isBadLink( $title ) {
+ return array_key_exists( $title, $this->mBadLinks );
}
- function addImageLink( $title )
- {
- if ( $this->mActive ) { $this->mImageLinks[$title] = 1; }
+ /**
+ * Add a link for the title to the link cache
+ * @param int $id
+ * @param Title $title
+ * @param int $len
+ * @param int $redir
+ */
+ public function addGoodLinkObj( $id, $title, $len = -1, $redir = NULL ) {
+ $dbkey = $title->getPrefixedDbKey();
+ $this->mGoodLinks[$dbkey] = $id;
+ $this->mGoodLinkFields[$dbkey] = array( 'length' => $len, 'redirect' => $redir );
}
- function clearBadLink( $title )
- {
- $index = array_search( $title, $this->mBadLinks );
- if ( isset( $index ) ) {
- unset( $this->mBadLinks[$index] );
+ public function addBadLinkObj( $title ) {
+ $dbkey = $title->getPrefixedDbKey();
+ if ( ! $this->isBadLink( $dbkey ) ) {
+ $this->mBadLinks[$dbkey] = 1;
}
}
- function suspend() { $this->mActive = false; }
- function resume() { $this->mActive = true; }
- function getGoodLinks() { return $this->mGoodLinks; }
- function getBadLinks() { return $this->mBadLinks; }
- function getImageLinks() { return $this->mImageLinks; }
+ public function clearBadLink( $title ) {
+ unset( $this->mBadLinks[$title] );
+ }
- function addLink( $title )
- {
- if ( $this->isBadLink( $title ) ) { return 0; }
- $id = $this->getGoodLinkID( $title );
- if ( 0 != $id ) { return $id; }
+ /* obsolete, for old $wgLinkCacheMemcached stuff */
+ public function clearLink( $title ) {}
- wfProfileIn( "LinkCache::addLink-checkdatabase" );
+ 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
+ * @param $len int, page size
+ * @param $redir bool, is redirect?
+ * @return integer
+ */
+ public function addLink( $title, $len = -1, $redir = NULL ) {
$nt = Title::newFromDBkey( $title );
- $ns = $nt->getNamespace();
- $t = $nt->getDBkey();
-
- if ( "" == $t ) { return 0; }
- $sql = "SELECT HIGH_PRIORITY cur_id FROM cur WHERE cur_namespace=" .
- "{$ns} AND cur_title='" . wfStrencode( $t ) . "'";
- $res = wfQuery( $sql, "LinkCache::addLink" );
-
- if ( 0 == wfNumRows( $res ) ) {
- $id = 0;
+ if( $nt ) {
+ return $this->addLinkObj( $nt, $len, $redir );
} else {
- $s = wfFetchObject( $res );
- $id = $s->cur_id;
- }
- if ( 0 == $id ) { $this->addBadLink( $title ); }
- else { $this->addGoodLink( $id, $title ); }
- wfProfileOut();
- return $id;
- }
-
- function preFill( $fromtitle )
- {
- wfProfileIn( "LinkCache::preFill" );
- # Note -- $fromtitle is a Title *object*
- $dbkeyfrom = wfStrencode( $fromtitle->getPrefixedDBKey() );
- $sql = "SELECT HIGH_PRIORITY cur_id,cur_namespace,cur_title
- FROM cur,links
- WHERE cur_id=l_to AND l_from='{$dbkeyfrom}'";
- $res = wfQuery( $sql, "LinkCache::preFill" );
- while( $s = wfFetchObject( $res ) ) {
- $this->addGoodLink( $s->cur_id,
- Title::makeName( $s->cur_namespace, $s->cur_title )
- );
- }
-
- $this->suspend();
- $id = $fromtitle->getArticleID();
- $this->resume();
-
- $sql = "SELECT HIGH_PRIORITY bl_to
- FROM brokenlinks
- WHERE bl_from='{$id}'";
- $res = wfQuery( $sql, "LinkCache::preFill" );
- while( $s = wfFetchObject( $res ) ) {
- $this->addBadLink( $s->bl_to );
+ return 0;
}
-
- $this->mOldBadLinks = $this->mBadLinks;
- $this->mOldGoodLinks = $this->mGoodLinks;
- $this->mPreFilled = true;
-
- wfProfileOut();
}
- function getGoodAdditions()
- {
- return array_diff( $this->mGoodLinks, $this->mOldGoodLinks );
- }
+ /**
+ * Add a title to the link cache, return the page_id or zero if non-existent
+ * @param $nt Title to add.
+ * @param $len int, page size
+ * @param $redir bool, is redirect?
+ * @return integer
+ */
+ public function addLinkObj( &$nt, $len = -1, $redirect = NULL ) {
+ global $wgAntiLockFlags, $wgProfiler;
- function getBadAdditions()
- {
- return array_values( array_diff( $this->mBadLinks, $this->mOldBadLinks ) );
- }
+ $title = $nt->getPrefixedDBkey();
+ if ( $this->isBadLink( $title ) ) { return 0; }
+ $id = $this->getGoodLinkID( $title );
+ if ( 0 != $id ) { return $id; }
- function getImageAdditions()
- {
- return array_diff_assoc( $this->mImageLinks, $this->mOldImageLinks );
- }
+ $fname = 'LinkCache::addLinkObj';
+ if ( isset( $wgProfiler ) ) {
+ $fname .= ' (' . $wgProfiler->getCurrentSection() . ')';
+ }
- function getGoodDeletions()
- {
- return array_diff( $this->mOldGoodLinks, $this->mGoodLinks );
- }
+ wfProfileIn( $fname );
- function getBadDeletions()
- {
- return array_values( array_diff( $this->mOldBadLinks, $this->mBadLinks ) );
- }
+ $ns = $nt->getNamespace();
+ $t = $nt->getDBkey();
- function getImageDeletions()
- {
- return array_diff_assoc( $this->mOldImageLinks, $this->mImageLinks );
- }
+ if ( '' == $title ) {
+ wfProfileOut( $fname );
+ return 0;
+ }
- # Parameters: $which is one of the LINKCACHE_xxx constants, $del and $add are
- # the incremental update arrays which will be filled. Returns whether or not it's
- # worth doing the incremental version. For example, if [[List of mathematical topics]]
- # was blanked, it would take a long, long time to do incrementally.
- function incrementalSetup( $which, &$del, &$add )
- {
- if ( ! $this->mPreFilled ) {
- return false;
+ # 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();
}
- switch ( $which ) {
- case LINKCACHE_GOOD:
- $old =& $this->mOldGoodLinks;
- $cur =& $this->mGoodLinks;
- $del = $this->getGoodDeletions();
- $add = $this->getGoodAdditions();
- break;
- case LINKCACHE_BAD:
- $old =& $this->mOldBadLinks;
- $cur =& $this->mBadLinks;
- $del = $this->getBadDeletions();
- $add = $this->getBadAdditions();
- break;
- default: # LINKCACHE_IMAGE
- return false;
+ $s = $db->selectRow( 'page',
+ array( 'page_id', 'page_len', 'page_is_redirect' ),
+ array( 'page_namespace' => $ns, 'page_title' => $t ),
+ $fname, $options );
+ # Set fields...
+ $id = $s ? $s->page_id : 0;
+ $len = $s ? $s->page_len : -1;
+ $redirect = $s ? $s->page_is_redirect : 0;
+
+ if( 0 == $id ) {
+ $this->addBadLinkObj( $nt );
+ } else {
+ $this->addGoodLinkObj( $id, $nt, $len, $redirect );
}
-
- return true;
+ wfProfileOut( $fname );
+ return $id;
}
- # Clears cache but leaves old preFill copies alone
- function clear()
- {
+ /**
+ * Clears cache
+ */
+ public function clear() {
$this->mGoodLinks = array();
+ $this->mGoodLinkFields = array();
$this->mBadLinks = array();
- $this->mImageLinks = array();
}
}
-?>