-<?
-# Cache for article titles and ids linked from one source
-
+<?php
+/**
+ * Cache for article titles (prefixed DB keys) and ids linked from one source
+ *
+ * @addtogroup 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
+ */
+ static function &singleton() {
+ static $instance;
+ if ( !isset( $instance ) ) {
+ $instance = new LinkCache;
+ }
+ return $instance;
+ }
- /* private */ var $mGoodLinks, $mBadLinks, $mActive;
- /* private */ var $mImageLinks;
-
- function LinkCache()
- {
- $this->mActive = true;
+ function __construct() {
+ $this->mForUpdate = false;
+ $this->mPageLinks = array();
$this->mGoodLinks = array();
$this->mBadLinks = array();
- $this->mImageLinks = array();
}
- function getGoodLinkID( $title )
- {
+ /* private */ function getKey( $title ) {
+ return wfMemcKey( '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 {
}
}
- function isBadLink( $title )
- {
- return in_array( $title, $this->mBadLinks );
+ function isBadLink( $title ) {
+ return array_key_exists( $title, $this->mBadLinks );
}
- function addGoodLink( $id, $title )
- {
- if ( $this->mActive ) {
- $this->mGoodLinks[$title] = $id;
- }
+ function addGoodLinkObj( $id, $title ) {
+ $dbkey = $title->getPrefixedDbKey();
+ $this->mGoodLinks[$dbkey] = $id;
+ $this->mPageLinks[$dbkey] = $title;
}
- function addBadLink( $title )
- {
- if ( $this->mActive && ( ! $this->isBadLink( $title ) ) ) {
- array_push( $this->mBadLinks, $title );
+ function addBadLinkObj( $title ) {
+ $dbkey = $title->getPrefixedDbKey();
+ if ( ! $this->isBadLink( $dbkey ) ) {
+ $this->mBadLinks[$dbkey] = 1;
+ $this->mPageLinks[$dbkey] = $title;
}
}
- function addImageLink( $title )
- {
- if ( $this->mActive ) { $this->mImageLinks[$title] = 1; }
+ function clearBadLink( $title ) {
+ unset( $this->mBadLinks[$title] );
+ $this->clearLink( $title );
}
- function clearBadLink( $title )
- {
- $index = array_search( $title, $this->mBadLinks );
- if ( isset( $index ) ) {
- unset( $this->mBadLinks[$index] );
- }
+ function clearLink( $title ) {
+ global $wgMemc, $wgLinkCacheMemcached;
+ if( $wgLinkCacheMemcached )
+ $wgMemc->delete( $this->getKey( $title ) );
}
- function suspend() { $this->mActive = false; }
- function resume() { $this->mActive = true; }
+ function getPageLinks() { return $this->mPageLinks; }
function getGoodLinks() { return $this->mGoodLinks; }
- function getBadLinks() { return $this->mBadLinks; }
- function getImageLinks() { return $this->mImageLinks; }
+ 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;
+ }
+ }
- function addLink( $title )
- {
+ /**
+ * 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; }
- wfProfileIn( "LinkCache::addLink-checkdatabase" );
+ $fname = 'LinkCache::addLinkObj';
+ global $wgProfiling, $wgProfiler;
+ if ( $wgProfiling && isset( $wgProfiler ) ) {
+ $fname .= ' (' . $wgProfiler->getCurrentSection() . ')';
+ }
+
+ wfProfileIn( $fname );
- $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;
- } else {
- $s = wfFetchObject( $res );
- $id = $s->cur_id;
+ if ( '' == $title ) {
+ wfProfileOut( $fname );
+ return 0;
}
- 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 )
- );
+ $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 );
}
- $sql = "SELECT HIGH_PRIORITY bl_to
- FROM brokenlinks
- WHERE bl_from='{$dbkeyfrom}'";
- $res = wfQuery( $sql, "LinkCache::preFill" );
- while( $s = wfFetchObject( $res ) ) {
- $this->addBadLink( $s->bl_to );
+ if( 0 == $id ) {
+ $this->addBadLinkObj( $nt );
+ } else {
+ $this->addGoodLinkObj( $id, $nt );
}
-
- wfProfileOut();
+ wfProfileOut( $fname );
+ return $id;
}
+ /**
+ * Clears cache
+ */
+ function clear() {
+ $this->mPageLinks = array();
+ $this->mGoodLinks = array();
+ $this->mBadLinks = array();
+ }
}
-?>