<?php
/**
* See docs/deferred.txt
*
* @todo document (e.g. one-sentence top-level class description).
*/
class LinksUpdate {
/**@{{
* @private
*/
var $mId, //!< Page ID of the article linked from
$mTitle, //!< Title object of the article linked from
$mLinks, //!< Map of title strings to IDs for the links in the document
$mImages, //!< DB keys of the images used, in the array key only
$mTemplates, //!< Map of title strings to IDs for the template references, including broken ones
$mExternals, //!< URLs of external links, array key only
$mCategories, //!< Map of category names to sort keys
$mInterlangs, //!< Map of language codes to titles
$mDb, //!< Database connection reference
$mOptions, //!< SELECT options to be used (array)
$mRecursive; //!< Whether to queue jobs for recursive updates
/**@}}*/
/**
* Constructor
*
* @param Title $title Title of the page we're updating
* @param ParserOutput $parserOutput Output from a full parse of this page
* @param bool $recursive Queue jobs for recursive updates?
*/
function LinksUpdate( $title, $parserOutput, $recursive = true ) {
global $wgAntiLockFlags;
if ( $wgAntiLockFlags & ALF_NO_LINK_LOCK ) {
$this->mOptions = array();
} else {
$this->mOptions = array( 'FOR UPDATE' );
}
$this->mDb = wfGetDB( DB_MASTER );
if ( !is_object( $title ) ) {
throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
"Please see Article::editUpdates() for an invocation example.\n" );
}
$this->mTitle = $title;
$this->mId = $title->getArticleID();
$this->mLinks = $parserOutput->getLinks();
$this->mImages = $parserOutput->getImages();
$this->mTemplates = $parserOutput->getTemplates();
$this->mExternals = $parserOutput->getExternalLinks();
$this->mCategories = $parserOutput->getCategories();
# Convert the format of the interlanguage links
# I didn't want to change it in the ParserOutput, because that array is passed all
# the way back to the skin, so either a skin API break would be required, or an
# inefficient back-conversion.
$ill = $parserOutput->getLanguageLinks();
$this->mInterlangs = array();
foreach ( $ill as $link ) {
list( $key, $title ) = explode( ':', $link, 2 );
$this->mInterlangs[$key] = $title;
}
$this->mRecursive = $recursive;
wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
}
/**
* Update link tables with outgoing links from an updated article
*/
function doUpdate() {
global $wgUseDumbLinkUpdate;
if ( $wgUseDumbLinkUpdate ) {
$this->doDumbUpdate();
} else {
$this->doIncrementalUpdate();
}
}
function doIncrementalUpdate() {
$fname = 'LinksUpdate::doIncrementalUpdate';
wfProfileIn( $fname );
# Page links
$existing = $this->getExistingLinks();
$this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
$this->getLinkInsertions( $existing ) );
# Image links
$existing = $this->getExistingImages();
$this->incrTableUpdate( 'imagelinks', 'il', $this->getImageDeletions( $existing ),
$this->getImageInsertions( $existing ) );
# Invalidate all image description pages which had links added or removed
$imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
$this->invalidateImageDescriptions( $imageUpdates );
# External links
$existing = $this->getExistingExternals();
$this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
$this->getExternalInsertions( $existing ) );
# Language links
$existing = $this->getExistingInterlangs();
$this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
$this->getInterlangInsertions( $existing ) );
# Template links
$existing = $this->getExistingTemplates();
$this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
$this->getTemplateInsertions( $existing ) );
# Category links
$existing = $this->getExistingCategories();
$this->incrTableUpdate( 'categorylinks', 'cl', $this->getCategoryDeletions( $existing ),
$this->getCategoryInsertions( $existing ) );
# Invalidate all categories which were added, deleted or changed (set symmetric difference)
$categoryUpdates = array_diff_assoc( $existing, $this->mCategories ) + array_diff_assoc( $this->mCategories, $existing );
$this->invalidateCategories( $categoryUpdates );
# Refresh links of all pages including this page
# This will be in a separate transaction
if ( $this->mRecursive ) {
$this->queueRecursiveJobs();
}
wfProfileOut( $fname );
}
/**
* Link update which clears the previous entries and inserts new ones
* May be slower or faster depending on level of lock contention and write speed of DB
* Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
*/
function doDumbUpdate() {
$fname = 'LinksUpdate::doDumbUpdate';
wfProfileIn( $fname );
# Refresh category pages and image description pages
$existing = $this->getExistingCategories();
$categoryUpdates = array_diff_assoc( $existing, $this->mCategories ) + array_diff_assoc( $this->mCategories, $existing );
$existing = $this->getExistingImages();
$imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
$this->dumbTableUpdate( 'pagelinks', $this->getLinkInsertions(), 'pl_from' );
$this->dumbTableUpdate( 'imagelinks', $this->getImageInsertions(), 'il_from' );
$this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
$this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
$this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
$this->dumbTableUpdate( 'langlinks', $this->getInterlangInsertions(), 'll_from' );
# Update the cache of all the category pages and image description pages which were changed
$this->invalidateCategories( $categoryUpdates );
$this->invalidateImageDescriptions( $imageUpdates );
# Refresh links of all pages including this page
# This will be in a separate transaction
if ( $this->mRecursive ) {
$this->queueRecursiveJobs();
}
wfProfileOut( $fname );
}
function queueRecursiveJobs() {
wfProfileIn( __METHOD__ );
$batchSize = 100;
$dbr = wfGetDB( DB_SLAVE );
$res = $dbr->select( array( 'templatelinks', 'page' ),
array( 'page_namespace', 'page_title' ),
array(
'page_id=tl_from',
'tl_namespace' => $this->mTitle->getNamespace(),
'tl_title' => $this->mTitle->getDBkey()
), __METHOD__
);
$done = false;
while ( !$done ) {
$jobs = array();
for ( $i = 0; $i < $batchSize; $i++ ) {
$row = $dbr->fetchObject( $res );
if ( !$row ) {
$done = true;
break;
}
$title = Title::makeTitle( $row->page_namespace, $row->page_title );
$jobs[] = new RefreshLinksJob( $title, '' );
}
Job::batchInsert( $jobs );
}
$dbr->freeResult( $res );
wfProfileOut( __METHOD__ );
}
/**
* Invalidate the cache of a list of pages from a single namespace
*
* @param integer $namespace
* @param array $dbkeys
*/
function invalidatePages( $namespace, $dbkeys ) {
$fname = 'LinksUpdate::invalidatePages';
if ( !count( $dbkeys ) ) {
return;
}
/**
* Determine which pages need to be updated
* This is necessary to prevent the job queue from smashing the DB with
* large numbers of concurrent invalidations of the same page
*/
$now = $this->mDb->timestamp();
$ids = array();
$res = $this->mDb->select( 'page', array( 'page_id' ),
array(
'page_namespace' => $namespace,
'page_title IN (' . $this->mDb->makeList( $dbkeys ) . ')',
'page_touched < ' . $this->mDb->addQuotes( $now )
), $fname
);
while ( $row = $this->mDb->fetchObject( $res ) ) {
$ids[] = $row->page_id;
}
if ( !count( $ids ) ) {
return;
}
/**
* Do the update
* We still need the page_touched condition, in case the row has changed since
* the non-locking select above.
*/
$this->mDb->update( 'page', array( 'page_touched' => $now ),
array(
'page_id IN (' . $this->mDb->makeList( $ids ) . ')',
'page_touched < ' . $this->mDb->addQuotes( $now )
), $fname
);
}
function invalidateCategories( $cats ) {
$this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
}
function invalidateImageDescriptions( $images ) {
$this->invalidatePages( NS_IMAGE, array_keys( $images ) );
}
function dumbTableUpdate( $table, $insertions, $fromField ) {
$fname = 'LinksUpdate::dumbTableUpdate';
$this->mDb->delete( $table, array( $fromField => $this->mId ), $fname );
if ( count( $insertions ) ) {
# The link array was constructed without FOR UPDATE, so there may be collisions
# This may cause minor link table inconsistencies, which is better than
# crippling the site with lock contention.
$this->mDb->insert( $table, $insertions, $fname, array( 'IGNORE' ) );
}
}
/**
* Make a WHERE clause from a 2-d NS/dbkey array
*
* @param array $arr 2-d array indexed by namespace and DB key
* @param string $prefix Field name prefix, without the underscore
*/
function makeWhereFrom2d( &$arr, $prefix ) {
$lb = new LinkBatch;
$lb->setArray( $arr );
return $lb->constructSet( $prefix, $this->mDb );
}
/**
* Update a table by doing a delete query then an insert query
* @private
*/
function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
$fname = 'LinksUpdate::incrTableUpdate';
$where = array( "{$prefix}_from" => $this->mId );
if ( $table == 'pagelinks' || $table == 'templatelinks' ) {
$clause = $this->makeWhereFrom2d( $deletions, $prefix );
if ( $clause ) {
$where[] = $clause;
} else {
$where = false;
}
} else {
if ( $table == 'langlinks' ) {
$toField = 'll_lang';
} else {
$toField = $prefix . '_to';
}
if ( count( $deletions ) ) {
$where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
} else {
$where = false;
}
}
if ( $where ) {
$this->mDb->delete( $table, $where, $fname );
}
if ( count( $insertions ) ) {
$this->mDb->insert( $table, $insertions, $fname, 'IGNORE' );
}
}
/**
* Get an array of pagelinks insertions for passing to the DB
* Skips the titles specified by the 2-D array $existing
* @private
*/
function getLinkInsertions( $existing = array() ) {
$arr = array();
foreach( $this->mLinks as $ns => $dbkeys ) {
# array_diff_key() was introduced in PHP 5.1, there is a compatibility function
# in GlobalFunctions.php
$diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
foreach ( $diffs as $dbk => $id ) {
$arr[] = array(
'pl_from' => $this->mId,
'pl_namespace' => $ns,
'pl_title' => $dbk
);
}
}
return $arr;
}
/**
* Get an array of template insertions. Like getLinkInsertions()
* @private
*/
function getTemplateInsertions( $existing = array() ) {
$arr = array();
foreach( $this->mTemplates as $ns => $dbkeys ) {
$diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
foreach ( $diffs as $dbk => $id ) {
$arr[] = array(
'tl_from' => $this->mId,
'tl_namespace' => $ns,
'tl_title' => $dbk
);
}
}
return $arr;
}
/**
* Get an array of image insertions
* Skips the names specified in $existing
* @private
*/
function getImageInsertions( $existing = array() ) {
$arr = array();
$diffs = array_diff_key( $this->mImages, $existing );
foreach( $diffs as $iname => $dummy ) {
$arr[] = array(
'il_from' => $this->mId,
'il_to' => $iname
);
}
return $arr;
}
/**
* Get an array of externallinks insertions. Skips the names specified in $existing
* @private
*/
function getExternalInsertions( $existing = array() ) {
$arr = array();
$diffs = array_diff_key( $this->mExternals, $existing );
foreach( $diffs as $url => $dummy ) {
$arr[] = array(
'el_from' => $this->mId,
'el_to' => $url,
'el_index' => wfMakeUrlIndex( $url ),
);
}
return $arr;
}
/**
* Get an array of category insertions
* @param array $existing Array mapping existing category names to sort keys. If both
* match a link in $this, the link will be omitted from the output
* @private
*/
function getCategoryInsertions( $existing = array() ) {
$diffs = array_diff_assoc( $this->mCategories, $existing );
$arr = array();
foreach ( $diffs as $name => $sortkey ) {
$arr[] = array(
'cl_from' => $this->mId,
'cl_to' => $name,
'cl_sortkey' => $sortkey,
'cl_timestamp' => $this->mDb->timestamp()
);
}
return $arr;
}
/**
* Get an array of interlanguage link insertions
* @param array $existing Array mapping existing language codes to titles
* @private
*/
function getInterlangInsertions( $existing = array() ) {
$diffs = array_diff_assoc( $this->mInterlangs, $existing );
$arr = array();
foreach( $diffs as $lang => $title ) {
$arr[] = array(
'll_from' => $this->mId,
'll_lang' => $lang,
'll_title' => $title
);
}
return $arr;
}
/**
* Given an array of existing links, returns those links which are not in $this
* and thus should be deleted.
* @private
*/
function getLinkDeletions( $existing ) {
$del = array();
foreach ( $existing as $ns => $dbkeys ) {
if ( isset( $this->mLinks[$ns] ) ) {
$del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
} else {
$del[$ns] = $existing[$ns];
}
}
return $del;
}
/**
* Given an array of existing templates, returns those templates which are not in $this
* and thus should be deleted.
* @private
*/
function getTemplateDeletions( $existing ) {
$del = array();
foreach ( $existing as $ns => $dbkeys ) {
if ( isset( $this->mTemplates[$ns] ) ) {
$del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
} else {
$del[$ns] = $existing[$ns];
}
}
return $del;
}
/**
* Given an array of existing images, returns those images which are not in $this
* and thus should be deleted.
* @private
*/
function getImageDeletions( $existing ) {
return array_diff_key( $existing, $this->mImages );
}
/**
* Given an array of existing external links, returns those links which are not
* in $this and thus should be deleted.
* @private
*/
function getExternalDeletions( $existing ) {
return array_diff_key( $existing, $this->mExternals );
}
/**
* Given an array of existing categories, returns those categories which are not in $this
* and thus should be deleted.
* @private
*/
function getCategoryDeletions( $existing ) {
return array_diff_assoc( $existing, $this->mCategories );
}
/**
* Given an array of existing interlanguage links, returns those links which are not
* in $this and thus should be deleted.
* @private
*/
function getInterlangDeletions( $existing ) {
return array_diff_assoc( $existing, $this->mInterlangs );
}
/**
* Get an array of existing links, as a 2-D array
* @private
*/
function getExistingLinks() {
$fname = 'LinksUpdate::getExistingLinks';
$res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
array( 'pl_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
if ( !isset( $arr[$row->pl_namespace] ) ) {
$arr[$row->pl_namespace] = array();
}
$arr[$row->pl_namespace][$row->pl_title] = 1;
}
$this->mDb->freeResult( $res );
return $arr;
}
/**
* Get an array of existing templates, as a 2-D array
* @private
*/
function getExistingTemplates() {
$fname = 'LinksUpdate::getExistingTemplates';
$res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
array( 'tl_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
if ( !isset( $arr[$row->tl_namespace] ) ) {
$arr[$row->tl_namespace] = array();
}
$arr[$row->tl_namespace][$row->tl_title] = 1;
}
$this->mDb->freeResult( $res );
return $arr;
}
/**
* Get an array of existing images, image names in the keys
* @private
*/
function getExistingImages() {
$fname = 'LinksUpdate::getExistingImages';
$res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
array( 'il_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
$arr[$row->il_to] = 1;
}
$this->mDb->freeResult( $res );
return $arr;
}
/**
* Get an array of existing external links, URLs in the keys
* @private
*/
function getExistingExternals() {
$fname = 'LinksUpdate::getExistingExternals';
$res = $this->mDb->select( 'externallinks', array( 'el_to' ),
array( 'el_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
$arr[$row->el_to] = 1;
}
$this->mDb->freeResult( $res );
return $arr;
}
/**
* Get an array of existing categories, with the name in the key and sort key in the value.
* @private
*/
function getExistingCategories() {
$fname = 'LinksUpdate::getExistingCategories';
$res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey' ),
array( 'cl_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
$arr[$row->cl_to] = $row->cl_sortkey;
}
$this->mDb->freeResult( $res );
return $arr;
}
/**
* Get an array of existing interlanguage links, with the language code in the key and the
* title in the value.
* @private
*/
function getExistingInterlangs() {
$fname = 'LinksUpdate::getExistingInterlangs';
$res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
array( 'll_from' => $this->mId ), $fname, $this->mOptions );
$arr = array();
while ( $row = $this->mDb->fetchObject( $res ) ) {
$arr[$row->ll_lang] = $row->ll_title;
}
return $arr;
}
}
