includes/cache/LinkBatch.php
<?php
/**
* Batch query to determine page existence.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Cache
*/
namespace MediaWiki\Cache;
use InvalidArgumentException;
use Language;
use MediaWiki\Linker\LinksMigration;
use MediaWiki\Linker\LinkTarget;
use MediaWiki\Page\PageIdentityValue;
use MediaWiki\Page\PageReference;
use MediaWiki\Page\ProperPageIdentity;
use MediaWiki\Title\TitleFormatter;
use MediaWiki\Title\TitleValue;
use Psr\Log\LoggerInterface;
use RuntimeException;
use Wikimedia\Assert\Assert;
use Wikimedia\Rdbms\IConnectionProvider;
use Wikimedia\Rdbms\IResultWrapper;
use Wikimedia\Rdbms\Platform\ISQLPlatform;
/**
* Class representing a list of titles
* The execute() method checks them all for existence and adds them to a LinkCache object
*
* @ingroup Cache
*/
class LinkBatch {
/**
* @var array<int,array<string,mixed>> 2-d array, first index namespace, second index dbkey, value arbitrary
*/
public $data = [];
/**
* @var ProperPageIdentity[]|null page identity objects corresponding to the links in the batch
*/
private $pageIdentities = null;
/**
* @var string|null For debugging which method is using this class.
*/
protected $caller;
/**
* @var LinkCache
*/
private $linkCache;
/**
* @var TitleFormatter
*/
private $titleFormatter;
/**
* @var Language
*/
private $contentLanguage;
/**
* @var GenderCache
*/
private $genderCache;
/**
* @var IConnectionProvider
*/
private $dbProvider;
/** @var LinksMigration */
private $linksMigration;
/** @var LoggerInterface */
private $logger;
/**
* @see \MediaWiki\Cache\LinkBatchFactory
*
* @internal
* @param iterable<LinkTarget>|iterable<PageReference> $arr Initial items to be added to the batch
* @param LinkCache $linkCache
* @param TitleFormatter $titleFormatter
* @param Language $contentLanguage
* @param GenderCache $genderCache
* @param IConnectionProvider $dbProvider
* @param LinksMigration $linksMigration
* @param LoggerInterface $logger
*/
public function __construct(
iterable $arr,
LinkCache $linkCache,
TitleFormatter $titleFormatter,
Language $contentLanguage,
GenderCache $genderCache,
IConnectionProvider $dbProvider,
LinksMigration $linksMigration,
LoggerInterface $logger
) {
$this->linkCache = $linkCache;
$this->titleFormatter = $titleFormatter;
$this->contentLanguage = $contentLanguage;
$this->genderCache = $genderCache;
$this->dbProvider = $dbProvider;
$this->linksMigration = $linksMigration;
$this->logger = $logger;
foreach ( $arr as $item ) {
$this->addObj( $item );
}
}
/**
* Use ->setCaller( __METHOD__ ) to indicate which code is using this
* class. Only used in debugging output.
* @since 1.17
*
* @param string $caller
* @return self (since 1.32)
*/
public function setCaller( $caller ) {
$this->caller = $caller;
return $this;
}
/**
* @param LinkTarget|PageReference $link
*/
public function addObj( $link ) {
if ( !$link ) {
// Don't die if we got null, just skip. There is nothing to do anyway.
// For now, let's avoid things like T282180. We should be more strict in the future.
$this->logger->warning(
'Skipping null link, probably due to a bad title.',
[ 'exception' => new RuntimeException() ]
);
return;
}
if ( $link instanceof LinkTarget && $link->isExternal() ) {
$this->logger->warning(
'Skipping interwiki link',
[ 'exception' => new RuntimeException() ]
);
return;
}
Assert::parameterType( [ LinkTarget::class, PageReference::class ], $link, '$link' );
$this->add( $link->getNamespace(), $link->getDBkey() );
}
/**
* @param int $ns
* @param string $dbkey
*/
public function add( $ns, $dbkey ) {
if ( $ns < 0 || $dbkey === '' ) {
// T137083
return;
}
$this->data[$ns][strtr( $dbkey, ' ', '_' )] = 1;
}
/**
* Set the link list to a given 2-d array
* First key is the namespace, second is the DB key, value arbitrary
*
* @param array<int,array<string,mixed>> $array
*/
public function setArray( $array ) {
$this->data = $array;
}
/**
* Returns true if no pages have been added, false otherwise.
*
* @return bool
*/
public function isEmpty() {
return $this->getSize() == 0;
}
/**
* Returns the size of the batch.
*
* @return int
*/
public function getSize() {
return count( $this->data );
}
/**
* Do the query and add the results to the LinkCache object
*
* @return int[] Mapping PDBK to ID
*/
public function execute() {
return $this->executeInto( $this->linkCache );
}
/**
* Do the query, add the results to the LinkCache object,
* and return ProperPageIdentity instances corresponding to the pages in the batch.
*
* @since 1.37
* @return ProperPageIdentity[] A list of ProperPageIdentities
*/
public function getPageIdentities(): array {
if ( $this->pageIdentities === null ) {
$this->execute();
}
return $this->pageIdentities;
}
/**
* Do the query and add the results to a given LinkCache object
* Return an array mapping PDBK to ID
*
* @param LinkCache $cache
* @return int[] Remaining IDs
*/
protected function executeInto( $cache ) {
$res = $this->doQuery();
$this->doGenderQuery();
return $this->addResultToCache( $cache, $res );
}
/**
* Add a result wrapper containing IDs and titles to a LinkCache object.
* As normal, titles will go into the static Title cache field.
* This function *also* stores extra fields of the title used for link
* parsing to avoid extra DB queries.
*
* @param LinkCache $cache
* @param IResultWrapper $res
* @return int[] Array of remaining titles
*/
public function addResultToCache( $cache, $res ) {
if ( !$res ) {
return [];
}
// For each returned entry, add it to the list of good links, and remove it from $remaining
$this->pageIdentities ??= [];
$ids = [];
$remaining = $this->data;
foreach ( $res as $row ) {
try {
$title = new TitleValue( (int)$row->page_namespace, $row->page_title );
$cache->addGoodLinkObjFromRow( $title, $row );
$pdbk = $this->titleFormatter->getPrefixedDBkey( $title );
$ids[$pdbk] = $row->page_id;
$pageIdentity = new PageIdentityValue(
(int)$row->page_id,
(int)$row->page_namespace,
$row->page_title,
ProperPageIdentity::LOCAL
);
$key = CacheKeyHelper::getKeyForPage( $pageIdentity );
$this->pageIdentities[$key] = $pageIdentity;
} catch ( InvalidArgumentException $ex ) {
$this->logger->warning(
'Encountered invalid title',
[ 'title_namespace' => $row->page_namespace, 'title_dbkey' => $row->page_title ]
);
}
unset( $remaining[$row->page_namespace][$row->page_title] );
}
// The remaining links in $data are bad links, register them as such
foreach ( $remaining as $ns => $dbkeys ) {
foreach ( $dbkeys as $dbkey => $unused ) {
try {
$title = new TitleValue( (int)$ns, (string)$dbkey );
$cache->addBadLinkObj( $title );
$pdbk = $this->titleFormatter->getPrefixedDBkey( $title );
$ids[$pdbk] = 0;
$pageIdentity = new PageIdentityValue( 0, (int)$ns, $dbkey, ProperPageIdentity::LOCAL );
$key = CacheKeyHelper::getKeyForPage( $pageIdentity );
$this->pageIdentities[$key] = $pageIdentity;
} catch ( InvalidArgumentException $ex ) {
$this->logger->warning(
'Encountered invalid title',
[ 'title_namespace' => $ns, 'title_dbkey' => $dbkey ]
);
}
}
}
return $ids;
}
/**
* Perform the existence test query, return a result wrapper with page_id fields
* @return IResultWrapper|false
*/
public function doQuery() {
if ( $this->isEmpty() ) {
return false;
}
// This is similar to LinkHolderArray::replaceInternal
$dbr = $this->dbProvider->getReplicaDatabase();
$queryBuilder = $dbr->newSelectQueryBuilder()
->select( LinkCache::getSelectFields() )
->from( 'page' )
->where( $this->constructSet( 'page', $dbr ) );
$caller = __METHOD__;
if ( strval( $this->caller ) !== '' ) {
$caller .= " (for {$this->caller})";
}
return $queryBuilder->caller( $caller )->fetchResultSet();
}
/**
* Do (and cache) {{GENDER:...}} information for userpages in this LinkBatch
*
* @return bool Whether the query was successful
*/
public function doGenderQuery() {
if ( $this->isEmpty() || !$this->contentLanguage->needsGenderDistinction() ) {
return false;
}
$this->genderCache->doLinkBatch( $this->data, $this->caller );
return true;
}
/**
* Construct a WHERE clause which will match all the given titles.
*
* It is the caller's responsibility to only call this if the LinkBatch is
* not empty, because there is no safe way to represent a SQL conditional
* for the empty set.
*
* @param string $prefix The appropriate table's field name prefix ('page', 'pl', etc)
* @param ISQLPlatform $db DB object to use
* @return string String with SQL where clause fragment
*/
public function constructSet( $prefix, $db ) {
if ( isset( $this->linksMigration::$prefixToTableMapping[$prefix] ) ) {
[ $blNamespace, $blTitle ] = $this->linksMigration->getTitleFields(
$this->linksMigration::$prefixToTableMapping[$prefix]
);
} else {
$blNamespace = "{$prefix}_namespace";
$blTitle = "{$prefix}_title";
}
return $db->makeWhereFrom2d( $this->data, $blNamespace, $blTitle );
}
}
/** @deprecated class alias since 1.42 */
class_alias( LinkBatch::class, 'LinkBatch' );