includes/api/ApiQueryBacklinksprop.php
<?php
/**
* API module to handle links table back-queries
*
* Copyright © 2014 Wikimedia Foundation and contributors
*
* 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
* @since 1.24
*/
use MediaWiki\Linker\LinksMigration;
use MediaWiki\MainConfigNames;
use MediaWiki\Title\Title;
use Wikimedia\ParamValidator\ParamValidator;
use Wikimedia\ParamValidator\TypeDef\IntegerDef;
use Wikimedia\Rdbms\OrExpressionGroup;
/**
* This implements prop=redirects, prop=linkshere, prop=catmembers,
* prop=transcludedin, and prop=fileusage
*
* @ingroup API
* @since 1.24
*/
class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
/** @var array Data for the various modules implemented by this class */
private static $settings = [
'redirects' => [
'code' => 'rd',
'prefix' => 'rd',
'linktable' => 'redirect',
'props' => [
'fragment',
],
'showredirects' => false,
'show' => [
'fragment',
'!fragment',
],
],
'linkshere' => [
'code' => 'lh',
'prefix' => 'pl',
'linktable' => 'pagelinks',
'indexes' => [ 'pl_namespace', 'pl_backlinks_namespace' ],
'from_namespace' => true,
'showredirects' => true,
],
'transcludedin' => [
'code' => 'ti',
'prefix' => 'tl',
'linktable' => 'templatelinks',
'from_namespace' => true,
'showredirects' => true,
],
'fileusage' => [
'code' => 'fu',
'prefix' => 'il',
'linktable' => 'imagelinks',
'indexes' => [ 'il_to', 'il_backlinks_namespace' ],
'from_namespace' => true,
'to_namespace' => NS_FILE,
'exampletitle' => 'File:Example.jpg',
'showredirects' => true,
],
];
private LinksMigration $linksMigration;
/**
* @param ApiQuery $query
* @param string $moduleName
* @param LinksMigration $linksMigration
*/
public function __construct(
ApiQuery $query,
$moduleName,
LinksMigration $linksMigration
) {
parent::__construct( $query, $moduleName, self::$settings[$moduleName]['code'] );
$this->linksMigration = $linksMigration;
}
public function execute() {
$this->run();
}
public function executeGenerator( $resultPageSet ) {
$this->run( $resultPageSet );
}
/**
* @param ApiPageSet|null $resultPageSet
*/
private function run( ApiPageSet $resultPageSet = null ) {
$settings = self::$settings[$this->getModuleName()];
$db = $this->getDB();
$params = $this->extractRequestParams();
$prop = array_fill_keys( $params['prop'], true );
$pageSet = $this->getPageSet();
$titles = $pageSet->getGoodAndMissingPages();
$map = $pageSet->getGoodAndMissingTitlesByNamespace();
// Add in special pages, they can theoretically have backlinks too.
// (although currently they only do for prop=redirects)
foreach ( $pageSet->getSpecialPages() as $id => $title ) {
$titles[] = $title;
$map[$title->getNamespace()][$title->getDBkey()] = $id;
}
// Determine our fields to query on
$p = $settings['prefix'];
$hasNS = !isset( $settings['to_namespace'] );
if ( $hasNS ) {
if ( isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
[ $bl_namespace, $bl_title ] = $this->linksMigration->getTitleFields( $settings['linktable'] );
} else {
$bl_namespace = "{$p}_namespace";
$bl_title = "{$p}_title";
}
} else {
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
$bl_namespace = $settings['to_namespace'];
$bl_title = "{$p}_to";
$titles = array_filter( $titles, static function ( $t ) use ( $bl_namespace ) {
return $t->getNamespace() === $bl_namespace;
} );
$map = array_intersect_key( $map, [ $bl_namespace => true ] );
}
$bl_from = "{$p}_from";
if ( !$titles ) {
return; // nothing to do
}
if ( $params['namespace'] !== null && count( $params['namespace'] ) === 0 ) {
return; // nothing to do
}
// Figure out what we're sorting by, and add associated WHERE clauses.
// MySQL's query planner screws up if we include a field in ORDER BY
// when it's constant in WHERE, so we have to test that for each field.
$sortby = [];
if ( $hasNS && count( $map ) > 1 ) {
$sortby[$bl_namespace] = 'int';
}
$theTitle = null;
foreach ( $map as $nsTitles ) {
$key = array_key_first( $nsTitles );
$theTitle ??= $key;
if ( count( $nsTitles ) > 1 || $key !== $theTitle ) {
$sortby[$bl_title] = 'string';
break;
}
}
$miser_ns = null;
if ( $params['namespace'] !== null ) {
if ( empty( $settings['from_namespace'] ) ) {
if ( $this->getConfig()->get( MainConfigNames::MiserMode ) ) {
$miser_ns = $params['namespace'];
} else {
$this->addWhereFld( 'page_namespace', $params['namespace'] );
}
} else {
$this->addWhereFld( "{$p}_from_namespace", $params['namespace'] );
if ( !empty( $settings['from_namespace'] )
&& $params['namespace'] !== null && count( $params['namespace'] ) > 1
) {
$sortby["{$p}_from_namespace"] = 'int';
}
}
}
$sortby[$bl_from] = 'int';
// Now use the $sortby to figure out the continuation
$continueFields = array_keys( $sortby );
$continueTypes = array_values( $sortby );
if ( $params['continue'] !== null ) {
$continueValues = $this->parseContinueParamOrDie( $params['continue'], $continueTypes );
$conds = array_combine( $continueFields, $continueValues );
$this->addWhere( $db->buildComparison( '>=', $conds ) );
}
// Populate the rest of the query
[ $idxNoFromNS, $idxWithFromNS ] = $settings['indexes'] ?? [ '', '' ];
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
if ( isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
$queryInfo = $this->linksMigration->getQueryInfo( $settings['linktable'] );
$this->addTables( array_merge( [ 'page' ], $queryInfo['tables'] ) );
$this->addJoinConds( $queryInfo['joins'] );
// TODO: Move to links migration
if ( in_array( 'linktarget', $queryInfo['tables'] ) ) {
$idxWithFromNS .= '_target_id';
}
} else {
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
$this->addTables( [ $settings['linktable'], 'page' ] );
}
$this->addWhere( "$bl_from = page_id" );
if ( $this->getModuleName() === 'redirects' ) {
$this->addWhereFld( 'rd_interwiki', '' );
}
$this->addFields( array_keys( $sortby ) );
$this->addFields( [ 'bl_namespace' => $bl_namespace, 'bl_title' => $bl_title ] );
if ( $resultPageSet === null ) {
$fld_pageid = isset( $prop['pageid'] );
$fld_title = isset( $prop['title'] );
$fld_redirect = isset( $prop['redirect'] );
$this->addFieldsIf( 'page_id', $fld_pageid );
$this->addFieldsIf( [ 'page_title', 'page_namespace' ], $fld_title );
$this->addFieldsIf( 'page_is_redirect', $fld_redirect );
// prop=redirects
$fld_fragment = isset( $prop['fragment'] );
$this->addFieldsIf( 'rd_fragment', $fld_fragment );
} else {
$this->addFields( $resultPageSet->getPageTableFields() );
}
$this->addFieldsIf( 'page_namespace', $miser_ns !== null );
if ( $hasNS && $map ) {
// Can't use LinkBatch because it throws away Special titles.
// And we already have the needed data structure anyway.
$this->addWhere( $db->makeWhereFrom2d( $map, $bl_namespace, $bl_title ) );
} else {
$where = [];
foreach ( $titles as $t ) {
if ( $t->getNamespace() == $bl_namespace ) {
$where[] = $db->expr( $bl_title, '=', $t->getDBkey() );
}
}
$this->addWhere( new OrExpressionGroup( ...$where ) );
}
if ( $params['show'] !== null ) {
// prop=redirects only
$show = array_fill_keys( $params['show'], true );
if ( ( isset( $show['fragment'] ) && isset( $show['!fragment'] ) ) ||
( isset( $show['redirect'] ) && isset( $show['!redirect'] ) )
) {
$this->dieWithError( 'apierror-show' );
}
$this->addWhereIf( $db->expr( 'rd_fragment', '!=', '' ), isset( $show['fragment'] ) );
$this->addWhereIf( [ 'rd_fragment' => '' ], isset( $show['!fragment'] ) );
$this->addWhereIf( [ 'page_is_redirect' => 1 ], isset( $show['redirect'] ) );
$this->addWhereIf( [ 'page_is_redirect' => 0 ], isset( $show['!redirect'] ) );
}
// Override any ORDER BY from above with what we calculated earlier.
$this->addOption( 'ORDER BY', array_keys( $sortby ) );
// MySQL's optimizer chokes if we have too many values in "$bl_title IN
// (...)" and chooses the wrong index, so specify the correct index to
// use for the query. See T139056 for details.
if ( !empty( $settings['indexes'] ) ) {
if (
$params['namespace'] !== null &&
count( $params['namespace'] ) == 1 &&
!empty( $settings['from_namespace'] )
) {
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
$this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxWithFromNS ] );
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
} elseif ( !isset( $this->linksMigration::$mapping[$settings['linktable']] ) ) {
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
$this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxNoFromNS ] );
}
}
$this->addOption( 'LIMIT', $params['limit'] + 1 );
$res = $this->select( __METHOD__ );
if ( $resultPageSet === null ) {
// @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
if ( $fld_title ) {
$this->executeGenderCacheFromResultWrapper( $res, __METHOD__ );
}
$count = 0;
foreach ( $res as $row ) {
if ( ++$count > $params['limit'] ) {
// We've reached the one extra which shows that
// there are additional pages to be had. Stop here...
$this->setContinue( $row, $sortby );
break;
}
if ( $miser_ns !== null && !in_array( $row->page_namespace, $miser_ns ) ) {
// Miser mode namespace check
continue;
}
// Get the ID of the current page
$id = $map[$row->bl_namespace][$row->bl_title];
$vals = [];
// @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
if ( $fld_pageid ) {
$vals['pageid'] = (int)$row->page_id;
}
if ( $fld_title ) {
ApiQueryBase::addTitleInfo( $vals,
Title::makeTitle( $row->page_namespace, $row->page_title )
);
}
// @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
if ( $fld_fragment && $row->rd_fragment !== '' ) {
$vals['fragment'] = $row->rd_fragment;
}
// @phan-suppress-next-line PhanPossiblyUndeclaredVariable set when used
if ( $fld_redirect ) {
$vals['redirect'] = (bool)$row->page_is_redirect;
}
$fit = $this->addPageSubItem( $id, $vals );
if ( !$fit ) {
$this->setContinue( $row, $sortby );
break;
}
}
} else {
$titles = [];
$count = 0;
foreach ( $res as $row ) {
if ( ++$count > $params['limit'] ) {
// We've reached the one extra which shows that
// there are additional pages to be had. Stop here...
$this->setContinue( $row, $sortby );
break;
}
if ( $miser_ns !== null && !in_array( $row->page_namespace, $miser_ns ) ) {
// Miser mode namespace check
continue;
}
$titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
}
$resultPageSet->populateFromTitles( $titles );
}
}
private function setContinue( $row, $sortby ) {
$cont = [];
foreach ( $sortby as $field => $v ) {
$cont[] = $row->$field;
}
$this->setContinueEnumParameter( 'continue', implode( '|', $cont ) );
}
public function getCacheMode( $params ) {
return 'public';
}
public function getAllowedParams() {
$settings = self::$settings[$this->getModuleName()];
$ret = [
'prop' => [
ParamValidator::PARAM_TYPE => [
'pageid',
'title',
],
ParamValidator::PARAM_ISMULTI => true,
ParamValidator::PARAM_DEFAULT => 'pageid|title',
ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
],
'namespace' => [
ParamValidator::PARAM_ISMULTI => true,
ParamValidator::PARAM_TYPE => 'namespace',
],
'show' => null, // Will be filled/removed below
'limit' => [
ParamValidator::PARAM_DEFAULT => 10,
ParamValidator::PARAM_TYPE => 'limit',
IntegerDef::PARAM_MIN => 1,
IntegerDef::PARAM_MAX => ApiBase::LIMIT_BIG1,
IntegerDef::PARAM_MAX2 => ApiBase::LIMIT_BIG2
],
'continue' => [
ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
],
];
if ( empty( $settings['from_namespace'] ) &&
$this->getConfig()->get( MainConfigNames::MiserMode ) ) {
$ret['namespace'][ApiBase::PARAM_HELP_MSG_APPEND] = [
'api-help-param-limited-in-miser-mode',
];
}
if ( !empty( $settings['showredirects'] ) ) {
$ret['prop'][ParamValidator::PARAM_TYPE][] = 'redirect';
$ret['prop'][ParamValidator::PARAM_DEFAULT] .= '|redirect';
}
if ( isset( $settings['props'] ) ) {
$ret['prop'][ParamValidator::PARAM_TYPE] = array_merge(
$ret['prop'][ParamValidator::PARAM_TYPE], $settings['props']
);
}
$show = [];
if ( !empty( $settings['showredirects'] ) ) {
$show[] = 'redirect';
$show[] = '!redirect';
}
if ( isset( $settings['show'] ) ) {
$show = array_merge( $show, $settings['show'] );
}
if ( $show ) {
$ret['show'] = [
ParamValidator::PARAM_TYPE => $show,
ParamValidator::PARAM_ISMULTI => true,
ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
];
} else {
unset( $ret['show'] );
}
return $ret;
}
protected function getExamplesMessages() {
$settings = self::$settings[$this->getModuleName()];
$name = $this->getModuleName();
$path = $this->getModulePath();
$title = $settings['exampletitle'] ?? Title::newMainPage()->getPrefixedText();
$etitle = rawurlencode( $title );
return [
"action=query&prop={$name}&titles={$etitle}"
=> "apihelp-$path-example-simple",
"action=query&generator={$name}&titles={$etitle}&prop=info"
=> "apihelp-$path-example-generator",
];
}
public function getHelpUrls() {
$name = ucfirst( $this->getModuleName() );
return "https://www.mediawiki.org/wiki/Special:MyLanguage/API:{$name}";
}
}