Introduced Maintenance::getDB() and corresponding setDB() to control externally what...

[mediawiki.git] / includes / api / ApiQueryAllLinks.php

<?php
/**
 *
 *
 * Created on July 7, 2007
 *
 * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
 *
 * 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
 */

if ( !defined( 'MEDIAWIKI' ) ) {
        // Eclipse helper - will be ignored in production
        require_once( 'ApiQueryBase.php' );
}

/**
 * Query module to enumerate links from all pages together.
 *
 * @ingroup API
 */
class ApiQueryAllLinks extends ApiQueryGeneratorBase {

        public function __construct( $query, $moduleName ) {
                parent::__construct( $query, $moduleName, 'al' );
        }

        public function execute() {
                $this->run();
        }

        public function getCacheMode( $params ) {
                return 'public';
        }

        public function executeGenerator( $resultPageSet ) {
                $this->run( $resultPageSet );
        }

        /**
         * @param $resultPageSet ApiPageSet
         * @return void
         */
        private function run( $resultPageSet = null ) {
                $db = $this->getDB();
                $params = $this->extractRequestParams();

                $prop = array_flip( $params['prop'] );
                $fld_ids = isset( $prop['ids'] );
                $fld_title = isset( $prop['title'] );

                if ( $params['unique'] ) {
                        if ( !is_null( $resultPageSet ) ) {
                                $this->dieUsage( $this->getModuleName() . ' cannot be used as a generator in unique links mode', 'params' );
                        }
                        if ( $fld_ids ) {
                                $this->dieUsage( $this->getModuleName() . ' cannot return corresponding page ids in unique links mode', 'params' );
                        }
                        $this->addOption( 'DISTINCT' );
                }

                $this->addTables( 'pagelinks' );
                $this->addWhereFld( 'pl_namespace', $params['namespace'] );

                if ( !is_null( $params['from'] ) && !is_null( $params['continue'] ) ) {
                        $this->dieUsage( 'alcontinue and alfrom cannot be used together', 'params' );
                }
                if ( !is_null( $params['continue'] ) ) {
                        $arr = explode( '|', $params['continue'] );
                        if ( count( $arr ) != 2 ) {
                                $this->dieUsage( 'Invalid continue parameter', 'badcontinue' );
                        }
                        $from = $this->getDB()->strencode( $this->titleToKey( $arr[0] ) );
                        $id = intval( $arr[1] );
                        $this->addWhere(
                                "pl_title > '$from' OR " .
                                "(pl_title = '$from' AND " .
                                "pl_from > $id)"
                        );
                }

                $from = ( is_null( $params['from'] ) ? null : $this->titlePartToKey( $params['from'] ) );
                $to = ( is_null( $params['to'] ) ? null : $this->titlePartToKey( $params['to'] ) );
                $this->addWhereRange( 'pl_title', 'newer', $from, $to );

                if ( isset( $params['prefix'] ) ) {
                        $this->addWhere( 'pl_title' . $db->buildLike( $this->titlePartToKey( $params['prefix'] ), $db->anyString() ) );
                }

                $this->addFields( 'pl_title' );
                $this->addFieldsIf( 'pl_from', !$params['unique'] );

                $this->addOption( 'USE INDEX', 'pl_namespace' );
                $limit = $params['limit'];
                $this->addOption( 'LIMIT', $limit + 1 );

                if ( !$params['unique'] ) {
                        $this->addOption( 'ORDER BY', 'pl_title, pl_from' );
                }

                $res = $this->select( __METHOD__ );

                $pageids = array();
                $count = 0;
                $result = $this->getResult();
                foreach ( $res as $row ) {
                        if ( ++ $count > $limit ) {
                                // We've reached the one extra which shows that there are additional pages to be had. Stop here...
                                // TODO: Security issue - if the user has no right to view next title, it will still be shown
                                if ( $params['unique'] ) {
                                        $this->setContinueEnumParameter( 'from', $this->keyToTitle( $row->pl_title ) );
                                } else {
                                        $this->setContinueEnumParameter( 'continue', $this->keyToTitle( $row->pl_title ) . "|" . $row->pl_from );
                                }
                                break;
                        }

                        if ( is_null( $resultPageSet ) ) {
                                $vals = array();
                                if ( $fld_ids ) {
                                        $vals['fromid'] = intval( $row->pl_from );
                                }
                                if ( $fld_title ) {
                                        $title = Title::makeTitle( $params['namespace'], $row->pl_title );
                                        ApiQueryBase::addTitleInfo( $vals, $title );
                                }
                                $fit = $result->addValue( array( 'query', $this->getModuleName() ), null, $vals );
                                if ( !$fit ) {
                                        if ( $params['unique'] ) {
                                                $this->setContinueEnumParameter( 'from', $this->keyToTitle( $row->pl_title ) );
                                        } else {
                                                $this->setContinueEnumParameter( 'continue', $this->keyToTitle( $row->pl_title ) . "|" . $row->pl_from );
                                        }
                                        break;
                                }
                        } else {
                                $pageids[] = $row->pl_from;
                        }
                }

                if ( is_null( $resultPageSet ) ) {
                        $result->setIndexedTagName_internal( array( 'query', $this->getModuleName() ), 'l' );
                } else {
                        $resultPageSet->populateFromPageIDs( $pageids );
                }
        }

        public function getAllowedParams() {
                return array(
                        'continue' => null,
                        'from' => null,
                        'to' => null,
                        'prefix' => null,
                        'unique' => false,
                        'prop' => array(
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_DFLT => 'title',
                                ApiBase::PARAM_TYPE => array(
                                        'ids',
                                        'title'
                                )
                        ),
                        'namespace' => array(
                                ApiBase::PARAM_DFLT => 0,
                                ApiBase::PARAM_TYPE => 'namespace'
                        ),
                        'limit' => array(
                                ApiBase::PARAM_DFLT => 10,
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
                        )
                );
        }

        public function getParamDescription() {
                $p = $this->getModulePrefix();
                return array(
                        'from' => 'The page title to start enumerating from',
                        'to' => 'The page title to stop enumerating at',
                        'prefix' => 'Search for all page titles that begin with this value',
                        'unique' => "Only show unique links. Cannot be used with generator or {$p}prop=ids",
                        'prop' => array(
                                'What pieces of information to include',
                                " ids    - Adds pageid of where the link is from (Cannot be used with {$p}unique)",
                                ' title  - Adds the title of the link',
                        ),
                        'namespace' => 'The namespace to enumerate',
                        'limit' => 'How many total links to return',
                        'continue' => 'When more results are available, use this to continue',
                );
        }

        public function getDescription() {
                return 'Enumerate all links that point to a given namespace';
        }

        public function getPossibleErrors() {
                $m = $this->getModuleName();
                return array_merge( parent::getPossibleErrors(), array(
                        array( 'code' => 'params', 'info' => "{$m} cannot be used as a generator in unique links mode" ),
                        array( 'code' => 'params', 'info' => "{$m} cannot return corresponding page ids in unique links mode" ),
                        array( 'code' => 'params', 'info' => 'alcontinue and alfrom cannot be used together' ),
                        array( 'code' => 'badcontinue', 'info' => 'Invalid continue parameter' ),
                ) );
        }

        protected function getExamples() {
                return array(
                        'api.php?action=query&list=alllinks&alunique=&alfrom=B',
                );
        }

        public function getVersion() {
                return __CLASS__ . ': $Id$';
        }
}