Move remaining LoadBalancer classes to Rdbms

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

<?php
/**
 * Query the list of contributors to a page
 *
 * Created on Nov 14, 2013
 *
 * Copyright © 2013 Brad Jorsch
 *
 * 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 1.23
 */

/**
 * A query module to show contributors to a page
 *
 * @ingroup API
 * @since 1.23
 */
class ApiQueryContributors extends ApiQueryBase {
        /** We don't want to process too many pages at once (it hits cold
         * database pages too heavily), so only do the first MAX_PAGES input pages
         * in each API call (leaving the rest for continuation).
         */
        const MAX_PAGES = 100;

        public function __construct( ApiQuery $query, $moduleName ) {
                // "pc" is short for "page contributors", "co" was already taken by the
                // GeoData extension's prop=coordinates.
                parent::__construct( $query, $moduleName, 'pc' );
        }

        public function execute() {
                $db = $this->getDB();
                $params = $this->extractRequestParams();
                $this->requireMaxOneParameter( $params, 'group', 'excludegroup', 'rights', 'excluderights' );

                // Only operate on existing pages
                $pages = array_keys( $this->getPageSet()->getGoodTitles() );

                // Filter out already-processed pages
                if ( $params['continue'] !== null ) {
                        $cont = explode( '|', $params['continue'] );
                        $this->dieContinueUsageIf( count( $cont ) != 2 );
                        $cont_page = (int)$cont[0];
                        $pages = array_filter( $pages, function ( $v ) use ( $cont_page ) {
                                return $v >= $cont_page;
                        } );
                }
                if ( !count( $pages ) ) {
                        // Nothing to do
                        return;
                }

                // Apply MAX_PAGES, leaving any over the limit for a continue.
                sort( $pages );
                $continuePages = null;
                if ( count( $pages ) > self::MAX_PAGES ) {
                        $continuePages = $pages[self::MAX_PAGES] . '|0';
                        $pages = array_slice( $pages, 0, self::MAX_PAGES );
                }

                $result = $this->getResult();

                // First, count anons
                $this->addTables( 'revision' );
                $this->addFields( [
                        'page' => 'rev_page',
                        'anons' => 'COUNT(DISTINCT rev_user_text)',
                ] );
                $this->addWhereFld( 'rev_page', $pages );
                $this->addWhere( 'rev_user = 0' );
                $this->addWhere( $db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0' );
                $this->addOption( 'GROUP BY', 'rev_page' );
                $res = $this->select( __METHOD__ );
                foreach ( $res as $row ) {
                        $fit = $result->addValue( [ 'query', 'pages', $row->page ],
                                'anoncontributors', (int)$row->anons
                        );
                        if ( !$fit ) {
                                // This not fitting isn't reasonable, so it probably means that
                                // some other module used up all the space. Just set a dummy
                                // continue and hope it works next time.
                                $this->setContinueEnumParameter( 'continue',
                                        $params['continue'] !== null ? $params['continue'] : '0|0'
                                );

                                return;
                        }
                }

                // Next, add logged-in users
                $this->resetQueryParams();
                $this->addTables( 'revision' );
                $this->addFields( [
                        'page' => 'rev_page',
                        'user' => 'rev_user',
                        'username' => 'MAX(rev_user_text)', // Non-MySQL databases don't like partial group-by
                ] );
                $this->addWhereFld( 'rev_page', $pages );
                $this->addWhere( 'rev_user != 0' );
                $this->addWhere( $db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0' );
                $this->addOption( 'GROUP BY', 'rev_page, rev_user' );
                $this->addOption( 'LIMIT', $params['limit'] + 1 );

                // Force a sort order to ensure that properties are grouped by page
                // But only if pp_page is not constant in the WHERE clause.
                if ( count( $pages ) > 1 ) {
                        $this->addOption( 'ORDER BY', 'rev_page, rev_user' );
                } else {
                        $this->addOption( 'ORDER BY', 'rev_user' );
                }

                $limitGroups = [];
                if ( $params['group'] ) {
                        $excludeGroups = false;
                        $limitGroups = $params['group'];
                } elseif ( $params['excludegroup'] ) {
                        $excludeGroups = true;
                        $limitGroups = $params['excludegroup'];
                } elseif ( $params['rights'] ) {
                        $excludeGroups = false;
                        foreach ( $params['rights'] as $r ) {
                                $limitGroups = array_merge( $limitGroups, User::getGroupsWithPermission( $r ) );
                        }

                        // If no group has the rights requested, no need to query
                        if ( !$limitGroups ) {
                                if ( $continuePages !== null ) {
                                        // But we still need to continue for the next page's worth
                                        // of anoncontributors
                                        $this->setContinueEnumParameter( 'continue', $continuePages );
                                }

                                return;
                        }
                } elseif ( $params['excluderights'] ) {
                        $excludeGroups = true;
                        foreach ( $params['excluderights'] as $r ) {
                                $limitGroups = array_merge( $limitGroups, User::getGroupsWithPermission( $r ) );
                        }
                }

                if ( $limitGroups ) {
                        $limitGroups = array_unique( $limitGroups );
                        $this->addTables( 'user_groups' );
                        $this->addJoinConds( [ 'user_groups' => [
                                $excludeGroups ? 'LEFT OUTER JOIN' : 'INNER JOIN',
                                [
                                        'ug_user=rev_user',
                                        'ug_group' => $limitGroups,
                                        $this->getConfig()->get( 'DisableUserGroupExpiry' ) ?
                                                '1' :
                                                'ug_expiry IS NULL OR ug_expiry >= ' . $db->addQuotes( $db->timestamp() )
                                ]
                        ] ] );
                        $this->addWhereIf( 'ug_user IS NULL', $excludeGroups );
                }

                if ( $params['continue'] !== null ) {
                        $cont = explode( '|', $params['continue'] );
                        $this->dieContinueUsageIf( count( $cont ) != 2 );
                        $cont_page = (int)$cont[0];
                        $cont_user = (int)$cont[1];
                        $this->addWhere(
                                "rev_page > $cont_page OR " .
                                "(rev_page = $cont_page AND " .
                                "rev_user >= $cont_user)"
                        );
                }

                $res = $this->select( __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->setContinueEnumParameter( 'continue', $row->page . '|' . $row->user );

                                return;
                        }

                        $fit = $this->addPageSubItem( $row->page,
                                [ 'userid' => (int)$row->user, 'name' => $row->username ],
                                'user'
                        );
                        if ( !$fit ) {
                                $this->setContinueEnumParameter( 'continue', $row->page . '|' . $row->user );

                                return;
                        }
                }

                if ( $continuePages !== null ) {
                        $this->setContinueEnumParameter( 'continue', $continuePages );
                }
        }

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

        public function getAllowedParams() {
                $userGroups = User::getAllGroups();
                $userRights = User::getAllRights();

                return [
                        'group' => [
                                ApiBase::PARAM_TYPE => $userGroups,
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'excludegroup' => [
                                ApiBase::PARAM_TYPE => $userGroups,
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'rights' => [
                                ApiBase::PARAM_TYPE => $userRights,
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'excluderights' => [
                                ApiBase::PARAM_TYPE => $userRights,
                                ApiBase::PARAM_ISMULTI => true,
                        ],
                        'limit' => [
                                ApiBase::PARAM_DFLT => 10,
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
                        ],
                        'continue' => [
                                ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
                        ],
                ];
        }

        protected function getExamplesMessages() {
                return [
                        'action=query&prop=contributors&titles=Main_Page'
                                => 'apihelp-query+contributors-example-simple',
                ];
        }

        public function getHelpUrls() {
                return 'https://www.mediawiki.org/wiki/API:Contributors';
        }
}