wikimedia/mediawiki-core

<?php
/**
 * Backend functions for suppressing and unsuppressing all references to a given user.
 *
 * 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 RevisionDelete
 */

use MediaWiki\MediaWikiServices;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Title\Title;
use Wikimedia\Rdbms\IDatabase;
use Wikimedia\Rdbms\RawSQLValue;

/**
 * Backend functions for suppressing and unsuppressing all references to a given user,
 * used when blocking with HideUser enabled.  This was spun out of SpecialBlockip.php
 * in 1.18; at some point it needs to be rewritten to either use RevisionDelete abstraction,
 * or at least schema abstraction.
 *
 * @ingroup RevisionDelete
 */
class RevisionDeleteUser {

    /**
     * Update *_deleted bitfields in various tables to hide or unhide usernames
     *
     * @param string $name Username
     * @param int $userId
     * @param string $op Operator '|' or '&'
     * @param null|IDatabase $dbw If you happen to have one lying around
     * @return bool True on success, false on failure (e.g. invalid user ID)
     */
    private static function setUsernameBitfields( $name, $userId, $op, IDatabase $dbw = null ) {
        if ( !$userId || ( $op !== '|' && $op !== '&' ) ) {
            return false;
        }
        if ( !$dbw instanceof IDatabase ) {
            $dbw = MediaWikiServices::getInstance()->getConnectionProvider()->getPrimaryDatabase();
        }

        # To suppress, we OR the current bitfields with RevisionRecord::DELETED_USER
        # to put a 1 in the username *_deleted bit. To unsuppress we AND the
        # current bitfields with the inverse of RevisionRecord::DELETED_USER. The
        # username bit is made to 0 (x & 0 = 0), while others are unchanged (x & 1 = x).
        # The same goes for the sysop-restricted *_deleted bit.
        $delUser = RevisionRecord::DELETED_USER | RevisionRecord::DELETED_RESTRICTED;
        $delAction = LogPage::DELETED_ACTION | RevisionRecord::DELETED_RESTRICTED;
        if ( $op === '&' ) {
            $delUser = $dbw->bitNot( $delUser );
            $delAction = $dbw->bitNot( $delAction );
        }

        # Normalize user name
        $userTitle = Title::makeTitleSafe( NS_USER, $name );
        $userDbKey = $userTitle->getDBkey();

        $actorId = $dbw->newSelectQueryBuilder()
            ->select( 'actor_id' )
            ->from( 'actor' )
            ->where( [ 'actor_name' => $name ] )
            ->caller( __METHOD__ )->fetchField();
        if ( $actorId ) {
            # Hide name from live edits
            $dbw->newUpdateQueryBuilder()
                ->update( 'revision' )
                ->set( self::buildSetBitDeletedField( 'rev_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'rev_actor' => $actorId ] )
                ->caller( __METHOD__ )->execute();

            # Hide name from deleted edits
            $dbw->newUpdateQueryBuilder()
                ->update( 'archive' )
                ->set( self::buildSetBitDeletedField( 'ar_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'ar_actor' => $actorId ] )
                ->caller( __METHOD__ )->execute();

            # Hide name from logs
            $dbw->newUpdateQueryBuilder()
                ->update( 'logging' )
                ->set( self::buildSetBitDeletedField( 'log_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'log_actor' => $actorId, $dbw->expr( 'log_type', '!=', 'suppress' ) ] )
                ->caller( __METHOD__ )->execute();

            # Hide name from RC
            $dbw->newUpdateQueryBuilder()
                ->update( 'recentchanges' )
                ->set( self::buildSetBitDeletedField( 'rc_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'rc_actor' => $actorId ] )
                ->caller( __METHOD__ )->execute();

            # Hide name from live images
            $dbw->newUpdateQueryBuilder()
                ->update( 'oldimage' )
                ->set( self::buildSetBitDeletedField( 'oi_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'oi_actor' => $actorId ] )
                ->caller( __METHOD__ )->execute();

            # Hide name from deleted images
            $dbw->newUpdateQueryBuilder()
                ->update( 'filearchive' )
                ->set( self::buildSetBitDeletedField( 'fa_deleted', $op, $delUser, $dbw ) )
                ->where( [ 'fa_actor' => $actorId ] )
                ->caller( __METHOD__ )->execute();
        }

        # Hide log entries pointing to the user page
        $dbw->newUpdateQueryBuilder()
            ->update( 'logging' )
            ->set( self::buildSetBitDeletedField( 'log_deleted', $op, $delAction, $dbw ) )
            ->where( [
                'log_namespace' => NS_USER,
                'log_title' => $userDbKey,
                $dbw->expr( 'log_type', '!=', 'suppress' )
            ] )
            ->caller( __METHOD__ )->execute();

        # Hide RC entries pointing to the user page
        $dbw->newUpdateQueryBuilder()
            ->update( 'recentchanges' )
            ->set( self::buildSetBitDeletedField( 'rc_deleted', $op, $delAction, $dbw ) )
            ->where( [ 'rc_namespace' => NS_USER, 'rc_title' => $userDbKey, $dbw->expr( 'rc_logid', '>', 0 ) ] )
            ->caller( __METHOD__ )->execute();

        return true;
    }

    private static function buildSetBitDeletedField( $field, $op, $value, IDatabase $dbw ) {
        return [ $field => new RawSQLValue( $op === '&'
            ? $dbw->bitAnd( $field, $value )
            : $dbw->bitOr( $field, $value )
        ) ];
    }

    /**
     * @param string $name User name
     * @param int $userId Both user name and ID must be provided
     * @param IDatabase|null $dbw If you happen to have one lying around
     * @return bool True on success, false on failure (e.g. invalid user ID)
     */
    public static function suppressUserName( $name, $userId, IDatabase $dbw = null ) {
        return self::setUsernameBitfields( $name, $userId, '|', $dbw );
    }

    /**
     * @param string $name User name
     * @param int $userId Both user name and ID must be provided
     * @param IDatabase|null $dbw If you happen to have one lying around
     * @return bool True on success, false on failure (e.g. invalid user ID)
     */
    public static function unsuppressUserName( $name, $userId, IDatabase $dbw = null ) {
        return self::setUsernameBitfields( $name, $userId, '&', $dbw );
    }
}