HideUserUtils.php

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<?php
 
namespace MediaWiki\Block;
 
use Wikimedia\Rdbms\IReadableDatabase;
use Wikimedia\Rdbms\SelectQueryBuilder;
 
class HideUserUtils {
    public const SHOWN_USERS = 1;
 
    public const HIDDEN_USERS = 2;
 
    private $readStage;
 
    public function __construct( $blockTargetMigrationStage ) {
        $this->readStage = $blockTargetMigrationStage & SCHEMA_COMPAT_READ_MASK;
    }
 
    public function getExpression(
        IReadableDatabase $dbr,
        string $userIdField = 'user_id',
        $status = self::SHOWN_USERS
    ) {
        if ( $this->readStage === SCHEMA_COMPAT_READ_OLD ) {
            $cond = $status === self::HIDDEN_USERS ? '' : 'NOT ';
            $cond .= 'EXISTS (' .
                $dbr->newSelectQueryBuilder()
                    ->select( '1' )
                    ->from( 'ipblocks', 'hu_ipblocks' )
                    ->where( [ "hu_ipblocks.ipb_user=$userIdField", 'hu_ipblocks.ipb_deleted' => 1 ] )
                    ->caller( __METHOD__ )
                    ->getSQL() .
                ')';
        } else {
            // Use a scalar subquery, not IN/EXISTS, to avoid materialization (T360160)
            $cond = '(' .
                $dbr->newSelectQueryBuilder()
                    ->select( '1' )
                    // $userIdField may be e.g. block_target.bt_user so an inner table
                    // alias is necessary to ensure that that refers to the outer copy
                    // of the block_target table.
                    ->from( 'block_target', 'hu_block_target' )
                    ->join( 'block', 'hu_block', 'hu_block.bl_target=hu_block_target.bt_id' )
                    ->where( [ "hu_block_target.bt_user=$userIdField", 'hu_block.bl_deleted' => 1 ] )
                    ->caller( __METHOD__ )
                    ->getSQL() .
                ') ' .
                ( $status === self::HIDDEN_USERS ? 'IS NOT NULL' : 'IS NULL' );
        }
        return $cond;
    }
 
    public function addFieldToBuilder(
        SelectQueryBuilder $qb,
        $userIdField = 'user_id',
        $deletedFieldAlias = 'hu_deleted'
    ) {
        if ( $this->readStage === SCHEMA_COMPAT_READ_OLD ) {
            $qb
                ->select( [ $deletedFieldAlias => 'ipb_deleted IS NOT NULL' ] )
                ->leftJoin(
                    'ipblocks', 'hide_user_ipblocks',
                    [ "ipb_user=$userIdField", 'ipb_deleted' => 1 ]
                );
        } else {
            $group = $qb->newJoinGroup()
                ->table( 'block_target' )
                ->join( 'block', 'hide_user_block', 'bl_target=bt_id' );
            $qb
                ->select( [ $deletedFieldAlias => 'bl_deleted IS NOT NULL' ] )
                ->leftJoin(
                    $group,
                    'hide_user_block_group',
                    [ "bt_user=$userIdField", 'bl_deleted' => 1 ]
                )
                ->groupBy( $userIdField );
        }
    }
}