PostgreSqlLockManager.php

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<?php
 
use Wikimedia\Rdbms\DBError;
 
class PostgreSqlLockManager extends DBLockManager {
    protected $lockTypeMap = [
        self::LOCK_SH => self::LOCK_SH,
        self::LOCK_UW => self::LOCK_SH,
        self::LOCK_EX => self::LOCK_EX
    ];
 
    protected function doGetLocksOnServer( $lockSrv, array $paths, $type ) {
        $status = StatusValue::newGood();
        if ( $paths === [] ) {
            return $status; // nothing to lock
        }
 
        $db = $this->getConnection( $lockSrv ); // checked in isServerUp()
        $bigints = array_unique( array_map(
            static function ( $key ) {
                return Wikimedia\base_convert( substr( $key, 0, 15 ), 16, 10 );
            },
            array_map( [ $this, 'sha1Base16Absolute' ], $paths )
        ) );
 
        // Try to acquire all the locks...
        $fields = [];
        foreach ( $bigints as $bigint ) {
            $fields[] = ( $type == self::LOCK_SH )
                ? "pg_try_advisory_lock_shared({$db->addQuotes( $bigint )}) AS K$bigint"
                : "pg_try_advisory_lock({$db->addQuotes( $bigint )}) AS K$bigint";
        }
        $res = $db->query( 'SELECT ' . implode( ', ', $fields ), __METHOD__ );
        $row = $res->fetchRow();
 
        if ( in_array( 'f', $row ) ) {
            // Release any acquired locks if some could not be acquired...
            $fields = [];
            foreach ( $row as $kbigint => $ok ) {
                if ( $ok === 't' ) { // locked
                    $bigint = substr( $kbigint, 1 ); // strip off the "K"
                    $fields[] = ( $type == self::LOCK_SH )
                        ? "pg_advisory_unlock_shared({$db->addQuotes( $bigint )})"
                        : "pg_advisory_unlock({$db->addQuotes( $bigint )})";
                }
            }
            if ( count( $fields ) ) {
                $db->query( 'SELECT ' . implode( ', ', $fields ), __METHOD__ );
            }
            foreach ( $paths as $path ) {
                $status->fatal( 'lockmanager-fail-acquirelock', $path );
            }
        }
 
        return $status;
    }
 
    protected function releaseAllLocks() {
        $status = StatusValue::newGood();
 
        foreach ( $this->conns as $lockDb => $db ) {
            try {
                $db->query( "SELECT pg_advisory_unlock_all()", __METHOD__ );
            } catch ( DBError $e ) {
                $status->fatal( 'lockmanager-fail-db-release', $lockDb );
            }
        }
 
        return $status;
    }
}