LSLockManager.php

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<?php
class LSLockManager extends QuorumLockManager {
    protected $lockTypeMap = array(
        self::LOCK_SH => self::LOCK_SH,
        self::LOCK_UW => self::LOCK_SH,
        self::LOCK_EX => self::LOCK_EX
    );

    protected $lockServers; // (server name => server config array)

    protected $conns = array();

    protected $connTimeout; // float number of seconds
    protected $session = ''; // random SHA-1 string

    public function __construct( array $config ) {
        parent::__construct( $config );

        $this->lockServers = $config['lockServers'];
        // Sanitize srvsByBucket config to prevent PHP errors
        $this->srvsByBucket = array_filter( $config['srvsByBucket'], 'is_array' );
        $this->srvsByBucket = array_values( $this->srvsByBucket ); // consecutive

        if ( isset( $config['connTimeout'] ) ) {
            $this->connTimeout = $config['connTimeout'];
        } else {
            $this->connTimeout = 3; // use some sane amount
        }

        $this->session = wfRandomString( 32 ); // 128 bits
    }

    protected function getLocksOnServer( $lockSrv, array $paths, $type ) {
        $status = Status::newGood();

        // Send out the command and get the response...
        $type = ( $type == self::LOCK_SH ) ? 'SH' : 'EX';
        $keys = array_unique( array_map( array( $this, 'sha1Base36Absolute' ), $paths ) );
        $response = $this->sendCommand( $lockSrv, 'ACQUIRE', $type, $keys );

        if ( $response !== 'ACQUIRED' ) {
            foreach ( $paths as $path ) {
                $status->fatal( 'lockmanager-fail-acquirelock', $path );
            }
        }

        return $status;
    }

    protected function freeLocksOnServer( $lockSrv, array $paths, $type ) {
        $status = Status::newGood();

        // Send out the command and get the response...
        $type = ( $type == self::LOCK_SH ) ? 'SH' : 'EX';
        $keys = array_unique( array_map( array( $this, 'sha1Base36Absolute' ), $paths ) );
        $response = $this->sendCommand( $lockSrv, 'RELEASE', $type, $keys );

        if ( $response !== 'RELEASED' ) {
            foreach ( $paths as $path ) {
                $status->fatal( 'lockmanager-fail-releaselock', $path );
            }
        }

        return $status;
    }

    protected function releaseAllLocks() {
        $status = Status::newGood();

        foreach ( $this->conns as $lockSrv => $conn ) {
            $response = $this->sendCommand( $lockSrv, 'RELEASE_ALL', '', array() );
            if ( $response !== 'RELEASED_ALL' ) {
                $status->fatal( 'lockmanager-fail-svr-release', $lockSrv );
            }
        }

        return $status;
    }

    protected function isServerUp( $lockSrv ) {
        return (bool)$this->getConnection( $lockSrv );
    }

    protected function sendCommand( $lockSrv, $action, $type, $values ) {
        $conn = $this->getConnection( $lockSrv );
        if ( !$conn ) {
            return false; // no connection
        }
        $authKey = $this->lockServers[$lockSrv]['authKey'];
        // Build of the command as a flat string...
        $values = implode( '|', $values );
        $key = hash_hmac( 'sha1', "{$this->session}\n{$action}\n{$type}\n{$values}", $authKey );
        // Send out the command...
        if ( fwrite( $conn, "{$this->session}:$key:$action:$type:$values\n" ) === false ) {
            return false;
        }
        // Get the response...
        $response = fgets( $conn );
        if ( $response === false ) {
            return false;
        }
        return trim( $response );
    }

    protected function getConnection( $lockSrv ) {
        if ( !isset( $this->conns[$lockSrv] ) ) {
            $cfg = $this->lockServers[$lockSrv];
            wfSuppressWarnings();
            $errno = $errstr = '';
            $conn = fsockopen( $cfg['host'], $cfg['port'], $errno, $errstr, $this->connTimeout );
            wfRestoreWarnings();
            if ( $conn === false ) {
                return null;
            }
            $sec = floor( $this->connTimeout );
            $usec = floor( ( $this->connTimeout - floor( $this->connTimeout ) ) * 1e6 );
            stream_set_timeout( $conn, $sec, $usec );
            $this->conns[$lockSrv] = $conn;
        }
        return $this->conns[$lockSrv];
    }

    function __destruct() {
        $this->releaseAllLocks();
        foreach ( $this->conns as $conn ) {
            fclose( $conn );
        }
    }
}