PhpOrient\Protocols\Binary\Abstracts\Operation::_readHeader PHP Method

    protected function _readHeader()
    {
        $status = $this->_readByte();
        $sessionId = $this->_readInt();
        /*
         *  we must recognize dbOpen and Connect messages
         */
        if (!$this instanceof DbOpen && !$this instanceof Connect && $this->_transport->isRequestToken()) {
            $token_refresh = $this->_readString();
            if (!empty($token_refresh)) {
                $this->_transport->setToken($token_refresh);
            }
        }
        if ($status === 1) {
            $this->_readByte();
            // discard the first byte of the error
            $error = $this->_readError();
            $this->_dump_streams();
            throw $error;
        } elseif ($status === 3) {
            // server push data for nodes up/down update info,
            // needed for failover on cluster
            # Push notification, Node cluster changed
            #
            # BYTE (OChannelBinaryProtocol.PUSH_DATA);  # WRITE 3
            # INT (Integer.MIN_VALUE);  # SESSION ID = 2^-31
            #       80: \x50 Request Push 1 byte: Push command id
            # STRING $payload
            $this->_pushReceived($this->_readByte(), CSV::unserialize($this->_readString()));
            $end_flag = $this->_readByte();
            # this flag can be set more than once
            while ($end_flag == 3) {
                $this->_readInt();
                # FAKE SESSION ID = 2^-31
                $this->_pushReceived($this->_readByte(), CSV::unserialize($this->_readString()));
                $end_flag = $this->_readByte();
            }
            $sessionId = $this->_readInt();
            //string termination
        }
    }