connection.py 文件源码

def __init__(self, host='127.0.0.1', port=9042, authenticator=None,
                 ssl_options=None, sockopts=None, compression=True,
                 cql_version=None, protocol_version=ProtocolVersion.MAX_SUPPORTED, is_control_connection=False,
                 user_type_map=None, connect_timeout=None, allow_beta_protocol_version=False):
        self.host = host
        self.port = port
        self.authenticator = authenticator
        self.ssl_options = ssl_options.copy() if ssl_options else None
        self.sockopts = sockopts
        self.compression = compression
        self.cql_version = cql_version
        self.protocol_version = protocol_version
        self.is_control_connection = is_control_connection
        self.user_type_map = user_type_map
        self.connect_timeout = connect_timeout
        self.allow_beta_protocol_version = allow_beta_protocol_version
        self._push_watchers = defaultdict(set)
        self._requests = {}
        self._iobuf = io.BytesIO()

        if ssl_options:
            self._check_hostname = bool(self.ssl_options.pop('check_hostname', False))
            if self._check_hostname:
                if not getattr(ssl, 'match_hostname', None):
                    raise RuntimeError("ssl_options specify 'check_hostname', but ssl.match_hostname is not provided. "
                                       "Patch or upgrade Python to use this option.")

        if protocol_version >= 3:
            self.max_request_id = min(self.max_in_flight - 1, (2 ** 15) - 1)
            # Don't fill the deque with 2**15 items right away. Start with some and add
            # more if needed.
            initial_size = min(300, self.max_in_flight)
            self.request_ids = deque(range(initial_size))
            self.highest_request_id = initial_size - 1
        else:
            self.max_request_id = min(self.max_in_flight, (2 ** 7) - 1)
            self.request_ids = deque(range(self.max_request_id + 1))
            self.highest_request_id = self.max_request_id

        self.lock = RLock()
        self.connected_event = Event()