pool.py 文件源码

def __init__(self, host, host_distance, session):
        self.host = host
        self.host_distance = host_distance
        self._session = weakref.proxy(session)
        self._lock = Lock()
        # this is used in conjunction with the connection streams. Not using the connection lock because the connection can be replaced in the lifetime of the pool.
        self._stream_available_condition = Condition(self._lock)
        self._is_replacing = False

        if host_distance == HostDistance.IGNORED:
            log.debug("Not opening connection to ignored host %s", self.host)
            return
        elif host_distance == HostDistance.REMOTE and not session.cluster.connect_to_remote_hosts:
            log.debug("Not opening connection to remote host %s", self.host)
            return

        log.debug("Initializing connection for host %s", self.host)
        self._connection = session.cluster.connection_factory(host.address)
        self._keyspace = session.keyspace
        if self._keyspace:
            self._connection.set_keyspace_blocking(self._keyspace)
        log.debug("Finished initializing connection for host %s", self.host)