psdns.py 文件源码

def __dns_resolve_host(host, ip_version, timeout):
    """
    Resolve a host using the system's facilities
    """
    family = socket.AF_INET if ip_version == 4 else socket.AF_INET6

    def proc(host, family, queue):
        try:
            queue.put(socket.getaddrinfo(host, 0, family))
        except socket.gaierror as ex:
            # TODO: Would be nice if we could isolate just the not
            # found error.
            queue.put([])
        except socket.timeout:
            # Don't care, we just want the queue to be empty if
            # there's an error.
            pass

    queue = Queue.Queue()
    thread = threading.Thread(target=proc, args=(host, family, queue))
    thread.setDaemon(True)
    thread.start()
    try:
        results = queue.get(True, timeout)
        if len(results) == 0:
            return None
        family, socktype, proto, canonname, sockaddr = results[0]
    except Queue.Empty:
        return None

    # NOTE: Don't make any attempt to kill the thread, as it will get
    # Python all confused if it holds the GIL.

    (ip) = sockaddr
    return str(ip[0])