Gecko [ v99win.today ]

Name	Size	Permission
__pycache__	[ DIR ]	drwxr-xr-x
rdtypes	[ DIR ]	drwxr-xr-x
__init__.py	1.56 KB	-rw-r--r--
_asyncbackend.py	1.53 KB	-rw-r--r--
_asyncio_backend.py	4.34 KB	-rw-r--r--
_curio_backend.py	3.33 KB	-rw-r--r--
_immutable_attr.py	2.92 KB	-rw-r--r--
_immutable_ctx.py	2.4 KB	-rw-r--r--
_trio_backend.py	3.68 KB	-rw-r--r--
asyncbackend.py	3 KB	-rw-r--r--
asyncquery.py	17.4 KB	-rw-r--r--
asyncresolver.py	8.71 KB	-rw-r--r--
dnssec.py	19.19 KB	-rw-r--r--
e164.py	3.6 KB	-rw-r--r--
edns.py	10.72 KB	-rw-r--r--
entropy.py	4.07 KB	-rw-r--r--
enum.py	2.75 KB	-rw-r--r--
exception.py	5.13 KB	-rw-r--r--
flags.py	2.58 KB	-rw-r--r--
grange.py	2.04 KB	-rw-r--r--
immutable.py	1.97 KB	-rw-r--r--
inet.py	4.74 KB	-rw-r--r--
ipv4.py	1.93 KB	-rw-r--r--
ipv6.py	5.92 KB	-rw-r--r--
message.py	52.73 KB	-rw-r--r--
name.py	31.54 KB	-rw-r--r--
namedict.py	3.83 KB	-rw-r--r--
node.py	6.42 KB	-rw-r--r--
opcode.py	2.58 KB	-rw-r--r--
py.typed	0 B	-rw-r--r--
query.py	40.46 KB	-rw-r--r--
rcode.py	3.9 KB	-rw-r--r--
rdata.py	24.32 KB	-rw-r--r--
rdataclass.py	2.81 KB	-rw-r--r--
rdataset.py	14.54 KB	-rw-r--r--
rdatatype.py	6.64 KB	-rw-r--r--
renderer.py	8.59 KB	-rw-r--r--
resolver.py	59.29 KB	-rw-r--r--
reversename.py	3.65 KB	-rw-r--r--
rrset.py	7.44 KB	-rw-r--r--
serial.py	3.53 KB	-rw-r--r--
set.py	7.64 KB	-rw-r--r--
tokenizer.py	21.86 KB	-rw-r--r--
transaction.py	16.93 KB	-rw-r--r--
tsig.py	10.93 KB	-rw-r--r--
tsigkeyring.py	2.43 KB	-rw-r--r--
ttl.py	2.58 KB	-rw-r--r--
update.py	10.55 KB	-rw-r--r--
version.py	1.55 KB	-rw-r--r--
versioned.py	15.91 KB	-rw-r--r--
wire.py	2.48 KB	-rw-r--r--
xfr.py	11.61 KB	-rw-r--r--
zone.py	34.25 KB	-rw-r--r--
zonefile.py	15.25 KB	-rw-r--r--

Code Editor : asyncbackend.py

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

import dns.exception

# pylint: disable=unused-import

from dns._asyncbackend import Socket, DatagramSocket, \
    StreamSocket, Backend  # noqa:

# pylint: enable=unused-import

_default_backend = None

_backends = {}

# Allow sniffio import to be disabled for testing purposes
_no_sniffio = False

class AsyncLibraryNotFoundError(dns.exception.DNSException):
    pass

def get_backend(name):
    """Get the specified asychronous backend.

*name*, a ``str``, the name of the backend.  Currently the "trio",
    "curio", and "asyncio" backends are available.

Raises NotImplementError if an unknown backend name is specified.
    """
    # pylint: disable=import-outside-toplevel,redefined-outer-name
    backend = _backends.get(name)
    if backend:
        return backend
    if name == 'trio':
        import dns._trio_backend
        backend = dns._trio_backend.Backend()
    elif name == 'curio':
        import dns._curio_backend
        backend = dns._curio_backend.Backend()
    elif name == 'asyncio':
        import dns._asyncio_backend
        backend = dns._asyncio_backend.Backend()
    else:
        raise NotImplementedError(f'unimplemented async backend {name}')
    _backends[name] = backend
    return backend

def sniff():
    """Attempt to determine the in-use asynchronous I/O library by using
    the ``sniffio`` module if it is available.

Returns the name of the library, or raises AsyncLibraryNotFoundError
    if the library cannot be determined.
    """
    # pylint: disable=import-outside-toplevel
    try:
        if _no_sniffio:
            raise ImportError
        import sniffio
        try:
            return sniffio.current_async_library()
        except sniffio.AsyncLibraryNotFoundError:
            raise AsyncLibraryNotFoundError('sniffio cannot determine ' +
                                            'async library')
    except ImportError:
        import asyncio
        try:
            asyncio.get_running_loop()
            return 'asyncio'
        except RuntimeError:
            raise AsyncLibraryNotFoundError('no async library detected')
        except AttributeError:  # pragma: no cover
            # we have to check current_task on 3.6
            if not asyncio.Task.current_task():
                raise AsyncLibraryNotFoundError('no async library detected')
            return 'asyncio'

def get_default_backend():
    """Get the default backend, initializing it if necessary.
    """
    if _default_backend:
        return _default_backend

return set_default_backend(sniff())

def set_default_backend(name):
    """Set the default backend.

It's not normally necessary to call this method, as
    ``get_default_backend()`` will initialize the backend
    appropriately in many cases.  If ``sniffio`` is not installed, or
    in testing situations, this function allows the backend to be set
    explicitly.
    """
    global _default_backend
    _default_backend = get_backend(name)
    return _default_backend

${this.title}

Code Editor : asyncbackend.py