plexpy/lib/dns/asyncbackend.py
dependabot[bot] cfefa928be
Bump dnspython from 2.4.2 to 2.6.1 (#2264)
* Bump dnspython from 2.4.2 to 2.6.1

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.4.2 to 2.6.1.
- [Release notes](https://github.com/rthalley/dnspython/releases)
- [Changelog](https://github.com/rthalley/dnspython/blob/main/doc/whatsnew.rst)
- [Commits](https://github.com/rthalley/dnspython/compare/v2.4.2...v2.6.1)

---
updated-dependencies:
- dependency-name: dnspython
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update dnspython==2.6.1

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: JonnyWong16 <9099342+JonnyWong16@users.noreply.github.com>

[skip ci]
2024-03-24 15:25:23 -07:00

102 lines
2.7 KiB
Python

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
from typing import Dict
import dns.exception
# pylint: disable=unused-import
from dns._asyncbackend import ( # noqa: F401 lgtm[py/unused-import]
Backend,
DatagramSocket,
Socket,
StreamSocket,
)
# pylint: enable=unused-import
_default_backend = None
_backends: Dict[str, Backend] = {}
# Allow sniffio import to be disabled for testing purposes
_no_sniffio = False
class AsyncLibraryNotFoundError(dns.exception.DNSException):
pass
def get_backend(name: str) -> Backend:
"""Get the specified asynchronous backend.
*name*, a ``str``, the name of the backend. Currently the "trio"
and "asyncio" backends are available.
Raises NotImplementedError 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 == "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() -> str:
"""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")
def get_default_backend() -> 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: str) -> Backend:
"""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