tuxbot-bot/venv/lib/python3.7/site-packages/aiohttp/resolver.py

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2019-12-16 18:12:10 +01:00
import asyncio
import socket
from typing import Any, Dict, List, Optional
from .abc import AbstractResolver
from .helpers import get_running_loop
__all__ = ('ThreadedResolver', 'AsyncResolver', 'DefaultResolver')
try:
import aiodns
# aiodns_default = hasattr(aiodns.DNSResolver, 'gethostbyname')
except ImportError: # pragma: no cover
aiodns = None
aiodns_default = False
class ThreadedResolver(AbstractResolver):
"""Use Executor for synchronous getaddrinfo() calls, which defaults to
concurrent.futures.ThreadPoolExecutor.
"""
def __init__(self, loop: Optional[asyncio.AbstractEventLoop]=None) -> None:
self._loop = get_running_loop(loop)
async def resolve(self, host: str, port: int=0,
family: int=socket.AF_INET) -> List[Dict[str, Any]]:
infos = await self._loop.getaddrinfo(
host, port, type=socket.SOCK_STREAM, family=family)
hosts = []
for family, _, proto, _, address in infos:
hosts.append(
{'hostname': host,
'host': address[0], 'port': address[1],
'family': family, 'proto': proto,
'flags': socket.AI_NUMERICHOST})
return hosts
async def close(self) -> None:
pass
class AsyncResolver(AbstractResolver):
"""Use the `aiodns` package to make asynchronous DNS lookups"""
def __init__(self, loop: Optional[asyncio.AbstractEventLoop]=None,
*args: Any, **kwargs: Any) -> None:
if aiodns is None:
raise RuntimeError("Resolver requires aiodns library")
self._loop = get_running_loop(loop)
self._resolver = aiodns.DNSResolver(*args, loop=loop, **kwargs)
if not hasattr(self._resolver, 'gethostbyname'):
# aiodns 1.1 is not available, fallback to DNSResolver.query
self.resolve = self._resolve_with_query # type: ignore
async def resolve(self, host: str, port: int=0,
family: int=socket.AF_INET) -> List[Dict[str, Any]]:
try:
resp = await self._resolver.gethostbyname(host, family)
except aiodns.error.DNSError as exc:
msg = exc.args[1] if len(exc.args) >= 1 else "DNS lookup failed"
raise OSError(msg) from exc
hosts = []
for address in resp.addresses:
hosts.append(
{'hostname': host,
'host': address, 'port': port,
'family': family, 'proto': 0,
'flags': socket.AI_NUMERICHOST})
if not hosts:
raise OSError("DNS lookup failed")
return hosts
async def _resolve_with_query(
self, host: str, port: int=0,
family: int=socket.AF_INET) -> List[Dict[str, Any]]:
if family == socket.AF_INET6:
qtype = 'AAAA'
else:
qtype = 'A'
try:
resp = await self._resolver.query(host, qtype)
except aiodns.error.DNSError as exc:
msg = exc.args[1] if len(exc.args) >= 1 else "DNS lookup failed"
raise OSError(msg) from exc
hosts = []
for rr in resp:
hosts.append(
{'hostname': host,
'host': rr.host, 'port': port,
'family': family, 'proto': 0,
'flags': socket.AI_NUMERICHOST})
if not hosts:
raise OSError("DNS lookup failed")
return hosts
async def close(self) -> None:
return self._resolver.cancel()
DefaultResolver = AsyncResolver if aiodns_default else ThreadedResolver