mirror of
https://github.com/esphome/esphome.git
synced 2025-01-14 00:23:18 +01:00
43 lines
1.3 KiB
Python
43 lines
1.3 KiB
Python
from __future__ import annotations
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import asyncio
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import sys
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from icmplib import NameLookupError, async_resolve
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if sys.version_info >= (3, 11):
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from asyncio import timeout as async_timeout
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else:
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from async_timeout import timeout as async_timeout
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async def _async_resolve_wrapper(hostname: str) -> list[str] | Exception:
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"""Wrap the icmplib async_resolve function."""
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try:
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async with async_timeout(2):
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return await async_resolve(hostname)
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except (asyncio.TimeoutError, NameLookupError, UnicodeError) as ex:
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return ex
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class DNSCache:
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"""DNS cache for the dashboard."""
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def __init__(self, ttl: int | None = 120) -> None:
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"""Initialize the DNSCache."""
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self._cache: dict[str, tuple[float, list[str] | Exception]] = {}
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self._ttl = ttl
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async def async_resolve(
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self, hostname: str, now_monotonic: float
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) -> list[str] | Exception:
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"""Resolve a hostname to a list of IP address."""
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if expire_time_addresses := self._cache.get(hostname):
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expire_time, addresses = expire_time_addresses
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if expire_time > now_monotonic:
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return addresses
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expires = now_monotonic + self._ttl
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addresses = await _async_resolve_wrapper(hostname)
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self._cache[hostname] = (expires, addresses)
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return addresses
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