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perf: precompute address hash instead of per-instance lru_cache #1774

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perf: precompute address hash instead of per-instance lru_cache #1774

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433dd40
test: add benchmarks for ipaddress object creation and hashing
bluetoothbot May 24, 2026
1a232c4
perf: precompute address hash instead of per-instance lru_cache
bluetoothbot May 24, 2026
7f7eea6
Merge branch 'master' into koan/fix-ipaddress-hash-caching
bdraco May 24, 2026
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18 changes: 13 additions & 5 deletions src/zeroconf/_utils/ipaddress.py
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Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@

from __future__ import annotations

from functools import cache, lru_cache
from functools import lru_cache
from ipaddress import AddressValueError, IPv4Address, IPv6Address, NetmaskValueError
from typing import Any

Expand All @@ -34,7 +34,7 @@


class ZeroconfIPv4Address(IPv4Address):
__slots__ = ("__hash__", "_is_link_local", "_is_loopback", "_is_unspecified", "_str", "zc_integer")
__slots__ = ("_hash", "_is_link_local", "_is_loopback", "_is_unspecified", "_str", "zc_integer")

def __init__(self, *args: Any, **kwargs: Any) -> None:
"""Initialize a new IPv4 address."""
Expand All @@ -43,13 +43,17 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
self._is_link_local = super().is_link_local
self._is_unspecified = super().is_unspecified
self._is_loopback = super().is_loopback
self.__hash__ = cache(lambda: IPv4Address.__hash__(self)) # type: ignore[method-assign]
self._hash = IPv4Address.__hash__(self)
self.zc_integer = int(self)

def __str__(self) -> str:
"""Return the string representation of the IPv4 address."""
return self._str

def __hash__(self) -> int:
"""Return the precomputed hash of the IPv4 address."""
return self._hash

@property
def is_link_local(self) -> bool:
"""Return True if this is a link-local address."""
Expand All @@ -67,7 +71,7 @@ def is_loopback(self) -> bool:


class ZeroconfIPv6Address(IPv6Address):
__slots__ = ("__hash__", "_is_link_local", "_is_loopback", "_is_unspecified", "_str", "zc_integer")
__slots__ = ("_hash", "_is_link_local", "_is_loopback", "_is_unspecified", "_str", "zc_integer")

def __init__(self, *args: Any, **kwargs: Any) -> None:
"""Initialize a new IPv6 address."""
Expand All @@ -76,13 +80,17 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
self._is_link_local = super().is_link_local
self._is_unspecified = super().is_unspecified
self._is_loopback = super().is_loopback
self.__hash__ = cache(lambda: IPv6Address.__hash__(self)) # type: ignore[method-assign]
self._hash = IPv6Address.__hash__(self)
self.zc_integer = int(self)

def __str__(self) -> str:
"""Return the string representation of the IPv6 address."""
return self._str

def __hash__(self) -> int:
"""Return the precomputed hash of the IPv6 address."""
return self._hash

@property
def is_link_local(self) -> bool:
"""Return True if this is a link-local address."""
Expand Down
14 changes: 14 additions & 0 deletions tests/utils/test_ipaddress.py
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,20 @@ def test_cached_ip_addresses_wrapper():
assert ipv6.is_unspecified is True


def test_address_hash_matches_stdlib_and_dedups():
"""Cached address objects hash like their stdlib equals and dedup in sets."""
v4 = ipaddress.cached_ip_addresses("192.168.1.1")
assert v4 is not None
assert hash(v4) == hash(ipaddress.IPv4Address("192.168.1.1"))
assert hash(v4) == hash(v4)
assert len({v4, ipaddress.ZeroconfIPv4Address("192.168.1.1")}) == 1

v6 = ipaddress.cached_ip_addresses("fe80::1")
assert v6 is not None
assert hash(v6) == hash(ipaddress.IPv6Address("fe80::1"))
assert len({v6, ipaddress.ZeroconfIPv6Address("fe80::1")}) == 1


def test_get_ip_address_object_from_record():
"""Test the get_ip_address_object_from_record."""
# not link local
Expand Down
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