test: add benchmarks for cache mark-to-expire path (#1780) (#1785)

bluetoothbot · web-flow · commit 29cc40504594 · 2026-06-03T08:34:45.000-05:00
diff --git a/tests/benchmarks/test_cache_mark_expire.py b/tests/benchmarks/test_cache_mark_expire.py
@@ -0,0 +1,124 @@
+"""Benchmarks for DNSCache.async_mark_unique_records_older_than_1s_to_expire.
+
+Covers the RFC 6762 §10.2 paragraph 2 path. ``_async_set_created_ttl``
+mutates cached records in place, so a repeated-iteration benchmark
+would only measure work on the first call. Each test uses
+``benchmark.pedantic`` with a per-round ``setup`` that rebuilds the
+stale cache; the ``async_add_records`` cost stays outside the timed
+window.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+from pytest_codspeed import BenchmarkFixture
+
+from zeroconf import DNSAddress, DNSCache, DNSPointer, current_time_millis
+from zeroconf.const import _CLASS_IN, _CLASS_UNIQUE, _TYPE_A, _TYPE_PTR
+
+_UNIQUE_CLASS = _CLASS_IN | _CLASS_UNIQUE
+
+
+def _ipv4_bytes(i: int) -> bytes:
+    return bytes(((i >> 24) & 0xFF, (i >> 16) & 0xFF, (i >> 8) & 0xFF, i & 0xFF))
+
+
+def test_mark_to_expire_1000_records_all_stale(benchmark: BenchmarkFixture) -> None:
+    """Worst-case mark-to-expire: 1000 stale unique A records, all mutated."""
+    now = current_time_millis()
+    name = "stale.local."
+    unique_types = {(name, _TYPE_A, _UNIQUE_CLASS)}
+    # Unrelated answer keeps every cached record in the "must expire"
+    # branch (no membership hit short-circuits the mutation).
+    answers = [DNSAddress(name, _TYPE_A, _UNIQUE_CLASS, 120, _ipv4_bytes(0xDEAD_BEEF))]
+
+    def _setup() -> tuple[tuple[Any, ...], dict[str, Any]]:
+        cache = DNSCache()
+        cache.async_add_records(
+            DNSAddress(
+                name,
+                _TYPE_A,
+                _UNIQUE_CLASS,
+                120,
+                _ipv4_bytes(i),
+                created=now - 5_000,
+            )
+            for i in range(1000)
+        )
+        return (cache,), {}
+
+    def _mark(cache: DNSCache) -> None:
+        cache.async_mark_unique_records_older_than_1s_to_expire(unique_types, answers, now)
+
+    benchmark.pedantic(_mark, setup=_setup)
+
+
+def test_mark_to_expire_1000_records_none_stale(benchmark: BenchmarkFixture) -> None:
+    """Scan-only path: 1000 fresh records, no mutation."""
+    now = current_time_millis()
+    name = "fresh.local."
+    unique_types = {(name, _TYPE_A, _UNIQUE_CLASS)}
+    answers = [DNSAddress(name, _TYPE_A, _UNIQUE_CLASS, 120, _ipv4_bytes(0xDEAD_BEEF))]
+
+    def _setup() -> tuple[tuple[Any, ...], dict[str, Any]]:
+        cache = DNSCache()
+        cache.async_add_records(
+            DNSAddress(
+                name,
+                _TYPE_A,
+                _UNIQUE_CLASS,
+                120,
+                _ipv4_bytes(i),
+                created=now,
+            )
+            for i in range(1000)
+        )
+        return (cache,), {}
+
+    def _mark(cache: DNSCache) -> None:
+        cache.async_mark_unique_records_older_than_1s_to_expire(unique_types, answers, now)
+
+    benchmark.pedantic(_mark, setup=_setup)
+
+
+def test_mark_to_expire_many_unique_types(benchmark: BenchmarkFixture) -> None:
+    """100 distinct (name, type, class) triplets, one stale record each."""
+    now = current_time_millis()
+    unique_types: set[tuple[str, int, int]] = {
+        (f"svc{i}.local.", _TYPE_PTR, _UNIQUE_CLASS) for i in range(100)
+    }
+    # New answers reference a different alias, so the cached entries are
+    # not equal to anything in ``answers_rrset`` and must be expired.
+    answers = [
+        DNSPointer(
+            f"svc{i}.local.",
+            _TYPE_PTR,
+            _UNIQUE_CLASS,
+            120,
+            f"new-target{i}.local.",
+        )
+        for i in range(100)
+    ]
+
+    def _setup() -> tuple[tuple[Any, ...], dict[str, Any]]:
+        cache = DNSCache()
+        for i in range(100):
+            cache.async_add_records(
+                [
+                    DNSPointer(
+                        f"svc{i}.local.",
+                        _TYPE_PTR,
+                        _UNIQUE_CLASS,
+                        120,
+                        f"target{i}.local.",
+                        created=now - 5_000,
+                    )
+                ]
+            )
+        return (cache,), {}
+
+    def _mark(cache: DNSCache) -> None:
+        cache.async_mark_unique_records_older_than_1s_to_expire(unique_types, answers, now)
+
+    benchmark.pedantic(_mark, setup=_setup)
