feat: avoid waking async_request when record updates are not relevant (#1153)

bdraco · web-flow · commit a3f970c7f660 · 2023-04-03T11:09:59.000-10:00
diff --git a/src/zeroconf/_services/info.py b/src/zeroconf/_services/info.py
@@ -20,6 +20,7 @@
     USA
 """
 
+import asyncio
 import ipaddress
 import random
 from functools import lru_cache
@@ -37,10 +38,14 @@
 from .._logger import log
 from .._protocol.outgoing import DNSOutgoing
 from .._updates import RecordUpdate, RecordUpdateListener
-from .._utils.asyncio import get_running_loop, run_coro_with_timeout
+from .._utils.asyncio import (
+    get_running_loop,
+    run_coro_with_timeout,
+    wait_event_or_timeout,
+)
 from .._utils.name import service_type_name
 from .._utils.net import IPVersion, _encode_address
-from .._utils.time import current_time_millis
+from .._utils.time import current_time_millis, millis_to_seconds
 from ..const import (
     _CLASS_IN,
     _CLASS_UNIQUE,
@@ -166,6 +171,7 @@ def __init__(
         self.host_ttl = host_ttl
         self.other_ttl = other_ttl
         self.interface_index = interface_index
+        self._notify_event: Optional[asyncio.Event] = None
 
     @property
     def name(self) -> str:
@@ -221,6 +227,12 @@ def properties(self) -> Dict:
         """
         return self._properties
 
+    async def async_wait(self, timeout: float) -> None:
+        """Calling task waits for a given number of milliseconds or until notified."""
+        if self._notify_event is None:
+            self._notify_event = asyncio.Event()
+        await wait_event_or_timeout(self._notify_event, timeout=millis_to_seconds(timeout))
+
     def addresses_by_version(self, version: IPVersion) -> List[bytes]:
         """List addresses matching IP version.
 
@@ -384,7 +396,9 @@ def async_update_records(self, zc: 'Zeroconf', now: float, records: List[RecordU
 
         This method will be run in the event loop.
         """
-        self._process_records_threadsafe(zc, now, records)
+        if self._process_records_threadsafe(zc, now, records) and self._notify_event:
+            self._notify_event.set()
+            self._notify_event.clear()
 
     def _process_records_threadsafe(self, zc: 'Zeroconf', now: float, records: List[RecordUpdate]) -> bool:
         """Thread safe record updating.
@@ -605,7 +619,7 @@ async def async_request(
                     delay *= 2
                     next_ += random.randint(*_AVOID_SYNC_DELAY_RANDOM_INTERVAL)
 
-                await zc.async_wait(min(next_, last) - now)
+                await self.async_wait(min(next_, last) - now)
                 now = current_time_millis()
         finally:
             zc.async_remove_listener(self)
