Cache data and update faster after failed updates in NWS (home-assist…

…ant#35722)

* add last_update_success_time  and a failed update interval

* add failed update interval annd valid times to nws

* Revert "add last_update_success_time  and a failed update interval"

This reverts commit 09428c9.

* extend DataUpdateCoordinator

homeassistant/components/nws/__init__.py

@@ -2,15 +2,18 @@
 import asyncio
 import datetime
 import logging
+from typing import Awaitable, Callable, Optional
 
 from pynws import SimpleNWS
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_API_KEY, CONF_LATITUDE, CONF_LONGITUDE
-from homeassistant.core import HomeAssistant
+from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers import debounce
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.helpers.event import async_track_point_in_utc_time
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator
+from homeassistant.util.dt import utcnow
 
 from .const import (
     CONF_STATION,
@@ -26,7 +29,7 @@
 PLATFORMS = ["weather"]
 
 DEFAULT_SCAN_INTERVAL = datetime.timedelta(minutes=10)
-
+FAILED_SCAN_INTERVAL = datetime.timedelta(minutes=1)
 DEBOUNCE_TIME = 60  # in seconds
 
 
@@ -40,6 +43,59 @@ async def async_setup(hass: HomeAssistant, config: dict):
     return True
 
 
+class NwsDataUpdateCoordinator(DataUpdateCoordinator):
+    """
+    NWS data update coordinator.
+
+    Implements faster data update intervals for failed updates and exposes a last successful update time.
+    """
+
+    def __init__(
+        self,
+        hass: HomeAssistant,
+        logger: logging.Logger,
+        *,
+        name: str,
+        update_interval: datetime.timedelta,
+        failed_update_interval: datetime.timedelta,
+        update_method: Optional[Callable[[], Awaitable]] = None,
+        request_refresh_debouncer: Optional[debounce.Debouncer] = None,
+    ):
+        """Initialize NWS coordinator."""
+        super().__init__(
+            hass,
+            logger,
+            name=name,
+            update_interval=update_interval,
+            update_method=update_method,
+            request_refresh_debouncer=request_refresh_debouncer,
+        )
+        self.failed_update_interval = failed_update_interval
+        self.last_update_success_time = None
+
+    @callback
+    def _schedule_refresh(self) -> None:
+        """Schedule a refresh."""
+        if self._unsub_refresh:
+            self._unsub_refresh()
+            self._unsub_refresh = None
+
+        # We _floor_ utcnow to create a schedule on a rounded second,
+        # minimizing the time between the point and the real activation.
+        # That way we obtain a constant update frequency,
+        # as long as the update process takes less than a second
+        if self.last_update_success:
+            update_interval = self.update_interval
+            self.last_update_success_time = utcnow()
+        else:
+            update_interval = self.failed_update_interval
+        self._unsub_refresh = async_track_point_in_utc_time(
+            self.hass,
+            self._handle_refresh_interval,
+            utcnow().replace(microsecond=0) + update_interval,
+        )
+
+
 async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry):
     """Set up a National Weather Service entry."""
     latitude = entry.data[CONF_LATITUDE]
@@ -53,34 +109,37 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry):
     nws_data = SimpleNWS(latitude, longitude, api_key, client_session)
     await nws_data.set_station(station)
 
-    coordinator_observation = DataUpdateCoordinator(
+    coordinator_observation = NwsDataUpdateCoordinator(
         hass,
         _LOGGER,
         name=f"NWS observation station {station}",
         update_method=nws_data.update_observation,
         update_interval=DEFAULT_SCAN_INTERVAL,
+        failed_update_interval=FAILED_SCAN_INTERVAL,
         request_refresh_debouncer=debounce.Debouncer(
             hass, _LOGGER, cooldown=DEBOUNCE_TIME, immediate=True
         ),
     )
 
-    coordinator_forecast = DataUpdateCoordinator(
+    coordinator_forecast = NwsDataUpdateCoordinator(
         hass,
         _LOGGER,
         name=f"NWS forecast station {station}",
         update_method=nws_data.update_forecast,
         update_interval=DEFAULT_SCAN_INTERVAL,
+        failed_update_interval=FAILED_SCAN_INTERVAL,
         request_refresh_debouncer=debounce.Debouncer(
             hass, _LOGGER, cooldown=DEBOUNCE_TIME, immediate=True
         ),
     )
 
-    coordinator_forecast_hourly = DataUpdateCoordinator(
+    coordinator_forecast_hourly = NwsDataUpdateCoordinator(
         hass,
         _LOGGER,
         name=f"NWS forecast hourly station {station}",
         update_method=nws_data.update_forecast_hourly,
         update_interval=DEFAULT_SCAN_INTERVAL,
+        failed_update_interval=FAILED_SCAN_INTERVAL,
         request_refresh_debouncer=debounce.Debouncer(
             hass, _LOGGER, cooldown=DEBOUNCE_TIME, immediate=True
         ),

homeassistant/components/nws/weather.py

@@ -1,4 +1,5 @@
 """Support for NWS weather service."""
+from datetime import timedelta
 import logging
 
 from homeassistant.components.weather import (
@@ -24,6 +25,7 @@
 from homeassistant.core import callback
 from homeassistant.helpers.typing import ConfigType, HomeAssistantType
 from homeassistant.util.distance import convert as convert_distance
+from homeassistant.util.dt import utcnow
 from homeassistant.util.pressure import convert as convert_pressure
 from homeassistant.util.temperature import convert as convert_temperature
 
@@ -47,6 +49,9 @@
 
 PARALLEL_UPDATES = 0
 
+OBSERVATION_VALID_TIME = timedelta(minutes=20)
+FORECAST_VALID_TIME = timedelta(minutes=45)
+
 
 def convert_condition(time, weather):
     """
@@ -287,10 +292,23 @@ def unique_id(self):
     @property
     def available(self):
         """Return if state is available."""
-        return (
+        last_success = (
             self.coordinator_observation.last_update_success
             and self.coordinator_forecast.last_update_success
         )
+        if (
+            self.coordinator_observation.last_update_success_time
+            and self.coordinator_forecast.last_update_success_time
+        ):
+            last_success_time = (
+                utcnow() - self.coordinator_observation.last_update_success_time
+                < OBSERVATION_VALID_TIME
+                and utcnow() - self.coordinator_forecast.last_update_success_time
+                < FORECAST_VALID_TIME
+            )
+        else:
+            last_success_time = False
+        return last_success or last_success_time
 
     async def async_update(self):
         """Update the entity.

tests/components/nws/test_weather.py

@@ -10,6 +10,7 @@
 import homeassistant.util.dt as dt_util
 from homeassistant.util.unit_system import IMPERIAL_SYSTEM, METRIC_SYSTEM
 
+from tests.async_mock import patch
 from tests.common import MockConfigEntry, async_fire_time_changed
 from tests.components.nws.const import (
     EXPECTED_FORECAST_IMPERIAL,
@@ -154,39 +155,79 @@ async def test_entity_refresh(hass, mock_simple_nws):
 
 async def test_error_observation(hass, mock_simple_nws):
     """Test error during update observation."""
-    instance = mock_simple_nws.return_value
-    instance.update_observation.side_effect = aiohttp.ClientError
+    utc_time = dt_util.utcnow()
+    with patch("homeassistant.components.nws.utcnow") as mock_utc, patch(
+        "homeassistant.components.nws.weather.utcnow"
+    ) as mock_utc_weather:
 
-    entry = MockConfigEntry(domain=nws.DOMAIN, data=NWS_CONFIG,)
-    entry.add_to_hass(hass)
-    await hass.config_entries.async_setup(entry.entry_id)
-    await hass.async_block_till_done()
+        def increment_time(time):
+            mock_utc.return_value += time
+            mock_utc_weather.return_value += time
+            async_fire_time_changed(hass, mock_utc.return_value)
 
-    instance.update_observation.assert_called_once()
+        mock_utc.return_value = utc_time
+        mock_utc_weather.return_value = utc_time
+        instance = mock_simple_nws.return_value
+        # first update fails
+        instance.update_observation.side_effect = aiohttp.ClientError
 
-    state = hass.states.get("weather.abc_daynight")
-    assert state
-    assert state.state == "unavailable"
+        entry = MockConfigEntry(domain=nws.DOMAIN, data=NWS_CONFIG,)
+        entry.add_to_hass(hass)
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
 
-    state = hass.states.get("weather.abc_hourly")
-    assert state
-    assert state.state == "unavailable"
+        instance.update_observation.assert_called_once()
 
-    instance.update_observation.side_effect = None
+        state = hass.states.get("weather.abc_daynight")
+        assert state
+        assert state.state == "unavailable"
 
-    future_time = dt_util.utcnow() + timedelta(minutes=15)
-    async_fire_time_changed(hass, future_time)
-    await hass.async_block_till_done()
+        state = hass.states.get("weather.abc_hourly")
+        assert state
+        assert state.state == "unavailable"
 
-    assert instance.update_observation.call_count == 2
+        # second update happens faster and succeeds
+        instance.update_observation.side_effect = None
+        increment_time(timedelta(minutes=1))
+        await hass.async_block_till_done()
 
-    state = hass.states.get("weather.abc_daynight")
-    assert state
-    assert state.state == "sunny"
+        assert instance.update_observation.call_count == 2
 
-    state = hass.states.get("weather.abc_hourly")
-    assert state
-    assert state.state == "sunny"
+        state = hass.states.get("weather.abc_daynight")
+        assert state
+        assert state.state == "sunny"
+
+        state = hass.states.get("weather.abc_hourly")
+        assert state
+        assert state.state == "sunny"
+
+        # third udate fails, but data is cached
+        instance.update_observation.side_effect = aiohttp.ClientError
+
+        increment_time(timedelta(minutes=10))
+        await hass.async_block_till_done()
+
+        assert instance.update_observation.call_count == 3
+
+        state = hass.states.get("weather.abc_daynight")
+        assert state
+        assert state.state == "sunny"
+
+        state = hass.states.get("weather.abc_hourly")
+        assert state
+        assert state.state == "sunny"
+
+        # after 20 minutes data caching expires, data is no longer shown
+        increment_time(timedelta(minutes=10))
+        await hass.async_block_till_done()
+
+        state = hass.states.get("weather.abc_daynight")
+        assert state
+        assert state.state == "unavailable"
+
+        state = hass.states.get("weather.abc_hourly")
+        assert state
+        assert state.state == "unavailable"
 
 
 async def test_error_forecast(hass, mock_simple_nws):
@@ -207,8 +248,7 @@ async def test_error_forecast(hass, mock_simple_nws):
 
     instance.update_forecast.side_effect = None
 
-    future_time = dt_util.utcnow() + timedelta(minutes=15)
-    async_fire_time_changed(hass, future_time)
+    async_fire_time_changed(hass, dt_util.utcnow() + timedelta(minutes=1))
     await hass.async_block_till_done()
 
     assert instance.update_forecast.call_count == 2
@@ -236,8 +276,7 @@ async def test_error_forecast_hourly(hass, mock_simple_nws):
 
     instance.update_forecast_hourly.side_effect = None
 
-    future_time = dt_util.utcnow() + timedelta(minutes=15)
-    async_fire_time_changed(hass, future_time)
+    async_fire_time_changed(hass, dt_util.utcnow() + timedelta(minutes=1))
     await hass.async_block_till_done()
 
     assert instance.update_forecast_hourly.call_count == 2