Change prusalink update cooldown to 0.5 seconds

While the standard update rate of this intgration is 30 seconds, it's
possible to use homeassistant.update_entity to poll more frequently,
see https://www.home-assistant.io/common-tasks/general/#why-use-an-automation-instead-of-changing-the-integrations-polling-configuration.

But this method is limited by the update coordinator default cooldown,
10 seconds, which is too long to collect rapidly-changing metrics like
temperature.

This change will allow homeassistant.update_entity to update up to
twice per second, which should be fast enough while still providing
some protection against polling the printer too fast.

Author: agoode

homeassistant/components/prusalink/coordinator.py

@@ -21,12 +21,16 @@
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers.debounce import Debouncer
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
 
 from .const import DOMAIN
 
 _LOGGER = logging.getLogger(__name__)
 
+# Allow automations using homeassistant.update_entity to collect
+# rapidly-changing metrics.
+_MINIMUM_REFRESH_INTERVAL = 0.5
 
 T = TypeVar("T", PrinterStatus, LegacyPrinterStatus, JobInfo)
 
@@ -49,6 +53,9 @@ def __init__(
             config_entry=config_entry,
             name=DOMAIN,
             update_interval=self._get_update_interval(None),
+            request_refresh_debouncer=Debouncer(
+                hass, _LOGGER, cooldown=_MINIMUM_REFRESH_INTERVAL, immediate=True
+            ),
         )
 
     async def _async_update_data(self) -> T: