Refactor Bluetooth Tracker to async (#26614)

* Convert bluetooth device tracker to async

* WIP

* WIP

* Fix callback

* Fix tracked devices

* Perform synchornized updates

* Add doc

* Run in executor

* Improve execution

* Improve execution

* Don't create a redundant task

* Optimize see_device to run concurrently

* Remove redundant initialization scan

homeassistant/components/bluetooth_tracker/device_tracker.py

@@ -1,6 +1,7 @@
 """Tracking for bluetooth devices."""
+import asyncio
 import logging
-from typing import List, Set, Tuple
+from typing import List, Set, Tuple, Optional
 
 # pylint: disable=import-error
 import bluetooth
@@ -21,10 +22,9 @@ from homeassistant.components.device_tracker.legacy import (
     async_load_config,
 )
 import homeassistant.helpers.config_validation as cv
-from homeassistant.helpers.event import track_point_in_utc_time
+from homeassistant.helpers.event import async_track_time_interval
 from homeassistant.helpers.typing import HomeAssistantType
-from homeassistant.util.async_ import run_coroutine_threadsafe
-import homeassistant.util.dt as dt_util
+
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -65,12 +65,15 @@ def discover_devices(device_id: int) -> List[Tuple[str, str]]:
     return result
 
 
-def see_device(see, mac: str, device_name: str, rssi=None) -> None:
+async def see_device(
+    hass: HomeAssistantType, async_see, mac: str, device_name: str, rssi=None
+) -> None:
     """Mark a device as seen."""
     attributes = {}
     if rssi is not None:
         attributes["rssi"] = rssi
-    see(
+
+    await async_see(
         mac=f"{BT_PREFIX}{mac}",
         host_name=device_name,
         attributes=attributes,
@@ -78,90 +81,111 @@ def see_device(see, mac: str, device_name: str, rssi=None) -> None:
     )
 
 
-def get_tracking_devices(hass: HomeAssistantType) -> Tuple[Set[str], Set[str]]:
+async def get_tracking_devices(hass: HomeAssistantType) -> Tuple[Set[str], Set[str]]:
     """
     Load all known devices.
 
     We just need the devices so set consider_home and home range to 0
     """
     yaml_path: str = hass.config.path(YAML_DEVICES)
-    devices_to_track: Set[str] = set()
-    devices_to_not_track: Set[str] = set()
 
-    for device in run_coroutine_threadsafe(
-        async_load_config(yaml_path, hass, 0), hass.loop
-    ).result():
-        # Check if device is a valid bluetooth device
-        if not is_bluetooth_device(device):
-            continue
+    devices = await async_load_config(yaml_path, hass, 0)
+    bluetooth_devices = [device for device in devices if is_bluetooth_device(device)]
 
-        normalized_mac: str = device.mac[3:]
-        if device.track:
-            devices_to_track.add(normalized_mac)
-        else:
-            devices_to_not_track.add(normalized_mac)
+    devices_to_track: Set[str] = {
+        device.mac[3:] for device in bluetooth_devices if device.track
+    }
+    devices_to_not_track: Set[str] = {
+        device.mac[3:] for device in bluetooth_devices if not device.track
+    }
 
     return devices_to_track, devices_to_not_track
 
 
-def setup_scanner(hass: HomeAssistantType, config: dict, see, discovery_info=None):
+def lookup_name(mac: str) -> Optional[str]:
+    """Lookup a Bluetooth device name."""
+    _LOGGER.debug("Scanning %s", mac)
+    return bluetooth.lookup_name(mac, timeout=5)
+
+
+async def async_setup_scanner(
+    hass: HomeAssistantType, config: dict, async_see, discovery_info=None
+):
     """Set up the Bluetooth Scanner."""
     device_id: int = config.get(CONF_DEVICE_ID)
-    devices_to_track, devices_to_not_track = get_tracking_devices(hass)
+    interval = config.get(CONF_SCAN_INTERVAL, SCAN_INTERVAL)
+    request_rssi = config.get(CONF_REQUEST_RSSI, False)
+    update_bluetooth_lock = asyncio.Lock()
 
     # If track new devices is true discover new devices on startup.
     track_new: bool = config.get(CONF_TRACK_NEW, DEFAULT_TRACK_NEW)
-    _LOGGER.debug("Tracking new devices = %s", track_new)
+    _LOGGER.debug("Tracking new devices is set to %s", track_new)
+
+    devices_to_track, devices_to_not_track = await get_tracking_devices(hass)
 
     if not devices_to_track and not track_new:
         _LOGGER.debug("No Bluetooth devices to track and not tracking new devices")
 
-    if track_new:
-        for mac, device_name in discover_devices(device_id):
-            if mac not in devices_to_track and mac not in devices_to_not_track:
-                devices_to_track.add(mac)
-                see_device(see, mac, device_name)
-
-    interval = config.get(CONF_SCAN_INTERVAL, SCAN_INTERVAL)
-
-    request_rssi = config.get(CONF_REQUEST_RSSI, False)
     if request_rssi:
         _LOGGER.debug("Detecting RSSI for devices")
 
-    def update_bluetooth(_):
-        """Update Bluetooth and set timer for the next update."""
-        update_bluetooth_once()
-        track_point_in_utc_time(hass, update_bluetooth, dt_util.utcnow() + interval)
+    async def perform_bluetooth_update():
+        """Discover Bluetooth devices and update status."""
+
+        _LOGGER.debug("Performing Bluetooth devices discovery and update")
+        tasks = []
 
-    def update_bluetooth_once():
-        """Lookup Bluetooth device and update status."""
         try:
             if track_new:
-                for mac, device_name in discover_devices(device_id):
+                devices = await hass.async_add_executor_job(discover_devices, device_id)
+                for mac, device_name in devices:
                     if mac not in devices_to_track and mac not in devices_to_not_track:
                         devices_to_track.add(mac)
 
             for mac in devices_to_track:
-                _LOGGER.debug("Scanning %s", mac)
-                device_name = bluetooth.lookup_name(mac, timeout=5)
-                rssi = None
-                if request_rssi:
-                    client = BluetoothRSSI(mac)
-                    rssi = client.request_rssi()
-                    client.close()
+                device_name = await hass.async_add_executor_job(lookup_name, mac)
                 if device_name is None:
                     # Could not lookup device name
                     continue
-                see_device(see, mac, device_name, rssi)
+
+                rssi = None
+                if request_rssi:
+                    client = BluetoothRSSI(mac)
+                    rssi = await hass.async_add_executor_job(client.request_rssi)
+                    client.close()
+
+                tasks.append(see_device(hass, async_see, mac, device_name, rssi))
+
+            if tasks:
+                await asyncio.wait(tasks)
+
         except bluetooth.BluetoothError:
             _LOGGER.exception("Error looking up Bluetooth device")
 
-    def handle_update_bluetooth(call):
+    async def update_bluetooth(now=None):
+        """Lookup Bluetooth devices and update status."""
+
+        # If an update is in progress, we don't do anything
+        if update_bluetooth_lock.locked():
+            _LOGGER.debug(
+                "Previous execution of update_bluetooth is taking longer than the scheduled update of interval %s",
+                interval,
+            )
+            return
+
+        async with update_bluetooth_lock:
+            await perform_bluetooth_update()
+
+    async def handle_manual_update_bluetooth(call):
         """Update bluetooth devices on demand."""
-        update_bluetooth_once()
 
-    update_bluetooth(dt_util.utcnow())
+        await update_bluetooth()
 
-    hass.services.register(DOMAIN, "bluetooth_tracker_update", handle_update_bluetooth)
+    hass.async_create_task(update_bluetooth())
+    async_track_time_interval(hass, update_bluetooth, interval)
+
+    hass.services.async_register(
+        DOMAIN, "bluetooth_tracker_update", handle_manual_update_bluetooth
+    )
 
     return True