Async logging file handler (#4901)

* Async logging file handler

* add time rotation handle

* new layout

* address paulus comments

* fix lint

homeassistant/bootstrap.py

@@ -20,6 +20,7 @@ import homeassistant.loader as loader
 import homeassistant.util.package as pkg_util
 from homeassistant.util.async import (
     run_coroutine_threadsafe, run_callback_threadsafe)
+from homeassistant.util.logging import AsyncHandler
 from homeassistant.util.yaml import clear_secret_cache
 from homeassistant.const import EVENT_COMPONENT_LOADED, PLATFORM_FORMAT
 from homeassistant.exceptions import HomeAssistantError
@@ -548,8 +549,11 @@ def enable_logging(hass: core.HomeAssistant, verbose: bool=False,
         err_handler.setFormatter(
             logging.Formatter('%(asctime)s %(name)s: %(message)s',
                               datefmt='%y-%m-%d %H:%M:%S'))
+
+        async_handler = AsyncHandler(hass.loop, err_handler)
+
         logger = logging.getLogger('')
-        logger.addHandler(err_handler)
+        logger.addHandler(async_handler)
         logger.setLevel(logging.INFO)
 
     else:

homeassistant/util/logging.py

@@ -1,5 +1,9 @@
 """Logging utilities."""
+import asyncio
 import logging
+import threading
+
+from .async import run_coroutine_threadsafe
 
 
 class HideSensitiveDataFilter(logging.Filter):
@@ -15,3 +19,94 @@ class HideSensitiveDataFilter(logging.Filter):
         record.msg = record.msg.replace(self.text, '*******')
 
         return True
+
+
+# pylint: disable=invalid-name
+class AsyncHandler(object):
+    """Logging handler wrapper to add a async layer."""
+
+    def __init__(self, loop, handler):
+        """Initialize async logging handler wrapper."""
+        self.handler = handler
+        self.loop = loop
+        self._queue = asyncio.Queue(loop=loop)
+        self._thread = threading.Thread(target=self._process)
+
+        # Delegate from handler
+        self.setLevel = handler.setLevel
+        self.setFormatter = handler.setFormatter
+        self.addFilter = handler.addFilter
+        self.removeFilter = handler.removeFilter
+        self.filter = handler.filter
+        self.flush = handler.flush
+        self.handle = handler.handle
+        self.handleError = handler.handleError
+        self.format = handler.format
+
+    def close(self):
+        """Wrap close to handler."""
+        self.emit(None)
+
+    def open(self):
+        """Wrap open to handler."""
+        self._thread.start()
+        self.handler.open()
+
+    def emit(self, record):
+        """Process a record."""
+        ident = self.loop.__dict__.get("_thread_ident")
+
+        # inside eventloop
+        if ident is not None and ident == threading.get_ident():
+            self._queue.put_nowait(record)
+        # from a thread/executor
+        else:
+            self.loop.call_soon_threadsafe(self._queue.put_nowait, record)
+
+    def __repr__(self):
+        """String name of this."""
+        return str(self.handler)
+
+    def _process(self):
+        """Process log in a thread."""
+        while True:
+            record = run_coroutine_threadsafe(
+                self._queue.get(), self.loop).result()
+
+            if record is None:
+                self.handler.close()
+                return
+
+            self.handler.emit(record)
+
+    def createLock(self):
+        """Ignore lock stuff."""
+        pass
+
+    def acquire(self):
+        """Ignore lock stuff."""
+        pass
+
+    def release(self):
+        """Ignore lock stuff."""
+        pass
+
+    @property
+    def level(self):
+        """Wrap property level to handler."""
+        return self.handler.level
+
+    @property
+    def formatter(self):
+        """Wrap property formatter to handler."""
+        return self.handler.formatter
+
+    @property
+    def name(self):
+        """Wrap property set_name to handler."""
+        return self.handler.get_name()
+
+    @name.setter
+    def set_name(self, name):
+        """Wrap property get_name to handler."""
+        self.handler.name = name