Refactory aiohttp clientsession handling in HA (#4602)

* Refactory aiohttp clientsession handling in HA

* remove from core / update platforms / rename file

homeassistant/helpers/aiohttp_client.py

@@ -0,0 +1,119 @@
+"""Helper for aiohttp webclient stuff."""
+import asyncio
+
+import aiohttp
+
+from homeassistant.core import callback
+from homeassistant.const import EVENT_HOMEASSISTANT_STOP
+
+
+DATA_CONNECTOR = 'aiohttp_connector'
+DATA_CONNECTOR_NOTVERIFY = 'aiohttp_connector_notverify'
+DATA_CLIENTSESSION = 'aiohttp_clientsession'
+DATA_CLIENTSESSION_NOTVERIFY = 'aiohttp_clientsession_notverify'
+
+
+@callback
+def async_get_clientsession(hass, verify_ssl=True):
+    """Return default aiohttp ClientSession.
+
+    This method must be run in the event loop.
+    """
+    if verify_ssl:
+        key = DATA_CLIENTSESSION
+    else:
+        key = DATA_CLIENTSESSION_NOTVERIFY
+
+    if key not in hass.data:
+        connector = _async_get_connector(hass, verify_ssl)
+        clientsession = aiohttp.ClientSession(
+            loop=hass.loop,
+            connector=connector
+        )
+        _async_register_clientsession_shutdown(hass, clientsession)
+        hass.data[key] = clientsession
+
+    return hass.data[key]
+
+
+@callback
+def async_create_clientsession(hass, verify_ssl=True, auto_cleanup=True,
+                               **kwargs):
+    """Create a new ClientSession with kwargs, i.e. for cookies.
+
+    If auto_cleanup is False, you need to call detach() after the session
+    returned is no longer used. Default is True, the session will be
+    automatically detached on homeassistant_stop.
+
+    This method must be run in the event loop.
+    """
+    connector = _async_get_connector(hass, verify_ssl)
+
+    clientsession = aiohttp.ClientSession(
+        loop=hass.loop,
+        connector=connector,
+        **kwargs
+    )
+
+    if auto_cleanup:
+        _async_register_clientsession_shutdown(hass, clientsession)
+
+    return clientsession
+
+
+@callback
+# pylint: disable=invalid-name
+def _async_register_clientsession_shutdown(hass, clientsession):
+    """Register ClientSession close on homeassistant shutdown.
+
+    This method must be run in the event loop.
+    """
+    @callback
+    def _async_close_websession(event):
+        """Close websession."""
+        clientsession.detach()
+
+    hass.bus.async_listen_once(
+        EVENT_HOMEASSISTANT_STOP, _async_close_websession)
+
+
+@callback
+def _async_get_connector(hass, verify_ssl=True):
+    """Return the connector pool for aiohttp.
+
+    This method must be run in the event loop.
+    """
+    if verify_ssl:
+        if DATA_CONNECTOR not in hass.data:
+            connector = aiohttp.TCPConnector(loop=hass.loop)
+            hass.data[DATA_CONNECTOR] = connector
+
+            _async_register_connector_shutdown(hass, connector)
+        else:
+            connector = hass.data[DATA_CONNECTOR]
+    else:
+        if DATA_CONNECTOR_NOTVERIFY not in hass.data:
+            connector = aiohttp.TCPConnector(loop=hass.loop, verify_ssl=False)
+            hass.data[DATA_CONNECTOR_NOTVERIFY] = connector
+
+            _async_register_connector_shutdown(hass, connector)
+        else:
+            connector = hass.data[DATA_CONNECTOR_NOTVERIFY]
+
+    return connector
+
+
+@callback
+# pylint: disable=invalid-name
+def _async_register_connector_shutdown(hass, connector):
+    """Register connector pool close on homeassistant shutdown.
+
+    This method must be run in the event loop.
+    """
+    @asyncio.coroutine
+    def _async_close_connector(event):
+        """Close websession on shutdown."""
+        yield from connector.close()
+
+    hass.bus.async_listen_once(
+        EVENT_HOMEASSISTANT_STOP, _async_close_connector)