Add support for HTTP/1.1 and random non-responsive devices #197

Homekit needs the headers and content sent
in a single write call or it will randomly
get connection reset by peer which leads
to iOS stalling and devices showing up
as non-responsive.

Without HTTP/1.1 keep-alives, 50+ devices
would cause a bridge to timeout or devices
to go non-responsive because homekit would
have to make a new connection to get / put
for each device.  With HTTP/1.1 it can avoid
all of this overhead

After this change, devices in homekit on
the bridges with > 80 devices were
now immediately responsive in testing.

pyhap/hap_server.py

@@ -24,6 +24,7 @@
 
 import pyhap.tlv as tlv
 from pyhap.util import long_to_bytes
+from pyhap.const import __version__
 
 logger = logging.getLogger(__name__)
 
@@ -137,6 +138,13 @@ def __init__(self, sock, client_addr, server, accessory_handler):
         self.state = self.accessory_handler.state
         self.enc_context = None
         self.is_encrypted = False
+        self.server_version = 'pyhap/' + __version__
+        # HTTP/1.1 allows a keep-alive which makes
+        # a large accessory list usable in homekit
+        # If iOS has to reconnect to query each accessory
+        # it can be painfully slow and lead to lock up on the
+        # client side as well as non-responsive devices
+        self.protocol_version = 'HTTP/1.1'
         # Redirect separate handlers to the dispatch method
         self.do_GET = self.do_POST = self.do_PUT = self.dispatch
 
@@ -190,9 +198,24 @@ def _upgrade_to_encrypted(self):
     def end_response(self, bytesdata, close_connection=False):
         """Combines adding a length header and actually sending the data."""
         self.send_header("Content-Length", len(bytesdata))
-        self.end_headers()
-        self.wfile.write(bytesdata)
-        self.close_connection = 1 if close_connection else 0
+        # Setting this head will take care of setting
+        # self.close_connection to the right value
+        self.send_header("Connection", ("close" if close_connection else "keep-alive"))
+        # Important: we need to send the headers and the
+        # content in a single write to avoid homekit
+        # on the client side stalling and making
+        # devices appear non-responsive.
+        #
+        # The below code does what end_headers does internally
+        # except it combines the headers and the content
+        # into a single write instead of two calls to
+        # self.wfile.write
+        #
+        # TODO: Is there a better way that doesn't involve
+        # touching _headers_buffer ?
+        #
+        self.connection.sendall(b"".join(self._headers_buffer) + b"\r\n" + bytesdata)
+        self._headers_buffer = []
 
     def dispatch(self):
         """Dispatch the request to the appropriate handler method."""

tests/test_hap_server.py

@@ -43,3 +43,36 @@ def raises(*args):
         server.finish_request(amock, client_addr)
 
     assert len(server.connections) == 0
+
+def test_uses_http11():
+    """Test that ``HAPServerHandler`` uses HTTP/1.1."""
+    amock = Mock()
+    from pyhap.const import __version__
+
+    with patch('pyhap.hap_server.HAPServerHandler.setup'), patch('pyhap.hap_server.HAPServerHandler.handle_one_request'), patch('pyhap.hap_server.HAPServerHandler.finish'):
+      handler = hap_server.HAPServerHandler("mocksock", "mockclient_addr", "mockserver", amock)
+      assert handler.protocol_version == "HTTP/1.1"
+      assert handler.server_version == 'pyhap/' + __version__
+
+def test_end_response_is_one_send():
+    """Test that ``HAPServerHandler`` sends the whole response at once."""
+    class ConnectionMock():
+       sent_bytes = []
+
+       def sendall(self, bytesdata):
+          self.sent_bytes.append([bytesdata])
+          return 1
+
+       def getsent(self):
+          return self.sent_bytes
+
+    amock = Mock()
+
+
+    with patch('pyhap.hap_server.HAPServerHandler.setup'), patch('pyhap.hap_server.HAPServerHandler.handle_one_request'), patch('pyhap.hap_server.HAPServerHandler.finish'):
+      handler = hap_server.HAPServerHandler("mocksock", "mockclient_addr", "mockserver", amock)
+      handler.request_version = 'HTTP/1.1'
+      handler.connection = ConnectionMock()
+      handler.end_response(b"body")
+      assert handler.connection.getsent() == [[b'Content-Length: 4\r\nConnection: keep-alive\r\n\r\nbody']]
+      assert handler._headers_buffer == []