improve performance

sanic/app.py

@@ -13,7 +13,7 @@ from sanic.constants import HTTP_METHODS
 from sanic.exceptions import ServerError, URLBuildError, SanicException
 from sanic.handlers import ErrorHandler
 from sanic.log import log
-from sanic.response import HTTPResponse
+from sanic.response import HTTPResponse, StreamingHTTPResponse
 from sanic.router import Router
 from sanic.server import serve, serve_multiple, HttpProtocol
 from sanic.static import register as static_register
@@ -342,14 +342,17 @@ class Sanic:
     def converted_response_type(self, response):
         pass
 
-    async def handle_request(self, request, response_callback):
+    async def handle_request(self, request, write_callback, stream_callback):
         """Take a request from the HTTP Server and return a response object
         to be sent back The HTTP Server only expects a response object, so
         exception handling must be done here
 
         :param request: HTTP Request object
-        :param response_callback: Response function to be called with the
-                                  response as the only argument
+        :param write_callback: Synchronous response function to be
+            called with the response as the only argument
+        :param stream_callback: Coroutine that handles streaming a
+            StreamingHTTPResponse if produced by the handler.
+
         :return: Nothing
         """
         try:
@@ -416,7 +419,11 @@ class Sanic:
                     response = HTTPResponse(
                         "An error occurred while handling an error")
 
-        await response_callback(response)
+        # pass the response to the correct callback
+        if isinstance(response, StreamingHTTPResponse):
+            await stream_callback(response)
+        else:
+            write_callback(response)
 
     # -------------------------------------------------------------------- #
     # Testing

sanic/server.py

@@ -162,23 +162,22 @@ class HttpProtocol(asyncio.Protocol):
             self.request.body = b''.join(self.request.body)
 
         self._request_handler_task = self.loop.create_task(
-            self.request_handler(self.request, self.write_response))
+            self.request_handler(
+                self.request,
+                self.write_response,
+                self.stream_response))
 
     # -------------------------------------------- #
     # Responding
     # -------------------------------------------- #
-    async def write_response(self, response):
+    def write_response(self, response):
+        """
+        Writes response content synchronously to the transport.
+        """
         try:
             keep_alive = (
                 self.parser.should_keep_alive() and not self.signal.stopped)
 
-            if isinstance(response, StreamingHTTPResponse):
-                # streaming responses should have direct write access to the
-                # transport
-                response.transport = self.transport
-                await response.stream(
-                    self.request.version, keep_alive, self.request_timeout)
-            else:
             self.transport.write(
                 response.output(
                     self.request.version, keep_alive,
@@ -204,6 +203,41 @@ class HttpProtocol(asyncio.Protocol):
                 self._last_request_time = current_time
                 self.cleanup()
 
+    async def stream_response(self, response):
+        """
+        Streams a response to the client asynchronously. Attaches
+        the transport to the response so the response consumer can
+        write to the response as needed.
+        """
+
+        try:
+            keep_alive = (
+                self.parser.should_keep_alive() and not self.signal.stopped)
+
+            response.transport = self.transport
+            await response.stream(
+                self.request.version, keep_alive, self.request_timeout)
+        except AttributeError:
+            log.error(
+                ('Invalid response object for url {}, '
+                 'Expected Type: HTTPResponse, Actual Type: {}').format(
+                    self.url, type(response)))
+            self.write_error(ServerError('Invalid response type'))
+        except RuntimeError:
+            log.error(
+                'Connection lost before response written @ {}'.format(
+                    self.request.ip))
+        except Exception as e:
+            self.bail_out(
+                "Writing response failed, connection closed {}".format(
+                    repr(e)))
+        finally:
+            if not keep_alive:
+                self.transport.close()
+            else:
+                self._last_request_time = current_time
+                self.cleanup()
+
     def write_error(self, exception):
         try:
             response = self.error_handler.response(self.request, exception)