Async write headers (#2762)

* Make _start a coroutine

* Make write_headers a coroutine

* Add change note

CHANGES/2762.feature

@@ -0,0 +1 @@
+Make ``writer.write_headers`` a coroutine.

aiohttp/client_reqrep.py

@@ -505,7 +505,7 @@ async def send(self, conn):
         # status + headers
         status_line = '{0} {1} HTTP/{2[0]}.{2[1]}\r\n'.format(
             self.method, path, self.version)
-        writer.write_headers(status_line, self.headers)
+        await writer.write_headers(status_line, self.headers)
 
         self._writer = self.loop.create_task(self.write_bytes(writer, conn))
 

aiohttp/http_writer.py

@@ -91,7 +91,7 @@ def write(self, chunk, *, drain=True, LIMIT=64*1024):
 
         return noop()
 
-    def write_headers(self, status_line, headers, SEP=': ', END='\r\n'):
+    async def write_headers(self, status_line, headers, SEP=': ', END='\r\n'):
         """Write request/response status and headers."""
         # status + headers
         headers = status_line + ''.join(

aiohttp/test_utils.py

@@ -463,7 +463,6 @@ def make_mocked_request(method, path, headers=None, *,
                         version=HttpVersion(1, 1), closing=False,
                         app=None,
                         writer=sentinel,
-                        payload_writer=sentinel,
                         protocol=sentinel,
                         transport=sentinel,
                         payload=sentinel,
@@ -509,22 +508,20 @@ def make_mocked_request(method, path, headers=None, *,
 
     if writer is sentinel:
         writer = mock.Mock()
+        writer.write_headers = make_mocked_coro(None)
+        writer.write = make_mocked_coro(None)
+        writer.write_eof = make_mocked_coro(None)
+        writer.drain = make_mocked_coro(None)
         writer.transport = transport
 
-    if payload_writer is sentinel:
-        payload_writer = mock.Mock()
-        payload_writer.write = make_mocked_coro(None)
-        payload_writer.write_eof = make_mocked_coro(None)
-        payload_writer.drain = make_mocked_coro(None)
-
     protocol.transport = transport
     protocol.writer = writer
 
     if payload is sentinel:
         payload = mock.Mock()
 
     req = Request(message, payload,
-                  protocol, payload_writer, task, loop,
+                  protocol, writer, task, loop,
                   client_max_size=client_max_size)
 
     match_info = UrlMappingMatchInfo(

aiohttp/web_response.py

@@ -297,19 +297,19 @@ async def prepare(self, request):
             return self._payload_writer
 
         await request._prepare_hook(self)
-        return self._start(request)
-
-    def _start(self, request,
-               HttpVersion10=HttpVersion10,
-               HttpVersion11=HttpVersion11,
-               CONNECTION=hdrs.CONNECTION,
-               DATE=hdrs.DATE,
-               SERVER=hdrs.SERVER,
-               CONTENT_TYPE=hdrs.CONTENT_TYPE,
-               CONTENT_LENGTH=hdrs.CONTENT_LENGTH,
-               SET_COOKIE=hdrs.SET_COOKIE,
-               SERVER_SOFTWARE=SERVER_SOFTWARE,
-               TRANSFER_ENCODING=hdrs.TRANSFER_ENCODING):
+        return await self._start(request)
+
+    async def _start(self, request,
+                     HttpVersion10=HttpVersion10,
+                     HttpVersion11=HttpVersion11,
+                     CONNECTION=hdrs.CONNECTION,
+                     DATE=hdrs.DATE,
+                     SERVER=hdrs.SERVER,
+                     CONTENT_TYPE=hdrs.CONTENT_TYPE,
+                     CONTENT_LENGTH=hdrs.CONTENT_LENGTH,
+                     SET_COOKIE=hdrs.SET_COOKIE,
+                     SERVER_SOFTWARE=SERVER_SOFTWARE,
+                     TRANSFER_ENCODING=hdrs.TRANSFER_ENCODING):
         self._req = request
 
         keep_alive = self._keep_alive
@@ -364,7 +364,7 @@ def _start(self, request,
         # status line
         status_line = 'HTTP/{}.{} {} {}\r\n'.format(
             version[0], version[1], self._status, self._reason)
-        writer.write_headers(status_line, headers)
+        await writer.write_headers(status_line, headers)
 
         return writer
 
@@ -594,15 +594,15 @@ async def write_eof(self):
         else:
             await super().write_eof()
 
-    def _start(self, request):
+    async def _start(self, request):
         if not self._chunked and hdrs.CONTENT_LENGTH not in self._headers:
             if not self._body_payload:
                 if self._body is not None:
                     self._headers[hdrs.CONTENT_LENGTH] = str(len(self._body))
                 else:
                     self._headers[hdrs.CONTENT_LENGTH] = '0'
 
-        return super()._start(request)
+        return await super()._start(request)
 
     def _do_start_compression(self, coding):
         if self._body_payload or self._chunked:

tests/test_client_request.py

@@ -17,6 +17,7 @@
 from aiohttp import BaseConnector, hdrs, payload
 from aiohttp.client_reqrep import (ClientRequest, ClientResponse, Fingerprint,
                                    _merge_ssl_params)
+from aiohttp.test_utils import make_mocked_coro
 
 
 @pytest.fixture
@@ -668,6 +669,7 @@ async def test_content_encoding(loop, conn):
     req = ClientRequest('post', URL('http://python.org/'), data='foo',
                         compress='deflate', loop=loop)
     with mock.patch('aiohttp.client_reqrep.StreamWriter') as m_writer:
+        m_writer.return_value.write_headers = make_mocked_coro()
         resp = await req.send(conn)
     assert req.headers['TRANSFER-ENCODING'] == 'chunked'
     assert req.headers['CONTENT-ENCODING'] == 'deflate'
@@ -693,6 +695,7 @@ async def test_content_encoding_header(loop, conn):
         'post', URL('http://python.org/'), data='foo',
         headers={'Content-Encoding': 'deflate'}, loop=loop)
     with mock.patch('aiohttp.client_reqrep.StreamWriter') as m_writer:
+        m_writer.return_value.write_headers = make_mocked_coro()
         resp = await req.send(conn)
 
     assert not m_writer.return_value.enable_compression.called
@@ -732,6 +735,7 @@ async def test_chunked_explicit(loop, conn):
     req = ClientRequest(
         'post', URL('http://python.org/'), chunked=True, loop=loop)
     with mock.patch('aiohttp.client_reqrep.StreamWriter') as m_writer:
+        m_writer.return_value.write_headers = make_mocked_coro()
         resp = await req.send(conn)
 
     assert 'chunked' == req.headers['TRANSFER-ENCODING']

tests/test_web_exceptions.py

@@ -24,7 +24,7 @@ def append(data=b''):
         buf.extend(data)
         return helpers.noop()
 
-    def write_headers(status_line, headers):
+    async def write_headers(status_line, headers):
         headers = status_line + ''.join(
             [k + ': ' + v + '\r\n' for k, v in headers.items()])
         headers = headers.encode('utf-8') + b'\r\n'
@@ -39,7 +39,7 @@ def write_headers(status_line, headers):
     app._debug = False
     app.on_response_prepare = signals.Signal(app)
     app.on_response_prepare.freeze()
-    req = make_mocked_request(method, path, app=app, payload_writer=writer)
+    req = make_mocked_request(method, path, app=app, writer=writer)
     return req