Issue #3709: a flush_headers method to BaseHTTPRequestHandler which manages the
sending of headers to output stream and flushing the internal headers buffer.
Patch contribution by Andrew Schaaf
diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index e3a3a10..d9539f7 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -179,16 +179,17 @@
.. method:: send_response(code, message=None)
- Sends a response header and logs the accepted request. The HTTP response
- line is sent, followed by *Server* and *Date* headers. The values for
- these two headers are picked up from the :meth:`version_string` and
- :meth:`date_time_string` methods, respectively.
+ Adds a response header to the headers buffer and logs the accepted
+ request. The HTTP response line is sent, followed by *Server* and
+ *Date* headers. The values for these two headers are picked up from
+ the :meth:`version_string` and :meth:`date_time_string` methods,
+ respectively.
.. method:: send_header(keyword, value)
- Stores the HTTP header to an internal buffer which will be written to the
- output stream when :meth:`end_headers` method is invoked.
- *keyword* should specify the header keyword, with *value*
+ Adds the HTTP header to an internal buffer which will be written to the
+ output stream when either :meth:`end_headers` or :meth:`flush_headers`
+ is invoked. *keyword* should specify the header keyword, with *value*
specifying its value.
.. versionchanged:: 3.2 Storing the headers in an internal buffer
@@ -205,11 +206,19 @@
.. method:: end_headers()
- Write the buffered HTTP headers to the output stream and send a blank
- line, indicating the end of the HTTP headers in the response.
+ Adds a blank line
+ (indicating the end of the HTTP headers in the response)
+ to the headers buffer and calls :meth:`flush_headers()`
.. versionchanged:: 3.2 Writing the buffered headers to the output stream.
+ .. method:: flush_headers()
+
+ Finally send the headers to the output stream and flush the internal
+ headers buffer.
+
+ .. versionadded:: 3.3
+
.. method:: log_request(code='-', size='-')
Logs an accepted (successful) request. *code* should specify the numeric
diff --git a/Lib/http/server.py b/Lib/http/server.py
index 6aacbbd..1d193f8 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -355,6 +355,7 @@
"""
self.send_response_only(100)
+ self.flush_headers()
return True
def handle_one_request(self):
@@ -432,7 +433,8 @@
self.wfile.write(content.encode('UTF-8', 'replace'))
def send_response(self, code, message=None):
- """Send the response header and log the response code.
+ """Add the response header to the headers buffer and log the
+ response code.
Also send two standard headers with the server software
version and the current date.
@@ -451,11 +453,14 @@
else:
message = ''
if self.request_version != 'HTTP/0.9':
- self.wfile.write(("%s %d %s\r\n" %
- (self.protocol_version, code, message)).encode('latin-1', 'strict'))
+ if not hasattr(self, '_headers_buffer'):
+ self._headers_buffer = []
+ self._headers_buffer.append(("%s %d %s\r\n" %
+ (self.protocol_version, code, message)).encode(
+ 'latin-1', 'strict'))
def send_header(self, keyword, value):
- """Send a MIME header."""
+ """Send a MIME header to the headers buffer."""
if self.request_version != 'HTTP/0.9':
if not hasattr(self, '_headers_buffer'):
self._headers_buffer = []
@@ -472,6 +477,10 @@
"""Send the blank line ending the MIME headers."""
if self.request_version != 'HTTP/0.9':
self._headers_buffer.append(b"\r\n")
+ self.flush_headers()
+
+ def flush_headers(self):
+ if hasattr(self, '_headers_buffer'):
self.wfile.write(b"".join(self._headers_buffer))
self._headers_buffer = []
@@ -1081,6 +1090,7 @@
env.setdefault(k, "")
self.send_response(200, "Script output follows")
+ self.flush_headers()
decoded_query = query.replace('+', ' ')
diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 39ebc26..1bbaf0e 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -461,6 +461,23 @@
self.send_error(417)
return False
+
+class AuditableBytesIO:
+
+ def __init__(self):
+ self.datas = []
+
+ def write(self, data):
+ self.datas.append(data)
+
+ def getData(self):
+ return b''.join(self.datas)
+
+ @property
+ def numWrites(self):
+ return len(self.datas)
+
+
class BaseHTTPRequestHandlerTestCase(unittest.TestCase):
"""Test the functionality of the BaseHTTPServer.
@@ -527,27 +544,49 @@
self.verify_get_called()
self.assertEqual(result[-1], b'<html><body>Data</body></html>\r\n')
- def test_header_buffering(self):
-
- def _readAndReseek(f):
- pos = f.tell()
- f.seek(0)
- data = f.read()
- f.seek(pos)
- return data
+ def test_header_buffering_of_send_error(self):
input = BytesIO(b'GET / HTTP/1.1\r\n\r\n')
- output = BytesIO()
- self.handler.rfile = input
- self.handler.wfile = output
- self.handler.request_version = 'HTTP/1.1'
+ output = AuditableBytesIO()
+ handler = SocketlessRequestHandler()
+ handler.rfile = input
+ handler.wfile = output
+ handler.request_version = 'HTTP/1.1'
+ handler.requestline = ''
+ handler.command = None
- self.handler.send_header('Foo', 'foo')
- self.handler.send_header('bar', 'bar')
- self.assertEqual(_readAndReseek(output), b'')
- self.handler.end_headers()
- self.assertEqual(_readAndReseek(output),
- b'Foo: foo\r\nbar: bar\r\n\r\n')
+ handler.send_error(418)
+ self.assertEqual(output.numWrites, 2)
+
+ def test_header_buffering_of_send_response_only(self):
+
+ input = BytesIO(b'GET / HTTP/1.1\r\n\r\n')
+ output = AuditableBytesIO()
+ handler = SocketlessRequestHandler()
+ handler.rfile = input
+ handler.wfile = output
+ handler.request_version = 'HTTP/1.1'
+
+ handler.send_response_only(418)
+ self.assertEqual(output.numWrites, 0)
+ handler.end_headers()
+ self.assertEqual(output.numWrites, 1)
+
+ def test_header_buffering_of_send_header(self):
+
+ input = BytesIO(b'GET / HTTP/1.1\r\n\r\n')
+ output = AuditableBytesIO()
+ handler = SocketlessRequestHandler()
+ handler.rfile = input
+ handler.wfile = output
+ handler.request_version = 'HTTP/1.1'
+
+ handler.send_header('Foo', 'foo')
+ handler.send_header('bar', 'bar')
+ self.assertEqual(output.numWrites, 0)
+ handler.end_headers()
+ self.assertEqual(output.getData(), b'Foo: foo\r\nbar: bar\r\n\r\n')
+ self.assertEqual(output.numWrites, 1)
def test_header_unbuffered_when_continue(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index 18a2a55..1c5ce69 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -140,6 +140,10 @@
Library
-------
+- Issue #3709: a flush_headers method to BaseHTTPRequestHandler which manages
+ the sending of headers to output stream and flushing the internal headers
+ buffer. Patch contribution by Andrew Schaaf
+
- Issue #11743: Rewrite multiprocessing connection classes in pure Python.
- Issue #11164: Stop trying to use _xmlplus in the xml module.