cherrypy-trailers.patch

Add support for trailer headers in streaming requests.

From: Lassi Tuura <lat@cern.ch>


---

 cherrypy/_cprequest.py          |    4 ++++
 cherrypy/_cpwsgi.py             |    9 +++++++--
 cherrypy/test/test_conn.py      |   35 ++++++++++++++++++++++++++++-------
 cherrypy/wsgiserver/__init__.py |   15 +++++++++++++--
 4 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/cherrypy/_cprequest.py b/cherrypy/_cprequest.py
index 23bdad2..9619dbc 100644
--- a/cherrypy/_cprequest.py
+++ b/cherrypy/_cprequest.py
@@ -861,6 +861,7 @@ class Response(object):
         
         headers = self.headers
         if self.stream:
+            self.headers = http.HeaderMap()
             if dict.get(headers, 'Content-Length') is None:
                 dict.pop(headers, 'Content-Length', None)
         elif code < 200 or code in (204, 205, 304):
@@ -888,6 +889,9 @@ class Response(object):
                 name, value = line.split(": ", 1)
                 h.append((name, value))
     
+    def trailer_headers(self):
+	return (self.stream and self.headers.output(cherrypy.request.protocol)) or []
+
     def check_timeout(self):
         """If now > self.time + self.timeout, set self.timed_out.
         
diff --git a/cherrypy/_cpwsgi.py b/cherrypy/_cpwsgi.py
index b23822e..e0a5b2e 100644
--- a/cherrypy/_cpwsgi.py
+++ b/cherrypy/_cpwsgi.py
@@ -76,9 +76,10 @@ class AppResponse(object):
     def setapp(self):
         try:
             self.request = self.get_request()
-            s, h, b = self.get_response()
+            s, h, b, t = self.get_response()
             self.iter_response = iter(b)
             self.start_response(s, h)
+            self.trailer = t
         except self.throws:
             self.close()
             raise
@@ -175,6 +176,9 @@ class AppResponse(object):
             self.close()
             self.iredirect(ir.path, ir.query_string)
         except StopIteration:
+            pass_trailer = self.environ.get('cherrypy.trailer_headers', None)
+            if pass_trailer:
+                pass_trailer(self.trailer())
             raise
         except:
             if getattr(self.request, "throw_errors", False):
@@ -217,7 +221,8 @@ class AppResponse(object):
         headers = self.translate_headers(self.environ)
         rfile = self.environ['wsgi.input']
         response = self.request.run(meth, path, qs, rproto, headers, rfile)
-        return response.status, response.header_list, response.body
+        return response.status, response.header_list, response.body, \
+               response.trailer_headers
     
     def get_request(self):
         """Create a Request object using environ."""
diff --git a/cherrypy/test/test_conn.py b/cherrypy/test/test_conn.py
index c1f902c..8d3e3dc 100644
--- a/cherrypy/test/test_conn.py
+++ b/cherrypy/test/test_conn.py
@@ -40,12 +40,17 @@ def setup_server():
             return str(cherrypy.server.httpserver.timeout)
         timeout.exposed = True
         
-        def stream(self, set_cl=False):
+        def stream(self, set_cl=False, with_trailer=False):
             if set_cl:
                 cherrypy.response.headers['Content-Length'] = 10
             
+	    if with_trailer:
+		cherrypy.response.headers['Trailer'] = "X-Trailer"
+
             def content():
                 for x in xrange(10):
+		    if with_trailer and x == 9:
+			cherrypy.response.headers['X-Trailer'] = 123
                     yield str(x)
             
             return content()
@@ -121,12 +126,14 @@ class ConnectionTests(helper.CPWebCase):
         self.assertRaises(httplib.NotConnected, self.getPage, "/")
     
     def test_Streaming_no_len(self):
-        self._streaming(set_cl=False)
+        self._streaming(set_cl=False, with_trailer=True)
+        self._streaming(set_cl=False, with_trailer=False)
     
     def test_Streaming_with_len(self):
-        self._streaming(set_cl=True)
+        self._streaming(set_cl=True, with_trailer=True)
+        self._streaming(set_cl=True, with_trailer=False)
     
-    def _streaming(self, set_cl):
+    def _streaming(self, set_cl, with_trailer):
         if cherrypy.server.protocol_version == "HTTP/1.1":
             self.PROTOCOL = "HTTP/1.1"
             
@@ -142,22 +149,35 @@ class ConnectionTests(helper.CPWebCase):
             if set_cl:
                 # When a Content-Length is provided, the content should stream
                 # without closing the connection.
-                self.getPage("/stream?set_cl=Yes")
+                self.getPage("/stream?set_cl=Yes" + ((with_trailer and "&with_trailer=Yes") or ""))
                 self.assertHeader("Content-Length")
                 self.assertNoHeader("Connection", "close")
                 self.assertNoHeader("Transfer-Encoding")
                 
                 self.assertStatus('200 OK')
                 self.assertBody('0123456789')
+
+		## NB: HTTPResponse eats trailer headers, so can't check for them.
+		# if with_trailer:
+		#     self.assertHeader("X-Trailer", "123")
+		# else:
+		#     self.assertNoHeader("X-Trailer")
+
             else:
                 # When no Content-Length response header is provided,
                 # streamed output will either close the connection, or use
                 # chunked encoding, to determine transfer-length.
-                self.getPage("/stream")
+                self.getPage("/stream" + ((with_trailer and "?with_trailer=Yes") or ""))
                 self.assertNoHeader("Content-Length")
                 self.assertStatus('200 OK')
                 self.assertBody('0123456789')
-                
+
+		## NB: HTTPResponse eats trailer headers, so can't check for them.
+		# if with_trailer:
+		#     self.assertHeader("X-Trailer", "123")
+		# else:
+		#     self.assertNoHeader("X-Trailer")
+
                 chunked_response = False
                 for k, v in self.headers:
                     if k.lower() == "transfer-encoding":
@@ -177,6 +197,7 @@ class ConnectionTests(helper.CPWebCase):
                 self.assertStatus('200 OK')
                 self.assertBody('')
                 self.assertNoHeader("Transfer-Encoding")
+                self.assertNoHeader("X-Trailer")
         else:
             self.PROTOCOL = "HTTP/1.0"
             
diff --git a/cherrypy/wsgiserver/__init__.py b/cherrypy/wsgiserver/__init__.py
index c380e18..5ed32e0 100644
--- a/cherrypy/wsgiserver/__init__.py
+++ b/cherrypy/wsgiserver/__init__.py
@@ -553,6 +553,7 @@ class HTTPRequest(object):
                 self.close_connection = True
                 return
         
+        self.environ["cherrypy.trailer_headers"] = self.outheaders.extend
         response = self.wsgi_app(self.environ, self.start_response)
         try:
             for chunk in response:
@@ -572,8 +573,17 @@ class HTTPRequest(object):
             self.sent_headers = True
             self.send_headers()
         if self.chunked_write:
-            self.wfile.sendall("0\r\n\r\n")
-    
+	    try:
+		trailer = ["0\r\n"] + [k + ": " + v + "\r\n" for k, v in self.outheaders] + ["\r\n"]
+	    except TypeError:
+		if not isinstance(k, str):
+		    raise TypeError("WSGI trailer header key %r is not a string.")
+		if not isinstance(v, str):
+		    raise TypeError("WSGI trailer header value %r is not a string.")
+		else:
+		    raise
+	    self.wfile.sendall("".join(trailer))
+
     def simple_response(self, status, msg=""):
         """Write a simple response back to the client."""
         status = str(status)
@@ -706,6 +716,7 @@ class HTTPRequest(object):
                 raise
         buf.append("\r\n")
         self.wfile.sendall("".join(buf))
+	self.outheaders[:] = []
 
 
 class NoSSLError(Exception):