Ticket #2504: get_content_length.diff

django/http/__init__.py

@@ -307 +307 @@
 
     content = property(_get_content, _set_content)
 
+    def get_content_length(self):
+        if isinstance(self._container, file):
+            if os.path.exists(self._container.name):
+                return os.path.getsize(self._container.name)
+            else:
+                return None
+        elif isinstance(self._container, (list, tuple)):
+            return len(self.content)
+        else:
+            return None
+
     def __iter__(self):
         self._iterator = iter(self._container)
         return self

django/middleware/http.py

@@ -13 +13 @@
     def process_response(self, request, response):
         response['Date'] = formatdate()[:26] + "GMT"
         if not response.has_header('Content-Length'):
-            response['Content-Length'] = str(len(response.content))
+            content_length = response.get_content_length()
+            if content_length is not None:
+                response['Content-Length'] = str(content_length)
 
         if response.has_header('ETag'):
             if_none_match = request.META.get('HTTP_IF_NONE_MATCH', None)

tests/regressiontests/httpwrappers/tests.py

@@ -391 +391 @@
 >>> q.getlist('foo')
 [u'bar', u'\ufffd']
 
+
+>>> r = HttpResponse()
+>>> r.get_content_length()
+0
+
+>>> r = HttpResponse('foo')
+>>> r.get_content_length()
+3
+
+>>> r = HttpResponse('foo')
+>>> r.write('bar')
+>>> r.get_content_length()
+6
+
+>>> r = HttpResponse(['foo', 'bar', 'foobar'])
+>>> r.get_content_length()
+12
+
+>>> r = HttpResponse(file(__file__))
+>>> assert r.get_content_length() > 0
+
+>>> def ten_foos():
+...     for i in range(10): yield 'foo'
+>>> r = HttpResponse(ten_foos())
+>>> assert r.get_content_length() is None
+>>> print r.content
+foofoofoofoofoofoofoofoofoofoo
+
 """
 
-from django.http import QueryDict
+from django.http import QueryDict, HttpResponse
 
 if __name__ == "__main__":
     import doctest

docs/request_response.txt

@@ -431 +431 @@
 ``write(content)``, ``flush()`` and ``tell()``
     These methods make an ``HttpResponse`` instance a file-like object.
 
+``get_content_length()``
+    Calculates the current length of ``content``. If a file was passed into
+    ``__init__``, its system filesize is returned. If a non-fixed size iterator
+    was passed into ``__init__``, then ``None`` will be returned because the size
+    of ``content`` cannot necessarily be determined.
+
 .. _HTTP Status code: http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10
 
 HttpResponse subclasses