Django源码分析——response.py

 1 class HttpResponse(HttpResponseBase):
 2     """
 3     An HTTP response class with a string as content.
 4 
 5     This content that can be read, appended to or replaced.
 6     """
 7 
 8     streaming = False
 9 
10     def __init__(self, content=‘‘, *args, **kwargs):
11         super(HttpResponse, self).__init__(*args, **kwargs)
12         # Content is a bytestring. See the `content` property methods.
13         self.content = content
14 
15     def serialize(self):
16         """Full HTTP message, including headers, as a bytestring."""
17         return self.serialize_headers() + b‘\r\n\r\n‘ + self.content
18 
19     if six.PY3:
20         __bytes__ = serialize
21     else:
22         __str__ = serialize
23 
24     def _consume_content(self):
25         # If the response was instantiated with an iterator, when its content
26         # is accessed, the iterator is going be exhausted and the content
27         # loaded in memory. At this point, it‘s better to abandon the original
28         # iterator and save the content for later reuse. This is a temporary
29         # solution. See the comment in __iter__ below for the long term plan.
30         if self._base_content_is_iter:
31             self.content = b‘‘.join(self.make_bytes(e) for e in self._container)
32 
33     @property
34     def content(self):
35         self._consume_content()
36         return b‘‘.join(self.make_bytes(e) for e in self._container)
37 
38     @content.setter
39     def content(self, value):
40         if hasattr(value, ‘__iter__‘) and not isinstance(value, (bytes, six.string_types)):
41             self._container = value
42             self._base_content_is_iter = True
43             if hasattr(value, ‘close‘):
44                 self._closable_objects.append(value)
45         else:
46             self._container = [value]
47             self._base_content_is_iter = False
48 
49     def __iter__(self):
50         # Raise a deprecation warning only if the content wasn‘t consumed yet,
51         # because the response may be intended to be streamed.
52         # Once the deprecation completes, iterators should be consumed upon
53         # assignment rather than upon access. The _consume_content method
54         # should be removed. See #6527.
55         if self._base_content_is_iter:
56             warnings.warn(
57                 ‘Creating streaming responses with `HttpResponse` is ‘
58                 ‘deprecated. Use `StreamingHttpResponse` instead ‘
59                 ‘if you need the streaming behavior.‘,
60                 PendingDeprecationWarning, stacklevel=2)
61         if not hasattr(self, ‘_iterator‘):
62             self._iterator = iter(self._container)
63         return self
64 
65     def write(self, content):
66         self._consume_content()
67         self._container.append(content)
68 
69     def tell(self):
70         self._consume_content()
71         return len(self.content)