serialize.py 文件源码

def prepare_response(self, request, cached):
        """Verify our vary headers match and construct a real urllib3
        HTTPResponse object.
        """
        # Special case the '*' Vary value as it means we cannot actually
        # determine if the cached response is suitable for this request.
        if "*" in cached.get("vary", {}):
            return

        # Ensure that the Vary headers for the cached response match our
        # request
        for header, value in cached.get("vary", {}).items():
            if request.headers.get(header, None) != value:
                return

        body_raw = cached["response"].pop("body")

        headers = CaseInsensitiveDict(data=cached['response']['headers'])
        if headers.get('transfer-encoding', '') == 'chunked':
            headers.pop('transfer-encoding')

        cached['response']['headers'] = headers

        try:
            body = io.BytesIO(body_raw)
        except TypeError:
            # This can happen if cachecontrol serialized to v1 format (pickle)
            # using Python 2. A Python 2 str(byte string) will be unpickled as
            # a Python 3 str (unicode string), which will cause the above to
            # fail with:
            #
            #     TypeError: 'str' does not support the buffer interface
            body = io.BytesIO(body_raw.encode('utf8'))

        return HTTPResponse(
            body=body,
            preload_content=False,
            **cached["response"]
        )