def __call__(self, env, start_response):
        request = Request(env)
        try:
            (version, account, container, objname) = split_path(request.path_info, 1, 4, True)
        except ValueError:
            response = request.get_response(self.app)
            return response(env, start_response)
        if not objname:
            response = request.get_response(self.app)
            if container:
                if not request.params.has_key('compress'):
                    response.body = response.body.replace(self.compress_suffix, '')
            return response(env, start_response)

        original_path_info = request.path_info
        request.path_info += self.compress_suffix
        if request.method == 'GET':
            if not request.params.has_key('compress'):
                # we need to decompress
                response = request.get_response(self.app)

                if response.status_int == 404:
                    # it may not be compressed, if admin added the compress filter after 
                    # some files have been uploaded
                    request.path_info = original_path_info
                    response = request.get_response(self.app)
                    return response(env, start_response)
                uncompressed_data = create_uncompress(response.body)
                response.body = uncompressed_data
                return response(env, start_response)
       
        if request.method == 'PUT':
            if hasattr(request, 'body_file'):
                data = ""
                while True:
                    chunk = request.body_file.read()
                    if not chunk:
                        break
                    data += chunk
                request.body = data
                compress_data = create_compress(data)
            else:
                compress_data = create_compress(request.body)
            if compress_data:
                request.body = compress_data

        response = request.get_response(self.app)
        return response(env, start_response)
    def _initialize(self):
        resp = None

        if self.swift_client:
            resp = self.swift_client.make_request('HEAD', self.path, {},
                                                  (2, 4))
        elif self.env:
            req = Request(self.env)
            req.method = 'HEAD'
            req.path_info = self.path
            req.headers['Content-Length'] = '0'
            resp = req.get_response(self.app)

        if resp is None:
            return

        self.status = resp.status_int

        if is_success(self.status):
            self.headers = resp.headers