Add Ring buffer to store last 10 response objects

Problem: 
Currently, response objects are not accessible through the SDK, making certain actions , like checking header data, impossible to do from the user side.

Solution: 
Store the last 10 response objects in a ring buffer and provide a function in archivist to retrieve  a user selected amount

Signed off: 
Serhiy: <Serhiy1@live.co.uk>

Author: serhiy

archivist/archivist.py

@@ -33,7 +33,8 @@
 
 import json
 from os.path import isfile as os_path_isfile
-from typing import BinaryIO, Dict, Optional
+from typing import BinaryIO, Dict, List, Optional
+from collections import deque
 from requests.models import Response
 
 from flatten_dict import flatten
@@ -93,6 +94,8 @@ class Archivist:  # pylint: disable=too-many-instance-attributes
 
     """
 
+    RING_BUFFER_MAX_LEN = 10
+
     def __init__(
         self,
         url: str,
@@ -121,6 +124,7 @@ def __init__(
                 raise ArchivistNotFoundError(f"Cert file {cert} does not exist")
 
         self._cert = cert
+        self._response_ring_buffer = deque(maxlen=self.RING_BUFFER_MAX_LEN)
 
         # keep these in sync with CLIENTS map above
         self.assets: _AssetsClient
@@ -191,6 +195,8 @@ def get(
             cert=self.cert,
         )
 
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
@@ -227,6 +233,9 @@ def get_file(
             cert=self.cert,
             stream=True,
         )
+
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
@@ -297,6 +306,8 @@ def post_file(self, path: str, fd: BinaryIO, mtype: str) -> Dict:
             cert=self.cert,
         )
 
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
@@ -326,6 +337,8 @@ def delete(
             cert=self.cert,
         )
 
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
@@ -363,6 +376,8 @@ def patch(
             cert=self.cert,
         )
 
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
@@ -379,12 +394,23 @@ def __list(self, path, args, *, headers=None) -> Response:
             verify=self.verify,
             cert=self.cert,
         )
+
+        self._response_ring_buffer.appendleft(response)
+
         error = _parse_response(response)
         if error is not None:
             raise error
 
         return response
 
+    def last_response(self, *, responses: int = 1) -> List[Response]:
+        """Returns the requested number of response objects from the response ring buffer
+        args:
+            responses (int): Number of responses to be returned in a list
+        """
+
+        return list(self._response_ring_buffer)[:responses]
+
     @staticmethod
     def __query(query: Optional[Dict]):
         return query and "&".join(

unittests/testarchivist.py

@@ -307,6 +307,16 @@ def test_get(self, mock_get):
             msg="GET method called incorrectly",
         )
 
+    @mock.patch("requests.get")
+    def test_ring_buffer(self, mock_get):
+        """
+        Test That the ring buffer for response objects works as expected
+        """
+        mock_get.return_value = MockResponse(200)
+        resp = self.arch.get("path/path", "entity/xxxxxxxx")
+        last_response = self.arch.last_response()
+        self.assertEqual(last_response, [mock_get.return_value])
+
     @mock.patch("requests.get")
     def test_get_with_error(self, mock_get):
         """