feat: support reversed scans

google/cloud/bigtable/table.py

@@ -573,6 +573,7 @@ def read_rows(
         end_inclusive=False,
         row_set=None,
         retry=DEFAULT_RETRY_READ_ROWS,
+        reversed=None,
     ):
         """Read rows from this table.
 
@@ -619,6 +620,11 @@ def read_rows(
             method or the :meth:`~google.api_core.retry.Retry.with_deadline`
             method.
 
+        :type reversed: bool
+        :param reversed: (Optional) Whether records should return in descending
+                         lexicographical order. The default is False
+                         (ascending).
+
         :rtype: :class:`.PartialRowsData`
         :returns: A :class:`.PartialRowsData` a generator for consuming
                   the streamed results.
@@ -632,6 +638,7 @@ def read_rows(
             end_inclusive=end_inclusive,
             app_profile_id=self._app_profile_id,
             row_set=row_set,
+            reversed=reversed,
         )
         data_client = self._instance._client.table_data_client
         return PartialRowsData(data_client.read_rows, request_pb, retry)
@@ -1265,6 +1272,7 @@ def _create_row_request(
     end_inclusive=False,
     app_profile_id=None,
     row_set=None,
+    reversed=None,
 ):
     """Creates a request to read rows in a table.
 
@@ -1301,6 +1309,9 @@ def _create_row_request(
     :param row_set: (Optional) The row set containing multiple row keys and
                     row_ranges.
 
+    :param reversed: (Optional) Whether records should return in descending
+                    lexicographical order. The default is False (ascending).
+
     :rtype: :class:`data_messages_v2_pb2.ReadRowsRequest`
     :returns: The ``ReadRowsRequest`` protobuf corresponding to the inputs.
     :raises: :class:`ValueError <exceptions.ValueError>` if both
@@ -1316,6 +1327,8 @@ def _create_row_request(
         request_kwargs["rows_limit"] = limit
     if app_profile_id is not None:
         request_kwargs["app_profile_id"] = app_profile_id
+    if reversed is not None:
+        request_kwargs["reversed"] = reversed
 
     message = data_messages_v2_pb2.ReadRowsRequest(**request_kwargs)
 

tests/unit/v2_client/test_table.py

@@ -684,6 +684,7 @@ def mock_create_row_request(table_name, **kwargs):
                 "app_profile_id": app_profile_id,
                 "end_key": None,
                 "limit": None,
+                "reversed": None,
                 "start_key": None,
                 "filter_": filter_obj,
             },
@@ -887,13 +888,15 @@ def mock_create_row_request(table_name, **kwargs):
     end_key = b"end-key"
     filter_obj = object()
     limit = 22
+    reversed = True
     with _Monkey(MUT, _create_row_request=mock_create_row_request):
         result = table.read_rows(
             start_key=start_key,
             end_key=end_key,
             filter_=filter_obj,
             limit=limit,
             retry=retry,
+            reversed=reversed,
         )
 
     assert result.rows == expected_result.rows
@@ -903,6 +906,7 @@ def mock_create_row_request(table_name, **kwargs):
         "end_key": end_key,
         "filter_": filter_obj,
         "limit": limit,
+        "reversed": reversed,
         "end_inclusive": False,
         "app_profile_id": app_profile_id,
         "row_set": None,
@@ -2102,6 +2106,16 @@ def test__create_row_request_with_limit():
     assert result == expected_result
 
 
+def test__create_row_request_with_reversed():
+    from google.cloud.bigtable.table import _create_row_request
+
+    table_name = "table_name"
+    reversed = True
+    result = _create_row_request(table_name, reversed=reversed)
+    expected_result = _ReadRowsRequestPB(table_name=table_name, reversed=reversed)
+    assert result == expected_result
+
+
 def test__create_row_request_with_row_set():
     from google.cloud.bigtable.table import _create_row_request
     from google.cloud.bigtable.row_set import RowSet