rohmu: add progress callback for transferred object keys

Added callback progress_fn to copy_files_from
which tracks the progress of transferred objects.

This does not measure the number of bytes
in order to avoid a provider based implementation.

rohmu/object_storage/base.py

@@ -35,7 +35,7 @@
     TypeVar,
     Union,
 )
-from typing_extensions import Self
+from typing_extensions import Self, TypeAlias
 
 import logging
 import os
@@ -55,6 +55,9 @@ class IterKeyItem(NamedTuple):
 # Argument is the additional number of bytes transferred
 IncrementalProgressCallbackType = Optional[Callable[[int], None]]
 
+# Argument is the transferred object key
+ObjectTransferProgressCallbackType: TypeAlias = Optional[Callable[[str], None]]
+
 
 @dataclass(frozen=True, unsafe_hash=True)
 class ConcurrentUpload:
@@ -202,10 +205,18 @@ def copy_file(
         cannot be copied with this method. If no metadata is given copies the existing metadata."""
         raise NotImplementedError
 
-    def copy_files_from(self, *, source: BaseTransfer[SourceStorageModelT], keys: Collection[str]) -> None:
+    def copy_files_from(
+        self,
+        *,
+        source: BaseTransfer[SourceStorageModelT],
+        keys: Collection[str],
+        progress_fn: ObjectTransferProgressCallbackType = None,
+    ) -> None:
         if isinstance(source, self.__class__):
             for key in keys:
                 self._copy_file_from_bucket(source_bucket=source, source_key=key, destination_key=key, timeout=15)
+                if progress_fn is not None:
+                    progress_fn(key)
         else:
             raise NotImplementedError
 

test/object_storage/test_object_storage.py

@@ -4,6 +4,8 @@
 from rohmu import errors
 from rohmu.object_storage.local import LocalTransfer
 from typing import Any
+from unittest import mock
+from unittest.mock import MagicMock
 
 import pytest
 
@@ -72,15 +74,14 @@ def test_copy(transfer_type: str, request: Any) -> None:
 def test_copy_local_files_from(tmp_path: Path) -> None:
     source = LocalTransfer(tmp_path / "source", prefix="s-prefix")
     destination = LocalTransfer(tmp_path / "destination", prefix="d-prefix")
+    mock_progress_fn = MagicMock(return_value=None)
 
     source.store_file_from_memory("some/a/key.ext", b"content_a", metadata={"info": "aaa"})
     source.store_file_from_memory("some/b/key.ext", b"content_b", metadata={"info": "bbb"})
-    destination.copy_files_from(
-        source=source,
-        keys=["some/a/key.ext", "some/b/key.ext"],
-    )
+    destination.copy_files_from(source=source, keys=["some/a/key.ext", "some/b/key.ext"], progress_fn=mock_progress_fn)
     assert destination.get_contents_to_string("some/a/key.ext") == (b"content_a", {"info": "aaa", "Content-Length": "9"})
     assert destination.get_contents_to_string("some/b/key.ext") == (b"content_b", {"info": "bbb", "Content-Length": "9"})
+    assert mock_progress_fn.call_args_list == [mock.call("some/a/key.ext"), mock.call("some/b/key.ext")]
 
 
 @pytest.mark.parametrize("transfer_type", ["local_transfer"])