Close container on deletion

In case the container is not used within a context and not correctly
closed. The sessions are now correctly closed if the container is picked
up by the garbage collection and deleted.

disk_objectstore/container.py

@@ -167,6 +167,10 @@ def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
         """Close the session when exiting the context."""
         self.close()
 
+    def __del__(self) -> None:
+        """Closes all connections on deletion."""
+        self.close()
+
     def _get_sandbox_folder(self) -> Path:
         """Return the path to the sandbox folder that is used during a new object creation.
 

tests/test_container.py

@@ -1146,7 +1146,7 @@ def test_sizes(
         assert size_info["total_size_loose"] == 0
 
 
-def test_get_objects_stream_closes(temp_container, generate_random_data):
+def test_get_objects_stream_closes(temp_dir, generate_random_data):
     """Test that get_objects_stream_and_meta closes intermediate streams.
 
     I also check that at most one additional file is open at any given time.
@@ -1155,6 +1155,15 @@ def test_get_objects_stream_closes(temp_container, generate_random_data):
        when it goes out of scope - so I add also the test that, inside the loop, at most one more file is open.
        The final check seems to always pass even if I forget to do close some file.
     """
+    # Check if it starts with 0 open files
+    current_process = psutil.Process()
+    assert 0 == len(
+        current_process.open_files()
+    ), "No files should be open at the beginning of test. Maybe some test did not properly close its files."
+
+    temp_container = Container(temp_dir)
+    temp_container.init_container()
+
     data = generate_random_data()
     # Store
     obj_md5s = _add_objects_loose_loop(temp_container, data)
@@ -1165,7 +1174,6 @@ def test_get_objects_stream_closes(temp_container, generate_random_data):
     # The following checks are still meaningful, I check that if I do it again I don't open more files.
     temp_container.get_objects_content(obj_md5s.keys())
 
-    current_process = psutil.Process()
     start_open_files = len(current_process.open_files())
 
     with temp_container.get_objects_stream_and_meta(
@@ -1274,6 +1282,38 @@ def test_get_objects_stream_closes(temp_container, generate_random_data):
     # Check that at the end nothing is left open
     assert len(current_process.open_files()) == start_open_files
 
+    # Check if it goes back to 0
+    temp_container.close()
+    assert len(current_process.open_files()) == 0
+
+
+def test_deletion_closes_file_descriptors(temp_dir, generate_random_data):
+    """Test if deletion of container closes correctly open file descriptors."""
+
+    current_process = psutil.Process()
+    assert 0 == len(
+        current_process.open_files()
+    ), "No files should be open at the beginning of test. Maybe some test did not properly close its files."
+
+    # Open files
+    temp_container = Container(temp_dir)
+    temp_container.init_container(clear=True)
+    # For Linux to open files it is required to reading from container, on macOS
+    # the initialization of container is enough
+    data = generate_random_data()
+    obj_md5s = _add_objects_loose_loop(temp_container, data)
+    _ = temp_container.get_objects_content(obj_md5s.keys())
+
+    # Checks if initalisation actually opens files
+    assert 0 < len(
+        current_process.open_files()
+    ), "No files have been opened during initalisation"
+
+    # Checks if deleting the container will close the files
+    del temp_container
+
+    assert 0 == len(current_process.open_files())
+
 
 def test_get_objects_meta_doesnt_open(
     temp_container, generate_random_data