bugfix: auto adapt batch size doesn't work with cls incr case (#2199)

* auto adapt consider cls incremental case

* align with pre-commit

* update changelog

CHANGELOG.md

@@ -25,6 +25,7 @@ All notable changes to this project will be documented in this file.
 ### Bug fixes
 
 - Fix async mode inference for demo in exportable code (<https://github.com/openvinotoolkit/training_extensions/pull/2154>)
+- Fix a bug that auto adapt batch size doesn't work with cls incr case (<https://github.com/openvinotoolkit/training_extensions/pull/2199>)
 
 ### Known issues
 

otx/algorithms/common/adapters/mmcv/utils/automatic_bs.py

@@ -145,6 +145,10 @@ def __init__(self, fullset, num_samples: int):
 
         self.fullset = fullset
         self.num_samples = num_samples
+        self.img_indices = {  # for class incremental case
+            "old": [i for i in range(num_samples // 2)],
+            "new": [i for i in range(num_samples // 2, num_samples)],
+        }
 
     def __len__(self) -> int:
         """Get length of subset."""

tests/unit/algorithms/common/adapters/mmcv/utils/test_automatic_bs.py

@@ -133,7 +133,10 @@ def set_up(self, mocker):
 
     def test_init(self, mocker):
         fullset = mocker.MagicMock()
-        SubDataset(fullset, 3)
+        subset = SubDataset(fullset, 3)
+
+        # test for class incremental case. If below assert can't be passed, ClsIncrSampler can't work well.
+        assert len(subset.img_indices["new"]) / len(subset.img_indices["old"]) + 1 <= self.num_samples
 
     @pytest.mark.parametrize("num_samples", [-1, 0])
     def test_init_w_wrong_num_samples(self, mocker, num_samples):