[Fix] fix bug in CombinedDataset and remove RepeatDataset (#1930)

mmpose/datasets/__init__.py

@@ -1,7 +1,7 @@
 # Copyright (c) OpenMMLab. All rights reserved.
 from .builder import build_dataset
-from .dataset_wrappers import CombinedDataset, RepeatDataset
+from .dataset_wrappers import CombinedDataset
 from .datasets import *  # noqa
 from .transforms import *  # noqa
 
-__all__ = ['build_dataset', 'RepeatDataset', 'CombinedDataset']
+__all__ = ['build_dataset', 'CombinedDataset']

mmpose/datasets/dataset_wrappers.py

@@ -10,35 +10,6 @@
 from .datasets.utils import parse_pose_metainfo
 
 
-@DATASETS.register_module()
-class RepeatDataset:
-    """A wrapper of repeated dataset.
-
-    The length of repeated dataset will be `times` larger than the original
-    dataset. This is useful when the data loading time is long but the dataset
-    is small. Using RepeatDataset can reduce the data loading time between
-    epochs.
-
-    Args:
-        dataset (:obj:`Dataset`): The dataset to be repeated.
-        times (int): Repeat times.
-    """
-
-    def __init__(self, dataset, times):
-        self.dataset = dataset
-        self.times = times
-
-        self._ori_len = len(self.dataset)
-
-    def __getitem__(self, idx):
-        """Get data."""
-        return self.dataset[idx % self._ori_len]
-
-    def __len__(self):
-        """Length after repetition."""
-        return self.times * self._ori_len
-
-
 @DATASETS.register_module()
 class CombinedDataset(BaseDataset):
     """A wrapper of combined dataset.
@@ -113,10 +84,7 @@ def prepare_data(self, idx: int) -> Any:
             Any: Depends on ``self.pipeline``.
         """
 
-        subset_idx, sample_idx = self._get_subset_index(idx)
-        # Get data sample from the subset
-        data_info = self.datasets[subset_idx].get_data_info(sample_idx)
-        data_info = self.datasets[subset_idx].pipeline(data_info)
+        data_info = self.get_data_info(idx)
 
         # Add metainfo items that are required in the pipeline and the model
         metainfo_keys = [
@@ -125,13 +93,24 @@ def prepare_data(self, idx: int) -> Any:
         ]
 
         for key in metainfo_keys:
-            assert key not in data_info, (
-                f'"{key}" is a reserved key for `metainfo`, but already '
-                'exists in the `data_info`.')
             data_info[key] = deepcopy(self._metainfo[key])
 
         return self.pipeline(data_info)
 
+    def get_data_info(self, idx: int) -> dict:
+        """Get annotation by index.
+
+        Args:
+            idx (int): Global index of ``CombinedDataset``.
+        Returns:
+            dict: The idx-th annotation of the datasets.
+        """
+        subset_idx, sample_idx = self._get_subset_index(idx)
+        # Get data sample processed by ``subset.pipeline``
+        data_info = self.datasets[subset_idx][sample_idx]
+
+        return data_info
+
     def full_init(self):
         """Fully initialize all sub datasets."""