cleanup prototype datasets (#4471)

* cleanup image folder

* make shuffling mandatory

* rename parameter in home() function

* don't show builtin list

* make categories optional in dataset info

* use pseudo-infinite buffer size for shuffler
Co-authored-by: Francisco Massa <fvsmassa@gmail.com>

torchvision/prototype/datasets/__init__.py

@@ -2,5 +2,5 @@ from ._home import home
 from . import decoder, utils
 
 # Load this last, since some parts depend on the above being loaded first
-from ._api import register, list, info, load
+from ._api import register, _list as list, info, load
 from ._folder import from_data_folder, from_image_folder

torchvision/prototype/datasets/_api.py

@@ -17,7 +17,8 @@ def register(dataset: Dataset) -> None:
     DATASETS[dataset.name] = dataset
 
 
-def list() -> List[str]:
+# This is exposed as 'list', but we avoid that here to not shadow the built-in 'list'
+def _list() -> List[str]:
     return sorted(DATASETS.keys())
 
 
@@ -45,7 +46,6 @@ def info(name: str) -> DatasetInfo:
 def load(
     name: str,
     *,
-    shuffler: Optional[Callable[[IterDataPipe], IterDataPipe]] = None,
     decoder: Optional[Callable[[io.IOBase], torch.Tensor]] = pil,
     split: str = "train",
     **options: Any,
@@ -55,4 +55,4 @@ def load(
     config = dataset.info.make_config(split=split, **options)
     root = home() / name
 
-    return dataset.to_datapipe(root, config=config, shuffler=shuffler, decoder=decoder)
+    return dataset.to_datapipe(root, config=config, decoder=decoder)

torchvision/prototype/datasets/_folder.py

@@ -10,13 +10,11 @@ from torch.utils.data import IterDataPipe
 from torch.utils.data.datapipes.iter import FileLister, FileLoader, Mapper, Shuffler, Filter
 
 from torchvision.prototype.datasets.decoder import pil
+from torchvision.prototype.datasets.utils._internal import INFINITE_BUFFER_SIZE
 
 
 __all__ = ["from_data_folder", "from_image_folder"]
 
-# pseudo-infinite buffer size until a true infinite buffer is supported
-INFINITE = 1_000_000_000
-
 
 def _is_not_top_level_file(path: str, *, root: pathlib.Path) -> bool:
     rel_path = pathlib.Path(path).relative_to(root)
@@ -45,7 +43,6 @@ def _collate_and_decode_data(
 def from_data_folder(
     root: Union[str, pathlib.Path],
     *,
-    shuffler: Optional[Callable[[IterDataPipe], IterDataPipe]] = lambda dp: Shuffler(dp, buffer_size=INFINITE),
     decoder: Optional[Callable[[io.IOBase], torch.Tensor]] = None,
     valid_extensions: Optional[Collection[str]] = None,
     recursive: bool = True,
@@ -55,8 +52,7 @@ def from_data_folder(
     masks: Union[List[str], str] = [f"*.{ext}" for ext in valid_extensions] if valid_extensions is not None else ""
     dp: IterDataPipe = FileLister(str(root), recursive=recursive, masks=masks)
     dp = Filter(dp, _is_not_top_level_file, fn_kwargs=dict(root=root))
-    if shuffler:
-        dp = shuffler(dp)
+    dp = Shuffler(dp, buffer_size=INFINITE_BUFFER_SIZE)
     dp = FileLoader(dp)
     return (
         Mapper(dp, _collate_and_decode_data, fn_kwargs=dict(root=root, categories=categories, decoder=decoder)),

torchvision/prototype/datasets/_home.py

@@ -7,14 +7,14 @@ from torch.hub import _get_torch_home
 HOME = pathlib.Path(_get_torch_home()) / "datasets" / "vision"
 
 
-def home(home: Optional[Union[str, pathlib.Path]] = None) -> pathlib.Path:
+def home(root: Optional[Union[str, pathlib.Path]] = None) -> pathlib.Path:
     global HOME
-    if home is not None:
-        HOME = pathlib.Path(home).expanduser().resolve()
+    if root is not None:
+        HOME = pathlib.Path(root).expanduser().resolve()
         return HOME
 
-    home = os.getenv("TORCHVISION_DATASETS_HOME")
-    if home is not None:
-        return pathlib.Path(home)
+    root = os.getenv("TORCHVISION_DATASETS_HOME")
+    if root is not None:
+        return pathlib.Path(root)
 
     return HOME

torchvision/prototype/datasets/decoder.py

 import io
 
-import numpy as np
 import PIL.Image
 import torch
 
+from torchvision.transforms.functional import pil_to_tensor
+
 __all__ = ["pil"]
 
 
 def pil(file: io.IOBase, mode: str = "RGB") -> torch.Tensor:
-    image = PIL.Image.open(file).convert(mode.upper())
-    return torch.from_numpy(np.array(image, copy=True)).permute((2, 0, 1))
+    return pil_to_tensor(PIL.Image.open(file).convert(mode.upper()))

torchvision/prototype/datasets/utils/_dataset.py

@@ -98,7 +98,7 @@ class DatasetInfo:
         self,
         name: str,
         *,
-        categories: Union[int, Sequence[str], str, pathlib.Path],
+        categories: Optional[Union[int, Sequence[str], str, pathlib.Path]] = None,
         citation: Optional[str] = None,
         homepage: Optional[str] = None,
         license: Optional[str] = None,
@@ -106,7 +106,9 @@ class DatasetInfo:
     ) -> None:
         self.name = name.lower()
 
-        if isinstance(categories, int):
+        if categories is None:
+            categories = []
+        elif isinstance(categories, int):
             categories = [str(label) for label in range(categories)]
         elif isinstance(categories, (str, pathlib.Path)):
             with open(pathlib.Path(categories).expanduser().resolve(), "r") as fh:
@@ -198,7 +200,6 @@ class Dataset(abc.ABC):
         resource_dps: List[IterDataPipe],
         *,
         config: DatasetConfig,
-        shuffler: Optional[Callable[[IterDataPipe], IterDataPipe]],
         decoder: Optional[Callable[[io.IOBase], torch.Tensor]],
     ) -> IterDataPipe[Dict[str, Any]]:
         pass
@@ -208,7 +209,6 @@ class Dataset(abc.ABC):
         root: Union[str, pathlib.Path],
         *,
         config: Optional[DatasetConfig] = None,
-        shuffler: Optional[Callable[[IterDataPipe], IterDataPipe]] = None,
         decoder: Optional[Callable[[io.IOBase], torch.Tensor]] = None,
     ) -> IterDataPipe[Dict[str, Any]]:
         if not config:
@@ -217,4 +217,4 @@ class Dataset(abc.ABC):
         resource_dps = [
             resource.to_datapipe(root) for resource in self.resources(config)
         ]
-        return self._make_datapipe(resource_dps, config=config, shuffler=shuffler, decoder=decoder)
+        return self._make_datapipe(resource_dps, config=config, decoder=decoder)

torchvision/prototype/datasets/utils/_internal.py

@@ -4,10 +4,14 @@ from typing import Collection, Sequence, Callable
 
 
 __all__ = [
+    "INFINITE_BUFFER_SIZE",
     "sequence_to_str",
     "add_suggestion",
 ]
 
+# pseudo-infinite until a true infinite buffer is supported by all datapipes
+INFINITE_BUFFER_SIZE = 1_000_000_000
+
 
 def sequence_to_str(seq: Sequence, separate_last: str = "") -> str:
     if len(seq) == 1: