Internal change.

PiperOrigin-RevId: 557561606

checkpoint/orbax/checkpoint/pytree_checkpoint_handler.py

@@ -53,7 +53,7 @@
 TypeHandler = type_handlers.TypeHandler
 AggregateHandler = aggregate_handlers.AggregateHandler
 MsgpackHandler = aggregate_handlers.MsgpackHandler
-TransformFn = Callable[[PyTree, PyTree, PyTree], Tuple[PyTree, PyTree]]
+LegacyTransformFn = Callable[[PyTree, PyTree, PyTree], Tuple[PyTree, PyTree]]
 Transform = transform_utils.Transform
 RestoreTransform = transform_utils.RestoreTransform
 JsonCheckpointHandler = json_checkpoint_handler.JsonCheckpointHandler
@@ -849,7 +849,7 @@ def restore(
       restore_args: Optional[PyTree] = None,
       transforms: Optional[PyTree] = None,
       transforms_default_to_original: bool = True,
-      transform_fn: Optional[TransformFn] = None,
+      legacy_transform_fn: Optional[LegacyTransformFn] = None,
   ) -> PyTree:
     """Restores a PyTree from the checkpoint directory at the given path.
 
@@ -940,9 +940,9 @@ class TrainState:
         completely.
         See `transform_utils` for further information.
       transforms_default_to_original: See transform_utils.apply_transformations.
-      transform_fn: WARNING: NOT GENERALLY SUPPORTED. A function which accepts
-        the `item` argument, a PyTree checkpoint structure and a PyTree of
-        ParamInfos based on the checkpoint. Returns a transformed PyTree
+      legacy_transform_fn: WARNING: NOT GENERALLY SUPPORTED. A function which
+        accepts the `item` argument, a PyTree checkpoint structure and a PyTree
+        of ParamInfos based on the checkpoint. Returns a transformed PyTree
         matching the desired return tree structure, and a matching ParamInfo
         tree.
 
@@ -982,10 +982,12 @@ async def _create_byte_limiter():
         transforms_default_to_original=transforms_default_to_original,
     )
 
-    if transform_fn is not None and transforms is not None:
-      raise ValueError('Cannot provide both `transforms` and `transform_fn`.')
-    if transform_fn is not None:
-      structure, param_infos = transform_fn(item, structure, param_infos)
+    if legacy_transform_fn is not None and transforms is not None:
+      raise ValueError(
+          'Cannot provide both `transforms` and `legacy_transform_fn`.'
+      )
+    if legacy_transform_fn is not None:
+      structure, param_infos = legacy_transform_fn(item, structure, param_infos)
       if restore_args is None:
         restore_args = jax.tree_util.tree_map(lambda x: RestoreArgs(), item)
       checkpoint_restore_args = restore_args
@@ -1009,7 +1011,7 @@ def _maybe_set_default_restore_types(
         self._maybe_deserialize(structure, param_infos, checkpoint_restore_args)
     )
 
-    if not transform_fn:
+    if not legacy_transform_fn:
       restored_item = _transform_checkpoint(
           item,
           restored_item,

checkpoint/orbax/checkpoint/type_handlers.py

@@ -443,9 +443,7 @@ def __init__(
           'Must provide a ts.Context if use_ocdbt is True. Ensure that the'
           ' context contains a coordinator address.'
       )
-    self._ts_context = ts_context or ts.Context(
-        {'file_io_concurrency': {'limit': 128}}
-    )
+    self._ts_context = ts_context or serialization.TS_CONTEXT
 
   def enable_ocdbt(self, ts_context: ts.Context) -> None:
     self._use_ocdbt = True
@@ -651,9 +649,7 @@ def __init__(
           'Must provide a ts.Context if use_ocdbt is True. Ensure that the'
           ' context contains a coordinator address.'
       )
-    self._ts_context = ts_context or ts.Context(
-        {'file_io_concurrency': {'limit': 128}}
-    )
+    self._ts_context = ts_context or serialization.TS_CONTEXT
 
   def enable_ocdbt(self, ts_context: ts.Context) -> None:
     self._use_ocdbt = True

checkpoint/orbax/checkpoint/value_metadata.py

@@ -36,7 +36,9 @@ class ArrayMetadata(Metadata):
     Tuple of integers describing the array shape.
   shards:
     Tuple of integers indicating how many shards each dimension is divided
-    into. May be None if the array is not sharded.
+    into. E.g. a dimension may be 1 if it is unsharded, or 2 if it is divided
+    into 2 chunks.
+    May be None if the array is not sharded.
   dtype:
     Dtype of array elements.
   """