[data] Make sure the tf and tensor iteration work in dataset pipeline (…

…ray-project#34248)

* Revert "[Datasets] Revert "Enable streaming executor by default (ray-project#32493)" (ray-project#33485)"

This reverts commit 5c79954.

* make sure tf and tensor iteration in datapipeline work

* Fix

* fix

* fix

* fix

* feedback

* feedback

* fix

python/ray/data/_internal/stats.py

@@ -786,6 +786,7 @@ def __init__(self, *, max_history: int = 3):
             "iter_get_s": Timer(),
             "iter_next_batch_s": Timer(),
             "iter_format_batch_s": Timer(),
+            "iter_collate_batch_s": Timer(),
             "iter_user_s": Timer(),
             "iter_total_s": Timer(),
         }

python/ray/data/dataset_iterator.py

@@ -31,6 +31,13 @@
     from ray.data.dataset import TensorFlowTensorBatchType
 
 
+def _is_tensor_dataset(schema) -> bool:
+    """Return ``True`` if this is an iterator over a tensor dataset."""
+    if schema is None or isinstance(schema, type):
+        return False
+    return _is_tensor_schema(schema.names)
+
+
 @PublicAPI(stability="beta")
 class DatasetIterator(abc.ABC):
     """An iterator for reading items from a :class:`~Dataset` or
@@ -728,13 +735,14 @@ def to_tf(
         except ImportError:
             raise ValueError("tensorflow must be installed!")
 
-        if self._is_tensor_dataset():
+        schema = self.schema()
+
+        if _is_tensor_dataset(schema):
             raise NotImplementedError(
                 "`to_tf` doesn't support single-column tensor datasets. Call the "
                 "more-flexible `iter_batches` instead."
             )
 
-        schema = self.schema()
         if isinstance(schema, type):
             raise NotImplementedError(
                 "`to_tf` doesn't support simple datasets. Call `map_batches` and "
@@ -818,10 +826,3 @@ def iter_epochs(self, max_epoch: int = -1) -> None:
             "To iterate over one epoch of data, use iter_batches(), "
             "iter_torch_batches(), or to_tf()."
         )
-
-    def _is_tensor_dataset(self) -> bool:
-        """Return ``True`` if this is an iterator over a tensor dataset."""
-        schema = self.schema()
-        if schema is None or isinstance(schema, type):
-            return False
-        return _is_tensor_schema(schema.names)

python/ray/data/dataset_pipeline.py

@@ -169,6 +169,8 @@ def gen_rows() -> Iterator[Union[T, TableRow]]:
     def iter_batches(
         self,
         *,
+        prefetch_batches: int = 1,
+        # Deprecated.
         prefetch_blocks: int = 0,
         batch_size: Optional[int] = 256,
         batch_format: Optional[str] = "default",
@@ -1071,7 +1073,7 @@ def iter_tf_batches(
         """Call
         :py:meth:`Dataset.iter_tf_batches <ray.data.Dataset.iter_tf_batches>`
         over the stream of output batches from the pipeline."""
-        return Dataset.iter_tf_batches(
+        return DatasetIterator.iter_tf_batches(
             self,
             prefetch_blocks=prefetch_blocks,
             batch_size=batch_size,
@@ -1097,7 +1099,7 @@ def iter_torch_batches(
         """Call
         :py:meth:`Dataset.iter_torch_batches <ray.data.Dataset.iter_torch_batches>`
         over the stream of output batches from the pipeline."""
-        return Dataset.iter_torch_batches(
+        return DatasetIterator.iter_torch_batches(
             self,
             prefetch_blocks=prefetch_blocks,
             batch_size=batch_size,
@@ -1122,7 +1124,7 @@ def to_tf(
     ) -> "tf.data.Dataset":
         """Call :py:meth:`Dataset.to_tf <ray.data.Dataset.to_tf>` over the stream of
         output batches from the pipeline"""
-        return Dataset.to_tf(
+        return DatasetIterator.to_tf(
             self,
             feature_columns=feature_columns,
             label_columns=label_columns,
@@ -1152,7 +1154,7 @@ def to_torch(
     ) -> "torch.utils.data.IterableDataset":
         """Call :py:meth:`Dataset.to_torch <ray.data.Dataset.to_torch>` over the stream
         of output batches from the pipeline"""
-        return Dataset.to_torch(
+        return DatasetIterator.to_torch(
             self,
             label_column=label_column,
             feature_columns=feature_columns,

python/ray/data/tests/test_dataset_pipeline.py

@@ -394,9 +394,31 @@ def test_iter_batches_basic(ray_start_regular_shared):
 
 
 def test_to_torch(ray_start_regular_shared):
-    pipe = ray.data.range(10, parallelism=10).window(blocks_per_window=2)
+    pipe = ray.data.range(10, parallelism=10).window(blocks_per_window=2).repeat(2)
     batches = list(pipe.to_torch(batch_size=None))
-    assert len(batches) == 10
+    assert len(batches) == 20
+
+
+def test_to_tf(ray_start_regular_shared):
+    ds = ray.data.range_tensor(10, shape=(1, 1, 1), parallelism=10)
+    ds = ds.add_column("label", lambda x: 1)
+    pipe = ds.window(blocks_per_window=2).repeat(2)
+    batches = list(
+        pipe.to_tf(feature_columns="__value__", label_columns="label", batch_size=None)
+    )
+    assert len(batches) == 20
+
+
+def test_iter_torch_batches(ray_start_regular_shared):
+    pipe = ray.data.range(10).repeat(2)
+    batches = list(pipe.iter_torch_batches(batch_size=1))
+    assert len(batches) == 20
+
+
+def test_iter_tf_batches(ray_start_regular_shared):
+    pipe = ray.data.range(10).repeat(2)
+    batches = list(pipe.iter_tf_batches(batch_size=1))
+    assert len(batches) == 20
 
 
 def test_iter_batches_batch_across_windows(ray_start_regular_shared):