Add as_cpu to TensorCPU and TensorListCPU

Signed-off-by: Joaquin Anton Guirao <[email protected]>

dali/python/backend_impl.cc

@@ -718,6 +718,11 @@ void ExposeTensor(py::module &m) {
       Returns a `TensorGPU` object being a copy of this `TensorCPU`.
       )code",
       py::return_value_policy::take_ownership)
+    .def("as_cpu", [](Tensor<CPUBackend> &t) -> Tensor<CPUBackend>& {
+          return t;
+        },
+      R"code(Bypass, since the object is already an instance of `TensorCPU`.)code",
+      py::return_value_policy::reference_internal)
     .def("copy_to_external",
         [](Tensor<CPUBackend> &t, py::object p) {
           CopyToExternal<mm::memory_kind::host>(ctypes_void_ptr(p), t, AccessOrder::host(), false);
@@ -1174,6 +1179,10 @@ void ExposeTensorList(py::module &m) {
       Returns a `TensorListGPU` object being a copy of this `TensorListCPU`.
       )code",
       py::return_value_policy::take_ownership)
+    .def("as_cpu", [](TensorList<CPUBackend> &t) {
+        return t;
+      }, R"code(No-op, as it is already an instance of `TensorListCPU`.)code",
+      py::return_value_policy::internal_reference)
     .def("layout", [](TensorList<CPUBackend> &t) {
       return t.GetLayout().str();
     })

dali/python/nvidia/dali/tensors.pyi

@@ -27,6 +27,7 @@ class TensorCPU:
     @overload
     def __init__(self, b, layout: str = ..., is_pinned: bool = ...) -> None: ...
     def _as_gpu(self, *args, **kwargs) -> Any: ...
+    def as_cpu(self) -> TensorCPU: ...
 
     # def __dlpack__(self, stream: Optional[int] = None) -> capsule: ...
 
@@ -92,7 +93,8 @@ class TensorListCPU:
     def __init__(self, list_of_tensors: list, layout: str = ...) -> None: ...
 
     # def _as_gpu(self, *args, **kwargs) -> TensorListGPU:  ...
-
+    def as_cpu(self) -> TensorListCPU: ...
+
     # def as_array(self) -> numpy.ndarray: ...
     def as_array(self) -> Any: ...
     def as_reshaped_tensor(self, arg0: List[int]) -> TensorCPU: ...

dali/test/python/auto_aug/test_augmentations.py

@@ -19,7 +19,6 @@
 from PIL import Image, ImageEnhance, ImageOps
 from nose2.tools import params, cartesian_params
 
-import nvidia.dali.tensors as _tensors
 from nvidia.dali import fn, pipeline_def
 from nvidia.dali.auto_aug import augmentations as a
 from nvidia.dali.auto_aug.core._utils import get_translations as _get_translations
@@ -91,8 +90,7 @@ def pipeline():
     if dev == "gpu":
         output = output.as_cpu()
     output = [np.array(sample) for sample in output]
-    if isinstance(data, _tensors.TensorListGPU):
-        data = data.as_cpu()
+    data = data.as_cpu()
     data = [np.array(sample) for sample in data]
 
     if modality == "image":

dali/test/python/auto_aug/test_rand_augment.py

@@ -21,7 +21,7 @@
 from scipy.stats import chisquare
 from nose2.tools import params
 
-from nvidia.dali import fn, tensors, types
+from nvidia.dali import fn, types
 from nvidia.dali import pipeline_def
 from nvidia.dali.auto_aug import rand_augment
 from nvidia.dali.auto_aug.core import augmentation
@@ -43,8 +43,7 @@ def debug_discrepancy_helper(*batch_pairs):
     """
 
     def as_array_list(batch):
-        if isinstance(batch, tensors.TensorListGPU):
-            batch = batch.as_cpu()
+        batch = batch.as_cpu()
         return [np.array(sample) for sample in batch]
 
     batch_names = [name for _, _, name in batch_pairs]

dali/test/python/checkpointing/test_dali_stateless_operators.py

@@ -16,7 +16,6 @@
 import glob
 import numpy as np
 import itertools
-import nvidia.dali as dali
 from nvidia.dali import fn, pipeline_def, types
 from test_utils import (
     compare_pipelines,
@@ -41,9 +40,7 @@
 
 
 def tensor_list_to_array(tensor_list):
-    if isinstance(tensor_list, dali.backend_impl.TensorListGPU):
-        tensor_list = tensor_list.as_cpu()
-    return tensor_list.as_array()
+    return tensor_list.as_cpu().as_array()
 
 
 # Check whether a given pipeline is stateless

dali/test/python/decoder/test_video.py

@@ -21,7 +21,6 @@
 import os
 from itertools import cycle
 from test_utils import get_dali_extra_path, is_mulit_gpu, skip_if_m60
-from nvidia.dali.backend import TensorListGPU
 from nose2.tools import params
 from nose_utils import SkipTest, attr, assert_raises
 
@@ -77,8 +76,7 @@ def video_decoder_iter(batch_size, epochs=1, device="cpu", module=fn.experimenta
     pipe.build()
     for _ in range(int((epochs * len(files) + batch_size - 1) / batch_size)):
         (output,) = pipe.run()
-        if isinstance(output, TensorListGPU):
-            output = output.as_cpu()
+        output = output.as_cpu()
         for i in range(batch_size):
             yield np.array(output[i])
 
@@ -89,8 +87,7 @@ def ref_iter(epochs=1, device="cpu"):
             pipe = reference_pipeline(filename, device=device)
             pipe.build()
             (output,) = pipe.run()
-            if isinstance(output, TensorListGPU):
-                output = output.as_cpu()
+            output = output.as_cpu()
             yield np.array(output[0])
 
 

dali/test/python/operator_1/test_arithmetic_ops.py

@@ -17,7 +17,6 @@
 import nvidia.dali.ops as ops
 import nvidia.dali.types as types
 import nvidia.dali.math as math
-from nvidia.dali.tensors import TensorListGPU
 import numpy as np
 from nose_utils import attr, raises, assert_raises, assert_equals
 from nose2.tools import params
@@ -226,12 +225,6 @@ def default_range(*types):
 ]
 
 
-def as_cpu(tl):
-    if isinstance(tl, TensorListGPU):
-        return tl.as_cpu()
-    return tl
-
-
 def max_dtype(kind, left_dtype, right_dtype):
     return np.dtype(kind + str(max(left_dtype.itemsize, right_dtype.itemsize)))
 
@@ -449,8 +442,8 @@ def get_numpy_input(input, kind, orig_type, target_type):
 
 
 def extract_un_data(pipe_out, sample_id, kind, target_type):
-    input = as_cpu(pipe_out[0]).at(sample_id)
-    out = as_cpu(pipe_out[1]).at(sample_id)
+    input = pipe_out[0].at(sample_id).as_cpu()
+    out = pipe_out[1].at(sample_id).as_cpu()
     assert_equals(out.dtype, target_type)
     in_np = get_numpy_input(input, kind, input.dtype.type, target_type)
     return in_np, out
@@ -465,15 +458,15 @@ def extract_data(pipe_out, sample_id, kinds, target_type):
     arity = len(kinds)
     inputs = []
     for i in range(arity):
-        dali_in = as_cpu(pipe_out[i]).at(sample_id)
+        dali_in = pipe_out[i].at(sample_id).as_cpu()
         numpy_in = get_numpy_input(
             dali_in,
             kinds[i],
             dali_in.dtype.type,
             target_type if target_type is not None else dali_in.dtype.type,
         )
         inputs.append(numpy_in)
-    out = as_cpu(pipe_out[arity]).at(sample_id)
+    out = pipe_out[arity].at(sample_id).as_cpu()
     return tuple(inputs) + (out,)
 
 

dali/test/python/operator_1/test_batch_permute.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import nvidia.dali as dali
 import nvidia.dali.fn as fn
 from nvidia.dali.pipeline import Pipeline
 import numpy as np
@@ -69,8 +68,7 @@ def _test_permute_batch(device, type):
     for i in range(10):
         orig, permuted, idxs = pipe.run()
         idxs = [int(idxs.at(i)) for i in range(batch_size)]
-        if isinstance(orig, dali.backend.TensorListGPU):
-            orig = orig.as_cpu()
+        orig = orig.as_cpu()
         ref = [orig.at(idx) for idx in idxs]
         check_batch(permuted, ref, len(ref), 0, 0, "abc")
 
@@ -91,10 +89,9 @@ def _test_permute_batch_fixed(device):
     pipe.set_outputs(data, fn.permute_batch(data, indices=idxs))
     pipe.build()
 
-    for i in range(10):
+    for _ in range(10):
         orig, permuted = pipe.run()
-        if isinstance(orig, dali.backend.TensorListGPU):
-            orig = orig.as_cpu()
+        orig = orig.as_cpu()
         ref = [orig.at(idx) for idx in idxs]
         check_batch(permuted, ref, len(ref), 0, 0, "abc")
 

dali/test/python/operator_1/test_coin_flip.py

@@ -14,7 +14,6 @@
 
 import numpy as np
 import nvidia.dali as dali
-from nvidia.dali.backend_impl import TensorListGPU
 from nvidia.dali.pipeline import Pipeline
 
 
@@ -53,10 +52,10 @@ def shape_gen_f():
         pipe.set_outputs(*outputs)
     pipe.build()
     outputs = pipe.run()
-    data_out = outputs[0].as_cpu() if isinstance(outputs[0], TensorListGPU) else outputs[0]
+    data_out = outputs[0].as_cpu()
     shapes_out = None
     if max_shape is not None:
-        shapes_out = outputs[1].as_cpu() if isinstance(outputs[1], TensorListGPU) else outputs[1]
+        shapes_out = outputs[1].as_cpu()
     p = p if p is not None else 0.5
     for i in range(batch_size):
         data = np.array(data_out[i])

dali/test/python/operator_1/test_coord_flip.py

@@ -70,7 +70,7 @@ def check_operator_coord_flip(device, batch_size, layout, shape, center_x, cente
         for sample in range(batch_size):
             in_coords = outputs[0].at(sample)
             if device == "gpu":
-                out_coords = outputs[1].as_cpu().at(sample)
+                out_coords = outputs[1].at(sample).as_cpu()
             else:
                 out_coords = outputs[1].at(sample)
             if in_coords.shape == () or in_coords.shape[0] == 0:

dali/test/python/operator_1/test_crop.py

@@ -16,7 +16,6 @@
 from nvidia.dali import pipeline_def, fn
 import nvidia.dali.ops as ops
 import nvidia.dali.types as types
-import nvidia.dali as dali
 import numpy as np
 import os
 from nose_utils import assert_raises
@@ -580,15 +579,10 @@ def check_crop_with_out_of_bounds_policy_support(
     if fill_values is None:
         fill_values = 0
     pipe.build()
-    for k in range(3):
+    for _ in range(3):
         outs = pipe.run()
-        out = outs[0]
-        in_data = outs[1]
-        if isinstance(out, dali.backend_impl.TensorListGPU):
-            out = out.as_cpu()
-        if isinstance(in_data, dali.backend_impl.TensorListGPU):
-            in_data = in_data.as_cpu()
-
+        out = outs[0].as_cpu()
+        in_data = outs[1].as_cpu()
         assert batch_size == len(out)
         for idx in range(batch_size):
             sample_in = in_data.at(idx)

dali/test/python/operator_1/test_crop_mirror_normalize.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import numpy as np
-import nvidia.dali as dali
 import nvidia.dali.fn as fn
 import nvidia.dali.ops as ops
 import nvidia.dali.types as types
@@ -773,10 +772,8 @@ def check_cmn_with_out_of_bounds_policy_support(
         out = outs[0]
         in_data = outs[1]
         mirror_data = outs[2]
-        if isinstance(out, dali.backend_impl.TensorListGPU):
-            out = out.as_cpu()
-        if isinstance(in_data, dali.backend_impl.TensorListGPU):
-            in_data = in_data.as_cpu()
+        out = out.as_cpu()
+        in_data = in_data.as_cpu()
 
         assert batch_size == len(out)
         for idx in range(batch_size):
@@ -907,14 +904,7 @@ def pipe():
     for _ in range(3):
         outs = p.run()
         for s in range(batch_size):
-            out, image_like, mean, std = [
-                (
-                    np.array(o[s].as_cpu())
-                    if isinstance(o, dali.backend_impl.TensorListGPU)
-                    else np.array(o[s])
-                )
-                for o in outs
-            ]
+            out, image_like, mean, std = [np.array(o[s].as_cpu()) for o in outs]
         ref_scale = scale or 1.0
         ref_shift = shift or 0.0
         ref_out = ref_scale * (image_like - mean) / std + ref_shift

dali/test/python/operator_1/test_input_promotion.py

@@ -46,7 +46,7 @@ def test_slice_fn():
     pipe.build()
     o = pipe.run()
     assert np.array_equal(o[0].at(0), np.array([[14], [17]]))
-    assert np.array_equal(o[1].as_cpu().at(0), np.array([[14], [17]]))
+    assert np.array_equal(o[1].at(0).as_cpu(), np.array([[14], [17]]))
 
 
 def test_slice_ops():
@@ -62,7 +62,7 @@ def test_slice_ops():
     pipe.build()
     o = pipe.run()
     assert np.array_equal(o[0].at(0), np.array([[14], [17]]))
-    assert np.array_equal(o[1].as_cpu().at(0), np.array([[14], [17]]))
+    assert np.array_equal(o[1].at(0).as_cpu(), np.array([[14], [17]]))
 
 
 def test_python_function():

dali/test/python/operator_1/test_normal_distribution.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 from nvidia.dali.pipeline import Pipeline
-from nvidia.dali.backend_impl import TensorListGPU
 import nvidia.dali.fn as fn
 import nvidia.dali.types as types
 import numpy as np
@@ -107,10 +106,7 @@ def shape_gen_f():
     pipe.build()
     for i in range(niter):
         outputs = pipe.run()
-        out, shapes, means, stddevs = tuple(
-            outputs[i].as_cpu() if isinstance(outputs[i], TensorListGPU) else outputs[i]
-            for i in range(len(outputs))
-        )
+        out, shapes, means, stddevs = tuple(outputs[i].as_cpu() for i in range(len(outputs)))
         for sample_idx in range(batch_size):
             sample = np.array(out[sample_idx])
             if sample.shape == ():

dali/test/python/operator_1/test_normalize.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 from nvidia.dali.pipeline import Pipeline
-from nvidia.dali import backend
 import nvidia.dali.ops as ops
 import numpy as np
 from test_utils import dali_type
@@ -395,8 +394,7 @@ def iter_setup(self):
 
 
 def to_list(tensor_list):
-    if isinstance(tensor_list, backend.TensorListGPU):
-        tensor_list = tensor_list.as_cpu()
+    tensor_list = tensor_list.as_cpu()
     out = []
     for i in range(len(tensor_list)):
         out.append(tensor_list.at(i))