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2026-07-13 13:35:51 +08:00

59 lines
2.1 KiB
Python

"""Feature storages for PyTorch tensors."""
import torch
from ..utils import gather_pinned_tensor_rows
from .base import register_storage_wrapper
from .tensor import BaseTensorStorage
def _fetch_cpu(indices, tensor, feature_shape, device, pin_memory, **kwargs):
result = torch.empty(
indices.shape[0],
*feature_shape,
dtype=tensor.dtype,
pin_memory=pin_memory,
)
torch.index_select(tensor, 0, indices, out=result)
kwargs["non_blocking"] = pin_memory
result = result.to(device, **kwargs)
return result
def _fetch_cuda(indices, tensor, device, **kwargs):
return torch.index_select(tensor, 0, indices).to(device, **kwargs)
@register_storage_wrapper(torch.Tensor)
class PyTorchTensorStorage(BaseTensorStorage):
"""Feature storages for slicing a PyTorch tensor."""
def fetch(self, indices, device, pin_memory=False, **kwargs):
device = torch.device(device)
storage_device_type = self.storage.device.type
indices_device_type = indices.device.type
if storage_device_type != "cuda":
if indices_device_type == "cuda":
if self.storage.is_pinned():
return gather_pinned_tensor_rows(self.storage, indices)
else:
raise ValueError(
f"Got indices on device {indices.device} whereas the feature tensor "
f"is on {self.storage.device}. Please either (1) move the graph "
f"to GPU with to() method, or (2) pin the graph with "
f"pin_memory_() method."
)
# CPU to CPU or CUDA - use pin_memory and async transfer if possible
else:
return _fetch_cpu(
indices,
self.storage,
self.storage.shape[1:],
device,
pin_memory,
**kwargs,
)
else:
# CUDA to CUDA or CPU
return _fetch_cuda(indices, self.storage, device, **kwargs)