chore: import upstream snapshot with attribution

python/dgl/storages/numpy.py

@@ -0,0 +1,25 @@
+"""Feature storage for ``numpy.memmap`` object."""
+import numpy as np
+
+from .. import backend as F
+from .base import FeatureStorage, register_storage_wrapper, ThreadedFuture
+
+
+@register_storage_wrapper(np.memmap)
+class NumpyStorage(FeatureStorage):
+    """FeatureStorage that asynchronously reads features from a ``numpy.memmap`` object."""
+
+    def __init__(self, arr):
+        self.arr = arr
+
+    # pylint: disable=unused-argument
+    def _fetch(self, indices, device, pin_memory=False):
+        result = F.zerocopy_from_numpy(self.arr[indices])
+        result = F.copy_to(result, device)
+        return result
+
+    # pylint: disable=unused-argument
+    def fetch(self, indices, device, pin_memory=False, **kwargs):
+        return ThreadedFuture(
+            target=self._fetch, args=(indices, device, pin_memory)
+        )