def test_multi_block_slice(self):
""" MultiBlockSlice -> ValueError """
with self.assertRaises(ValueError):
self.dset[h5py.MultiBlockSlice()]
# The frames from each block are contiguous within each file
# e.g. 1.h5 = [..., 998, 999, 4000, 4001, ... ]
files = ["1.h5", "2.h5", "3.h5", "4.h5"]
dataset_name = "data"
dtype = "float"
source_shape = (25000, 256, 512)
target_shape = (100000, 256, 512)
block_size = 1000
v_layout = h5py.VirtualLayout(shape=target_shape, dtype=dtype)
for file_idx, file_path in enumerate(files):
v_source = h5py.VirtualSource(file_path,
name=dataset_name,
shape=source_shape,
dtype=dtype)
dataset_frames = v_source.shape[0]
# A single raw file maps to every len(files)th block of frames in the VDS
start = file_idx * block_size # 0, 1000, 2000, 3000
stride = len(files) * block_size # 4000
count = dataset_frames // block_size # 25
block = block_size # 1000
# MultiBlockSlice for frame dimension and full extent for height and width
v_layout[
h5py.MultiBlockSlice(start, stride, count, block), :, :] = v_source
with h5py.File("interleave_vds.h5", "w", libver="latest") as f:
f.create_virtual_dataset(dataset_name, v_layout, fillvalue=0)
