def test_03_write(self):
a = np.random.randint(0, 65535, (64, 64, 64), np.uint16)
with make_files(1) as (dir_file, block_files):
directory = Directory(1024, 1024, 1024, np.uint16, dir_file,
compression=Compression.zstd,
block_filenames=block_files)
directory.create()
directory.write_block(a, 64, 128, 192)
directory.close()
with open(block_files[0], "rb") as fd:
block = fd.read()
blosc = Blosc("zstd")
a_out = np.frombuffer(blosc.decode(block), np.uint16)\
.reshape(64, 64, 64)
np.testing.assert_array_equal(a, a_out)
def read_block(self, x, y, z):
offset = self.offsetof(x, y, z)
shape = self.get_block_size(x, y, z)
idx = offset % len(self.block_filenames)
directory_offset = self.directory_offset + \
offset * self.directory_entry_size
if self.filesize(self.directory_filename) <\
directory_offset + self.directory_entry_size:
return np.zeros(shape, self.dtype)
fd = self.file_handle(self.directory_filename)
fd.seek(directory_offset, os.SEEK_SET)
data = fd.read(self.directory_entry_size)
m = np.frombuffer(data, dtype=np.uint8)
offset, size = self.decode_directory_entry(m)
if size == 0:
return np.zeros(shape, self.dtype)
fd = self.file_handle(self.block_filenames[idx])
fd.seek(offset)
uncompressed = fd.read(size)
blosc = Blosc(self.compression, self.compression_level)
data = blosc.decode(uncompressed)
return np.frombuffer(data, self.dtype).reshape(shape)