re-chunk and save it in the original path

[Peterpan-Coder]

Hi. I'm learning to use Zarr. I have two questions. I hope I can get an answer here.
The first, When I want to rechunk and save the result in the original path, the data in the file becomes 0 as shown in the following figure.
However, if the file is saved in a new path, the file data can be saved to a block file. Is it because the file is saved in memory and not written to disk?

The sample code is as follows:

def depress_chunk(path):
    buf = zlib.decompress(open(path, 'rb').read())
    chunk = np.frombuffer(buf, 'i4')
    print('chunk path:', path, 'chunk:', chunk)

if __name__ == '__main__':
    a = np.arange(12).reshape(3, 4)
    z1 = zarr.array(a, chunks=(1, 2), store='20221207/test1', overwrite=True, compressor=zarr.Zlib(level=1))
    print(z1.get_basic_selection())
    depress_chunk('20221207/test1/0.0')
    print("-----------------分割线--------------------------")
    z2 = zarr.array(z1, chunks=(3, 2), store='20221207/test1', overwrite=True, compressor=zarr.Zlib(level=1))
    print(z2.get_basic_selection())
    depress_chunk('20221207/test1/0.0')

Second, based on the above question, I thought of the function: zarr.save(). However, I found that the second zlib.decompress() will report the following error, is rechunk will change the header format?
zlib.error: Error -3 while decompressing data: incorrect header check
The sample code is as follows:

import numpy as np
import zarr
def depress_chunk(path):
    buf = zlib.decompress(open(path, 'rb').read())
    chunk = np.frombuffer(buf, 'i4')
    print('chunk path:', path, 'chunk:', chunk)


if __name__ == '__main__':
    a = np.arange(12).reshape(3, 4)
    z1 = zarr.array(a, chunks=(1, 2), store='20221207/test1', overwrite=True, compressor=zarr.Zlib(level=1))
    print(z1.get_basic_selection())
    depress_chunk('20221207/test1/0.0')
    print("-----------------split line--------------------------")
    z2 = zarr.array(z1, chunks=(3, 2), overwrite=True, compressor=zarr.Zlib(level=1))
    zarr.save('20221207/test1', z2)
    print(z2.get_basic_selection())
    depress_chunk('20221207/test1/0.0')