Reshape chunk ourselves since it is an ndarray

As we already ensured the `chunk` is an `ndarray` viewing the original
data, there is no need for us to do that here as well. Plus the checks
performed by `ensure_contiguous_ndarray` are not needed for our use case
here. Particularly as we have already handled the unusual type cases
above. We also don't need to constrain the buffer size. As such the only
thing we really need is to flatten the array and make it contiguous,
which is what we handle here directly.

Author: jakirkham

zarr/core.py

@@ -8,7 +8,7 @@
 
 
 import numpy as np
-from numcodecs.compat import ensure_ndarray, ensure_contiguous_ndarray
+from numcodecs.compat import ensure_ndarray
 
 
 from zarr.util import (is_total_slice, human_readable_size, normalize_resize_args,
@@ -1761,7 +1761,7 @@ def _decode_chunk(self, cdata):
                 # array during decoding.
                 raise RuntimeError('cannot read object array without object codec')
         else:
-            chunk = ensure_contiguous_ndarray(chunk).view(self._dtype)
+            chunk = chunk.reshape(-1, order='A').view(self._dtype)
 
         # ensure correct chunk shape
         chunk = chunk.reshape(self._chunks, order=self._order)