Function _chunk_ds

xarray/backends/api.py:221–270

(
    backend_ds,
    filename_or_obj,
    engine,
    chunks,
    overwrite_encoded_chunks,
    inline_array,
    chunked_array_type,
    from_array_kwargs,
    **extra_tokens,
)

def _chunk_ds(
    backend_ds,
    filename_or_obj,
    engine,
    chunks,
    overwrite_encoded_chunks,
    inline_array,
    chunked_array_type,
    from_array_kwargs,
    **extra_tokens,
):
    chunkmanager = guess_chunkmanager(chunked_array_type)

    # TODO refactor to move this dask-specific logic inside the DaskManager class
    if isinstance(chunkmanager, DaskManager):
        from dask.base import tokenize

        mtime = _get_mtime(filename_or_obj)
        token = tokenize(filename_or_obj, mtime, engine, chunks, **extra_tokens)
        name_prefix = "open_dataset-"
    else:
        # not used
        token = (None,)
        name_prefix = None

    variables = {}
    for name, var in backend_ds.variables.items():
        if var._in_memory:
            variables[name] = var
            continue
        var_chunks = _get_chunk(
            var._data,
            chunks,
            chunkmanager,
            preferred_chunks=var.encoding.get("preferred_chunks", {}),
            dims=var.dims,
        )
        variables[name] = _maybe_chunk(
            name,
            var,
            var_chunks,
            overwrite_encoded_chunks=overwrite_encoded_chunks,
            name_prefix=name_prefix,
            token=token,
            inline_array=inline_array,
            chunked_array_type=chunkmanager,
            from_array_kwargs=from_array_kwargs.copy(),
            just_use_token=True,
        )
    return backend_ds._replace(variables)


def _maybe_create_default_indexes(ds):