No file lock on imod.idf.open

In GitLab by @Huite on Jan 18, 2023, 15:53

This goes rather wrong:

for _ in range(3):
    da = imod.idf.open(path)
    new = da.isel(y=slice(1,-1))
    imod.idf.save(path, new)

I.e. the save path is the same as the open path. It will also give weird errors: the dask graph expects to find a certain file at path, but finds one with a reduced number of rows.

Ideally, we could throw a PermissionError in this case when trying to save there, but not when it has been .computed or .loaded. I'm not sure how difficult that is to implement.

Start at the imod.idf.open and imod.idf.save entry points and trace how the dask graph retains the input path. Reproduce the loop shown in the issue, then compare saving before and after the data is computed or loaded. Done means saving to the same path raises PermissionError only while the opened data still depends on that file.