Should all raw source data be preserved?

[kzollove]

When a source data file is downloaded for the first time, as part of loadGeometry or loadVariable, should it be preserved as-is in the repository file system?

A good location would be inst/data//.ext

loadgeometry and loadVariable currently look in the tmpdir for downloaded files so that they are only downloaded per user session. Saving them here would allow for them to only ever be downloaded once per instance of gaiadb.

Maybe a preserve data flag to allow users to opt out of saving the file locally. Or a clean storage function to allow them to clear the files.

[kzollove]

Question: How would this apply to an API data_source/variable_source?