persistent storage for Emacs packages

[Tyler Smith]

Hello,

I am developing a small Emacs extension I would like to distribute as a package. This package provides an interface to the GRASS gis software. During initialization, a table of completions is generated. This takes several minutes, but only needs to be done once. Where should I be saving this data?

I'm currently using customize-save-variable, but as users aren't expected to modify the values directly this is not correct. Is there a location I can count on having read and write access to across platforms? Or should I be requiring each user to specify the location of the data file as a customization option?

I would appreciate any suggestions.

Thank you,

Tyler Smith