This Bugzilla instance is a read-only archive of historic NetBeans bug reports. To report a bug in NetBeans please follow the project's instructions for reporting issues.
AFAIK Retouche currently uses ${userdir}/var/cache/index/ for storing signature files and other Java source information caches. For source roots owned by a project (the normal case) consider using a project's CacheDirectoryProvider instead. This would help keep caches near the files they are caching, and prevent disk space leaks from deleted projects. I am assuming that the caches for independent source roots are themselves independent, i.e. there is no need for a unified database.
You are right, the caches for independent source roots are independent. The only thing I am afraid is that people will complain about the quite big IDE data under the project root.
Normally users who use a versioning system for sharing projects should not care. But if the user wants to zip a project and send it to a friend, then it might be a problem. Can you estimate how big is the cache for 100, 1000, ... files big project?
The cache directory is under nbproject/private/ so (like other private settings) it should never be included in a project source ZIP. BTW we should really productize the Project Packager module...
Not sure if this is WONTFIX for one reason or another, but FYI there is now a method in ProjectUtils to get a cache dir for a project.
Reassigning all moonko's java/source bugs to myself.
This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue. Thanks for your cooperation, NetBeans IDE 8.2 Release Boss