This change is a fix to http://git.eclipse.org/r/c/jgit/jgit/+/183562
that was reverted in http://git.eclipse.org/r/c/jgit/jgit/+/184978
due to deadlocks. Separate locks in DfsBlockFile are removed to rely
on getting value from DfsBlockCache with region locking in place.
With this change bitmap index creation is not blocked on index and
reverse index full initialization in DfsPackFile. Now bitmap index
and index could be read from storage in parallel in separate threads.
A unit test is added for parallel index loading.
Signed-off-by: Alina Djamankulova <adjama@google.com>
Change-Id: Ic6d9c5a4a254628636aa98a5008447a27a003f69
3b960ae72d