The --remerge-diff option will need to create new blobs and trees
representing the "automatic merge" state. If one is traversing a
long project history, one can easily get hundreds of thousands of
loose objects generated during `log --remerge-diff`. However, none of
those loose objects are needed after we have completed our diff
operation; they can be summarily deleted.
Add a new helper function to tmp_objdir to discard all the contained
objects, and call it after each merge is handled.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tmp_objdir API provides the ability to create temporary object
directories, but was designed with the goal of having subprocesses
access these object stores, followed by the main process migrating
objects from it to the main object store or just deleting it. The
subprocesses would view it as their primary datastore and write to it.
Here we add the tmp_objdir_replace_primary_odb function that replaces
the current process's writable "main" object directory with the
specified one. The previous main object directory is restored in either
tmp_objdir_migrate or tmp_objdir_destroy.
For the --remerge-diff usecase, add a new `will_destroy` flag in `struct
object_database` to mark ephemeral object databases that do not require
fsync durability.
Add 'git prune' support for removing temporary object databases, and
make sure that they have a name starting with tmp_ and containing an
operation-specific name.
Based-on-patch-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Once objects are added to the object database by a process,
they cannot easily be deleted, as we don't know what other
processes may have started referencing them. We have to
clean them up with git-gc, which will apply the usual
reachability and grace-period checks.
This patch provides an alternative: it helps callers create
a temporary directory inside the object directory, and a
temporary environment which can be passed to sub-programs to
ask them to write there (the original object directory
remains accessible as an alternate of the temporary one).
See tmp-objdir.h for details on the API.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
