On Wed, Mar 30, 2022 at 10:47 AM Junio C Hamano <gitster@xxxxxxxxx> wrote:
>
> "Neeraj Singh via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
>
> > From: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
> >
> > Take advantage of the odb transaction infrastructure around writing the
> > cached tree to the object database.
> >
> > Signed-off-by: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
> > ---
> > cache-tree.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/cache-tree.c b/cache-tree.c
> > index 6752f69d515..8c5e8822716 100644
> > --- a/cache-tree.c
> > +++ b/cache-tree.c
> > @@ -3,6 +3,7 @@
> > #include "tree.h"
> > #include "tree-walk.h"
> > #include "cache-tree.h"
> > +#include "bulk-checkin.h"
> > #include "object-store.h"
> > #include "replace-object.h"
> > #include "promisor-remote.h"
> > @@ -474,8 +475,10 @@ int cache_tree_update(struct index_state *istate, int flags)
> >
> > trace_performance_enter();
> > trace2_region_enter("cache_tree", "update", the_repository);
>
> There is no I/O in update_one() when the WRITE_TREE_DRY_RUN bit is
> set, so we _could_ optimize the begin/end away with
>
> if (!(flags & WRITE_TREE_DRY_RUN))
> begin_odb_transaction()
>
> > + begin_odb_transaction();
> > i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
> > "", 0, &skip, flags);
> > + end_odb_transaction();
> > trace2_region_leave("cache_tree", "update", the_repository);
> > trace_performance_leave("cache_tree_update");
> > if (i < 0)
>
> I do not know if that is worth it. If we do not do any object
> creation inside begin/end, we don't even create the temporary object
> directory and there is nothing we need to do when we "unplug". So
> this would be fine as-is, but I may be overlooking something, so I
> thought I'd mention it for completeness.
>
Yes, with the current series, beginning and ending a transaction will
just manipulate a few global variables in bulk-checkin.c unless there
is something real to flush.
Thanks,
Neeraj
