Re: [PATCH v5 05/14] cache-tree: use ODB transaction around writing a tree

>
> "Neeraj Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: Neeraj Singh <neerajsi@microsoft.com>
> >
> > Take advantage of the odb transaction infrastructure around writing the
> > cached tree to the object database.
> >
> > Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
> > ---
> >  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.
>