Re: [StGit PATCH 03/14] Write to a stack log when stack is modified

> 2008/6/23 Karl Hasselström <kha@treskal.com>:
>
> > Two optimizations would hopefully make it fast:
> >
> >  1. If the patch's sha1 hasn't changed, we don't have to
> >     regenerate the diff.
> >
> >  2. If the patch's sha1 has changed, but git apply was sufficient
> >     during the merge stage, we can just reuse that patch. We do
> >     have to write it to a blob, but we have already generated the
> >     diff and don't need to do so again. (I've shamelessly stolen
> >     your idea here.)
>
> It can be optimised a bit more to actually apply the diff in the
> blob directly rather than the current way of generating the diff
> (since we don't store the diff).

> > In most cases, (1) would make sure that only a small handful of
> > patches would need to be considered. In the cases where a lot of
> > patches are touched, such as rebase, (2) would provide a good
> > speedup (except for the cases where we had to call
> > merge-recursive, and those are slow anyway).
>
> I think it should work. Rebase is indeed my worry but it might be
> even faster for most of the patches to apply the blob than computing
> the diff. In my experience with the Linux kernel, full merge is
> rarely needed.