Re: Fw: Curiosity

> Martin Fick mfick@codeaurora.org writes:
>
> > On 2021-12-16 14:20, João Victor Bonfim wrote:
> >
> > > > To expand on this, if what you're storing is already compressed, like
> > > >
> > > > Ogg Vorbis files or PNGs, like are found in that repository, then
> > > >
> > > > generally they will not delta well. This is also true of things like
> > > >
> > > > Microsoft Office or OpenOffice documents, because they're essentially
> > > >
> > > > Zip files.
> > > >
> > > > The delta algorithm looks for similarities between files to
> > > >
> > > > compress
> > > >
> > > > them. If a file is already compressed using something like Deflate,
> > > >
> > > > used in PNGs and Zip files, then even very similar files will
> > > >
> > > > generally
> > > >
> > > > look very different, so deltification will generally be ineffective.
> > > >
> > > > ...
> > > >
> > > > Maybe I am thinking too outside the box, but wouldn't it be quite more
> > > >
> > > > effective for git to identify compressed files, specially on edge cases
> > > >
> > > > where the compression doesn't have a good chemistry with delta
> > > >
> > > > compression,
> > > >
> > > > decompress them for repo storage while also storing the compression
> > > >
> > > > algorithm as some metadata tag (like a text string or an ID code
> > > >
> > > > decided
> > > >
> > > > beforehand), and, when creating the work mirrors, return the
> > > >
> > > > compression
> > > >
> > > > to its default state before checkout?
> >
> > I suspect that for most algorithms and their implementations, this would
> >
> > not result in repeatable "recompressed" results. Thus the checked-out
> >
> > files might be different every time you checked them out. :(
>
> That is probably too application specific to be in core-git, but it
>
> is probably a good application for smudge/clean filters like brian
>
> alluded to?