Re: Fw: Curiosity

[Martin Fick <mfick@codeaurora.org>]

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. :(

-Martin

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