Re: [offtopic?] xdelta patch format wrapper

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 13, 2008, 03:32 UTC
Message-ID: <7vy79py1it.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <47B24D8A.5090703@catalyst.net.nz>

Martin Langhoff <martin@catalyst.net.nz> writes:

Show 21 quoted lines

> So my question is what is a good format for the header? My thinking sofar:
>
>  - have a prefix to scan for, such as "xdelta" at the beginning of
>    the file, or after a newline/whitespace
>
>  - keep the <fromsha1> <tosha1> line
>
>  - \0 delimited filenames
>
>  - filenames as ambiguous bag'o'bytes or utf-8?
>    (should we have another flamewar on this? ;-) )
>
>  - keep file modes and perhaps support copy/move headers
>
>  - keep a/ b/ prefixes?
>
>  - last line in the header is length: <length-in-bytes>, followed by
>    a newline and the xdelta itself
>
>  - one or more newlines follow the end of the xdelta if there is another
>    header coming

I am lost as to your objective because you seem to be keeping a whole LOT more than I would have imagined for a specialized purpose file format.

If you want to reuse that much of git, maybe our binary patch format is good enough for you? We always produce two xdelta so that we can apply in reverse, but it is Ok to add a one-way option.