[darcs-devel] a measurement of using 7z instead of gz to compress patches

[John Meacham]

On Thu, Jan 17, 2008 at 10:02:40AM +0900, Stephen J. Turnbull wrote:
> zooko writes:
> 
>  > In short, it probably isn't worth it, unless the new repository  
>  > formats (which I haven't looked at) tend to bundle more patches  
>  > together into one file for the compression tool to find redundancy in:
> 
> Better to use zip format than tar, as zip has an index (that's why
> it's used by jar files and Python eggs, IIRC).  Doesn't 7zip have a
> full archive mode like zip?

Well, the tar version compresses much better than zip because it is
streaming and doesn't have an index. since you tar then gzip, it doesn't
compress each patch independently but rather compresses a single stream
containing all the patches. since patches are extremely similar, this
results in substantial improvements over individually compressing each
file like zip does in order to individually access them via its index.

        John

-- 
John Meacham - ⑆repetae.net⑆john⑈