[Yum-devel] [PATCH] createrepo: compress .xml files with 'compress_type'

[Zdenek Pavlas]

> > Dump metadata to uncompressed files first, then compress with
> > 'compress_type'.
> > This is more flexible and saves one (two with -d) .xml.gz
> > decompressions.
> 
>  Have you timed this?
>  If so, can you put the roughly improvement into the commit and ACK.

createrepo on 364 packages:

before: 0m9.961s 0m10.114s 0m9.944s
after: 0m9.987s 0m9.903s 0m10.016s

Given that ungzip is only about 10-20x slower than memcpy I didn't
expect any significant improvement.  Very large uncompressed .xml
files might not fit in buffer cache, so it may even become worse.

In order to support compress != .gz we must either dump to
uncompressed XML or re-compress at the end.  That's actually simpler
and more conservative, but ... feels wrong.