Bug#888572: [git-buildpackage/master] Turn on several threads when creating xz/lzma tarballs

[Guido Günther]

tag 888572 pending
thanks

Date:   Mon Jan 29 15:25:39 2018 +0100
Author: Guido Günther <a...@sigxcpu.org>
Commit ID: fd81e454339de50931594bd150857eb88a516a98
Commit URL: 
https://git.sigxcpu.org/cgit/git-buildpackage//commit/?id=fd81e454339de50931594bd150857eb88a516a98
Patch URL: 
https://git.sigxcpu.org/cgit/git-buildpackage//patch/?id=fd81e454339de50931594bd150857eb88a516a98

    Turn on several threads when creating xz/lzma tarballs

    and not using pristine-tar.

    Gives a 50% speedup on my machine:

    $ time gbp export-orig --no-pristine-tar --force-create
    gbp:info: Creating thunderbird_52.6.0.orig.tar.xz from 'upstream/52.6.0'
    gbp:info: Creating additional tarball 
'thunderbird_52.6.0.orig-thunderbird-l10n.tar.xz' from 
'dea43c2b49f11d68f05edac2bd9d6c5d1e1f4bcb'
    gbp:info: Creating additional tarball 
'thunderbird_52.6.0.orig-lightning-l10n.tar.xz' from 
'9adcd261726ccb160c4fd6947f7cbfe9df2e581b'

    real        8m27,153s
    user        7m23,717s
    sys 0m3,015s

    0|agx@bogon:/var/scratch/debian/icedove/icedove (debian/wheezy)$ time 
gbp-from-sourcetree export-orig --no-pristine-tar --force-create
    gbp:info: Creating thunderbird_52.6.0.orig.tar.xz from 'upstream/52.6.0'
    gbp:info: Creating additional tarball 
'thunderbird_52.6.0.orig-thunderbird-l10n.tar.xz' from 
'dea43c2b49f11d68f05edac2bd9d6c5d1e1f4bcb'
    gbp:info: Creating additional tarball 
'thunderbird_52.6.0.orig-lightning-l10n.tar.xz' from 
'9adcd261726ccb160c4fd6947f7cbfe9df2e581b'

    real        4m3,080s
    user        11m18,733s
    sys 0m3,499s

    Thanks: Carsten Schönert for the suggestion
    Closes: #888572