[pacman-dev] [PATCH] [Idea] makepkg: Extract from any file bsdtar can recognize

[Dan McGee]

On Sat, May 29, 2010 at 4:22 PM, Andres P <aepd87 at gmail.com> wrote:
> On Sat, May 29, 2010 at 04:17:16PM -0500, Dan McGee wrote:
>> > If bsdtar -tf is deemed as reliable, then it should make the file(1)
>> > check redundant, seeing that makepkg uses bsdtar to extract.
>>
>> Except you've now introduced the overhead of reading every archive
>> twice which is really stupid, since 95% of files will pass the "file"
>> check.
>>
> I realized that it was slower before I mentioned it:
>    $ time for i in {1..1000}; do file -bizL neon-0.29.3-2-i686.pkg.tar.xz >/dev/null; done
>    real    0m20.664s
>    $ time for i in {1..1000}; do bsdtar -tf neon-0.29.3-2-i686.pkg.tar.xz >/dev/null; done
>    real    1m16.193s
>
> But it greatly simplifies code :/
>
> It's the python dilemma...

neon? What is that, 172K? Try something that would really suck. I
don't care if it greatly simplifies code.

dmcgee at dublin ~
$ ll /var/cache/makepkg/src/linux-2.6.34.tar.bz2
-rw-r--r-- 1 dmcgee wheel 65M May 16 20:46
/var/cache/makepkg/src/linux-2.6.34.tar.bz2

This is *ONE* iteration:

dmcgee at dublin ~
$ time bsdtar -tf /var/cache/makepkg/src/linux-2.6.34.tar.bz2 >/dev/null

real    0m51.631s
user    0m49.940s
sys     0m0.287s

-Dan