Re: [Dragora-users] Proposal: add to qi possibility to switch type of tarlz compression granularity

[Matías Fonzo]

El 2022-05-17 03:04, DustDFG escribió:
> Hello!
>
> I want to know why you use tarlz. If I right understand, you use tarlz
> archive format (not usual tar.lz or something else) because it has
> multi-threaded facilities. Am I right?

Not only for the multi-thread capabilities, which speeds up the checking 
of a tarball when testing it, there are a number of reasons, one of them 
is that tarlz creates a more secure format than the one proposed by 
POSIX pax format; tarlz is based on the lzip format, its inclusion is a 
decision that was made for Dragora in 2008.  Now expanded elsewhere, it 
is the only reliable format that I know of.

> I read the source code of qi and found that qi uses tarlz with option
> --solid. It means that tarlz can't unpack this archive with using
> multi-threading [1] [2].

This does not mean that it can be done in the future, I understand that 
it is not easy to implement.  Beyond implementation, --solid is the 
recommended option for packages, as it is the final product.

> I understand that you want to get the
> smallest possible size of an archive. If I have a fully empty disk
> with 1TB capacity, I may want to get more speed especially if I build
> packages for testing (not for release)...

And this has been optimized in Dragora, not to mention that it is also 
subject to build systems, hardware, parallel jobs for the compiler....

> I want to propose you to add to qi possibility to point compression
> granularity level through new option or maybe through qirc file. Note:
> I don't propose to change default compression granularity level. I
> simply want to have a possibility to change it when I want it.
>
> [1] https://www.nongnu.org/lzip/manual/tarlz_manual.html#Introduction
> [2] 
> https://www.nongnu.org/lzip/manual/tarlz_manual.html#Multi_002dthreaded-decoding

Let's see what our friend, the author, has to say.  :-)