allow usage of multicore implementations of compression tools

[Karl-Philipp Richter]

It'd be great to be able to use compression formation implementations which allow multicore CPU usage (e.g. `pigz` for gunzip, `pbzip2` for bzip2, etc.). Imo there's no argument against using them by default because most user just will see an significant increase of speed with some decent default values for parallelization options (`-p` of `pigz`, etc.) based on the CPU (cores).

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: file-roller 3.14.2-0ubuntu5
Uname: Linux 4.0.5-040005-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Jun 21 00:59:43 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-06-08 (12 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: file-roller
UpgradeStatus: Upgraded to vivid on 2015-06-09 (11 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Karl-Philipp Richter (krichter722)]

This seems to be fixed in Ubuntu 16.10 based on simple observation (as opposed to a systematic test).

[Jop (jopv)]

Not fixed at all, File Roller still uses only one core of my quad-core CPU...

[Karl-Philipp Richter (krichter722)]

> Not fixed at all, File Roller still uses only one core of my quad-core CPU...
Right, I was confusing this with `nautilus`' archive creation/compress feature. I guess that parallelization depends on the compression algorithm used, but `file-roller` doesn't even use parallelization for gzip for which there's a parallel algorithm out for years, maybe decades.

[Gao Shichao (xgdgsc)]

Any progress in this?