Re: 7-Zip / Bzip2

[Cristi Magherusan <cristi.magherusan@xxxxxxxxxxxxx>]

Hello,

On Tue, 2008-05-06 at 09:51 -0700, Samuel J. Greear wrote:
> "Samuel J. Greear" <dragonflybsd@evilcode.net> wrote in message 
> 481fc50e$0$869$415eb37d@crater_reader.dragonflybsd.org">news:481fc50e$0$869$415eb37d@crater_reader.dragonflybsd.org...
> >
> > "Matthew Dillon" <dillon@apollo.backplane.com> wrote in message 
> > 200805060047.m460lrhj094676@apollo.backplane.com">news:200805060047.m460lrhj094676@apollo.backplane.com...
> >>
> >> :Hi,
> >> :
> >> :Posted this to kernel@ by accident, please reply here instead :)
> >> :
> >> :I just wanted to know if there's any interest for the devs to add
> >> :something like p7zip to the base install; even if it's a simple fork
> >> :that only supports 7z.  While 7zip is about as obnoxiously slow as
> >> :bzip2, it usually gets much better compression.
> >> :
> >> :That's not why I'm suggesting it though - what really gets me is that
> >> :bzip2 has no "list" option.  Does that 10 gb bzip2 backup archive
> >> :contain 100gb of data, or 200gb?  Other than dumping the entire
> >> :archive to /dev/null through wc, there's really no way to do it.  Gzip
> >> :will list files, but its compression ratio is awful.
> >> :
> >> :I imagine that other OSes are going to be watching Dragonfly very
> >> :carefully in the next while as new the features (especially HAMMER)
> >> :mature.  Maybe adding 7z will get yet another bandwagon going and
> >> :there will be support across the board :)
> >> :
> >> :Best Regards,
> >> :Ben Cadieux
> >>
> >>    Well, I think not in base, at least not unless a lot of people
> >>    are using it.  p7zip is readily available via the pkgsrc tree
> >>    and that's the most reasonable method of accessibility for
> >>    now.
> >>
> >> -Matt
> >> Matthew Dillon
> >> <dillon@backplane.com>
> >
> > I do not know if DragonFly is actively tracking libarchive, but it seems
> > to be "the ticket" for implementing new archiving/compression methods
> > through a common mechanism. If one wanted to see 7z functionality
> > in base implementing a libarchive provider is probably the way to go.
> >
> > I did a quick test at one point on the dfly distribution ISO and as I
> > recall 7z was ~60% the size of bzip2 using standard settings.
> > food+thought, etc.
> >
> > Sam
> 
> I got yelled at on IRC for not providing times, so here:
> 
> Key:
>     Selected Archiver - Compression Time - Threads - FileSize
> 
> Source file:
>     dfly-1.12.2_REL.iso - 295,512KB
> 
> Bzip2 - 0:27 - 4 - 108,742KB
> Bzip2 - 1:24 - 1 - 108,742KB
> Decompress: 0:10
> 
> GZip - 0:55 - 1 - 118,024KB
> Decompress: 0:10
> 
> Zip - 0:55 - 4 - 118,024KB
> Zip - 0:55 - 1 - 118,024KB
> Decompress: 0:11
> 
> 7Zip - 1:50 - 2 - 73,952KB
> 7Zip - 3:09 - 1 - 73,952KB
> Decompress: 0:12
> 
> 
> All done via the most unscientific methods available (reporting
> user time as displayed by the 7Zip user interface), so treat it
> as such. Tested on an Intel Q6600 (4x2.4GHz) w/ single SATA
> disk.
> 
> "Default" compression settings were used across the board.
> Everything was tested using the windows 7-Zip program, which
> integrates all of these algorithms.
> 
> Sam 
> 

The compression time is not an issue for install disks, and
decompression extra time of 7z is insignificant, but the best usage for
this would be when packaging sources, not the installer CD, whose size
will grow slower than the size of CD/DVD/BlueRay... Anyway our CD image
could easily fit a mini-CD, so we don't need this, for now.

Regards, Cristi.

-- 
Cristi Magherusan,
Universitatea Tehnica din Cluj - Napoca
Centrul de Comunicatii "Pusztai Kalman"
Tel. 0264/401247  http://cc.utcluj.ro

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