Compressing GHC tarballs with LZMA
Out of curiousity, I downloaded a binary distribution for GHC-6.12.2, and tried compressing and recompressing it with bzip2 and lzma compression, using no command line arguments (all default parameters) file: http://haskell.org/ghc/dist/6.12.2/ghc-6.12.2-x86_64-unknown-linux-n.tar.bz2 bzip2 lzma size 106M 72M compression time 2:01 9:51 decompression time 0:25 0:12 the time is reported as "minutes:seconds". At it default compression level, lzma was almost five times slower than bzip2, but it's approximately twice as fast when decompressing and produced a file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly, and that both debian's dpkg and red hat's rpm now use lzma, maybe it's time to consider offering .tar.lzma as a download option for GHC's binary (and maybe source-code) bundles. Best, Leon
Hello Leon, Saturday, April 24, 2010, 12:23:58 AM, you wrote:
file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly
isn't latest version of lzma-based compression use .xz extension? -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com
On Sat, Apr 24, 2010 at 11:02:35AM +0400, Bulat Ziganshin wrote:
Hello Leon,
Saturday, April 24, 2010, 12:23:58 AM, you wrote:
file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly
isn't latest version of lzma-based compression use .xz extension?
.lzma is used for the format output by the "lzma" program that is now
deprecated.
It is recommended to use the newer xz container also based on the lzma
algorithm, hence the "xz" program and .xz extension.
Anyway, recent versions of gnu tar support both. Only xz benefits from a
short option, "-J", clearly favoring it over "--lzma".
One can also pipe xzcat to any version of tar, it's compatible with -J.
Cheers
--
Benoit Triquet
On 24/04/10 08:02, Bulat Ziganshin wrote:
Hello Leon,
Saturday, April 24, 2010, 12:23:58 AM, you wrote:
file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly
isn't latest version of lzma-based compression use .xz extension?
How common is support for .xz on the platforms we are interested in here? I just passed a .tar.xz to a Mac user and got an email back that he couldn't unpack it. Rather than dig deeper I just sent him a .tar.gz, so I don't know what tool he was using. /M -- Magnus Therning (OpenPGP: 0xAB4DFBA4) magnus＠therning．org Jabber: magnus＠therning．org http://therning.org/magnus identi.ca|twitter: magthe
Magnus Therning wrote:
On 24/04/10 08:02, Bulat Ziganshin wrote:
Hello Leon,
Saturday, April 24, 2010, 12:23:58 AM, you wrote:
file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly isn't latest version of lzma-based compression use .xz extension?
How common is support for .xz on the platforms we are interested in here?
I just passed a .tar.xz to a Mac user and got an email back that he couldn't unpack it. Rather than dig deeper I just sent him a .tar.gz, so I don't know what tool he was using.
Not very. dpkg may support it in the future, but that is a somewhat closed platform where Debian folks are in charge of both the archive and the tool used to unpack it. I would be shocked to find xz preinstalled on a MacOS, AIX, or Solaris box. That even goes for bzip2 on some of those platforms. (At least we seem to be beyond the days when we still had to provide .Z files...)
How common is support for .xz on the platforms we are interested in here?
Not very. dpkg may support it in the future, but that is a somewhat closed platform where Debian folks are in charge of both the archive and the tool used to unpack it.
Trying to install xz on kubuntu brings a serious warning : The following packages will be REMOVED: lzma The following NEW packages will be installed: xz-utils WARNING: The following essential packages will be removed. This should NOT be done unless you know exactly what you are doing! lzma (due to dpkg) 0 upgraded, 1 newly installed, 1 to remove and 8 not upgraded. Need to get 173kB of archives. After this operation, 233kB of additional disk space will be used. You are about to do something potentially harmful. To continue type in the phrase 'Yes, do as I say!'
participants (6)
-
Benoit T -
Bulat Ziganshin -
David Virebayre -
John Goerzen -
Leon Smith -
Magnus Therning