Harald Schilly wrote: > On Jul 9, 5:20 pm, Kevin Horton <[email protected]> wrote: >> I have tried compressing the sage.*.tar files using gzip and bzip2. >> The compression is insignificant, at least when using the default >> compression levels. >> >> % ls -l *tar* >> -rw-r--r-- 1 XXX staff 215244800 Jun 19 08:46 sage-4.0.2.tar >> -rw-r--r-- 1 XXX staff 214183786 Jun 19 08:46 sage-4.0.2.tar.gz >> -rw-r--r-- 1 XXX staff 215169684 Jun 19 08:46 sage-4.0.2.tar.bz2 >> > > Out of curiosity I tried to use lzma with "7z" in ubuntu linux to > shrink the included spkgs smaller: > > in $SAGE/spkg/standard/ > > for i in *.spkg; do > echo $i > tar xjf $i > 7z a -t7z -m0=lzma -mx=9 -mfb=64 -md=32m -ms=on $i.7z ${i%\.spkg} > rm -rf ${i%\.spkg} > done > > result: > ["insgesamt" = total] > > $ du -csh *.spkg | grep insges > 205M insgesamt > $ du -csh *.7z | grep insges > 159M insgesamt > $ echo "159/205" | bc -l > .77560975609756097560 > > but 7z not installed by default and we would have to include the 7z > sources, compile them, and then do the extraction. > > h
A 22% saving in disk space and download time is pretty significant on a file as big as the Sage one. Is the extraction much slower than bz2 ? I know there have been competitions to make the best compressor of files, and I recall one winning such a competition, but it took a week to do the compression. I've certainly added things to the .spkg files, then compressed them and they are smaller than the oringal ones, simply because I used the -9 option to bzip2. I don't know if there is a way of getting that directly into GNU tar, so it would avoid having to do it in two stages. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
