Tom said:
Since 1.2.2(?) they have something similar to pack200. If you were to
dig up a copy of 1.2.1, you should find it much larger.
Doesn't look like they're using the pack200 distributed with the
jdk, that creates archives that are 48% of original size. No real
difference from gzip.
Sun's jdk.*.bin downloads are 39% of the original size. The only
tool does better is lzma, which creates archives that are 34% of the
original size.
# sh jdk-1_5_0_11-linux-amd64.bin && du -bs jdk1.5.0_11
113483747 jdk1.5.0_11
# jar cMf jdk1.5.0_11.jar jdk1.5.0_11 && du -bs jdk1.5.0_11.jar
55557396 jdk1.5.0_11.jar (49% of original size)
# tar czvf jdk1.5.0_11.tgz jdk1.5.0_11 && du -bs jdk1.5.0_11.tgz
54730784 jdk1.5.0_11.tgz (48% of original size)
# pack200 -J-Xmx500M -S-1 -E9 x.pack.gz jdk1.5.0_11.jar && \
# du -bs x.pack.gz
54622334 x.pack.gz (48% of original size)
# du -bs jdk-1_5_0_11-linux-amd64.bin (Sun original)
43930095 jdk-1_5_0_11-linux-amd64.bin (39% of original size)
# tar cvf - jdk1.5.0_11 | lzma -9 > jdk1.5.0_11.tar.lzma && \
# du -bs jdk1.5.0_11.tar.lzma
39714345 jdk1.5.0_11.tar.lzma (34% of original size)
Since Sun's shar files contain self-extracting SFX archives they must have
some custom software that can be decompressed with gzip/unzipsfx.
NM