4 ms·

Not a scientific experiment or something like that, just tried it on uncompressed jQuery for fun; Original file: 268381 bytes Zopfli (with -i1000) 75730 bytes

by eknkc 14y ago

Not a scientific experiment or something like that, just tried it on uncompressed jQuery for fun; Original file: 268381 bytes Zopfli (with -i1000) 75730 bytes in 950ms Gzip (with -9) 79388 bytes in 30ms It's really slow but the difference seems significant enough. (They have more data here: https://zopfli.googlecode.com/files/Data_compression_using_Zopfli.pdf https://zopfli.googlecode.com/files/Data_compression_using_Z...)

duskwuff 14y ago
Importantly, though, the decompression speed is the same as deflate (e.g, gzip). It's only slower during compression.
Jach 14y ago
As I suspected, XZ performs better at least for jquery. I was disappointed it was missing from benchmarks. For comparison on my machine: zopfli -i1000 takes [real, sys]=[1069ms, 21ms], 75730 bytes. xz -9 takes [148ms, 15ms], 69476 bytes. (Though as mentioned as a pro of zopfli, xz would lose on decompression speed for a larger file.)
- andrewf 14y ago
  Yeah but the point here is to produce a .gz file which is compatible with standard tools like gunzip, PNG decoders, your browser's handling of "Content-Encoding: gzip", etc. If you control the compressor and decompressor then applying new tricks to producing a Deflate stream is far less interesting, just use a better compressor.
  - Jach 14y ago
    Can we get browsers to support LZMA? :) (Hey, a bug report! https://bugzilla.mozilla.org/show_bug.cgi?id=366559 https://bugzilla.mozilla.org/show_bug.cgi?id=366559) But yeah, zopfli does seem like an excellent fit when you can't force a particular decompressor.
- EwanToo 14y ago
  and bzip2 gets it down to 65195 bytes. I've not used xz, I'm sure it's good, but the point isn't really about which compression algorithm is the best in the world, but which works best in the (depressingly limited) real world conditions.
  - SageRaven 14y ago
    If it is any indicator, current versions of FreeBSD and some Linux distros have "xz" as part of the base system, along with their gzip and bzip2 counterparts, including xzcat/xzless/etc., newsyslog/logrotate compression options for xz, xz-compressed tarballs for source distributions (tar.xz / txz), as well as binary packages for FreeBSD compressed with the format. LZMA compression has gained a lot of traction over the past few years.
    - EwanToo 14y ago
      Thanks - I meant to update my comment after I went and looked up xz, I've used 7zip and LZMA before, but I've never directly come across a .xz file, odd!
sciurus 14y ago
For my tests I used the default compression levels, so 6 (out of 1-9) for gzip, 6 (out of 1-9) for xz, and 15 (out of 5-1000) for zopfli. My input was the linux kernel 3.8.1 source tarball. This was run on a macbook pro with OS X 10.8.2 and a 2.2 GHZ i7 processor. time size format n/a 987640 uncompressed 18.44 210896 gzip 281.44 143128 xz 3604.21 200640 zopfil
Yver 14y ago
Tried compressing the minified jQuery, got: 32653 gzip -9 31763 7z -tgzip -si -mx=9 -mfb=258 -mpass=16 31691 zopfli -i1000 IOW, it yields a much smaller benefit as data gets harder to compress. Of course this is not at all surprising.
ck2 14y ago
gzip with 32KB dictionary and 128 word size code.jquery.com/jquery-1.9.1.js original 268381 gzip 76070 zopfli 75730 Zopfli only has 340 bytes savings and 20x time increase. Not worth it.

by eknkc 14y ago

duskwuff 14y ago

Importantly, though, the decompression speed is the same as deflate (e.g, gzip). It's only slower during compression.

Jach 14y ago

As I suspected, XZ performs better at least for jquery. I was disappointed it was missing from benchmarks. For comparison on my machine: zopfli -i1000 takes [real, sys]=[1069ms, 21ms], 75730 bytes. xz -9 takes [148ms, 15ms], 69476 bytes. (Though as mentioned as a pro of zopfli, xz would lose on decompression speed for a larger file.)

andrewf 14y ago
Yeah but the point here is to produce a .gz file which is compatible with standard tools like gunzip, PNG decoders, your browser's handling of "Content-Encoding: gzip", etc. If you control the compressor and decompressor then applying new tricks to producing a Deflate stream is far less interesting, just use a better compressor.
- Jach 14y ago
  Can we get browsers to support LZMA? :) (Hey, a bug report! https://bugzilla.mozilla.org/show_bug.cgi?id=366559 https://bugzilla.mozilla.org/show_bug.cgi?id=366559) But yeah, zopfli does seem like an excellent fit when you can't force a particular decompressor.
EwanToo 14y ago
and bzip2 gets it down to 65195 bytes. I've not used xz, I'm sure it's good, but the point isn't really about which compression algorithm is the best in the world, but which works best in the (depressingly limited) real world conditions.
- SageRaven 14y ago
  If it is any indicator, current versions of FreeBSD and some Linux distros have "xz" as part of the base system, along with their gzip and bzip2 counterparts, including xzcat/xzless/etc., newsyslog/logrotate compression options for xz, xz-compressed tarballs for source distributions (tar.xz / txz), as well as binary packages for FreeBSD compressed with the format. LZMA compression has gained a lot of traction over the past few years.
  - EwanToo 14y ago
    Thanks - I meant to update my comment after I went and looked up xz, I've used 7zip and LZMA before, but I've never directly come across a .xz file, odd!

sciurus 14y ago

For my tests I used the default compression levels, so 6 (out of 1-9) for gzip, 6 (out of 1-9) for xz, and 15 (out of 5-1000) for zopfli. My input was the linux kernel 3.8.1 source tarball. This was run on a macbook pro with OS X 10.8.2 and a 2.2 GHZ i7 processor. time size format n/a 987640 uncompressed 18.44 210896 gzip 281.44 143128 xz 3604.21 200640 zopfil

Yver 14y ago

Tried compressing the minified jQuery, got: 32653 gzip -9 31763 7z -tgzip -si -mx=9 -mfb=258 -mpass=16 31691 zopfli -i1000 IOW, it yields a much smaller benefit as data gets harder to compress. Of course this is not at all surprising.

ck2 14y ago

gzip with 32KB dictionary and 128 word size code.jquery.com/jquery-1.9.1.js original 268381 gzip 76070 zopfli 75730 Zopfli only has 340 bytes savings and 20x time increase. Not worth it.