> From: Phil Pennock [mailto:[email protected]] > > it's premature to declare anything else obsolete, as some of us have to > worry about people deliberately choosing to interact via worst-cases to > see what fun they can have.
It's true that I assumed nobody was pushing maliciously formulated data into my compressor for the sake of exploiting my compressor. It's true that you have to explore security concerns in-depth for any technology you expose to the Internet for random people to use. I cannot say if any of these algorithms is "safer" to use, if you allow random people to push possibly malicious data through your compressor. So I'll just qualify my statement: As long as what you care about is speed and compression ratio, lzma --fast or xz --fast make bzip2 obsolete. And although gzip --fast is still faster, the speed margin is small enough and the compression margin is large enough, that I think lzma(xz) --fast is sufficiently attractive as an alternative of gzip. Years ago when bzip2 first came out, I heard a lot of people saying bzip2 was going to obsolete gzip, but then I think people noticed how slow it is. Now you've got something which is hands-down better and faster than bzip2, and it could actually become reality. In any event, I'll encourage people to look at lzma and xz. Assuming you're using it in typical use cases. http://tukaani.org/lzma/ and http://tukaani.org/xz/ > You also haven't touched memory stability -- do some situations, while > streaming, suddenly cause the available implementations to balloon in > memory requirements? I can't say if it's possible or impossible for such a thing to happen. I can only say that in my recent benchmarks, lzma --fast and xz -1 stabilized around ~3M or ~7M of memory usage. When I attempted the "strong" compressions, they stabilized around ~90M. > There's a lot more than "how fast and how small" to choosing a > compression algorithm for many situations beside just "shrink some > files > somewhere under my homedir". True. Unless you're using it to shrink some files under your homedir. Or your users' homedirs, your server, or some source code or project that you're releasing to the public, or just a bunch of files you're sending to somebody ... That is: "how fast and small" is pretty much all that matters for the typical case. Special cases need special attention, and if the special cases have already evaluated and adopted something else ... like libz ... then those special cases might not put any effort into exploring something newer (possibly better, but not proven). Or those special cases might actually put in the effort to evaluate and figure out if there's a benefit to change, in their special situation. _______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
