On 2012-11-14 Jack Duston wrote: > Given time involved in compressing and the quantity of data, I am > hesitant to use the 5.1.2alpha code. > I am paying attention when your web page says it should be considered > unstable!
It is good to be cautious with unstable releases. There are people using 5.1.2alpha and I haven't got bug reports. I'm not aware of any data corruption bugs. So in this particular case I think it's not too dangerous to use the development version. You get threading in addition to the --block-size option. Another option is to use for example pixz: https://github.com/vasi/pixz XZ Utils 5.1.2alpha and pixz both can create a single .xz stream that contains many blocks, and thus make random access reading possible. I haven't used truly pixz myself so I cannot say anything else about it. > I see in the Release Notes that the "--block-size" option was added > to the April, 2011 alpha release, and we are fast approaching 2013. > I don't know how complex the code change is, or if it goes against > your release policy, but would you consider back-porting the > "--block-size" option to a 5.0.5 Stable Release? I surely can't be > the only one who would love to make use of the option. I don't like to add any new features in a stable branch. I'm doing this to (hopefully) make it easier for downstream distributions to include bug fixes in stable distributions where the distro maintainers want only bug/security fixes to minimize the risk of new bugs. Adding --block-size isn't a huge patch, but in this particular case I think it should be safe to try 5.1.2alpha. > My ultimate end is to incorporate the XZ library or Embedded into our > application to search and read the compressed files directly. > In any case, thanks again for all the work you've put into xz, I will > be compressing with your utility either way. Random access can be done with liblzma, but the provided APIs are too low level to make it nice to use. See src/xz/list.c in XZ Utils what kind of things you need to do. There is an old plan to have a file I/O library that makes things easy for the most common use cases. I even started writing it long ago but didn't get very far. There is random access support in XZ for Java, but I guess it doesn't help you. -- Lasse Collin | IRC: Larhzu @ IRCnet & Freenode