LZOP is a very fast compression program by Markus F.X.J. Oberhumer. The source, documentation and contact information can be found here.

July 14, 2003: New SMP patch version! Please test this patch against the lzop 1.01 source tree. You should be able to apply the patch against a clean source tree and simply run ./configure to find your POSIX threads library. Lots of little buglets have been fixed in lzop 1.01, and you can ignore the rest of this page if this works for you. TEST TEST TEST.

The Rest Of This Page:

I have worked with this compression program and have made a couple of patches against the 1.0.0 source code.

• The world's fastest general purpose compression program is now even faster on multiple-CPU computers. This patch adds support for UNIX SMP boxes with a suitable POSIX threads library as found on Linux, AIX, Sun, DEC/Compaq/HP Tru64 and possibly others. I have tested this patch only on Tru64 5.1, Linux 2.4.19, and AIX 5.1L.
  Solaris operation has been confirmed; click here for details.
  See the "threads" man page on Solaris for more info.

  As I have been the main tester thusfar, use it at your own risk, test it, love it because it can compress hundreds of megabytes per second on the right hardware. :)

  Instructions as of 09/28/2002:

  1. Get the source from the link at the top of this page. Get liblzo from there too. Run ./configure. Run "make". Make sure everything works as it should.
     
  2. Get the patch and apply it with the GNU "patch" tool.
     
  3. Edit your /src/Makefile and make these changes:
     add -DUSE_PTHREADS to the DEFS line. If you want large file support, also add the required flags for your OS here.
          For Solaris, this works: -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
          For Linux, this works: -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
          For AIX, this works: -D_LARGE_FILES
     add -lpthread to the LIBS line.
  4. Run "make clean; make" to rebuild.
  5. In the src/ directory, run ./pthreadtest.sh to see if this version is any faster on your SMP system. Experiment with the number of threads that gives you the best results via the new -T option.
  6. Let me know your results :)

  UPDATE 12/24/2002: I've fixed a buglett with the patch that caused the parallel version to stop processing after the first file was complete. If more than one file was specified, or if the -U option was specified, it just got silently ignored... oops.

  UPDATE 12/30/2002: Another problem with compressing multiple files has been fixed. The patch has been updated. Thanks go to Roland Kletzing for finding and testing this.

  UPDATE 01/20/2003: Various pre-compiled binaries for large-file aware SMP-enabled lzop can be found on Roland Kletzing's site.

  UPDATE 02/13/2003: I've updated the patch to integrate the stdin fix below, and also to fix a buffer overflow problem in lzop that can result in this message:
  lzop: p_lzo.c:350: lzo_compress: Assertion `dst_len <= block2.size' failed.
  Note that this is a very rare problem with lzop 1.00 only, and Markus is working on a new version to fix this problem.

• This patch fixes a mildly-annoying bug in which lzop thinks its input is stdin when there is no controlling terminal, even if you have specified an input file.

Don't bug the author of lzop about these patches. They are mine and yours, released under the "whatever" license. If you improve them, please send me diffs. I expressly disclaim all implications that they even compile, much less work, without distroying your data.