source: vbox/trunk/src/libs/liblzf-3.6/Changes

3.6  Mon Feb  7 17:37:31 CET 2011
        - fixed hash calculation in C♯ version (Tiago Freitas Leal).
        - unroll copy for small sizes, use memcpy for larger sizes,
          greatly speeding up decompression in most cases.
        - finally disable rep movsb - it's a big loss on modern intel cpus,
          and only a small win on amd cpus.
        - improve C++ compatibility of the code.
        - slightly improve compressor speed.
        - halved memory requirements for compressor on 64 bit architectures,
          which can improve the speed quite a bit on older cpus.

3.5  Fri May  1 02:28:42 CEST 2009
        - lzf_compress did sometimes write one octet past the given output
          buffer (analyzed and nice testcase by Salvatore Sanfilippo).

3.4  Tue Sep  2 06:45:00 CEST 2008
        - the fix from 3.3 introduced a compression bug, which is fixed in
          this release (which explains the mysterious prerelease...). Thanks
          once more to Clément Calmels.

3.3  Mon Aug 25 03:17:42 CEST 2008
        - lzf_compress could access memory after the given input buffer
          when outputting back references. reported with nice testcase
          by Clément Calmels.

3.2  Fri May  9 18:52:23 CEST 2008
        - include a workaround for failing POSIX and real-world compliance
          on 64 bit windows (microsoft claims to support POSIX, but is far
          from it). (bug found and analysed nicely by John Lilley).

3.1  Fri Nov 30 11:33:04 CET 2007
        - IMPORTANT BUGFIX: a too long final literal run would corrupt data
          in the encoder (this was introduced in 3.0 only, earlier versions
          are safe).

3.0  Tue Nov 13 22:13:09 CET 2007
        - switched to 2-clause bsd with "GPL v2 or any later version" option.
        - speed up compression by ~10-15% in common cases
          by some manual unrolling.
        - import some compiler tricks from JSON::XS, for further speed-ups.
        - tune hash functions depending on ULTRA_FAST or VERY_FAST settings.
        - for typical binary data (e.g. /bin/bash, memory dumps,
          canterbury corpus etc.), speed is now comparable to fastlz, but
          with better compression ratio. with ULTRA_FAST, it's typically
          3-15% faster than fastlz while still maintaining a similar ratio.
          (amd64 and core 2 duo, ymmv). thanks a lot for the competition :)
        - undo inline assembly in compressor, it is no longer helpful.
        - no changes to the decompressor.
        - use a HLOG of 16 by default now (formerly 15).

2.1  Fri Nov  2 13:34:42 CET 2007
        - switched to a 2-clause bsd license with GPL exception.
        - get rid of memcpy.
        - tentatively use rep movsb on x86 and x86_64 (gcc only) for a
          moderate speed improvement.
        - applied patch by Kein-Hong Man to maske lzf.c compile under
          the crippled mingw32 environment.

2.0  Fri Feb 16 23:11:18 CET 2007
        - replaced lzf demo by industrial-strength lzf utility with behaviour
          similar other compression utilities. Thanks for Stefan Traby for
          rewriting it!
        - fix state arg prototype.

1.7  Wed Sep 27 17:29:15 CEST 2006
        - remove bogus "unlzf" patch.
          note to self: never accept well-meant patches.
        - make lzf more robust in presence of padding bytes or sudden eof.

1.6  Fri Jul  7 17:31:26 CEST 2006
        - the lzf example utility will now uncompress if invoked
          as "unlzf" (patch by Scott Feeney).
        - add CHECK_INPUT option that adds more checks for input
          data validity.
        - help applications that do not pass in the correct length
          (such as php) by returning either EINVAL or E2BIG.
        - default HLOG size is now 15 (cpu caches have increased).
        - documentation fixes.

1.51 Thu Apr 14 22:15:46 CEST 2005
        - incorporated C♯ implementation of both the en- and decoder,
          written by "Oren J. Maurice".
          You can find it in the cs/ subdirectory.
        - make FRST, NEXT IDX overridable if lzf_c.c is directly included
          in the code.

1.5  Tue Mar  8 20:23:23 CET 2005
        - incorporated improvements by Adam D. Moss,
          which includes a new VERY_FAST mode which is
          a bit slower than ULTRA_FAST but much better,
          and enabled it as default.

1.401 Thu Mar  3 18:00:52 CET 2005
        - use cstring in c++, not string.h.
        - change of contact address.

1.4  Wed Dec 15 08:08:49 CET 2004
        - very very slight tuning of the hashing function.

1.3  Thu Mar 25 15:41:17 CET 2004
        - changed license of lzf core code to explicitly allow
          relicensing under the GPLv2.
        - added VPATH support as suggested by Björn Eriksson.

1.2  Mon Dec 29 13:47:28 CET 2003
        - avoid spurious memory accesses after the to-be-compressed
          memory region. originally reported by Michal Zalewski.
        - flip LZF_STACK_ARG meaning (to be correct).

1.1  Tue Dec 23 05:48:32 CET 2003
        - removed #warn directive, it's not worth the hassle.
        - add LZF_STACK_ARG and AVOID_ERRNO configurations
          for embedded systems.
        - make it compile cleanly as c++.
        - some small documentation and code fixes.

1.0  Sun Nov 17 12:37:37 CET 2002
        - slightly better compression ratio, almost unmeasurably
          slower.
        - some documentation fixes.

0.4  Thu Jun 13 14:11:10 CEST 2002
        - typoe fix.
        - lzf demo program now properly decompresses small files.
        - fix another 64 bit issue, found by Laurent Deniel.

0.3  Tue Jan 16 13:21:14 CET 2001
        - fix silly beginners 32/64 bit mistake.

0.2  Thu Jan  4 05:56:42 CET 2001
        - now totally independent of autoconfig, for
          easy inclusion into other programs.
        - much better fine-tuning, faster and better than 0.1.

0.1  2000
        - initial release.