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Revision: 1.62
Committed: Tue Nov 12 12:46:28 2024 UTC (5 months, 1 week ago) by root
Branch: MAIN
CVS Tags: HEAD
Changes since 1.61: +2 -1 lines
Log Message:
*** empty log message ***

File Contents

# Content
1
2 TODO: try unaligned copy again in decompressor
3 TODO: allow size-optimised binaries by avoiding unrolling
4 TODO: implement lzf_c_best in lzf.
5
6 3.8 (unreleased)
7 - support a state arg for lzf_c_best.
8 - disable STRICT_ALIGN by default, as unaligned accesses can trap
9 or worse even on x86.
10
11 3.7 (unreleased)
12 - add lzf_c_best.c, a slower but better compressor.
13 - switch to a multiplicative hash (developed with Steinar Gunderson),
14 which is faster on modern cpus and compresses a bit better. The old
15 hash function which uses only shifts is still available.
16 - allow user configurable hash table slots, which makes it possible
17 to use e.g. 16 bit offsets for a smaller hashtable (if your data is
18 always < 64kb).
19 - use _WIN32, not WIN32, when testing for windows (fails with bcc),
20 patch by Tamas Tevesz.
21 - try to port to win64+gcc, which is non-posix but doesn't have _int64
22 (reported by Maciej Adamczyk).
23
24 3.6 Mon Feb 7 17:37:31 CET 2011
25 - fixed hash calculation in C♯ version (Tiago Freitas Leal).
26 - unroll copy for small sizes, use memcpy for larger sizes,
27 greatly speeding up decompression in most cases.
28 - finally disable rep movsb - it's a big loss on modern intel cpus,
29 and only a small win on amd cpus.
30 - improve C++ compatibility of the code.
31 - slightly improve compressor speed.
32 - halved memory requirements for compressor on 64 bit architectures,
33 which can improve the speed quite a bit on older cpus.
34
35 3.5 Fri May 1 02:28:42 CEST 2009
36 - lzf_compress did sometimes write one octet past the given output
37 buffer (analyzed and nice testcase by Salvatore Sanfilippo).
38
39 3.4 Tue Sep 2 06:45:00 CEST 2008
40 - the fix from 3.3 introduced a compression bug, which is fixed in
41 this release (which explains the mysterious prerelease...). Thanks
42 once more to Clément Calmels.
43
44 3.3 Mon Aug 25 03:17:42 CEST 2008
45 - lzf_compress could access memory after the given input buffer
46 when outputting back references. reported with nice testcase
47 by Clément Calmels.
48
49 3.2 Fri May 9 18:52:23 CEST 2008
50 - include a workaround for failing POSIX and real-world compliance
51 on 64 bit windows (microsoft claims to support POSIX, but is far
52 from it). (bug found and analysed nicely by John Lilley).
53
54 3.1 Fri Nov 30 11:33:04 CET 2007
55 - IMPORTANT BUGFIX: a too long final literal run would corrupt data
56 in the encoder (this was introduced in 3.0 only, earlier versions
57 are safe).
58
59 3.0 Tue Nov 13 22:13:09 CET 2007
60 - switched to 2-clause bsd with "GPL v2 or any later version" option.
61 - speed up compression by ~10-15% in common cases
62 by some manual unrolling.
63 - import some compiler tricks from JSON::XS, for further speed-ups.
64 - tune hash functions depending on ULTRA_FAST or VERY_FAST settings.
65 - for typical binary data (e.g. /bin/bash, memory dumps,
66 canterbury corpus etc.), speed is now comparable to fastlz, but
67 with better compression ratio. with ULTRA_FAST, it's typically
68 3-15% faster than fastlz while still maintaining a similar ratio.
69 (amd64 and core 2 duo, ymmv). thanks a lot for the competition :)
70 - undo inline assembly in compressor, it is no longer helpful.
71 - no changes to the decompressor.
72 - use a HLOG of 16 by default now (formerly 15).
73
74 2.1 Fri Nov 2 13:34:42 CET 2007
75 - switched to a 2-clause bsd license with GPL exception.
76 - get rid of memcpy.
77 - tentatively use rep movsb on x86 and x86_64 (gcc only) for a
78 moderate speed improvement.
79 - applied patch by Kein-Hong Man to make lzf.c compile under
80 the crippled mingw32 environment.
81
82 2.0 Fri Feb 16 23:11:18 CET 2007
83 - replaced lzf demo by industrial-strength lzf utility with behaviour
84 similar other compression utilities. Thanks for Stefan Traby for
85 rewriting it!
86 - fix state arg prototype.
87
88 1.7 Wed Sep 27 17:29:15 CEST 2006
89 - remove bogus "unlzf" patch.
90 note to self: never accept well-meant patches.
91 - make lzf more robust in presence of padding bytes or sudden eof.
92
93 1.6 Fri Jul 7 17:31:26 CEST 2006
94 - the lzf example utility will now uncompress if invoked
95 as "unlzf" (patch by Scott Feeney).
96 - add CHECK_INPUT option that adds more checks for input
97 data validity.
98 - help applications that do not pass in the correct length
99 (such as php) by returning either EINVAL or E2BIG.
100 - default HLOG size is now 15 (cpu caches have increased).
101 - documentation fixes.
102
103 1.51 Thu Apr 14 22:15:46 CEST 2005
104 - incorporated C♯ implementation of both the en- and decoder,
105 written by "Oren J. Maurice".
106 You can find it in the cs/ subdirectory.
107 - make FRST, NEXT IDX overridable if lzf_c.c is directly included
108 in the code.
109
110 1.5 Tue Mar 8 20:23:23 CET 2005
111 - incorporated improvements by Adam D. Moss,
112 which includes a new VERY_FAST mode which is
113 a bit slower than ULTRA_FAST but much better,
114 and enabled it as default.
115
116 1.401 Thu Mar 3 18:00:52 CET 2005
117 - use cstring in c++, not string.h.
118 - change of contact address.
119
120 1.4 Wed Dec 15 08:08:49 CET 2004
121 - very very slight tuning of the hashing function.
122
123 1.3 Thu Mar 25 15:41:17 CET 2004
124 - changed license of lzf core code to explicitly allow
125 relicensing under the GPLv2.
126 - added VPATH support as suggested by Björn Eriksson.
127
128 1.2 Mon Dec 29 13:47:28 CET 2003
129 - avoid spurious memory accesses after the to-be-compressed
130 memory region. originally reported by Michal Zalewski.
131 - flip LZF_STACK_ARG meaning (to be correct).
132
133 1.1 Tue Dec 23 05:48:32 CET 2003
134 - removed #warn directive, it's not worth the hassle.
135 - add LZF_STACK_ARG and AVOID_ERRNO configurations
136 for embedded systems.
137 - make it compile cleanly as c++.
138 - some small documentation and code fixes.
139
140 1.0 Sun Nov 17 12:37:37 CET 2002
141 - slightly better compression ratio, almost unmeasurably
142 slower.
143 - some documentation fixes.
144
145 0.4 Thu Jun 13 14:11:10 CEST 2002
146 - typoe fix.
147 - lzf demo program now properly decompresses small files.
148 - fix another 64 bit issue, found by Laurent Deniel.
149
150 0.3 Tue Jan 16 13:21:14 CET 2001
151 - fix silly beginners 32/64 bit mistake.
152
153 0.2 Thu Jan 4 05:56:42 CET 2001
154 - now totally independent of autoconfig, for
155 easy inclusion into other programs.
156 - much better fine-tuning, faster and better than 0.1.
157
158 0.1 2000
159 - initial release.