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Revision: 1.61
Committed: Sun Mar 3 11:31:01 2019 UTC (5 years, 1 month ago) by root
Branch: MAIN
CVS Tags: HEAD
Changes since 1.60: +1 -0 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 TODO: undefined unaligned access
6
7 3.8 (unreleased)
8 - support a state arg for lzf_c_best.
9
10 3.7 (unreleased)
11 - add lzf_c_best.c, a slower but better compressor.
12 - switch to a multiplicative hash (developed with Steinar Gunderson),
13 which is faster on modern cpus and compresses a bit better. The old
14 hash function which uses only shifts is still available.
15 - allow user configurable hash table slots, which makes it possible
16 to use e.g. 16 bit offsets for a smaller hashtable (if your data is
17 always < 64kb).
18 - use _WIN32, not WIN32, when testing for windows (fails with bcc),
19 patch by Tamas Tevesz.
20 - try to port to win64+gcc, which is non-posix but doesn't have _int64
21 (reported by Maciej Adamczyk).
22
23 3.6 Mon Feb 7 17:37:31 CET 2011
24 - fixed hash calculation in C♯ version (Tiago Freitas Leal).
25 - unroll copy for small sizes, use memcpy for larger sizes,
26 greatly speeding up decompression in most cases.
27 - finally disable rep movsb - it's a big loss on modern intel cpus,
28 and only a small win on amd cpus.
29 - improve C++ compatibility of the code.
30 - slightly improve compressor speed.
31 - halved memory requirements for compressor on 64 bit architectures,
32 which can improve the speed quite a bit on older cpus.
33
34 3.5 Fri May 1 02:28:42 CEST 2009
35 - lzf_compress did sometimes write one octet past the given output
36 buffer (analyzed and nice testcase by Salvatore Sanfilippo).
37
38 3.4 Tue Sep 2 06:45:00 CEST 2008
39 - the fix from 3.3 introduced a compression bug, which is fixed in
40 this release (which explains the mysterious prerelease...). Thanks
41 once more to Clément Calmels.
42
43 3.3 Mon Aug 25 03:17:42 CEST 2008
44 - lzf_compress could access memory after the given input buffer
45 when outputting back references. reported with nice testcase
46 by Clément Calmels.
47
48 3.2 Fri May 9 18:52:23 CEST 2008
49 - include a workaround for failing POSIX and real-world compliance
50 on 64 bit windows (microsoft claims to support POSIX, but is far
51 from it). (bug found and analysed nicely by John Lilley).
52
53 3.1 Fri Nov 30 11:33:04 CET 2007
54 - IMPORTANT BUGFIX: a too long final literal run would corrupt data
55 in the encoder (this was introduced in 3.0 only, earlier versions
56 are safe).
57
58 3.0 Tue Nov 13 22:13:09 CET 2007
59 - switched to 2-clause bsd with "GPL v2 or any later version" option.
60 - speed up compression by ~10-15% in common cases
61 by some manual unrolling.
62 - import some compiler tricks from JSON::XS, for further speed-ups.
63 - tune hash functions depending on ULTRA_FAST or VERY_FAST settings.
64 - for typical binary data (e.g. /bin/bash, memory dumps,
65 canterbury corpus etc.), speed is now comparable to fastlz, but
66 with better compression ratio. with ULTRA_FAST, it's typically
67 3-15% faster than fastlz while still maintaining a similar ratio.
68 (amd64 and core 2 duo, ymmv). thanks a lot for the competition :)
69 - undo inline assembly in compressor, it is no longer helpful.
70 - no changes to the decompressor.
71 - use a HLOG of 16 by default now (formerly 15).
72
73 2.1 Fri Nov 2 13:34:42 CET 2007
74 - switched to a 2-clause bsd license with GPL exception.
75 - get rid of memcpy.
76 - tentatively use rep movsb on x86 and x86_64 (gcc only) for a
77 moderate speed improvement.
78 - applied patch by Kein-Hong Man to make lzf.c compile under
79 the crippled mingw32 environment.
80
81 2.0 Fri Feb 16 23:11:18 CET 2007
82 - replaced lzf demo by industrial-strength lzf utility with behaviour
83 similar other compression utilities. Thanks for Stefan Traby for
84 rewriting it!
85 - fix state arg prototype.
86
87 1.7 Wed Sep 27 17:29:15 CEST 2006
88 - remove bogus "unlzf" patch.
89 note to self: never accept well-meant patches.
90 - make lzf more robust in presence of padding bytes or sudden eof.
91
92 1.6 Fri Jul 7 17:31:26 CEST 2006
93 - the lzf example utility will now uncompress if invoked
94 as "unlzf" (patch by Scott Feeney).
95 - add CHECK_INPUT option that adds more checks for input
96 data validity.
97 - help applications that do not pass in the correct length
98 (such as php) by returning either EINVAL or E2BIG.
99 - default HLOG size is now 15 (cpu caches have increased).
100 - documentation fixes.
101
102 1.51 Thu Apr 14 22:15:46 CEST 2005
103 - incorporated C♯ implementation of both the en- and decoder,
104 written by "Oren J. Maurice".
105 You can find it in the cs/ subdirectory.
106 - make FRST, NEXT IDX overridable if lzf_c.c is directly included
107 in the code.
108
109 1.5 Tue Mar 8 20:23:23 CET 2005
110 - incorporated improvements by Adam D. Moss,
111 which includes a new VERY_FAST mode which is
112 a bit slower than ULTRA_FAST but much better,
113 and enabled it as default.
114
115 1.401 Thu Mar 3 18:00:52 CET 2005
116 - use cstring in c++, not string.h.
117 - change of contact address.
118
119 1.4 Wed Dec 15 08:08:49 CET 2004
120 - very very slight tuning of the hashing function.
121
122 1.3 Thu Mar 25 15:41:17 CET 2004
123 - changed license of lzf core code to explicitly allow
124 relicensing under the GPLv2.
125 - added VPATH support as suggested by Björn Eriksson.
126
127 1.2 Mon Dec 29 13:47:28 CET 2003
128 - avoid spurious memory accesses after the to-be-compressed
129 memory region. originally reported by Michal Zalewski.
130 - flip LZF_STACK_ARG meaning (to be correct).
131
132 1.1 Tue Dec 23 05:48:32 CET 2003
133 - removed #warn directive, it's not worth the hassle.
134 - add LZF_STACK_ARG and AVOID_ERRNO configurations
135 for embedded systems.
136 - make it compile cleanly as c++.
137 - some small documentation and code fixes.
138
139 1.0 Sun Nov 17 12:37:37 CET 2002
140 - slightly better compression ratio, almost unmeasurably
141 slower.
142 - some documentation fixes.
143
144 0.4 Thu Jun 13 14:11:10 CEST 2002
145 - typoe fix.
146 - lzf demo program now properly decompresses small files.
147 - fix another 64 bit issue, found by Laurent Deniel.
148
149 0.3 Tue Jan 16 13:21:14 CET 2001
150 - fix silly beginners 32/64 bit mistake.
151
152 0.2 Thu Jan 4 05:56:42 CET 2001
153 - now totally independent of autoconfig, for
154 easy inclusion into other programs.
155 - much better fine-tuning, faster and better than 0.1.
156
157 0.1 2000
158 - initial release.