[ViewVC] Diff of: cvs/liblzf/lzf

Comparing liblzf/lzf_c.c (file contents):
Revision 1.2 by root, Thu Sep 5 03:31:00 2002 UTC vs.
Revision 1.28 by root, Fri Nov 30 10:34:26 2007 UTC

…		…
1	/*	1	/*
2	* Copyright (c) 2000 Marc Alexander Lehmann <pcg@goof.com>	2	* Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
3	*	3	*
4	* Redistribution and use in source and binary forms, with or without modifica-	4	* Redistribution and use in source and binary forms, with or without modifica-
5	* tion, are permitted provided that the following conditions are met:	5	* tion, are permitted provided that the following conditions are met:
6	*	6	*
7	* 1. Redistributions of source code must retain the above copyright notice,	7	* 1. Redistributions of source code must retain the above copyright notice,
8	* this list of conditions and the following disclaimer.	8	* this list of conditions and the following disclaimer.
9	*	9	*
10	* 2. Redistributions in binary form must reproduce the above copyright	10	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the	11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.	12	* documentation and/or other materials provided with the distribution.
13	*
14	* 3. The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.
16	*	13	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-	15	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19	* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO	16	* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-	17	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;	19	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,	20	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-	21	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25	* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED	22	* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26	* OF THE POSSIBILITY OF SUCH DAMAGE.	23	* OF THE POSSIBILITY OF SUCH DAMAGE.
		24	*
		25	* Alternatively, the contents of this file may be used under the terms of
		26	* the GNU General Public License ("GPL") version 2 or any later version,
		27	* in which case the provisions of the GPL are applicable instead of
		28	* the above. If you wish to allow the use of your version of this file
		29	* only under the terms of the GPL and not to allow others to use your
		30	* version of this file under the BSD license, indicate your decision
		31	* by deleting the provisions above and replace them with the notice
		32	* and other provisions required by the GPL. If you do not delete the
		33	* provisions above, a recipient may use your version of this file under
		34	* either the BSD or the GPL.
27	*/	35	*/
28		36
29	#include "lzfP.h"	37	#include "lzfP.h"
30		38
31	#define HSIZE (1 << (HLOG))	39	#define HSIZE (1 << (HLOG))
…		…
34	* don't play with this unless you benchmark!	42	* don't play with this unless you benchmark!
35	* decompression is not dependent on the hash function	43	* decompression is not dependent on the hash function
36	* the hashing function might seem strange, just believe me	44	* the hashing function might seem strange, just believe me
37	* it works ;)	45	* it works ;)
38	*/	46	*/
		47	#ifndef FRST
39	#define FRST(p) (((p[0]) << 8) + p[1])	48	# define FRST(p) (((p[0]) << 8) \| p[1])
40	#define NEXT(v,p) (((v) << 8) + p[2])	49	# define NEXT(v,p) (((v) << 8) \| p[2])
		50	# if ULTRA_FAST
		51	# define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1))
		52	# elif VERY_FAST
		53	# define IDX(h) ((( h >> (38 - HLOG)) - h5) & (HSIZE - 1))
		54	# else
41	#define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) + h3) & (HSIZE - 1))	55	# define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) - h5) & (HSIZE - 1))
		56	# endif
		57	#endif
42	/*	58	/*
43	* IDX works because it is very similar to a multiplicative hash, e.g.	59	* IDX works because it is very similar to a multiplicative hash, e.g.
44	* (h * 57321 >> (3*8 - HLOG))	60	* ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))
		61	* the latter is also quite fast on newer CPUs, and compresses similarly.
		62	*
45	* the next one is also quite good, albeit slow ;)	63	* the next one is also quite good, albeit slow ;)
46	* (int)(cos(h & 0xffffff) * 1e6)	64	* (int)(cos(h & 0xffffff) * 1e6)
47	*/	65	*/
48		66
49	#if 0	67	#if 0
50	/* original lzv-like hash function */	68	/* original lzv-like hash function, much worse and thus slower */
51	# define FRST(p) (p[0] << 5) ^ p[1]	69	# define FRST(p) (p[0] << 5) ^ p[1]
52	# define NEXT(v,p) ((v) << 5) ^ p[2]	70	# define NEXT(v,p) ((v) << 5) ^ p[2]
53	# define IDX(h) ((h) & (HSIZE - 1))	71	# define IDX(h) ((h) & (HSIZE - 1))
54	#endif	72	#endif
55		73
56	#define MAX_LIT (1 << 5)	74	#define MAX_LIT (1 << 5)
57	#define MAX_OFF (1 << 13)	75	#define MAX_OFF (1 << 13)
58	#define MAX_REF ((1 << 8) + (1 << 3))	76	#define MAX_REF ((1 << 8) + (1 << 3))
		77
		78	#if __GNUC__ >= 3
		79	# define expect(expr,value) __builtin_expect ((expr),(value))
		80	# define inline inline
		81	#else
		82	# define expect(expr,value) (expr)
		83	# define inline static
		84	#endif
		85
		86	#define expect_false(expr) expect ((expr) != 0, 0)
		87	#define expect_true(expr) expect ((expr) != 0, 1)
59		88
60	/*	89	/*
61	* compressed format	90	* compressed format
62	*	91	*
63	* 000LLLLL <L+1> ; literal	92	* 000LLLLL <L+1> ; literal
64	* LLLOOOOO oooooooo ; backref L	93	* LLLooooo oooooooo ; backref L
65	* 111OOOOO LLLLLLLL oooooooo ; backref L+7	94	* 111ooooo LLLLLLLL oooooooo ; backref L+7
66	*	95	*
67	*/	96	*/
68		97
69	unsigned int	98	unsigned int
70	lzf_compress (const void *const in_data, unsigned int in_len,	99	lzf_compress (const void *const in_data, unsigned int in_len,
71	void *out_data, unsigned int out_len)	100	void *out_data, unsigned int out_len
		101	#if LZF_STATE_ARG
		102	, LZF_STATE htab
		103	#endif
		104	)
72	{	105	{
73	const u8 *htab[HSIZE];	106	#if !LZF_STATE_ARG
		107	LZF_STATE htab;
		108	#endif
74	const u8 **hslot;	109	const u8 **hslot;
75	const u8 *ip = in_data;	110	const u8 ip = (const u8 )in_data;
76	u8 *op = out_data;	111	u8 op = (u8 )out_data;
77	const u8 *in_end = ip + in_len;	112	const u8 *in_end = ip + in_len;
78	u8 *out_end = op + out_len;	113	u8 *out_end = op + out_len;
79	const u8 *ref;	114	const u8 *ref;
80		115
81	unsigned int hval = FRST (ip);	116	unsigned int hval;
82	unsigned long off;	117	unsigned long off;
83	int lit = 0;	118	int lit;
		119
		120	if (!in_len \|\| !out_len)
		121	return 0;
84		122
85	#if INIT_HTAB	123	#if INIT_HTAB
86	# if USE_MEMCPY
87	memset (htab, 0, sizeof (htab));	124	memset (htab, 0, sizeof (htab));
88	# else	125	# if 0
89	for (hslot = htab; hslot < htab + HSIZE; hslot++)	126	for (hslot = htab; hslot < htab + HSIZE; hslot++)
90	*hslot++ = ip;	127	*hslot++ = ip;
91	# endif	128	# endif
92	#endif	129	#endif
93		130
94	do	131	lit = 0; op++; /* start run */
		132
		133	hval = FRST (ip);
		134	while (ip < in_end - 2)
95	{	135	{
96	hval = NEXT (hval, ip);	136	hval = NEXT (hval, ip);
97	hslot = htab + IDX (hval);	137	hslot = htab + IDX (hval);
98	ref = hslot; hslot = ip;	138	ref = hslot; hslot = ip;
99		139
100	if (1	140	if (1
101	#if INIT_HTAB && !USE_MEMCPY	141	#if INIT_HTAB
102	&& ref < ip /* the next test will actually take care of this, but it is faster */	142	&& ref < ip /* the next test will actually take care of this, but this is faster */
103	#endif	143	#endif
104	&& (off = ip - ref - 1) < MAX_OFF	144	&& (off = ip - ref - 1) < MAX_OFF
105	&& ip + 4 < in_end	145	&& ip + 4 < in_end
106	&& ref > (u8 *)in_data	146	&& ref > (u8 *)in_data
107	#if STRICT_ALIGN	147	#if STRICT_ALIGN
108	&& ref[0] == ip[0]	148	&& ref[0] == ip[0]
109	&& ref[1] == ip[1]	149	&& ref[1] == ip[1]
110	&& ref[2] == ip[2]	150	&& ref[2] == ip[2]
111	#else	151	#else
112	&& (u16 )ref == (u16 )ip	152	&& (u16 )ref == (u16 )ip
113	&& ref[2] == ip[2]	153	&& ref[2] == ip[2]
114	#endif	154	#endif
115	)	155	)
116	{	156	{
117	/* match found at ref++ /	157	/* match found at ref++ /
118	unsigned int len = 2;	158	unsigned int len = 2;
119	unsigned int maxlen = in_end - ip - len;	159	unsigned int maxlen = in_end - ip - len;
120	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;	160	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
121		161
122	do	162	if (maxlen > 8) maxlen = 8;//D
123	len++;	163
		164	op [- lit - 1] = lit - 1; /* stop run */
		165	op -= !lit; /* undo run if length is zero */
		166
		167	if (expect_false (op + 3 + 1 >= out_end))
		168	return 0;
		169
		170	for (;;)
		171	{
		172	if (expect_true (maxlen > 16))
		173	{
		174	len++; if (ref [len] != ip [len]) break;
		175	len++; if (ref [len] != ip [len]) break;
		176	len++; if (ref [len] != ip [len]) break;
		177	len++; if (ref [len] != ip [len]) break;
		178
		179	len++; if (ref [len] != ip [len]) break;
		180	len++; if (ref [len] != ip [len]) break;
		181	len++; if (ref [len] != ip [len]) break;
		182	len++; if (ref [len] != ip [len]) break;
		183
		184	len++; if (ref [len] != ip [len]) break;
		185	len++; if (ref [len] != ip [len]) break;
		186	len++; if (ref [len] != ip [len]) break;
		187	len++; if (ref [len] != ip [len]) break;
		188
		189	len++; if (ref [len] != ip [len]) break;
		190	len++; if (ref [len] != ip [len]) break;
		191	len++; if (ref [len] != ip [len]) break;
		192	len++; if (ref [len] != ip [len]) break;
		193	}
		194
		195	do
		196	len++;
124	while (len < maxlen && ref[len] == ip[len]);	197	while (len < maxlen && ref[len] == ip[len]);
125		198
126	if (op + lit + 1 + 3 >= out_end)	199	break;
127	return 0;	200	}
128		201
129	if (lit)	202	len -= 2;
130	{	203	ip++;
131	*op++ = lit - 1;
132	lit = -lit;
133	do
134	*op++ = ip[lit];
135	while (++lit);
136	}
137		204
138	len -= 2;
139	ip++;
140
141	if (len < 7)	205	if (len < 7)
142	{	206	{
143	*op++ = (off >> 8) + (len << 5);	207	*op++ = (off >> 8) + (len << 5);
144	}	208	}
145	else	209	else
146	{	210	{
147	*op++ = (off >> 8) + ( 7 << 5);	211	*op++ = (off >> 8) + ( 7 << 5);
148	*op++ = len - 7;	212	*op++ = len - 7;
149	}	213	}
150		214
151	*op++ = off;	215	*op++ = off;
152		216
153	#if ULTRA_FAST	217	#if ULTRA_FAST \|\| VERY_FAST
154	ip += len;	218	ip += len;
		219	#if VERY_FAST && !ULTRA_FAST
		220	--ip;
		221	#endif
155	hval = FRST (ip);	222	hval = FRST (ip);
		223
156	hval = NEXT (hval, ip);	224	hval = NEXT (hval, ip);
157	htab[IDX (hval)] = ip;	225	htab[IDX (hval)] = ip;
158	ip++;	226	ip++;
		227
		228	#if VERY_FAST && !ULTRA_FAST
		229	hval = NEXT (hval, ip);
		230	htab[IDX (hval)] = ip;
		231	ip++;
		232	#endif
159	#else	233	#else
160	do	234	do
161	{	235	{
162	hval = NEXT (hval, ip);	236	hval = NEXT (hval, ip);
163	htab[IDX (hval)] = ip;	237	htab[IDX (hval)] = ip;
164	ip++;	238	ip++;
165	}	239	}
166	while (len--);	240	while (len--);
167	#endif	241	#endif
168	}	242
		243	lit = 0; op++; /* start run */
		244	}
169	else	245	else
170	{	246	{
171	/* one more literal byte we must copy */	247	/* one more literal byte we must copy */
172	lit++;	248	if (expect_false (op >= out_end))
173	ip++;	249	return 0;
174		250
175	if (lit == MAX_LIT)	251	lit++; op++ = ip++;
176	{
177	if (op + 1 + MAX_LIT >= out_end)
178	return 0;
179		252
180	*op++ = MAX_LIT - 1;	253	if (expect_false (lit == MAX_LIT))
181	#if USE_MEMCPY	254	{
182	memcpy (op, ip - MAX_LIT, MAX_LIT);	255	op [- lit - 1] = lit - 1; /* stop run */
183	op += MAX_LIT;	256	lit = 0; op++; /* start run */
184	lit = 0;	257	}
185	#else	258	}
186	lit = -lit;
187	do
188	*op++ = ip[lit];
189	while (++lit);
190	#endif
191	}
192	}
193	}	259	}
		260
		261	if (op + 2 > out_end) /* at most 2 bytes can be missing here */
		262	return 0;
		263
194	while (ip < in_end);	264	while (ip < in_end)
195
196	if (lit)
197	{	265	{
198	if (op + lit + 1 >= out_end)	266	lit++; op++ = ip++;
199	return 0;
200		267
201	*op++ = lit - 1;	268	if (expect_false (lit == MAX_LIT))
202	lit = -lit;	269	{
203	do	270	op [- lit - 1] = lit - 1; /* stop run */
204	*op++ = ip[lit];	271	lit = 0; op++; /* start run */
205	while (++lit);	272	}
206	}	273	}
207		274
		275	op [- lit - 1] = lit - 1; /* end run */
		276	op -= !lit; /* undo run if length is zero */
		277
208	return op - (u8 *) out_data;	278	return op - (u8 *)out_data;
209	}	279	}
		280

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Comparing liblzf/lzf_c.c (file contents): Revision 1.2 by root, Thu Sep 5 03:31:00 2002 UTC vs. Revision 1.28 by root, Fri Nov 30 10:34:26 2007 UTC

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Comparing liblzf/lzf_c.c (file contents):
Revision 1.2 by root, Thu Sep 5 03:31:00 2002 UTC vs.
Revision 1.28 by root, Fri Nov 30 10:34:26 2007 UTC