[ViewVC] Diff of: cvs/liblzf/lzf

Comparing liblzf/lzf_c.c (file contents):
Revision 1.8 by root, Thu Mar 3 17:06:44 2005 UTC vs.
Revision 1.31 by root, Tue May 6 22:49:18 2008 UTC

…		…
1	/*	1	/*
2	* Copyright (c) 2000-2005 Marc Alexander Lehmann <schmorp@schmorp.de>	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-
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.
27	*	24	*
28	* Alternatively, the contents of this file may be used under the terms of	25	* Alternatively, the contents of this file may be used under the terms of
29	* the GNU General Public License version 2 (the "GPL"), in which case the	26	* the GNU General Public License ("GPL") version 2 or any later version,
30	* provisions of the GPL are applicable instead of the above. If you wish to	27	* in which case the provisions of the GPL are applicable instead of
31	* allow the use of your version of this file only under the terms of the	28	* the above. If you wish to allow the use of your version of this file
32	* GPL and not to allow others to use your version of this file under the	29	* only under the terms of the GPL and not to allow others to use your
33	* BSD license, indicate your decision by deleting the provisions above and	30	* version of this file under the BSD license, indicate your decision
34	* replace them with the notice and other provisions required by the GPL. If	31	* by deleting the provisions above and replace them with the notice
35	* you do not delete the provisions above, a recipient may use your version	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
36	* of this file under either the BSD or the GPL.	34	* either the BSD or the GPL.
37	*/	35	*/
38		36
39	#include "lzfP.h"	37	#include "lzfP.h"
40		38
41	#define HSIZE (1 << (HLOG))	39	#define HSIZE (1 << (HLOG))
…		…
44	* don't play with this unless you benchmark!	42	* don't play with this unless you benchmark!
45	* decompression is not dependent on the hash function	43	* decompression is not dependent on the hash function
46	* the hashing function might seem strange, just believe me	44	* the hashing function might seem strange, just believe me
47	* it works ;)	45	* it works ;)
48	*/	46	*/
		47	#ifndef FRST
49	#define FRST(p) (((p[0]) << 8) + p[1])	48	# define FRST(p) (((p[0]) << 8) \| p[1])
50	#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
51	#define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) - h5) & (HSIZE - 1))	55	# define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) - h5) & (HSIZE - 1))
		56	# endif
		57	#endif
52	/*	58	/*
53	* 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.
54	* ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))	60	* ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))
55	* the latter is also quite fast on newer CPUs, and sligthly better	61	* the latter is also quite fast on newer CPUs, and compresses similarly.
56	*	62	*
57	* the next one is also quite good, albeit slow ;)	63	* the next one is also quite good, albeit slow ;)
58	* (int)(cos(h & 0xffffff) * 1e6)	64	* (int)(cos(h & 0xffffff) * 1e6)
59	*/	65	*/
60		66
…		…
65	# define IDX(h) ((h) & (HSIZE - 1))	71	# define IDX(h) ((h) & (HSIZE - 1))
66	#endif	72	#endif
67		73
68	#define MAX_LIT (1 << 5)	74	#define MAX_LIT (1 << 5)
69	#define MAX_OFF (1 << 13)	75	#define MAX_OFF (1 << 13)
70	#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)
71		88
72	/*	89	/*
73	* compressed format	90	* compressed format
74	*	91	*
75	* 000LLLLL <L+1> ; literal	92	* 000LLLLL <L+1> ; literal
76	* LLLOOOOO oooooooo ; backref L	93	* LLLooooo oooooooo ; backref L
77	* 111OOOOO LLLLLLLL oooooooo ; backref L+7	94	* 111ooooo LLLLLLLL oooooooo ; backref L+7
78	*	95	*
79	*/	96	*/
80		97
81	unsigned int	98	unsigned int
82	lzf_compress (const void *const in_data, unsigned int in_len,	99	lzf_compress (const void *const in_data, unsigned int in_len,
83	void *out_data, unsigned int out_len	100	void *out_data, unsigned int out_len
84	#if LZF_STATE_ARG	101	#if LZF_STATE_ARG
85	, LZF_STATE *htab	102	, LZF_STATE htab
86	#endif	103	#endif
87	)	104	)
88	{	105	{
89	#if !LZF_STATE_ARG	106	#if !LZF_STATE_ARG
90	LZF_STATE htab;	107	LZF_STATE htab;
…		…
94	u8 op = (u8 )out_data;	111	u8 op = (u8 )out_data;
95	const u8 *in_end = ip + in_len;	112	const u8 *in_end = ip + in_len;
96	u8 *out_end = op + out_len;	113	u8 *out_end = op + out_len;
97	const u8 *ref;	114	const u8 *ref;
98		115
99	unsigned int hval = FRST (ip);	116	unsigned int hval;
		117	#if WIN32
		118	unsigned _int64 off; /* workaround for microsoft bug (they claim to support POSIX) */
		119	#else
100	unsigned long off;	120	unsigned long off;
101	int lit = 0;	121	#endif
		122	int lit;
		123
		124	if (!in_len \|\| !out_len)
		125	return 0;
102		126
103	#if INIT_HTAB	127	#if INIT_HTAB
104	# if USE_MEMCPY
105	memset (htab, 0, sizeof (htab));	128	memset (htab, 0, sizeof (htab));
106	# else	129	# if 0
107	for (hslot = htab; hslot < htab + HSIZE; hslot++)	130	for (hslot = htab; hslot < htab + HSIZE; hslot++)
108	*hslot++ = ip;	131	*hslot++ = ip;
109	# endif	132	# endif
110	#endif	133	#endif
111		134
112	for (;;)	135	lit = 0; op++; /* start run */
		136
		137	hval = FRST (ip);
		138	while (ip < in_end - 2)
113	{	139	{
114	if (ip < in_end - 2)	140	hval = NEXT (hval, ip);
		141	hslot = htab + IDX (hval);
		142	ref = hslot; hslot = ip;
		143
		144	if (1
		145	#if INIT_HTAB
		146	&& ref < ip /* the next test will actually take care of this, but this is faster */
		147	#endif
		148	&& (off = ip - ref - 1) < MAX_OFF
		149	&& ip + 4 < in_end
		150	&& ref > (u8 *)in_data
		151	#if STRICT_ALIGN
		152	&& ref[0] == ip[0]
		153	&& ref[1] == ip[1]
		154	&& ref[2] == ip[2]
		155	#else
		156	&& (u16 )ref == (u16 )ip
		157	&& ref[2] == ip[2]
		158	#endif
		159	)
115	{	160	{
116	hval = NEXT (hval, ip);
117	hslot = htab + IDX (hval);
118	ref = hslot; hslot = ip;
119
120	if (1
121	#if INIT_HTAB && !USE_MEMCPY
122	&& ref < ip /* the next test will actually take care of this, but this is faster */
123	#endif
124	&& (off = ip - ref - 1) < MAX_OFF
125	&& ip + 4 < in_end
126	&& ref > (u8 *)in_data
127	#if STRICT_ALIGN
128	&& ref[0] == ip[0]
129	&& ref[1] == ip[1]
130	&& ref[2] == ip[2]
131	#else
132	&& (u16 )ref == (u16 )ip
133	&& ref[2] == ip[2]
134	#endif
135	)
136	{
137	/* match found at ref++ /	161	/* match found at ref++ /
138	unsigned int len = 2;	162	unsigned int len = 2;
139	unsigned int maxlen = in_end - ip - len;	163	unsigned int maxlen = in_end - ip - len;
140	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;	164	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
		165
		166	op [- lit - 1] = lit - 1; /* stop run */
		167	op -= !lit; /* undo run if length is zero */
		168
		169	if (expect_false (op + 3 + 1 >= out_end))
		170	return 0;
		171
		172	for (;;)
		173	{
		174	if (expect_true (maxlen > 16))
		175	{
		176	len++; if (ref [len] != ip [len]) break;
		177	len++; if (ref [len] != ip [len]) break;
		178	len++; if (ref [len] != ip [len]) break;
		179	len++; if (ref [len] != ip [len]) break;
		180
		181	len++; if (ref [len] != ip [len]) break;
		182	len++; if (ref [len] != ip [len]) break;
		183	len++; if (ref [len] != ip [len]) break;
		184	len++; if (ref [len] != ip [len]) break;
		185
		186	len++; if (ref [len] != ip [len]) break;
		187	len++; if (ref [len] != ip [len]) break;
		188	len++; if (ref [len] != ip [len]) break;
		189	len++; if (ref [len] != ip [len]) break;
		190
		191	len++; if (ref [len] != ip [len]) break;
		192	len++; if (ref [len] != ip [len]) break;
		193	len++; if (ref [len] != ip [len]) break;
		194	len++; if (ref [len] != ip [len]) break;
		195	}
141		196
142	do	197	do
143	len++;	198	len++;
144	while (len < maxlen && ref[len] == ip[len]);	199	while (len < maxlen && ref[len] == ip[len]);
145		200
146	if (op + lit + 1 + 3 >= out_end)
147	return 0;
148
149	if (lit)
150	{	201	break;
151	*op++ = lit - 1;
152	lit = -lit;
153	do
154	*op++ = ip[lit];
155	while (++lit);
156	}	202	}
157		203
158	len -= 2;	204	len -= 2;
159	ip++;	205	ip++;
160		206
161	if (len < 7)	207	if (len < 7)
162	{	208	{
163	*op++ = (off >> 8) + (len << 5);	209	*op++ = (off >> 8) + (len << 5);
164	}	210	}
165	else	211	else
166	{	212	{
167	*op++ = (off >> 8) + ( 7 << 5);	213	*op++ = (off >> 8) + ( 7 << 5);
168	*op++ = len - 7;	214	*op++ = len - 7;
169	}	215	}
170		216
171	*op++ = off;	217	*op++ = off;
172		218
173	#if ULTRA_FAST	219	#if ULTRA_FAST \|\| VERY_FAST
174	ip += len;	220	ip += len;
		221	#if VERY_FAST && !ULTRA_FAST
		222	--ip;
		223	#endif
175	hval = FRST (ip);	224	hval = FRST (ip);
		225
		226	hval = NEXT (hval, ip);
		227	htab[IDX (hval)] = ip;
		228	ip++;
		229
		230	#if VERY_FAST && !ULTRA_FAST
		231	hval = NEXT (hval, ip);
		232	htab[IDX (hval)] = ip;
		233	ip++;
		234	#endif
		235	#else
		236	do
		237	{
176	hval = NEXT (hval, ip);	238	hval = NEXT (hval, ip);
177	htab[IDX (hval)] = ip;	239	htab[IDX (hval)] = ip;
178	ip++;	240	ip++;
179	#else
180	do
181	{
182	hval = NEXT (hval, ip);
183	htab[IDX (hval)] = ip;
184	ip++;
185	}	241	}
186	while (len--);	242	while (len--);
187	#endif	243	#endif
188	continue;	244
189	}	245	lit = 0; op++; /* start run */
190	}	246	}
191	else if (ip == in_end)	247	else
192	break;
193
194	/* one more literal byte we must copy */
195	lit++;
196	ip++;
197
198	if (lit == MAX_LIT)
199	{	248	{
200	if (op + 1 + MAX_LIT >= out_end)	249	/* one more literal byte we must copy */
		250	if (expect_false (op >= out_end))
201	return 0;	251	return 0;
202		252
203	*op++ = MAX_LIT - 1;	253	lit++; op++ = ip++;
204	#if USE_MEMCPY	254
205	memcpy (op, ip - MAX_LIT, MAX_LIT);	255	if (expect_false (lit == MAX_LIT))
206	op += MAX_LIT;
207	lit = 0;
208	#else
209	lit = -lit;
210	do	256	{
211	*op++ = ip[lit];	257	op [- lit - 1] = lit - 1; /* stop run */
212	while (++lit);	258	lit = 0; op++; /* start run */
213	#endif	259	}
214	}	260	}
215	}	261	}
216		262
217	if (lit)	263	if (op + 3 > out_end) /* at most 3 bytes can be missing here */
		264	return 0;
		265
		266	while (ip < in_end)
218	{	267	{
219	if (op + lit + 1 >= out_end)	268	lit++; op++ = ip++;
220	return 0;
221		269
222	*op++ = lit - 1;	270	if (expect_false (lit == MAX_LIT))
223	lit = -lit;	271	{
224	do	272	op [- lit - 1] = lit - 1; /* stop run */
225	*op++ = ip[lit];	273	lit = 0; op++; /* start run */
226	while (++lit);	274	}
227	}	275	}
228		276
		277	op [- lit - 1] = lit - 1; /* end run */
		278	op -= !lit; /* undo run if length is zero */
		279
229	return op - (u8 *) out_data;	280	return op - (u8 *)out_data;
230	}	281	}
		282

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Comparing liblzf/lzf_c.c (file contents): Revision 1.8 by root, Thu Mar 3 17:06:44 2005 UTC vs. Revision 1.31 by root, Tue May 6 22:49:18 2008 UTC

Diff Legend

Comparing liblzf/lzf_c.c (file contents):
Revision 1.8 by root, Thu Mar 3 17:06:44 2005 UTC vs.
Revision 1.31 by root, Tue May 6 22:49:18 2008 UTC