[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 1.38 by root, Sun May 30 05:46:56 2010 UTC

…		…
1	/*	1	/*
2	* Copyright (c) 2000-2005 Marc Alexander Lehmann <schmorp@schmorp.de>	2	* Copyright (c) 2000-2009 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, L+1=1..33 octets
76	* LLLOOOOO oooooooo ; backref L	93	* LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset
77	* 111OOOOO LLLLLLLL oooooooo ; backref L+7	94	* 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset
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	/* off requires a type wide enough to hold a general pointer difference.
		117	* ISO C doesn't have that (size_t might not be enough and ptrdiff_t only
		118	* works for differences within a single object). We also assume that no
		119	* no bit pattern traps. Since the only platform that is both non-POSIX
		120	* and fails to support both assumptions is windows 64 bit, we make a
		121	* special workaround for it.
		122	*/
		123	#if defined (WIN32) && defined (_M_X64)
		124	unsigned _int64 off; /* workaround for missing POSIX compliance */
		125	#else
100	unsigned long off;	126	unsigned long off;
101	int lit = 0;	127	#endif
		128	unsigned int hval;
		129	int lit;
		130
		131	if (!in_len \|\| !out_len)
		132	return 0;
102		133
103	#if INIT_HTAB	134	#if INIT_HTAB
104	# if USE_MEMCPY
105	memset (htab, 0, sizeof (htab));	135	memset (htab, 0, sizeof (htab));
106	# else	136	# if 0
107	for (hslot = htab; hslot < htab + HSIZE; hslot++)	137	for (hslot = htab; hslot < htab + HSIZE; hslot++)
108	*hslot++ = ip;	138	*hslot++ = ip;
109	# endif
110	#endif	139	# endif
		140	#endif
111		141
112	for (;;)	142	lit = 0; op++; /* start run */
		143
		144	hval = FRST (ip);
		145	while (ip < in_end - 2)
113	{	146	{
114	if (ip < in_end - 2)	147	hval = NEXT (hval, ip);
		148	hslot = htab + IDX (hval);
		149	ref = hslot; hslot = ip;
		150
		151	if (1
		152	#if INIT_HTAB
		153	&& ref < ip /* the next test will actually take care of this, but this is faster */
		154	#endif
		155	&& (off = ip - ref - 1) < MAX_OFF
		156	&& ip + 4 < in_end
		157	&& ref > (u8 *)in_data
		158	#if STRICT_ALIGN
		159	&& ref[0] == ip[0]
		160	&& ref[1] == ip[1]
		161	&& ref[2] == ip[2]
		162	#else
		163	&& (u16 )ref == (u16 )ip
		164	&& ref[2] == ip[2]
		165	#endif
		166	)
115	{	167	{
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++ /	168	/* match found at ref++ /
138	unsigned int len = 2;	169	unsigned int len = 2;
139	unsigned int maxlen = in_end - ip - len;	170	unsigned int maxlen = in_end - ip - len;
140	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;	171	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
		172
		173	if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */
		174	if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */
		175	return 0;
		176
		177	op [- lit - 1] = lit - 1; /* stop run */
		178	op -= !lit; /* undo run if length is zero */
		179
		180	for (;;)
		181	{
		182	if (expect_true (maxlen > 16))
		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	len++; if (ref [len] != ip [len]) break;
		195	len++; if (ref [len] != ip [len]) break;
		196	len++; if (ref [len] != ip [len]) break;
		197	len++; if (ref [len] != ip [len]) break;
		198
		199	len++; if (ref [len] != ip [len]) break;
		200	len++; if (ref [len] != ip [len]) break;
		201	len++; if (ref [len] != ip [len]) break;
		202	len++; if (ref [len] != ip [len]) break;
		203	}
141		204
142	do	205	do
143	len++;	206	len++;
144	while (len < maxlen && ref[len] == ip[len]);	207	while (len < maxlen && ref[len] == ip[len]);
145		208
146	if (op + lit + 1 + 3 >= out_end)
147	return 0;
148
149	if (lit)
150	{	209	break;
151	*op++ = lit - 1;
152	lit = -lit;
153	do
154	*op++ = ip[lit];
155	while (++lit);
156	}	210	}
157		211
158	len -= 2;	212	len -= 2; /* len is now #octets - 1 */
159	ip++;	213	ip++;
160		214
161	if (len < 7)	215	if (len < 7)
162	{	216	{
163	*op++ = (off >> 8) + (len << 5);	217	*op++ = (off >> 8) + (len << 5);
164	}	218	}
165	else	219	else
166	{	220	{
167	*op++ = (off >> 8) + ( 7 << 5);	221	*op++ = (off >> 8) + ( 7 << 5);
168	*op++ = len - 7;	222	*op++ = len - 7;
169	}	223	}
170		224
171	*op++ = off;	225	*op++ = off;
		226	lit = 0; op++; /* start run */
172		227
173	#if ULTRA_FAST
174	ip += len;	228	ip += len + 1;
		229
		230	if (expect_false (ip >= in_end - 2))
		231	break;
		232
		233	#if ULTRA_FAST \|\| VERY_FAST
		234	--ip;
		235	# if VERY_FAST && !ULTRA_FAST
		236	--ip;
		237	# endif
175	hval = FRST (ip);	238	hval = FRST (ip);
		239
		240	hval = NEXT (hval, ip);
		241	htab[IDX (hval)] = ip;
		242	ip++;
		243
		244	# if VERY_FAST && !ULTRA_FAST
		245	hval = NEXT (hval, ip);
		246	htab[IDX (hval)] = ip;
		247	ip++;
		248	# endif
		249	#else
		250	ip -= len + 1;
		251
		252	do
		253	{
176	hval = NEXT (hval, ip);	254	hval = NEXT (hval, ip);
177	htab[IDX (hval)] = ip;	255	htab[IDX (hval)] = ip;
178	ip++;	256	ip++;
179	#else
180	do
181	{
182	hval = NEXT (hval, ip);
183	htab[IDX (hval)] = ip;
184	ip++;
185	}	257	}
186	while (len--);	258	while (len--);
187	#endif	259	#endif
188	continue;
189	}
190	}	260	}
191	else if (ip == in_end)	261	else
192	break;
193
194	/* one more literal byte we must copy */
195	lit++;
196	ip++;
197
198	if (lit == MAX_LIT)
199	{	262	{
200	if (op + 1 + MAX_LIT >= out_end)	263	/* one more literal byte we must copy */
		264	if (expect_false (op >= out_end))
201	return 0;	265	return 0;
202		266
203	*op++ = MAX_LIT - 1;	267	lit++; op++ = ip++;
204	#if USE_MEMCPY	268
205	memcpy (op, ip - MAX_LIT, MAX_LIT);	269	if (expect_false (lit == MAX_LIT))
206	op += MAX_LIT;
207	lit = 0;
208	#else
209	lit = -lit;
210	do	270	{
211	*op++ = ip[lit];	271	op [- lit - 1] = lit - 1; /* stop run */
212	while (++lit);	272	lit = 0; op++; /* start run */
213	#endif	273	}
214	}	274	}
215	}	275	}
216		276
217	if (lit)	277	if (op + 3 > out_end) /* at most 3 bytes can be missing here */
		278	return 0;
		279
		280	while (ip < in_end)
218	{	281	{
219	if (op + lit + 1 >= out_end)	282	lit++; op++ = ip++;
220	return 0;
221		283
222	*op++ = lit - 1;	284	if (expect_false (lit == MAX_LIT))
223	lit = -lit;	285	{
224	do	286	op [- lit - 1] = lit - 1; /* stop run */
225	*op++ = ip[lit];	287	lit = 0; op++; /* start run */
226	while (++lit);	288	}
227	}	289	}
228		290
		291	op [- lit - 1] = lit - 1; /* end run */
		292	op -= !lit; /* undo run if length is zero */
		293
229	return op - (u8 *) out_data;	294	return op - (u8 *)out_data;
230	}	295	}
		296

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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 1.38 by root, Sun May 30 05:46:56 2010 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 1.38 by root, Sun May 30 05:46:56 2010 UTC