[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 1.50 by root, Mon Jun 29 23:34:41 2015 UTC

1	/*	1	/*
2	* Copyright (c) 2000 Marc Alexander Lehmann <pcg@goof.com>	2	* Copyright (c) 2000-2010,2012 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	*	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	*
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-
21	* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,	18	* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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))
32		40
33	/*	41	/*
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	* the data format is not dependent on the hash function.
36	* the hashing function might seem strange, just believe me	44	* the hash 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 MULTIPLICATION_IS_SLOW
		51	# if ULTRA_FAST
		52	# define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1))
		53	# elif VERY_FAST
		54	# define IDX(h) ((( h >> (38 - HLOG)) - h5) & (HSIZE - 1))
		55	# else
41	#define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) + h3) & (HSIZE - 1))	56	# define IDX(h) ((((h ^ (h << 5)) >> (38 - HLOG)) - h5) & (HSIZE - 1))
42	/*	57	# endif
43	* IDX works because it is very similar to a multiplicative hash, e.g.	58	# else
44	* (h * 57321 >> (3*8 - HLOG))	59	/* this one was developed with sesse,
45	* the next one is also quite good, albeit slow ;)	60	* and is very similar to the one in snappy.
46	* (int)(cos(h & 0xffffff) * 1e6)	61	* it does need a modern enough cpu with a fast multiplication.
47	*/	62	*/
		63	# define IDX(h) (((h * 0x1e35a7bdU) >> (32 - HLOG - 8)) & (HSIZE - 1))
		64	# endif
		65	#endif
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	#if __GNUC__ >= 3
57	#define MAX_OFF (1 << 13)	75	# define expect(expr,value) __builtin_expect ((expr),(value))
58	#define MAX_REF ((1 << 8) + (1 << 3))	76	# define inline inline
		77	#else
		78	# define expect(expr,value) (expr)
		79	# define inline static
		80	#endif
		81
		82	#define expect_false(expr) expect ((expr) != 0, 0)
		83	#define expect_true(expr) expect ((expr) != 0, 1)
59		84
60	/*	85	/*
61	* compressed format	86	* compressed format
62	*	87	*
63	* 000LLLLL <L+1> ; literal	88	* 000LLLLL <L+1> ; literal, L+1=1..33 octets
64	* LLLOOOOO oooooooo ; backref L	89	* LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset
65	* 111OOOOO LLLLLLLL oooooooo ; backref L+7	90	* 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset
66	*	91	*
67	*/	92	*/
68		93
69	unsigned int	94	unsigned int
70	lzf_compress (const void *const in_data, unsigned int in_len,	95	lzf_compress (const void *const in_data, unsigned int in_len,
71	void *out_data, unsigned int out_len)	96	void *out_data, unsigned int out_len
		97	#if LZF_STATE_ARG
		98	, LZF_STATE htab
		99	#endif
		100	)
72	{	101	{
73	const u8 *htab[HSIZE];	102	#if !LZF_STATE_ARG
74	const u8 **hslot;	103	LZF_STATE htab;
		104	#endif
75	const u8 *ip = in_data;	105	const u8 ip = (const u8 )in_data;
76	u8 *op = out_data;	106	u8 op = (u8 )out_data;
77	const u8 *in_end = ip + in_len;	107	const u8 *in_end = ip + in_len;
78	u8 *out_end = op + out_len;	108	u8 *out_end = op + out_len;
79	const u8 *ref;	109	const u8 *ref;
80		110
81	unsigned int hval = FRST (ip);	111	/* off requires a type wide enough to hold a general pointer difference.
		112	* ISO C doesn't have that (size_t might not be enough and ptrdiff_t only
		113	* works for differences within a single object). We also assume that
		114	* no bit pattern traps. Since the only platform that is both non-POSIX
		115	* and fails to support both assumptions is windows 64 bit, we make a
		116	* special workaround for it.
		117	*/
		118	#if defined (_WIN32) && defined (_M_X64)
		119	/* workaround for missing POSIX compliance */
		120	#if __GNUC__
		121	unsigned long long off;
		122	#else
		123	unsigned __int64 off;
		124	#endif
		125	#else
82	unsigned long off;	126	unsigned long off;
83	int lit = 0;	127	#endif
		128	unsigned int hval;
		129	int lit;
		130
		131	if (!in_len \|\| !out_len)
		132	return 0;
84		133
85	#if INIT_HTAB	134	#if INIT_HTAB
86	# if USE_MEMCPY
87	memset (htab, 0, sizeof (htab));	135	memset (htab, 0, sizeof (htab));
88	# else
89	for (hslot = htab; hslot < htab + HSIZE; hslot++)
90	*hslot++ = ip;
91	# endif	136	#endif
92	#endif
93		137
94	do	138	lit = 0; op++; /* start run */
		139
		140	hval = FRST (ip);
		141	while (ip < in_end - 2)
95	{	142	{
		143	LZF_HSLOT *hslot;
		144
96	hval = NEXT (hval, ip);	145	hval = NEXT (hval, ip);
97	hslot = htab + IDX (hval);	146	hslot = htab + IDX (hval);
98	ref = hslot; hslot = ip;	147	ref = hslot + LZF_HSLOT_BIAS; hslot = ip - LZF_HSLOT_BIAS;
99		148
100	if (1	149	if (1
101	#if INIT_HTAB && !USE_MEMCPY	150	#if INIT_HTAB
102	&& ref < ip /* the next test will actually take care of this, but it is faster */	151	&& ref < ip /* the next test will actually take care of this, but this is faster */
103	#endif	152	#endif
104	&& (off = ip - ref - 1) < MAX_OFF	153	&& (off = ip - ref - 1) < LZF_MAX_OFF
105	&& ip + 4 < in_end
106	&& ref > (u8 *)in_data	154	&& ref > (u8 *)in_data
		155	&& ref[2] == ip[2]
107	#if STRICT_ALIGN	156	#if STRICT_ALIGN
108	&& ref[0] == ip[0]	157	&& ((ref[1] << 8) \| ref[0]) == ((ip[1] << 8) \| ip[0])
109	&& ref[1] == ip[1]
110	&& ref[2] == ip[2]
111	#else	158	#else
112	&& (u16 )ref == (u16 )ip	159	&& (u16 )ref == (u16 )ip
113	&& ref[2] == ip[2]
114	#endif	160	#endif
115	)	161	)
116	{	162	{
117	/* match found at ref++ /	163	/* match found at ref++ /
118	unsigned int len = 2;	164	unsigned int len = 2;
119	unsigned int maxlen = in_end - ip - len;	165	unsigned int maxlen = in_end - ip - len;
120	maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;	166	maxlen = maxlen > LZF_MAX_REF ? LZF_MAX_REF : maxlen;
121		167
122	do	168	if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */
123	len++;	169	if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */
		170	return 0;
		171
		172	op [- lit - 1] = lit - 1; /* stop run */
		173	op -= !lit; /* undo run if length is zero */
		174
		175	for (;;)
		176	{
		177	if (expect_true (maxlen > 16))
		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	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
		200	do
		201	len++;
124	while (len < maxlen && ref[len] == ip[len]);	202	while (len < maxlen && ref[len] == ip[len]);
125		203
126	if (op + lit + 1 + 3 >= out_end)	204	break;
127	return 0;	205	}
128		206
129	if (lit)	207	len -= 2; /* len is now #octets - 1 */
130	{	208	ip++;
131	*op++ = lit - 1;
132	lit = -lit;
133	do
134	*op++ = ip[lit];
135	while (++lit);
136	}
137		209
138	len -= 2;
139	ip++;
140
141	if (len < 7)	210	if (len < 7)
142	{	211	{
143	*op++ = (off >> 8) + (len << 5);	212	*op++ = (off >> 8) + (len << 5);
144	}	213	}
145	else	214	else
146	{	215	{
147	*op++ = (off >> 8) + ( 7 << 5);	216	*op++ = (off >> 8) + ( 7 << 5);
148	*op++ = len - 7;	217	*op++ = len - 7;
149	}	218	}
150		219
151	*op++ = off;	220	*op++ = off;
152		221
153	#if ULTRA_FAST	222	lit = 0; op++; /* start run */
		223
154	ip += len;	224	ip += len + 1;
		225
		226	if (expect_false (ip >= in_end - 2))
		227	break;
		228
		229	#if ULTRA_FAST \|\| VERY_FAST
		230	--ip;
		231	# if VERY_FAST && !ULTRA_FAST
		232	--ip;
		233	# endif
155	hval = FRST (ip);	234	hval = FRST (ip);
		235
156	hval = NEXT (hval, ip);	236	hval = NEXT (hval, ip);
157	htab[IDX (hval)] = ip;	237	htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
158	ip++;	238	ip++;
159	#else	239
160	do	240	# if VERY_FAST && !ULTRA_FAST
161	{
162	hval = NEXT (hval, ip);	241	hval = NEXT (hval, ip);
163	htab[IDX (hval)] = ip;	242	htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
164	ip++;	243	ip++;
165	}
166	while (len--);
167	#endif	244	# endif
168	}	245	#else
		246	ip -= len + 1;
		247
		248	do
		249	{
		250	hval = NEXT (hval, ip);
		251	htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
		252	ip++;
		253	}
		254	while (len--);
		255	#endif
		256	}
169	else	257	else
170	{	258	{
171	/* one more literal byte we must copy */	259	/* one more literal byte we must copy */
172	lit++;	260	if (expect_false (op >= out_end))
173	ip++;	261	return 0;
174		262
175	if (lit == MAX_LIT)	263	lit++; op++ = ip++;
176	{
177	if (op + 1 + MAX_LIT >= out_end)
178	return 0;
179		264
180	*op++ = MAX_LIT - 1;	265	if (expect_false (lit == LZF_MAX_LIT))
181	#if USE_MEMCPY	266	{
182	memcpy (op, ip - MAX_LIT, MAX_LIT);	267	op [- lit - 1] = lit - 1; /* stop run */
183	op += MAX_LIT;	268	lit = 0; op++; /* start run */
184	lit = 0;	269	}
185	#else	270	}
186	lit = -lit;
187	do
188	*op++ = ip[lit];
189	while (++lit);
190	#endif
191	}
192	}
193	}	271	}
		272
		273	if (op + 3 > out_end) /* at most 3 bytes can be missing here */
		274	return 0;
		275
194	while (ip < in_end);	276	while (ip < in_end)
195
196	if (lit)
197	{	277	{
198	if (op + lit + 1 >= out_end)	278	lit++; op++ = ip++;
199	return 0;
200		279
201	*op++ = lit - 1;	280	if (expect_false (lit == LZF_MAX_LIT))
202	lit = -lit;	281	{
203	do	282	op [- lit - 1] = lit - 1; /* stop run */
204	*op++ = ip[lit];	283	lit = 0; op++; /* start run */
205	while (++lit);	284	}
206	}	285	}
207		286
		287	op [- lit - 1] = lit - 1; /* end run */
		288	op -= !lit; /* undo run if length is zero */
		289
208	return op - (u8 *) out_data;	290	return op - (u8 *)out_data;
209	}	291	}
		292

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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 1.50 by root, Mon Jun 29 23:34:41 2015 UTC

Diff Legend

Comparing liblzf/lzf_c.c (file contents):
Revision 1.2 by root, Thu Sep 5 03:31:00 2002 UTC vs.
Revision 1.50 by root, Mon Jun 29 23:34:41 2015 UTC