liblzf/lzf_d.c

/*
 * Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp@schmorp.de>
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 *
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

#include "lzfP.h"

#if AVOID_ERRNO
# define SET_ERRNO(n)
#else
# include <errno.h>
# define SET_ERRNO(n) errno = (n)
#endif

#if USE_REP_MOVSB /* small win on amd, big loss on intel */
#if (__i386 || __amd64) && __GNUC__ >= 3
# define lzf_movsb(dst, src, len)                \
   asm ("rep movsb"                              \
        : "=D" (dst), "=S" (src), "=c" (len)     \
        :  "0" (dst),  "1" (src),  "2" (len));
#endif
#endif

unsigned int
lzf_decompress (const void *const in_data,  unsigned int in_len,
                void             *out_data, unsigned int out_len)
{
  u8 const *ip = (const u8 *)in_data;
  u8       *op = (u8 *)out_data;
  u8 const *const in_end  = ip + in_len;
  u8       *const out_end = op + out_len;

  do
    {
      unsigned int ctrl = *ip++;

      if (ctrl < (1 << 5)) /* literal run */
        {
          ctrl++;

          if (op + ctrl > out_end)
            {
              SET_ERRNO (E2BIG);
              return 0;
            }

#if CHECK_INPUT
          if (ip + ctrl > in_end)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }
#endif

#ifdef lzf_movsb
          lzf_movsb (op, ip, ctrl);
#elif OPTIMISE_SIZE
          while (ctrl--)
            *op++ = *ip++;
#else
          switch (ctrl)
            {
              case 32: *op++ = *ip++; case 31: *op++ = *ip++; case 30: *op++ = *ip++; case 29: *op++ = *ip++;
              case 28: *op++ = *ip++; case 27: *op++ = *ip++; case 26: *op++ = *ip++; case 25: *op++ = *ip++;
              case 24: *op++ = *ip++; case 23: *op++ = *ip++; case 22: *op++ = *ip++; case 21: *op++ = *ip++;
              case 20: *op++ = *ip++; case 19: *op++ = *ip++; case 18: *op++ = *ip++; case 17: *op++ = *ip++;
              case 16: *op++ = *ip++; case 15: *op++ = *ip++; case 14: *op++ = *ip++; case 13: *op++ = *ip++;
              case 12: *op++ = *ip++; case 11: *op++ = *ip++; case 10: *op++ = *ip++; case  9: *op++ = *ip++;
              case  8: *op++ = *ip++; case  7: *op++ = *ip++; case  6: *op++ = *ip++; case  5: *op++ = *ip++;
              case  4: *op++ = *ip++; case  3: *op++ = *ip++; case  2: *op++ = *ip++; case  1: *op++ = *ip++;
            }
#endif
        }
      else /* back reference */
        {
          unsigned int len = ctrl >> 5;

          u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;

#if CHECK_INPUT
          if (ip >= in_end)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }
#endif
          if (len == 7)
            {
              len += *ip++;
#if CHECK_INPUT
              if (ip >= in_end)
                {
                  SET_ERRNO (EINVAL);
                  return 0;
                }
#endif
            }

          ref -= *ip++;

          if (op + len + 2 > out_end)
            {
              SET_ERRNO (E2BIG);
              return 0;
            }

          if (ref < (u8 *)out_data)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }

#ifdef lzf_movsb
          len += 2;
          lzf_movsb (op, ref, len);
#elif OPTIMISE_SIZE
          len += 2;

          do
            *op++ = *ref++;
          while (--len);
#else
          switch (len)
            {
              default:
                len += 2;

                if (op >= ref + len)
                  {
                    /* disjunct areas */
                    memcpy (op, ref, len);
                    op += len;
                  }
                else
                  {
                    /* overlapping, use octet by octet copying */
                    do
                      *op++ = *ref++;
                    while (--len);
                  }

                break;

              case 9: *op++ = *ref++;
              case 8: *op++ = *ref++;
              case 7: *op++ = *ref++;
              case 6: *op++ = *ref++;
              case 5: *op++ = *ref++;
              case 4: *op++ = *ref++;
              case 3: *op++ = *ref++;
              case 2: *op++ = *ref++;
              case 1: *op++ = *ref++;
              case 0: *op++ = *ref++; /* two octets more */
                      *op++ = *ref++;
            }
#endif
        }
    }
  while (ip < in_end);

  return op - (u8 *)out_data;
}

Revision:	1.16
Committed:	Mon Feb 23 23:46:10 2015 UTC (9 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.15:	+11 -2 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.11	* Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.15	*
4	root	1.1	* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6	root	1.15	*
7	root	1.1	* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9	root	1.15	*
10	root	1.1	* 2. Redistributions in binary form must reproduce the above copyright
11			* notice, this list of conditions and the following disclaimer in the
12			* documentation and/or other materials provided with the distribution.
13	root	1.15	*
14	root	1.1	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
15			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
16			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
17			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
18			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
20			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
21			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
22			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
23			* OF THE POSSIBILITY OF SUCH DAMAGE.
24	pcg	1.4	*
25			* Alternatively, the contents of this file may be used under the terms of
26	root	1.9	* 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.
35	root	1.1	*/
36
37	pcg	1.3	#include "lzfP.h"
38	root	1.1
39	pcg	1.3	#if AVOID_ERRNO
40			# define SET_ERRNO(n)
41			#else
42			# include <errno.h>
43			# define SET_ERRNO(n) errno = (n)
44			#endif
45	root	1.1
46	root	1.10	#if USE_REP_MOVSB /* small win on amd, big loss on intel */
47	root	1.7	#if (__i386 \|\| __amd64) && __GNUC__ >= 3
48			# define lzf_movsb(dst, src, len) \
49			asm ("rep movsb" \
50			: "=D" (dst), "=S" (src), "=c" (len) \
51			: "0" (dst), "1" (src), "2" (len));
52			#endif
53	root	1.10	#endif
54	root	1.7
55	root	1.16	unsigned int
56	root	1.1	lzf_decompress (const void *const in_data, unsigned int in_len,
57			void *out_data, unsigned int out_len)
58			{
59	pcg	1.3	u8 const ip = (const u8 )in_data;
60			u8 op = (u8 )out_data;
61	root	1.1	u8 const *const in_end = ip + in_len;
62			u8 *const out_end = op + out_len;
63
64			do
65			{
66			unsigned int ctrl = *ip++;
67
68			if (ctrl < (1 << 5)) /* literal run */
69			{
70			ctrl++;
71
72			if (op + ctrl > out_end)
73			{
74	pcg	1.3	SET_ERRNO (E2BIG);
75	root	1.1	return 0;
76			}
77
78	root	1.6	#if CHECK_INPUT
79			if (ip + ctrl > in_end)
80			{
81			SET_ERRNO (EINVAL);
82			return 0;
83			}
84			#endif
85
86	root	1.7	#ifdef lzf_movsb
87			lzf_movsb (op, ip, ctrl);
88	root	1.16	#elif OPTIMISE_SIZE
89			while (ctrl--)
90			op++ = ip++;
91	root	1.1	#else
92	root	1.10	switch (ctrl)
93			{
94			case 32: op++ = ip++; case 31: op++ = ip++; case 30: op++ = ip++; case 29: op++ = ip++;
95			case 28: op++ = ip++; case 27: op++ = ip++; case 26: op++ = ip++; case 25: op++ = ip++;
96			case 24: op++ = ip++; case 23: op++ = ip++; case 22: op++ = ip++; case 21: op++ = ip++;
97			case 20: op++ = ip++; case 19: op++ = ip++; case 18: op++ = ip++; case 17: op++ = ip++;
98			case 16: op++ = ip++; case 15: op++ = ip++; case 14: op++ = ip++; case 13: op++ = ip++;
99			case 12: op++ = ip++; case 11: op++ = ip++; case 10: op++ = ip++; case 9: op++ = ip++;
100			case 8: op++ = ip++; case 7: op++ = ip++; case 6: op++ = ip++; case 5: op++ = ip++;
101			case 4: op++ = ip++; case 3: op++ = ip++; case 2: op++ = ip++; case 1: op++ = ip++;
102			}
103	root	1.1	#endif
104			}
105			else /* back reference */
106			{
107			unsigned int len = ctrl >> 5;
108
109			u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
110
111	root	1.6	#if CHECK_INPUT
112			if (ip >= in_end)
113			{
114			SET_ERRNO (EINVAL);
115			return 0;
116			}
117			#endif
118	root	1.1	if (len == 7)
119	root	1.6	{
120			len += *ip++;
121			#if CHECK_INPUT
122			if (ip >= in_end)
123			{
124			SET_ERRNO (EINVAL);
125			return 0;
126			}
127			#endif
128			}
129
130	root	1.1	ref -= *ip++;
131
132			if (op + len + 2 > out_end)
133			{
134	pcg	1.3	SET_ERRNO (E2BIG);
135	root	1.1	return 0;
136			}
137
138			if (ref < (u8 *)out_data)
139			{
140	pcg	1.3	SET_ERRNO (EINVAL);
141	root	1.1	return 0;
142			}
143
144	root	1.7	#ifdef lzf_movsb
145			len += 2;
146			lzf_movsb (op, ref, len);
147	root	1.16	#elif OPTIMISE_SIZE
148			len += 2;
149
150			do
151			op++ = ref++;
152			while (--len);
153	root	1.7	#else
154	root	1.10	switch (len)
155			{
156			default:
157			len += 2;
158	root	1.1
159	root	1.10	if (op >= ref + len)
160			{
161			/* disjunct areas */
162			memcpy (op, ref, len);
163			op += len;
164			}
165			else
166			{
167	root	1.16	/* overlapping, use octet by octet copying */
168	root	1.10	do
169			op++ = ref++;
170			while (--len);
171			}
172
173			break;
174
175			case 9: op++ = ref++;
176			case 8: op++ = ref++;
177			case 7: op++ = ref++;
178			case 6: op++ = ref++;
179			case 5: op++ = ref++;
180			case 4: op++ = ref++;
181			case 3: op++ = ref++;
182			case 2: op++ = ref++;
183			case 1: op++ = ref++;
184			case 0: op++ = ref++; /* two octets more */
185			op++ = ref++;
186			}
187	root	1.7	#endif
188	root	1.1	}
189			}
190	root	1.6	while (ip < in_end);
191	root	1.1
192			return op - (u8 *)out_data;
193			}
194