cvsroot/Compress-LZF/lzf_d.c

/*
 * Copyright (c) 2000-2007 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"

#include <string.h> /* for memcpy/memset */

#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);
#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);
#else
          switch (len)
            {
              default:
                len += 2;

                if (op >= ref + len)
                  {
                    /* disjunct areas */
                    memcpy (op, ref, len);
                    op += len;
                  }
                else
                  {
                    /* overlapping, use octte by octte 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:	1.7
Committed:	Sun May 30 05:51:09 2010 UTC (16 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.6:	+47 -8 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.6	* Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.1	*
4			* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6			*
7			* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9			*
10			* 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			*
14			* 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	1.2	*
25			* Alternatively, the contents of this file may be used under the terms of
26	root	1.6	* 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	1.2	#include "lzfP.h"
38	root	1.1
39	root	1.7	#include <string.h> /* for memcpy/memset */
40
41	pcg	1.2	#if AVOID_ERRNO
42			# define SET_ERRNO(n)
43			#else
44			# include <errno.h>
45			# define SET_ERRNO(n) errno = (n)
46			#endif
47	root	1.1
48	root	1.7	#if USE_REP_MOVSB /* small win on amd, big loss on intel */
49	root	1.5	#if (__i386 \|\| __amd64) && __GNUC__ >= 3
50			# define lzf_movsb(dst, src, len) \
51			asm ("rep movsb" \
52			: "=D" (dst), "=S" (src), "=c" (len) \
53			: "0" (dst), "1" (src), "2" (len));
54			#endif
55	root	1.7	#endif
56	root	1.5
57	root	1.1	unsigned int
58			lzf_decompress (const void *const in_data, unsigned int in_len,
59			void *out_data, unsigned int out_len)
60			{
61	pcg	1.2	u8 const ip = (const u8 )in_data;
62			u8 op = (u8 )out_data;
63	root	1.1	u8 const *const in_end = ip + in_len;
64			u8 *const out_end = op + out_len;
65
66			do
67			{
68			unsigned int ctrl = *ip++;
69
70			if (ctrl < (1 << 5)) /* literal run */
71			{
72			ctrl++;
73
74			if (op + ctrl > out_end)
75			{
76	pcg	1.2	SET_ERRNO (E2BIG);
77	root	1.1	return 0;
78			}
79
80	root	1.4	#if CHECK_INPUT
81			if (ip + ctrl > in_end)
82			{
83			SET_ERRNO (EINVAL);
84			return 0;
85			}
86			#endif
87
88	root	1.5	#ifdef lzf_movsb
89			lzf_movsb (op, ip, ctrl);
90	root	1.1	#else
91	root	1.7	switch (ctrl)
92			{
93			case 32: op++ = ip++; case 31: op++ = ip++; case 30: op++ = ip++; case 29: op++ = ip++;
94			case 28: op++ = ip++; case 27: op++ = ip++; case 26: op++ = ip++; case 25: op++ = ip++;
95			case 24: op++ = ip++; case 23: op++ = ip++; case 22: op++ = ip++; case 21: op++ = ip++;
96			case 20: op++ = ip++; case 19: op++ = ip++; case 18: op++ = ip++; case 17: op++ = ip++;
97			case 16: op++ = ip++; case 15: op++ = ip++; case 14: op++ = ip++; case 13: op++ = ip++;
98			case 12: op++ = ip++; case 11: op++ = ip++; case 10: op++ = ip++; case 9: op++ = ip++;
99			case 8: op++ = ip++; case 7: op++ = ip++; case 6: op++ = ip++; case 5: op++ = ip++;
100			case 4: op++ = ip++; case 3: op++ = ip++; case 2: op++ = ip++; case 1: op++ = ip++;
101			}
102	root	1.1	#endif
103			}
104			else /* back reference */
105			{
106			unsigned int len = ctrl >> 5;
107
108			u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
109
110	root	1.4	#if CHECK_INPUT
111			if (ip >= in_end)
112			{
113			SET_ERRNO (EINVAL);
114			return 0;
115			}
116			#endif
117	root	1.1	if (len == 7)
118	root	1.4	{
119			len += *ip++;
120			#if CHECK_INPUT
121			if (ip >= in_end)
122			{
123			SET_ERRNO (EINVAL);
124			return 0;
125			}
126			#endif
127			}
128
129	root	1.1	ref -= *ip++;
130
131			if (op + len + 2 > out_end)
132			{
133	pcg	1.2	SET_ERRNO (E2BIG);
134	root	1.1	return 0;
135			}
136
137			if (ref < (u8 *)out_data)
138			{
139	pcg	1.2	SET_ERRNO (EINVAL);
140	root	1.1	return 0;
141			}
142
143	root	1.5	#ifdef lzf_movsb
144			len += 2;
145			lzf_movsb (op, ref, len);
146			#else
147	root	1.7	switch (len)
148			{
149			default:
150			len += 2;
151	root	1.1
152	root	1.7	if (op >= ref + len)
153			{
154			/* disjunct areas */
155			memcpy (op, ref, len);
156			op += len;
157			}
158			else
159			{
160			/* overlapping, use octte by octte copying */
161			do
162			op++ = ref++;
163			while (--len);
164			}
165
166			break;
167
168			case 9: op++ = ref++;
169			case 8: op++ = ref++;
170			case 7: op++ = ref++;
171			case 6: op++ = ref++;
172			case 5: op++ = ref++;
173			case 4: op++ = ref++;
174			case 3: op++ = ref++;
175			case 2: op++ = ref++;
176			case 1: op++ = ref++;
177			case 0: op++ = ref++; /* two octets more */
178			op++ = ref++;
179			}
180	root	1.5	#endif
181	root	1.1	}
182			}
183	root	1.4	while (ip < in_end);
184	root	1.1
185			return op - (u8 *)out_data;
186			}
187