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/cvs/liblzf/lzf_c.c
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Comparing liblzf/lzf_c.c (file contents):
Revision 1.28 by root, Fri Nov 30 10:34:26 2007 UTC vs.
Revision 1.33 by root, Mon Aug 25 01:40:31 2008 UTC

1/* 1/*
2 * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de> 2 * Copyright (c) 2000-2008 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,
111 u8 *op = (u8 *)out_data; 111 u8 *op = (u8 *)out_data;
112 const u8 *in_end = ip + in_len; 112 const u8 *in_end = ip + in_len;
113 u8 *out_end = op + out_len; 113 u8 *out_end = op + out_len;
114 const u8 *ref; 114 const u8 *ref;
115 115
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
126 unsigned long off;
127#endif
116 unsigned int hval; 128 unsigned int hval;
117 unsigned long off;
118 int lit; 129 int lit;
119 130
120 if (!in_len || !out_len) 131 if (!in_len || !out_len)
121 return 0; 132 return 0;
122 133
157 /* match found at *ref++ */ 168 /* match found at *ref++ */
158 unsigned int len = 2; 169 unsigned int len = 2;
159 unsigned int maxlen = in_end - ip - len; 170 unsigned int maxlen = in_end - ip - len;
160 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; 171 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
161 172
162 if (maxlen > 8) maxlen = 8;//D
163
164 op [- lit - 1] = lit - 1; /* stop run */ 173 op [- lit - 1] = lit - 1; /* stop run */
165 op -= !lit; /* undo run if length is zero */ 174 op -= !lit; /* undo run if length is zero */
166 175
167 if (expect_false (op + 3 + 1 >= out_end)) 176 if (expect_false (op + 3 + 1 >= out_end))
168 return 0; 177 return 0;
197 while (len < maxlen && ref[len] == ip[len]); 206 while (len < maxlen && ref[len] == ip[len]);
198 207
199 break; 208 break;
200 } 209 }
201 210
202 len -= 2; 211 len -= 2; /* len is now #octets - 1 */
203 ip++; 212 ip++;
204 213
205 if (len < 7) 214 if (len < 7)
206 { 215 {
207 *op++ = (off >> 8) + (len << 5); 216 *op++ = (off >> 8) + (len << 5);
212 *op++ = len - 7; 221 *op++ = len - 7;
213 } 222 }
214 223
215 *op++ = off; 224 *op++ = off;
216 225
226 if (expect_true (ip + len < in_end - 2))
227 {
217#if ULTRA_FAST || VERY_FAST 228#if ULTRA_FAST || VERY_FAST
218 ip += len; 229 ip += len;
219#if VERY_FAST && !ULTRA_FAST 230# if VERY_FAST && !ULTRA_FAST
220 --ip; 231 --ip;
221#endif 232# endif
222 hval = FRST (ip); 233 hval = FRST (ip);
223 234
224 hval = NEXT (hval, ip);
225 htab[IDX (hval)] = ip;
226 ip++;
227
228#if VERY_FAST && !ULTRA_FAST
229 hval = NEXT (hval, ip);
230 htab[IDX (hval)] = ip;
231 ip++;
232#endif
233#else
234 do
235 {
236 hval = NEXT (hval, ip); 235 hval = NEXT (hval, ip);
237 htab[IDX (hval)] = ip; 236 htab[IDX (hval)] = ip;
238 ip++; 237 ip++;
238
239# if VERY_FAST && !ULTRA_FAST
240 hval = NEXT (hval, ip);
241 htab[IDX (hval)] = ip;
239 } 242 ip++;
240 while (len--);
241#endif 243# endif
244#else
245 do
246 {
247 hval = NEXT (hval, ip);
248 htab[IDX (hval)] = ip;
249 ip++;
250 }
251 while (len--);
252#endif
253 }
242 254
243 lit = 0; op++; /* start run */ 255 lit = 0; op++; /* start run */
244 } 256 }
245 else 257 else
246 { 258 {
256 lit = 0; op++; /* start run */ 268 lit = 0; op++; /* start run */
257 } 269 }
258 } 270 }
259 } 271 }
260 272
261 if (op + 2 > out_end) /* at most 2 bytes can be missing here */ 273 if (op + 3 > out_end) /* at most 3 bytes can be missing here */
262 return 0; 274 return 0;
263 275
264 while (ip < in_end) 276 while (ip < in_end)
265 { 277 {
266 lit++; *op++ = *ip++; 278 lit++; *op++ = *ip++;

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