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/cvs/liblzf/lzf_c.c
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Comparing liblzf/lzf_c.c (file contents):
Revision 1.3 by root, Sun Nov 17 11:39:26 2002 UTC vs.
Revision 1.5 by pcg, Mon Dec 29 12:48:16 2003 UTC

1/* 1/*
2 * Copyright (c) 2000-2002 Marc Alexander Lehmann <pcg@goof.com> 2 * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
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,
… …
66 * 66 *
67 */ 67 */
68 68
69unsigned int 69unsigned int
70lzf_compress (const void *const in_data, unsigned int in_len, 70lzf_compress (const void *const in_data, unsigned int in_len,
71 void *out_data, unsigned int out_len) 71 void *out_data, unsigned int out_len
72#if LZF_STATE_ARG
73 , LZF_STATE *htab
74#endif
75 )
72{ 76{
73 const u8 *htab[HSIZE]; 77#if !LZF_STATE_ARG
78 LZF_STATE htab;
79#endif
74 const u8 **hslot; 80 const u8 **hslot;
75 const u8 *ip = in_data; 81 const u8 *ip = (const u8 *)in_data;
76 u8 *op = out_data; 82 u8 *op = (u8 *)out_data;
77 const u8 *in_end = ip + in_len; 83 const u8 *in_end = ip + in_len;
78 u8 *out_end = op + out_len; 84 u8 *out_end = op + out_len;
79 const u8 *ref; 85 const u8 *ref;
80 86
81 unsigned int hval = FRST (ip); 87 unsigned int hval = FRST (ip);
… …
89 for (hslot = htab; hslot < htab + HSIZE; hslot++) 95 for (hslot = htab; hslot < htab + HSIZE; hslot++)
90 *hslot++ = ip; 96 *hslot++ = ip;
91# endif 97# endif
92#endif 98#endif
93 99
94 do 100 for (;;)
95 { 101 {
102 if (ip < in_end - 2)
103 {
96 hval = NEXT (hval, ip); 104 hval = NEXT (hval, ip);
97 hslot = htab + IDX (hval); 105 hslot = htab + IDX (hval);
98 ref = *hslot; *hslot = ip; 106 ref = *hslot; *hslot = ip;
99 107
100 if (1 108 if (1
101#if INIT_HTAB && !USE_MEMCPY 109#if INIT_HTAB && !USE_MEMCPY
102 && ref < ip /* the next test will actually take care of this, but it is faster */ 110 && ref < ip /* the next test will actually take care of this, but this is faster */
103#endif 111#endif
104 && (off = ip - ref - 1) < MAX_OFF 112 && (off = ip - ref - 1) < MAX_OFF
105 && ip + 4 < in_end 113 && ip + 4 < in_end
106 && ref > (u8 *)in_data 114 && ref > (u8 *)in_data
107#if STRICT_ALIGN 115#if STRICT_ALIGN
108 && ref[0] == ip[0] 116 && ref[0] == ip[0]
109 && ref[1] == ip[1] 117 && ref[1] == ip[1]
110 && ref[2] == ip[2] 118 && ref[2] == ip[2]
111#else 119#else
112 && *(u16 *)ref == *(u16 *)ip 120 && *(u16 *)ref == *(u16 *)ip
113 && ref[2] == ip[2] 121 && ref[2] == ip[2]
114#endif 122#endif
115 ) 123 )
116 { 124 {
117 /* match found at *ref++ */ 125 /* match found at *ref++ */
118 unsigned int len = 2; 126 unsigned int len = 2;
119 unsigned int maxlen = in_end - ip - len; 127 unsigned int maxlen = in_end - ip - len;
120 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; 128 maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
121 129
122 do 130 do
123 len++; 131 len++;
124 while (len < maxlen && ref[len] == ip[len]); 132 while (len < maxlen && ref[len] == ip[len]);
125 133
126 if (op + lit + 1 + 3 >= out_end) 134 if (op + lit + 1 + 3 >= out_end)
127 return 0; 135 return 0;
128 136
129 if (lit) 137 if (lit)
130 { 138 {
131 *op++ = lit - 1; 139 *op++ = lit - 1;
132 lit = -lit; 140 lit = -lit;
133 do 141 do
134 *op++ = ip[lit]; 142 *op++ = ip[lit];
135 while (++lit); 143 while (++lit);
136 } 144 }
137 145
138 len -= 2; 146 len -= 2;
139 ip++; 147 ip++;
140 148
141 if (len < 7) 149 if (len < 7)
142 { 150 {
143 *op++ = (off >> 8) + (len << 5); 151 *op++ = (off >> 8) + (len << 5);
144 } 152 }
145 else 153 else
146 { 154 {
147 *op++ = (off >> 8) + ( 7 << 5); 155 *op++ = (off >> 8) + ( 7 << 5);
148 *op++ = len - 7; 156 *op++ = len - 7;
149 } 157 }
150 158
151 *op++ = off; 159 *op++ = off;
152 160
153#if ULTRA_FAST 161#if ULTRA_FAST
154 ip += len; 162 ip += len;
155 hval = FRST (ip); 163 hval = FRST (ip);
156 hval = NEXT (hval, ip); 164 hval = NEXT (hval, ip);
157 htab[IDX (hval)] = ip; 165 htab[IDX (hval)] = ip;
158 ip++; 166 ip++;
159#else 167#else
160 do 168 do
161 { 169 {
162 hval = NEXT (hval, ip); 170 hval = NEXT (hval, ip);
163 htab[IDX (hval)] = ip; 171 htab[IDX (hval)] = ip;
172 ip++;
173 }
174 while (len--);
175#endif
176 continue;
177 }
178 }
179 else if (ip == in_end)
180 break;
181
182 /* one more literal byte we must copy */
183 lit++;
164 ip++; 184 ip++;
165 }
166 while (len--);
167#endif
168 }
169 else
170 {
171 /* one more literal byte we must copy */
172 lit++;
173 ip++;
174 185
175 if (lit == MAX_LIT) 186 if (lit == MAX_LIT)
176 { 187 {
177 if (op + 1 + MAX_LIT >= out_end) 188 if (op + 1 + MAX_LIT >= out_end)
178 return 0; 189 return 0;
179 190
180 *op++ = MAX_LIT - 1; 191 *op++ = MAX_LIT - 1;
181#if USE_MEMCPY 192#if USE_MEMCPY
182 memcpy (op, ip - MAX_LIT, MAX_LIT); 193 memcpy (op, ip - MAX_LIT, MAX_LIT);
183 op += MAX_LIT; 194 op += MAX_LIT;
184 lit = 0; 195 lit = 0;
185#else 196#else
186 lit = -lit; 197 lit = -lit;
187 do 198 do
188 *op++ = ip[lit]; 199 *op++ = ip[lit];
189 while (++lit); 200 while (++lit);
190#endif 201#endif
191 } 202 }
192 }
193 } 203 }
194 while (ip < in_end);
195 204
196 if (lit) 205 if (lit)
197 { 206 {
198 if (op + lit + 1 >= out_end) 207 if (op + lit + 1 >= out_end)
199 return 0; 208 return 0;

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