| … | |
… | |
| 44 | * don't play with this unless you benchmark! |
44 | * don't play with this unless you benchmark! |
| 45 | * decompression is not dependent on the hash function |
45 | * decompression is not dependent on the hash function |
| 46 | * the hashing function might seem strange, just believe me |
46 | * the hashing function might seem strange, just believe me |
| 47 | * it works ;) |
47 | * it works ;) |
| 48 | */ |
48 | */ |
|
|
49 | #ifndef FRST |
| 49 | #define FRST(p) (((p[0]) << 8) | p[1]) |
50 | # define FRST(p) (((p[0]) << 8) | p[1]) |
| 50 | #define NEXT(v,p) (((v) << 8) | p[2]) |
51 | # define NEXT(v,p) (((v) << 8) | p[2]) |
| 51 | #define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
52 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
|
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53 | /*# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1))*/ |
|
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54 | #endif |
| 52 | /* |
55 | /* |
| 53 | * IDX works because it is very similar to a multiplicative hash, e.g. |
56 | * IDX works because it is very similar to a multiplicative hash, e.g. |
| 54 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
57 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
| 55 | * the latter is also quite fast on newer CPUs, and sligthly better |
58 | * the latter is also quite fast on newer CPUs, and compresses similarly. |
| 56 | * |
59 | * |
| 57 | * the next one is also quite good, albeit slow ;) |
60 | * the next one is also quite good, albeit slow ;) |
| 58 | * (int)(cos(h & 0xffffff) * 1e6) |
61 | * (int)(cos(h & 0xffffff) * 1e6) |
| 59 | */ |
62 | */ |
| 60 | |
63 | |
| … | |
… | |
| 65 | # define IDX(h) ((h) & (HSIZE - 1)) |
68 | # define IDX(h) ((h) & (HSIZE - 1)) |
| 66 | #endif |
69 | #endif |
| 67 | |
70 | |
| 68 | #define MAX_LIT (1 << 5) |
71 | #define MAX_LIT (1 << 5) |
| 69 | #define MAX_OFF (1 << 13) |
72 | #define MAX_OFF (1 << 13) |
| 70 | #define MAX_REF ((1 << 8) + (1 << 3)) |
73 | #define MAX_REF ((1 << 8) + (1 << 3)) |
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74 | |
|
|
75 | #if (__i386 || __amd64) && __GNUC__ >= 3 |
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76 | # define lzf_movsb(dst, src, len) \ |
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77 | asm ("rep movsb" \ |
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78 | : "=D" (dst), "=S" (src), "=c" (len) \ |
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79 | : "0" (dst), "1" (src), "2" (len)); |
|
|
80 | #endif |
| 71 | |
81 | |
| 72 | /* |
82 | /* |
| 73 | * compressed format |
83 | * compressed format |
| 74 | * |
84 | * |
| 75 | * 000LLLLL <L+1> ; literal |
85 | * 000LLLLL <L+1> ; literal |
| 76 | * LLLOOOOO oooooooo ; backref L |
86 | * LLLooooo oooooooo ; backref L |
| 77 | * 111OOOOO LLLLLLLL oooooooo ; backref L+7 |
87 | * 111ooooo LLLLLLLL oooooooo ; backref L+7 |
| 78 | * |
88 | * |
| 79 | */ |
89 | */ |
| 80 | |
90 | |
| 81 | unsigned int |
91 | unsigned int |
| 82 | lzf_compress (const void *const in_data, unsigned int in_len, |
92 | lzf_compress (const void *const in_data, unsigned int in_len, |
| 83 | void *out_data, unsigned int out_len |
93 | void *out_data, unsigned int out_len |
| 84 | #if LZF_STATE_ARG |
94 | #if LZF_STATE_ARG |
| 85 | , LZF_STATE *htab |
95 | , LZF_STATE htab |
| 86 | #endif |
96 | #endif |
| 87 | ) |
97 | ) |
| 88 | { |
98 | { |
| 89 | #if !LZF_STATE_ARG |
99 | #if !LZF_STATE_ARG |
| 90 | LZF_STATE htab; |
100 | LZF_STATE htab; |
| … | |
… | |
| 99 | unsigned int hval = FRST (ip); |
109 | unsigned int hval = FRST (ip); |
| 100 | unsigned long off; |
110 | unsigned long off; |
| 101 | int lit = 0; |
111 | int lit = 0; |
| 102 | |
112 | |
| 103 | #if INIT_HTAB |
113 | #if INIT_HTAB |
| 104 | # if USE_MEMCPY |
|
|
| 105 | memset (htab, 0, sizeof (htab)); |
114 | memset (htab, 0, sizeof (htab)); |
| 106 | # else |
115 | # if 0 |
| 107 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
116 | for (hslot = htab; hslot < htab + HSIZE; hslot++) |
| 108 | *hslot++ = ip; |
117 | *hslot++ = ip; |
| 109 | # endif |
118 | # endif |
| 110 | #endif |
119 | #endif |
| 111 | |
120 | |
| 112 | for (;;) |
121 | for (;;) |
| 113 | { |
122 | { |
| … | |
… | |
| 209 | { |
218 | { |
| 210 | if (op + 1 + MAX_LIT >= out_end) |
219 | if (op + 1 + MAX_LIT >= out_end) |
| 211 | return 0; |
220 | return 0; |
| 212 | |
221 | |
| 213 | *op++ = MAX_LIT - 1; |
222 | *op++ = MAX_LIT - 1; |
| 214 | #if USE_MEMCPY |
223 | |
| 215 | memcpy (op, ip - MAX_LIT, MAX_LIT); |
224 | #ifdef lzf_movsb |
| 216 | op += MAX_LIT; |
225 | ip -= lit; |
| 217 | lit = 0; |
226 | lzf_movsb (op, ip, lit); |
| 218 | #else |
227 | #else |
| 219 | lit = -lit; |
228 | lit = -lit; |
| 220 | do |
229 | do |
| 221 | *op++ = ip[lit]; |
230 | *op++ = ip[lit]; |
| 222 | while (++lit); |
231 | while (++lit); |
| … | |
… | |
| 228 | { |
237 | { |
| 229 | if (op + lit + 1 >= out_end) |
238 | if (op + lit + 1 >= out_end) |
| 230 | return 0; |
239 | return 0; |
| 231 | |
240 | |
| 232 | *op++ = lit - 1; |
241 | *op++ = lit - 1; |
|
|
242 | #ifdef lzf_movsb |
|
|
243 | ip -= lit; |
|
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244 | lzf_movsb (op, ip, lit); |
|
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245 | #else |
| 233 | lit = -lit; |
246 | lit = -lit; |
| 234 | do |
247 | do |
| 235 | *op++ = ip[lit]; |
248 | *op++ = ip[lit]; |
| 236 | while (++lit); |
249 | while (++lit); |
|
|
250 | #endif |
| 237 | } |
251 | } |
| 238 | |
252 | |
| 239 | return op - (u8 *) out_data; |
253 | return op - (u8 *) out_data; |
| 240 | } |
254 | } |
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|
255 | |
