| … | |
… | |
| 46 | */ |
46 | */ |
| 47 | #ifndef FRST |
47 | #ifndef FRST |
| 48 | # define FRST(p) (((p[0]) << 8) | p[1]) |
48 | # define FRST(p) (((p[0]) << 8) | p[1]) |
| 49 | # define NEXT(v,p) (((v) << 8) | p[2]) |
49 | # define NEXT(v,p) (((v) << 8) | p[2]) |
| 50 | # if ULTRA_FAST |
50 | # if ULTRA_FAST |
| 51 | # define IDX(h) (((h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) |
51 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1)) |
| 52 | # elif VERY_FAST |
52 | # elif VERY_FAST |
| 53 | # define IDX(h) (((h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
53 | # define IDX(h) ((( h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
| 54 | # else |
54 | # else |
| 55 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
55 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
| 56 | # endif |
56 | # endif |
| 57 | /*# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1))*/ |
|
|
| 58 | #endif |
57 | #endif |
| 59 | /* |
58 | /* |
| 60 | * IDX works because it is very similar to a multiplicative hash, e.g. |
59 | * IDX works because it is very similar to a multiplicative hash, e.g. |
| 61 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
60 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
| 62 | * the latter is also quite fast on newer CPUs, and compresses similarly. |
61 | * the latter is also quite fast on newer CPUs, and compresses similarly. |
| … | |
… | |
| 137 | hval = NEXT (hval, ip); |
136 | hval = NEXT (hval, ip); |
| 138 | hslot = htab + IDX (hval); |
137 | hslot = htab + IDX (hval); |
| 139 | ref = *hslot; *hslot = ip; |
138 | ref = *hslot; *hslot = ip; |
| 140 | |
139 | |
| 141 | if (1 |
140 | if (1 |
| 142 | #if INIT_HTAB && !USE_MEMCPY |
141 | #if INIT_HTAB |
| 143 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
142 | && ref < ip /* the next test will actually take care of this, but this is faster */ |
| 144 | #endif |
143 | #endif |
| 145 | && (off = ip - ref - 1) < MAX_OFF |
144 | && (off = ip - ref - 1) < MAX_OFF |
| 146 | && ip + 4 < in_end |
145 | && ip + 4 < in_end |
| 147 | && ref > (u8 *)in_data |
146 | && ref > (u8 *)in_data |
| … | |
… | |
| 158 | /* match found at *ref++ */ |
157 | /* match found at *ref++ */ |
| 159 | unsigned int len = 2; |
158 | unsigned int len = 2; |
| 160 | unsigned int maxlen = in_end - ip - len; |
159 | unsigned int maxlen = in_end - ip - len; |
| 161 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
160 | maxlen = maxlen > MAX_REF ? MAX_REF : maxlen; |
| 162 | |
161 | |
| 163 | if (expect_false (op + 1 + 3 >= out_end)) |
|
|
| 164 | return 0; |
|
|
| 165 | |
|
|
| 166 | op [- lit - 1] = lit - 1; /* stop run */ |
162 | op [- lit - 1] = lit - 1; /* stop run */ |
| 167 | op -= !lit; /* undo run if length is zero */ |
163 | op -= !lit; /* undo run if length is zero */ |
|
|
164 | |
|
|
165 | if (expect_false (op + 3 + 1 >= out_end)) |
|
|
166 | return 0; |
| 168 | |
167 | |
| 169 | for (;;) |
168 | for (;;) |
| 170 | { |
169 | { |
| 171 | if (expect_true (maxlen > 16)) |
170 | if (expect_true (maxlen > 16)) |
| 172 | { |
171 | { |
| … | |
… | |
| 236 | htab[IDX (hval)] = ip; |
235 | htab[IDX (hval)] = ip; |
| 237 | ip++; |
236 | ip++; |
| 238 | } |
237 | } |
| 239 | while (len--); |
238 | while (len--); |
| 240 | #endif |
239 | #endif |
|
|
240 | |
| 241 | lit = 0; op++; /* start run */ |
241 | lit = 0; op++; /* start run */ |
| 242 | continue; |
|
|
| 243 | } |
242 | } |
| 244 | |
243 | else |
|
|
244 | { |
| 245 | /* one more literal byte we must copy */ |
245 | /* one more literal byte we must copy */ |
| 246 | |
|
|
| 247 | if (expect_false (op >= out_end)) |
246 | if (expect_false (op >= out_end)) |
| 248 | return 0; |
247 | return 0; |
| 249 | |
248 | |
| 250 | lit++; |
249 | lit++; *op++ = *ip++; |
|
|
250 | |
|
|
251 | if (expect_false (lit == MAX_LIT)) |
|
|
252 | { |
|
|
253 | op [- lit - 1] = lit - 1; /* stop run */ |
|
|
254 | lit = 0; op++; /* start run */ |
|
|
255 | } |
|
|
256 | } |
|
|
257 | } |
|
|
258 | |
|
|
259 | if (op + 3 > out_end) /* at most 3 bytes can be missing here */ |
|
|
260 | return 0; |
|
|
261 | |
|
|
262 | while (ip < in_end) |
|
|
263 | { |
| 251 | *op++ = *ip++; |
264 | lit++; *op++ = *ip++; |
| 252 | |
265 | |
| 253 | if (expect_false (lit == MAX_LIT)) |
266 | if (expect_false (lit == MAX_LIT)) |
| 254 | { |
267 | { |
| 255 | op [- lit - 1] = lit - 1; /* stop run */ |
268 | op [- lit - 1] = lit - 1; /* stop run */ |
| 256 | lit = 0; op++; /* start run */ |
269 | lit = 0; op++; /* start run */ |
| 257 | } |
270 | } |
| 258 | } |
271 | } |
| 259 | |
272 | |
| 260 | if (op + lit + 2 >= out_end) |
|
|
| 261 | return 0; |
|
|
| 262 | |
|
|
| 263 | while (ip < in_end) |
|
|
| 264 | { |
|
|
| 265 | lit++; |
|
|
| 266 | *op++ = *ip++; |
|
|
| 267 | } |
|
|
| 268 | |
|
|
| 269 | op [- lit - 1] = lit - 1; |
273 | op [- lit - 1] = lit - 1; /* end run */ |
|
|
274 | op -= !lit; /* undo run if length is zero */ |
| 270 | |
275 | |
| 271 | return op - (u8 *)out_data; |
276 | return op - (u8 *)out_data; |
| 272 | } |
277 | } |
| 273 | |
278 | |
