lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* LzFind.c -- Match finder for LZ algorithms |
| 2 | 2009-04-22 : Igor Pavlov : Public domain */ |
| 3 | |
| 4 | //#include <string.h> |
| 5 | |
| 6 | #include "linux/lzma/LzFind.h" |
| 7 | #include "linux/lzma/LzHash.h" |
| 8 | |
| 9 | #define kEmptyHashValue 0 |
| 10 | #define kMaxValForNormalize ((UInt32)0xFFFFFFFF) |
| 11 | #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */ |
| 12 | #define kNormalizeMask (~(kNormalizeStepMin - 1)) |
| 13 | #define kMaxHistorySize ((UInt32)3 << 30) |
| 14 | |
| 15 | #define kStartMaxLen 3 |
| 16 | |
| 17 | static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc) |
| 18 | { |
| 19 | if (!p->directInput) |
| 20 | { |
| 21 | alloc->Free(alloc, p->bufferBase); |
| 22 | p->bufferBase = 0; |
| 23 | } |
| 24 | } |
| 25 | |
| 26 | /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */ |
| 27 | |
| 28 | static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc) |
| 29 | { |
| 30 | UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv; |
| 31 | if (p->directInput) |
| 32 | { |
| 33 | p->blockSize = blockSize; |
| 34 | return 1; |
| 35 | } |
| 36 | if (p->bufferBase == 0 || p->blockSize != blockSize) |
| 37 | { |
| 38 | LzInWindow_Free(p, alloc); |
| 39 | p->blockSize = blockSize; |
| 40 | p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize); |
| 41 | } |
| 42 | return (p->bufferBase != 0); |
| 43 | } |
| 44 | |
| 45 | Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; } |
| 46 | Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; } |
| 47 | |
| 48 | UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; } |
| 49 | |
| 50 | void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue) |
| 51 | { |
| 52 | p->posLimit -= subValue; |
| 53 | p->pos -= subValue; |
| 54 | p->streamPos -= subValue; |
| 55 | } |
| 56 | |
| 57 | static void MatchFinder_ReadBlock(CMatchFinder *p) |
| 58 | { |
| 59 | if (p->streamEndWasReached || p->result != SZ_OK) |
| 60 | return; |
| 61 | if (p->directInput) |
| 62 | { |
| 63 | UInt32 curSize = 0xFFFFFFFF - p->streamPos; |
| 64 | if (curSize > p->directInputRem) |
| 65 | curSize = (UInt32)p->directInputRem; |
| 66 | p->directInputRem -= curSize; |
| 67 | p->streamPos += curSize; |
| 68 | if (p->directInputRem == 0) |
| 69 | p->streamEndWasReached = 1; |
| 70 | return; |
| 71 | } |
| 72 | for (;;) |
| 73 | { |
| 74 | Byte *dest = p->buffer + (p->streamPos - p->pos); |
| 75 | size_t size = (p->bufferBase + p->blockSize - dest); |
| 76 | if (size == 0) |
| 77 | return; |
| 78 | p->result = p->stream->Read(p->stream, dest, &size); |
| 79 | if (p->result != SZ_OK) |
| 80 | return; |
| 81 | if (size == 0) |
| 82 | { |
| 83 | p->streamEndWasReached = 1; |
| 84 | return; |
| 85 | } |
| 86 | p->streamPos += (UInt32)size; |
| 87 | if (p->streamPos - p->pos > p->keepSizeAfter) |
| 88 | return; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | void MatchFinder_MoveBlock(CMatchFinder *p) |
| 93 | { |
| 94 | memmove(p->bufferBase, |
| 95 | p->buffer - p->keepSizeBefore, |
| 96 | (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); |
| 97 | p->buffer = p->bufferBase + p->keepSizeBefore; |
| 98 | } |
| 99 | |
| 100 | int MatchFinder_NeedMove(CMatchFinder *p) |
| 101 | { |
| 102 | if (p->directInput) |
| 103 | return 0; |
| 104 | /* if (p->streamEndWasReached) return 0; */ |
| 105 | return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter); |
| 106 | } |
| 107 | |
| 108 | void MatchFinder_ReadIfRequired(CMatchFinder *p) |
| 109 | { |
| 110 | if (p->streamEndWasReached) |
| 111 | return; |
| 112 | if (p->keepSizeAfter >= p->streamPos - p->pos) |
| 113 | MatchFinder_ReadBlock(p); |
| 114 | } |
| 115 | |
| 116 | static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) |
| 117 | { |
| 118 | if (MatchFinder_NeedMove(p)) |
| 119 | MatchFinder_MoveBlock(p); |
| 120 | MatchFinder_ReadBlock(p); |
| 121 | } |
| 122 | |
| 123 | static void MatchFinder_SetDefaultSettings(CMatchFinder *p) |
| 124 | { |
| 125 | p->cutValue = 32; |
| 126 | p->btMode = 1; |
| 127 | p->numHashBytes = 4; |
| 128 | p->bigHash = 0; |
| 129 | } |
| 130 | |
| 131 | #define kCrcPoly 0xEDB88320 |
| 132 | |
| 133 | void MatchFinder_Construct(CMatchFinder *p) |
| 134 | { |
| 135 | UInt32 i; |
| 136 | p->bufferBase = 0; |
| 137 | p->directInput = 0; |
| 138 | p->hash = 0; |
| 139 | MatchFinder_SetDefaultSettings(p); |
| 140 | |
| 141 | for (i = 0; i < 256; i++) |
| 142 | { |
| 143 | UInt32 r = i; |
| 144 | int j; |
| 145 | for (j = 0; j < 8; j++) |
| 146 | r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); |
| 147 | p->crc[i] = r; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) |
| 152 | { |
| 153 | alloc->Free(alloc, p->hash); |
| 154 | p->hash = 0; |
| 155 | } |
| 156 | |
| 157 | void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) |
| 158 | { |
| 159 | MatchFinder_FreeThisClassMemory(p, alloc); |
| 160 | LzInWindow_Free(p, alloc); |
| 161 | } |
| 162 | |
| 163 | static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) |
| 164 | { |
| 165 | size_t sizeInBytes = (size_t)num * sizeof(CLzRef); |
| 166 | if (sizeInBytes / sizeof(CLzRef) != num) |
| 167 | return 0; |
| 168 | return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); |
| 169 | } |
| 170 | |
| 171 | int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, |
| 172 | UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, |
| 173 | ISzAlloc *alloc) |
| 174 | { |
| 175 | UInt32 sizeReserv; |
| 176 | if (historySize > kMaxHistorySize) |
| 177 | { |
| 178 | MatchFinder_Free(p, alloc); |
| 179 | return 0; |
| 180 | } |
| 181 | sizeReserv = historySize >> 1; |
| 182 | if (historySize > ((UInt32)2 << 30)) |
| 183 | sizeReserv = historySize >> 2; |
| 184 | sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); |
| 185 | |
| 186 | p->keepSizeBefore = historySize + keepAddBufferBefore + 1; |
| 187 | p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; |
| 188 | /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ |
| 189 | if (LzInWindow_Create(p, sizeReserv, alloc)) |
| 190 | { |
| 191 | UInt32 newCyclicBufferSize = historySize + 1; |
| 192 | UInt32 hs; |
| 193 | p->matchMaxLen = matchMaxLen; |
| 194 | { |
| 195 | p->fixedHashSize = 0; |
| 196 | if (p->numHashBytes == 2) |
| 197 | hs = (1 << 16) - 1; |
| 198 | else |
| 199 | { |
| 200 | hs = historySize - 1; |
| 201 | hs |= (hs >> 1); |
| 202 | hs |= (hs >> 2); |
| 203 | hs |= (hs >> 4); |
| 204 | hs |= (hs >> 8); |
| 205 | hs >>= 1; |
| 206 | hs |= 0xFFFF; /* don't change it! It's required for Deflate */ |
| 207 | if (hs > (1 << 24)) |
| 208 | { |
| 209 | if (p->numHashBytes == 3) |
| 210 | hs = (1 << 24) - 1; |
| 211 | else |
| 212 | hs >>= 1; |
| 213 | } |
| 214 | } |
| 215 | p->hashMask = hs; |
| 216 | hs++; |
| 217 | if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; |
| 218 | if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; |
| 219 | if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; |
| 220 | hs += p->fixedHashSize; |
| 221 | } |
| 222 | |
| 223 | { |
| 224 | UInt32 prevSize = p->hashSizeSum + p->numSons; |
| 225 | UInt32 newSize; |
| 226 | p->historySize = historySize; |
| 227 | p->hashSizeSum = hs; |
| 228 | p->cyclicBufferSize = newCyclicBufferSize; |
| 229 | p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); |
| 230 | newSize = p->hashSizeSum + p->numSons; |
| 231 | if (p->hash != 0 && prevSize == newSize) |
| 232 | return 1; |
| 233 | MatchFinder_FreeThisClassMemory(p, alloc); |
| 234 | p->hash = AllocRefs(newSize, alloc); |
| 235 | if (p->hash != 0) |
| 236 | { |
| 237 | p->son = p->hash + p->hashSizeSum; |
| 238 | return 1; |
| 239 | } |
| 240 | } |
| 241 | } |
| 242 | MatchFinder_Free(p, alloc); |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | static void MatchFinder_SetLimits(CMatchFinder *p) |
| 247 | { |
| 248 | UInt32 limit = kMaxValForNormalize - p->pos; |
| 249 | UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; |
| 250 | if (limit2 < limit) |
| 251 | limit = limit2; |
| 252 | limit2 = p->streamPos - p->pos; |
| 253 | if (limit2 <= p->keepSizeAfter) |
| 254 | { |
| 255 | if (limit2 > 0) |
| 256 | limit2 = 1; |
| 257 | } |
| 258 | else |
| 259 | limit2 -= p->keepSizeAfter; |
| 260 | if (limit2 < limit) |
| 261 | limit = limit2; |
| 262 | { |
| 263 | UInt32 lenLimit = p->streamPos - p->pos; |
| 264 | if (lenLimit > p->matchMaxLen) |
| 265 | lenLimit = p->matchMaxLen; |
| 266 | p->lenLimit = lenLimit; |
| 267 | } |
| 268 | p->posLimit = p->pos + limit; |
| 269 | } |
| 270 | |
| 271 | void MatchFinder_Init(CMatchFinder *p) |
| 272 | { |
| 273 | UInt32 i; |
| 274 | for (i = 0; i < p->hashSizeSum; i++) |
| 275 | p->hash[i] = kEmptyHashValue; |
| 276 | p->cyclicBufferPos = 0; |
| 277 | p->buffer = p->bufferBase; |
| 278 | p->pos = p->streamPos = p->cyclicBufferSize; |
| 279 | p->result = SZ_OK; |
| 280 | p->streamEndWasReached = 0; |
| 281 | MatchFinder_ReadBlock(p); |
| 282 | MatchFinder_SetLimits(p); |
| 283 | } |
| 284 | |
| 285 | static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) |
| 286 | { |
| 287 | return (p->pos - p->historySize - 1) & kNormalizeMask; |
| 288 | } |
| 289 | |
| 290 | void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) |
| 291 | { |
| 292 | UInt32 i; |
| 293 | for (i = 0; i < numItems; i++) |
| 294 | { |
| 295 | UInt32 value = items[i]; |
| 296 | if (value <= subValue) |
| 297 | value = kEmptyHashValue; |
| 298 | else |
| 299 | value -= subValue; |
| 300 | items[i] = value; |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | static void MatchFinder_Normalize(CMatchFinder *p) |
| 305 | { |
| 306 | UInt32 subValue = MatchFinder_GetSubValue(p); |
| 307 | MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); |
| 308 | MatchFinder_ReduceOffsets(p, subValue); |
| 309 | } |
| 310 | |
| 311 | static void MatchFinder_CheckLimits(CMatchFinder *p) |
| 312 | { |
| 313 | if (p->pos == kMaxValForNormalize) |
| 314 | MatchFinder_Normalize(p); |
| 315 | if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) |
| 316 | MatchFinder_CheckAndMoveAndRead(p); |
| 317 | if (p->cyclicBufferPos == p->cyclicBufferSize) |
| 318 | p->cyclicBufferPos = 0; |
| 319 | MatchFinder_SetLimits(p); |
| 320 | } |
| 321 | |
| 322 | static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, |
| 323 | UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, |
| 324 | UInt32 *distances, UInt32 maxLen) |
| 325 | { |
| 326 | son[_cyclicBufferPos] = curMatch; |
| 327 | for (;;) |
| 328 | { |
| 329 | UInt32 delta = pos - curMatch; |
| 330 | if (cutValue-- == 0 || delta >= _cyclicBufferSize) |
| 331 | return distances; |
| 332 | { |
| 333 | const Byte *pb = cur - delta; |
| 334 | curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; |
| 335 | if (pb[maxLen] == cur[maxLen] && *pb == *cur) |
| 336 | { |
| 337 | UInt32 len = 0; |
| 338 | while (++len != lenLimit) |
| 339 | if (pb[len] != cur[len]) |
| 340 | break; |
| 341 | if (maxLen < len) |
| 342 | { |
| 343 | *distances++ = maxLen = len; |
| 344 | *distances++ = delta - 1; |
| 345 | if (len == lenLimit) |
| 346 | return distances; |
| 347 | } |
| 348 | } |
| 349 | } |
| 350 | } |
| 351 | } |
| 352 | |
| 353 | UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, |
| 354 | UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, |
| 355 | UInt32 *distances, UInt32 maxLen) |
| 356 | { |
| 357 | CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; |
| 358 | CLzRef *ptr1 = son + (_cyclicBufferPos << 1); |
| 359 | UInt32 len0 = 0, len1 = 0; |
| 360 | for (;;) |
| 361 | { |
| 362 | UInt32 delta = pos - curMatch; |
| 363 | if (cutValue-- == 0 || delta >= _cyclicBufferSize) |
| 364 | { |
| 365 | *ptr0 = *ptr1 = kEmptyHashValue; |
| 366 | return distances; |
| 367 | } |
| 368 | { |
| 369 | CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); |
| 370 | const Byte *pb = cur - delta; |
| 371 | UInt32 len = (len0 < len1 ? len0 : len1); |
| 372 | if (pb[len] == cur[len]) |
| 373 | { |
| 374 | if (++len != lenLimit && pb[len] == cur[len]) |
| 375 | while (++len != lenLimit) |
| 376 | if (pb[len] != cur[len]) |
| 377 | break; |
| 378 | if (maxLen < len) |
| 379 | { |
| 380 | *distances++ = maxLen = len; |
| 381 | *distances++ = delta - 1; |
| 382 | if (len == lenLimit) |
| 383 | { |
| 384 | *ptr1 = pair[0]; |
| 385 | *ptr0 = pair[1]; |
| 386 | return distances; |
| 387 | } |
| 388 | } |
| 389 | } |
| 390 | if (pb[len] < cur[len]) |
| 391 | { |
| 392 | *ptr1 = curMatch; |
| 393 | ptr1 = pair + 1; |
| 394 | curMatch = *ptr1; |
| 395 | len1 = len; |
| 396 | } |
| 397 | else |
| 398 | { |
| 399 | *ptr0 = curMatch; |
| 400 | ptr0 = pair; |
| 401 | curMatch = *ptr0; |
| 402 | len0 = len; |
| 403 | } |
| 404 | } |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son, |
| 409 | UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) |
| 410 | { |
| 411 | CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; |
| 412 | CLzRef *ptr1 = son + (_cyclicBufferPos << 1); |
| 413 | UInt32 len0 = 0, len1 = 0; |
| 414 | for (;;) |
| 415 | { |
| 416 | UInt32 delta = pos - curMatch; |
| 417 | if (cutValue-- == 0 || delta >= _cyclicBufferSize) |
| 418 | { |
| 419 | *ptr0 = *ptr1 = kEmptyHashValue; |
| 420 | return; |
| 421 | } |
| 422 | { |
| 423 | CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); |
| 424 | const Byte *pb = cur - delta; |
| 425 | UInt32 len = (len0 < len1 ? len0 : len1); |
| 426 | if (pb[len] == cur[len]) |
| 427 | { |
| 428 | while (++len != lenLimit) |
| 429 | if (pb[len] != cur[len]) |
| 430 | break; |
| 431 | { |
| 432 | if (len == lenLimit) |
| 433 | { |
| 434 | *ptr1 = pair[0]; |
| 435 | *ptr0 = pair[1]; |
| 436 | return; |
| 437 | } |
| 438 | } |
| 439 | } |
| 440 | if (pb[len] < cur[len]) |
| 441 | { |
| 442 | *ptr1 = curMatch; |
| 443 | ptr1 = pair + 1; |
| 444 | curMatch = *ptr1; |
| 445 | len1 = len; |
| 446 | } |
| 447 | else |
| 448 | { |
| 449 | *ptr0 = curMatch; |
| 450 | ptr0 = pair; |
| 451 | curMatch = *ptr0; |
| 452 | len0 = len; |
| 453 | } |
| 454 | } |
| 455 | } |
| 456 | } |
| 457 | |
| 458 | #define MOVE_POS \ |
| 459 | ++p->cyclicBufferPos; \ |
| 460 | p->buffer++; \ |
| 461 | if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); |
| 462 | |
| 463 | #define MOVE_POS_RET MOVE_POS return offset; |
| 464 | |
| 465 | static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } |
| 466 | |
| 467 | #define GET_MATCHES_HEADER2(minLen, ret_op) \ |
| 468 | UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ |
| 469 | lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \ |
| 470 | cur = p->buffer; |
| 471 | |
| 472 | #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) |
| 473 | #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) |
| 474 | |
| 475 | #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue |
| 476 | |
| 477 | #define GET_MATCHES_FOOTER(offset, maxLen) \ |
| 478 | offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ |
| 479 | distances + offset, maxLen) - distances); MOVE_POS_RET; |
| 480 | |
| 481 | #define SKIP_FOOTER \ |
| 482 | SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; |
| 483 | |
| 484 | static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 485 | { |
| 486 | UInt32 offset; |
| 487 | GET_MATCHES_HEADER(2) |
| 488 | HASH2_CALC; |
| 489 | curMatch = p->hash[hashValue]; |
| 490 | p->hash[hashValue] = p->pos; |
| 491 | offset = 0; |
| 492 | GET_MATCHES_FOOTER(offset, 1) |
| 493 | } |
| 494 | |
| 495 | UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 496 | { |
| 497 | UInt32 offset; |
| 498 | GET_MATCHES_HEADER(3) |
| 499 | HASH_ZIP_CALC; |
| 500 | curMatch = p->hash[hashValue]; |
| 501 | p->hash[hashValue] = p->pos; |
| 502 | offset = 0; |
| 503 | GET_MATCHES_FOOTER(offset, 2) |
| 504 | } |
| 505 | |
| 506 | static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 507 | { |
| 508 | UInt32 hash2Value, delta2, maxLen, offset; |
| 509 | GET_MATCHES_HEADER(3) |
| 510 | |
| 511 | HASH3_CALC; |
| 512 | |
| 513 | delta2 = p->pos - p->hash[hash2Value]; |
| 514 | curMatch = p->hash[kFix3HashSize + hashValue]; |
| 515 | |
| 516 | p->hash[hash2Value] = |
| 517 | p->hash[kFix3HashSize + hashValue] = p->pos; |
| 518 | |
| 519 | |
| 520 | maxLen = 2; |
| 521 | offset = 0; |
| 522 | if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) |
| 523 | { |
| 524 | for (; maxLen != lenLimit; maxLen++) |
| 525 | if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) |
| 526 | break; |
| 527 | distances[0] = maxLen; |
| 528 | distances[1] = delta2 - 1; |
| 529 | offset = 2; |
| 530 | if (maxLen == lenLimit) |
| 531 | { |
| 532 | SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); |
| 533 | MOVE_POS_RET; |
| 534 | } |
| 535 | } |
| 536 | GET_MATCHES_FOOTER(offset, maxLen) |
| 537 | } |
| 538 | |
| 539 | static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 540 | { |
| 541 | UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; |
| 542 | GET_MATCHES_HEADER(4) |
| 543 | |
| 544 | HASH4_CALC; |
| 545 | |
| 546 | delta2 = p->pos - p->hash[ hash2Value]; |
| 547 | delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; |
| 548 | curMatch = p->hash[kFix4HashSize + hashValue]; |
| 549 | |
| 550 | p->hash[ hash2Value] = |
| 551 | p->hash[kFix3HashSize + hash3Value] = |
| 552 | p->hash[kFix4HashSize + hashValue] = p->pos; |
| 553 | |
| 554 | maxLen = 1; |
| 555 | offset = 0; |
| 556 | if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) |
| 557 | { |
| 558 | distances[0] = maxLen = 2; |
| 559 | distances[1] = delta2 - 1; |
| 560 | offset = 2; |
| 561 | } |
| 562 | if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) |
| 563 | { |
| 564 | maxLen = 3; |
| 565 | distances[offset + 1] = delta3 - 1; |
| 566 | offset += 2; |
| 567 | delta2 = delta3; |
| 568 | } |
| 569 | if (offset != 0) |
| 570 | { |
| 571 | for (; maxLen != lenLimit; maxLen++) |
| 572 | if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) |
| 573 | break; |
| 574 | distances[offset - 2] = maxLen; |
| 575 | if (maxLen == lenLimit) |
| 576 | { |
| 577 | SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); |
| 578 | MOVE_POS_RET; |
| 579 | } |
| 580 | } |
| 581 | if (maxLen < 3) |
| 582 | maxLen = 3; |
| 583 | GET_MATCHES_FOOTER(offset, maxLen) |
| 584 | } |
| 585 | |
| 586 | static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 587 | { |
| 588 | UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; |
| 589 | GET_MATCHES_HEADER(4) |
| 590 | |
| 591 | HASH4_CALC; |
| 592 | |
| 593 | delta2 = p->pos - p->hash[ hash2Value]; |
| 594 | delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; |
| 595 | curMatch = p->hash[kFix4HashSize + hashValue]; |
| 596 | |
| 597 | p->hash[ hash2Value] = |
| 598 | p->hash[kFix3HashSize + hash3Value] = |
| 599 | p->hash[kFix4HashSize + hashValue] = p->pos; |
| 600 | |
| 601 | maxLen = 1; |
| 602 | offset = 0; |
| 603 | if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) |
| 604 | { |
| 605 | distances[0] = maxLen = 2; |
| 606 | distances[1] = delta2 - 1; |
| 607 | offset = 2; |
| 608 | } |
| 609 | if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) |
| 610 | { |
| 611 | maxLen = 3; |
| 612 | distances[offset + 1] = delta3 - 1; |
| 613 | offset += 2; |
| 614 | delta2 = delta3; |
| 615 | } |
| 616 | if (offset != 0) |
| 617 | { |
| 618 | for (; maxLen != lenLimit; maxLen++) |
| 619 | if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) |
| 620 | break; |
| 621 | distances[offset - 2] = maxLen; |
| 622 | if (maxLen == lenLimit) |
| 623 | { |
| 624 | p->son[p->cyclicBufferPos] = curMatch; |
| 625 | MOVE_POS_RET; |
| 626 | } |
| 627 | } |
| 628 | if (maxLen < 3) |
| 629 | maxLen = 3; |
| 630 | offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), |
| 631 | distances + offset, maxLen) - (distances)); |
| 632 | MOVE_POS_RET |
| 633 | } |
| 634 | |
| 635 | UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) |
| 636 | { |
| 637 | UInt32 offset; |
| 638 | GET_MATCHES_HEADER(3) |
| 639 | HASH_ZIP_CALC; |
| 640 | curMatch = p->hash[hashValue]; |
| 641 | p->hash[hashValue] = p->pos; |
| 642 | offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), |
| 643 | distances, 2) - (distances)); |
| 644 | MOVE_POS_RET |
| 645 | } |
| 646 | |
| 647 | static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 648 | { |
| 649 | do |
| 650 | { |
| 651 | SKIP_HEADER(2) |
| 652 | HASH2_CALC; |
| 653 | curMatch = p->hash[hashValue]; |
| 654 | p->hash[hashValue] = p->pos; |
| 655 | SKIP_FOOTER |
| 656 | } |
| 657 | while (--num != 0); |
| 658 | } |
| 659 | |
| 660 | void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 661 | { |
| 662 | do |
| 663 | { |
| 664 | SKIP_HEADER(3) |
| 665 | HASH_ZIP_CALC; |
| 666 | curMatch = p->hash[hashValue]; |
| 667 | p->hash[hashValue] = p->pos; |
| 668 | SKIP_FOOTER |
| 669 | } |
| 670 | while (--num != 0); |
| 671 | } |
| 672 | |
| 673 | static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 674 | { |
| 675 | do |
| 676 | { |
| 677 | UInt32 hash2Value; |
| 678 | SKIP_HEADER(3) |
| 679 | HASH3_CALC; |
| 680 | curMatch = p->hash[kFix3HashSize + hashValue]; |
| 681 | p->hash[hash2Value] = |
| 682 | p->hash[kFix3HashSize + hashValue] = p->pos; |
| 683 | SKIP_FOOTER |
| 684 | } |
| 685 | while (--num != 0); |
| 686 | } |
| 687 | |
| 688 | static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 689 | { |
| 690 | do |
| 691 | { |
| 692 | UInt32 hash2Value, hash3Value; |
| 693 | SKIP_HEADER(4) |
| 694 | HASH4_CALC; |
| 695 | curMatch = p->hash[kFix4HashSize + hashValue]; |
| 696 | p->hash[ hash2Value] = |
| 697 | p->hash[kFix3HashSize + hash3Value] = p->pos; |
| 698 | p->hash[kFix4HashSize + hashValue] = p->pos; |
| 699 | SKIP_FOOTER |
| 700 | } |
| 701 | while (--num != 0); |
| 702 | } |
| 703 | |
| 704 | static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 705 | { |
| 706 | do |
| 707 | { |
| 708 | UInt32 hash2Value, hash3Value; |
| 709 | SKIP_HEADER(4) |
| 710 | HASH4_CALC; |
| 711 | curMatch = p->hash[kFix4HashSize + hashValue]; |
| 712 | p->hash[ hash2Value] = |
| 713 | p->hash[kFix3HashSize + hash3Value] = |
| 714 | p->hash[kFix4HashSize + hashValue] = p->pos; |
| 715 | p->son[p->cyclicBufferPos] = curMatch; |
| 716 | MOVE_POS |
| 717 | } |
| 718 | while (--num != 0); |
| 719 | } |
| 720 | |
| 721 | void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) |
| 722 | { |
| 723 | do |
| 724 | { |
| 725 | SKIP_HEADER(3) |
| 726 | HASH_ZIP_CALC; |
| 727 | curMatch = p->hash[hashValue]; |
| 728 | p->hash[hashValue] = p->pos; |
| 729 | p->son[p->cyclicBufferPos] = curMatch; |
| 730 | MOVE_POS |
| 731 | } |
| 732 | while (--num != 0); |
| 733 | } |
| 734 | |
| 735 | void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) |
| 736 | { |
| 737 | vTable->Init = (Mf_Init_Func)MatchFinder_Init; |
| 738 | vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; |
| 739 | vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes; |
| 740 | vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos; |
| 741 | if (!p->btMode) |
| 742 | { |
| 743 | vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; |
| 744 | vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; |
| 745 | } |
| 746 | else if (p->numHashBytes == 2) |
| 747 | { |
| 748 | vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; |
| 749 | vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; |
| 750 | } |
| 751 | else if (p->numHashBytes == 3) |
| 752 | { |
| 753 | vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; |
| 754 | vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; |
| 755 | } |
| 756 | else |
| 757 | { |
| 758 | vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; |
| 759 | vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; |
| 760 | } |
| 761 | } |