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| 1 /* LzFind.c -- Match finder for LZ algorithms | |
| 2 2008-10-04 : Igor Pavlov : Public domain */ | |
| 3 | |
| 4 #include <string.h> | |
| 5 | |
| 6 #include "LzFind.h" | |
| 7 #include "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 *a
lloc) | |
| 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[i
ndex]; } | |
| 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 for (;;) | |
| 62 { | |
| 63 Byte *dest = p->buffer + (p->streamPos - p->pos); | |
| 64 size_t size = (p->bufferBase + p->blockSize - dest); | |
| 65 if (size == 0) | |
| 66 return; | |
| 67 p->result = p->stream->Read(p->stream, dest, &size); | |
| 68 if (p->result != SZ_OK) | |
| 69 return; | |
| 70 if (size == 0) | |
| 71 { | |
| 72 p->streamEndWasReached = 1; | |
| 73 return; | |
| 74 } | |
| 75 p->streamPos += (UInt32)size; | |
| 76 if (p->streamPos - p->pos > p->keepSizeAfter) | |
| 77 return; | |
| 78 } | |
| 79 } | |
| 80 | |
| 81 void MatchFinder_MoveBlock(CMatchFinder *p) | |
| 82 { | |
| 83 memmove(p->bufferBase, | |
| 84 p->buffer - p->keepSizeBefore, | |
| 85 (size_t)(p->streamPos - p->pos + p->keepSizeBefore)); | |
| 86 p->buffer = p->bufferBase + p->keepSizeBefore; | |
| 87 } | |
| 88 | |
| 89 int MatchFinder_NeedMove(CMatchFinder *p) | |
| 90 { | |
| 91 /* if (p->streamEndWasReached) return 0; */ | |
| 92 return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter
); | |
| 93 } | |
| 94 | |
| 95 void MatchFinder_ReadIfRequired(CMatchFinder *p) | |
| 96 { | |
| 97 if (p->streamEndWasReached) | |
| 98 return; | |
| 99 if (p->keepSizeAfter >= p->streamPos - p->pos) | |
| 100 MatchFinder_ReadBlock(p); | |
| 101 } | |
| 102 | |
| 103 static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p) | |
| 104 { | |
| 105 if (MatchFinder_NeedMove(p)) | |
| 106 MatchFinder_MoveBlock(p); | |
| 107 MatchFinder_ReadBlock(p); | |
| 108 } | |
| 109 | |
| 110 static void MatchFinder_SetDefaultSettings(CMatchFinder *p) | |
| 111 { | |
| 112 p->cutValue = 32; | |
| 113 p->btMode = 1; | |
| 114 p->numHashBytes = 4; | |
| 115 /* p->skipModeBits = 0; */ | |
| 116 p->directInput = 0; | |
| 117 p->bigHash = 0; | |
| 118 } | |
| 119 | |
| 120 #define kCrcPoly 0xEDB88320 | |
| 121 | |
| 122 void MatchFinder_Construct(CMatchFinder *p) | |
| 123 { | |
| 124 UInt32 i; | |
| 125 p->bufferBase = 0; | |
| 126 p->directInput = 0; | |
| 127 p->hash = 0; | |
| 128 MatchFinder_SetDefaultSettings(p); | |
| 129 | |
| 130 for (i = 0; i < 256; i++) | |
| 131 { | |
| 132 UInt32 r = i; | |
| 133 int j; | |
| 134 for (j = 0; j < 8; j++) | |
| 135 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); | |
| 136 p->crc[i] = r; | |
| 137 } | |
| 138 } | |
| 139 | |
| 140 static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc) | |
| 141 { | |
| 142 alloc->Free(alloc, p->hash); | |
| 143 p->hash = 0; | |
| 144 } | |
| 145 | |
| 146 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc) | |
| 147 { | |
| 148 MatchFinder_FreeThisClassMemory(p, alloc); | |
| 149 LzInWindow_Free(p, alloc); | |
| 150 } | |
| 151 | |
| 152 static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc) | |
| 153 { | |
| 154 size_t sizeInBytes = (size_t)num * sizeof(CLzRef); | |
| 155 if (sizeInBytes / sizeof(CLzRef) != num) | |
| 156 return 0; | |
| 157 return (CLzRef *)alloc->Alloc(alloc, sizeInBytes); | |
| 158 } | |
| 159 | |
| 160 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize, | |
| 161 UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter, | |
| 162 ISzAlloc *alloc) | |
| 163 { | |
| 164 UInt32 sizeReserv; | |
| 165 if (historySize > kMaxHistorySize) | |
| 166 { | |
| 167 MatchFinder_Free(p, alloc); | |
| 168 return 0; | |
| 169 } | |
| 170 sizeReserv = historySize >> 1; | |
| 171 if (historySize > ((UInt32)2 << 30)) | |
| 172 sizeReserv = historySize >> 2; | |
| 173 sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (
1 << 19); | |
| 174 | |
| 175 p->keepSizeBefore = historySize + keepAddBufferBefore + 1; | |
| 176 p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; | |
| 177 /* we need one additional byte, since we use MoveBlock after pos++ and before
dictionary using */ | |
| 178 if (LzInWindow_Create(p, sizeReserv, alloc)) | |
| 179 { | |
| 180 UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1; | |
| 181 UInt32 hs; | |
| 182 p->matchMaxLen = matchMaxLen; | |
| 183 { | |
| 184 p->fixedHashSize = 0; | |
| 185 if (p->numHashBytes == 2) | |
| 186 hs = (1 << 16) - 1; | |
| 187 else | |
| 188 { | |
| 189 hs = historySize - 1; | |
| 190 hs |= (hs >> 1); | |
| 191 hs |= (hs >> 2); | |
| 192 hs |= (hs >> 4); | |
| 193 hs |= (hs >> 8); | |
| 194 hs >>= 1; | |
| 195 /* hs >>= p->skipModeBits; */ | |
| 196 hs |= 0xFFFF; /* don't change it! It's required for Deflate */ | |
| 197 if (hs > (1 << 24)) | |
| 198 { | |
| 199 if (p->numHashBytes == 3) | |
| 200 hs = (1 << 24) - 1; | |
| 201 else | |
| 202 hs >>= 1; | |
| 203 } | |
| 204 } | |
| 205 p->hashMask = hs; | |
| 206 hs++; | |
| 207 if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size; | |
| 208 if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size; | |
| 209 if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size; | |
| 210 hs += p->fixedHashSize; | |
| 211 } | |
| 212 | |
| 213 { | |
| 214 UInt32 prevSize = p->hashSizeSum + p->numSons; | |
| 215 UInt32 newSize; | |
| 216 p->historySize = historySize; | |
| 217 p->hashSizeSum = hs; | |
| 218 p->cyclicBufferSize = newCyclicBufferSize; | |
| 219 p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); | |
| 220 newSize = p->hashSizeSum + p->numSons; | |
| 221 if (p->hash != 0 && prevSize == newSize) | |
| 222 return 1; | |
| 223 MatchFinder_FreeThisClassMemory(p, alloc); | |
| 224 p->hash = AllocRefs(newSize, alloc); | |
| 225 if (p->hash != 0) | |
| 226 { | |
| 227 p->son = p->hash + p->hashSizeSum; | |
| 228 return 1; | |
| 229 } | |
| 230 } | |
| 231 } | |
| 232 MatchFinder_Free(p, alloc); | |
| 233 return 0; | |
| 234 } | |
| 235 | |
| 236 static void MatchFinder_SetLimits(CMatchFinder *p) | |
| 237 { | |
| 238 UInt32 limit = kMaxValForNormalize - p->pos; | |
| 239 UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos; | |
| 240 if (limit2 < limit) | |
| 241 limit = limit2; | |
| 242 limit2 = p->streamPos - p->pos; | |
| 243 if (limit2 <= p->keepSizeAfter) | |
| 244 { | |
| 245 if (limit2 > 0) | |
| 246 limit2 = 1; | |
| 247 } | |
| 248 else | |
| 249 limit2 -= p->keepSizeAfter; | |
| 250 if (limit2 < limit) | |
| 251 limit = limit2; | |
| 252 { | |
| 253 UInt32 lenLimit = p->streamPos - p->pos; | |
| 254 if (lenLimit > p->matchMaxLen) | |
| 255 lenLimit = p->matchMaxLen; | |
| 256 p->lenLimit = lenLimit; | |
| 257 } | |
| 258 p->posLimit = p->pos + limit; | |
| 259 } | |
| 260 | |
| 261 void MatchFinder_Init(CMatchFinder *p) | |
| 262 { | |
| 263 UInt32 i; | |
| 264 for (i = 0; i < p->hashSizeSum; i++) | |
| 265 p->hash[i] = kEmptyHashValue; | |
| 266 p->cyclicBufferPos = 0; | |
| 267 p->buffer = p->bufferBase; | |
| 268 p->pos = p->streamPos = p->cyclicBufferSize; | |
| 269 p->result = SZ_OK; | |
| 270 p->streamEndWasReached = 0; | |
| 271 MatchFinder_ReadBlock(p); | |
| 272 MatchFinder_SetLimits(p); | |
| 273 } | |
| 274 | |
| 275 static UInt32 MatchFinder_GetSubValue(CMatchFinder *p) | |
| 276 { | |
| 277 return (p->pos - p->historySize - 1) & kNormalizeMask; | |
| 278 } | |
| 279 | |
| 280 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems) | |
| 281 { | |
| 282 UInt32 i; | |
| 283 for (i = 0; i < numItems; i++) | |
| 284 { | |
| 285 UInt32 value = items[i]; | |
| 286 if (value <= subValue) | |
| 287 value = kEmptyHashValue; | |
| 288 else | |
| 289 value -= subValue; | |
| 290 items[i] = value; | |
| 291 } | |
| 292 } | |
| 293 | |
| 294 static void MatchFinder_Normalize(CMatchFinder *p) | |
| 295 { | |
| 296 UInt32 subValue = MatchFinder_GetSubValue(p); | |
| 297 MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); | |
| 298 MatchFinder_ReduceOffsets(p, subValue); | |
| 299 } | |
| 300 | |
| 301 static void MatchFinder_CheckLimits(CMatchFinder *p) | |
| 302 { | |
| 303 if (p->pos == kMaxValForNormalize) | |
| 304 MatchFinder_Normalize(p); | |
| 305 if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) | |
| 306 MatchFinder_CheckAndMoveAndRead(p); | |
| 307 if (p->cyclicBufferPos == p->cyclicBufferSize) | |
| 308 p->cyclicBufferPos = 0; | |
| 309 MatchFinder_SetLimits(p); | |
| 310 } | |
| 311 | |
| 312 static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos,
const Byte *cur, CLzRef *son, | |
| 313 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, | |
| 314 UInt32 *distances, UInt32 maxLen) | |
| 315 { | |
| 316 son[_cyclicBufferPos] = curMatch; | |
| 317 for (;;) | |
| 318 { | |
| 319 UInt32 delta = pos - curMatch; | |
| 320 if (cutValue-- == 0 || delta >= _cyclicBufferSize) | |
| 321 return distances; | |
| 322 { | |
| 323 const Byte *pb = cur - delta; | |
| 324 curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _c
yclicBufferSize : 0)]; | |
| 325 if (pb[maxLen] == cur[maxLen] && *pb == *cur) | |
| 326 { | |
| 327 UInt32 len = 0; | |
| 328 while (++len != lenLimit) | |
| 329 if (pb[len] != cur[len]) | |
| 330 break; | |
| 331 if (maxLen < len) | |
| 332 { | |
| 333 *distances++ = maxLen = len; | |
| 334 *distances++ = delta - 1; | |
| 335 if (len == lenLimit) | |
| 336 return distances; | |
| 337 } | |
| 338 } | |
| 339 } | |
| 340 } | |
| 341 } | |
| 342 | |
| 343 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byt
e *cur, CLzRef *son, | |
| 344 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue, | |
| 345 UInt32 *distances, UInt32 maxLen) | |
| 346 { | |
| 347 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; | |
| 348 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); | |
| 349 UInt32 len0 = 0, len1 = 0; | |
| 350 for (;;) | |
| 351 { | |
| 352 UInt32 delta = pos - curMatch; | |
| 353 if (cutValue-- == 0 || delta >= _cyclicBufferSize) | |
| 354 { | |
| 355 *ptr0 = *ptr1 = kEmptyHashValue; | |
| 356 return distances; | |
| 357 } | |
| 358 { | |
| 359 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferP
os) ? _cyclicBufferSize : 0)) << 1); | |
| 360 const Byte *pb = cur - delta; | |
| 361 UInt32 len = (len0 < len1 ? len0 : len1); | |
| 362 if (pb[len] == cur[len]) | |
| 363 { | |
| 364 if (++len != lenLimit && pb[len] == cur[len]) | |
| 365 while (++len != lenLimit) | |
| 366 if (pb[len] != cur[len]) | |
| 367 break; | |
| 368 if (maxLen < len) | |
| 369 { | |
| 370 *distances++ = maxLen = len; | |
| 371 *distances++ = delta - 1; | |
| 372 if (len == lenLimit) | |
| 373 { | |
| 374 *ptr1 = pair[0]; | |
| 375 *ptr0 = pair[1]; | |
| 376 return distances; | |
| 377 } | |
| 378 } | |
| 379 } | |
| 380 if (pb[len] < cur[len]) | |
| 381 { | |
| 382 *ptr1 = curMatch; | |
| 383 ptr1 = pair + 1; | |
| 384 curMatch = *ptr1; | |
| 385 len1 = len; | |
| 386 } | |
| 387 else | |
| 388 { | |
| 389 *ptr0 = curMatch; | |
| 390 ptr0 = pair; | |
| 391 curMatch = *ptr0; | |
| 392 len0 = len; | |
| 393 } | |
| 394 } | |
| 395 } | |
| 396 } | |
| 397 | |
| 398 static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const
Byte *cur, CLzRef *son, | |
| 399 UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue) | |
| 400 { | |
| 401 CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; | |
| 402 CLzRef *ptr1 = son + (_cyclicBufferPos << 1); | |
| 403 UInt32 len0 = 0, len1 = 0; | |
| 404 for (;;) | |
| 405 { | |
| 406 UInt32 delta = pos - curMatch; | |
| 407 if (cutValue-- == 0 || delta >= _cyclicBufferSize) | |
| 408 { | |
| 409 *ptr0 = *ptr1 = kEmptyHashValue; | |
| 410 return; | |
| 411 } | |
| 412 { | |
| 413 CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferP
os) ? _cyclicBufferSize : 0)) << 1); | |
| 414 const Byte *pb = cur - delta; | |
| 415 UInt32 len = (len0 < len1 ? len0 : len1); | |
| 416 if (pb[len] == cur[len]) | |
| 417 { | |
| 418 while (++len != lenLimit) | |
| 419 if (pb[len] != cur[len]) | |
| 420 break; | |
| 421 { | |
| 422 if (len == lenLimit) | |
| 423 { | |
| 424 *ptr1 = pair[0]; | |
| 425 *ptr0 = pair[1]; | |
| 426 return; | |
| 427 } | |
| 428 } | |
| 429 } | |
| 430 if (pb[len] < cur[len]) | |
| 431 { | |
| 432 *ptr1 = curMatch; | |
| 433 ptr1 = pair + 1; | |
| 434 curMatch = *ptr1; | |
| 435 len1 = len; | |
| 436 } | |
| 437 else | |
| 438 { | |
| 439 *ptr0 = curMatch; | |
| 440 ptr0 = pair; | |
| 441 curMatch = *ptr0; | |
| 442 len0 = len; | |
| 443 } | |
| 444 } | |
| 445 } | |
| 446 } | |
| 447 | |
| 448 #define MOVE_POS \ | |
| 449 ++p->cyclicBufferPos; \ | |
| 450 p->buffer++; \ | |
| 451 if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p); | |
| 452 | |
| 453 #define MOVE_POS_RET MOVE_POS return offset; | |
| 454 | |
| 455 static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; } | |
| 456 | |
| 457 #define GET_MATCHES_HEADER2(minLen, ret_op) \ | |
| 458 UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \ | |
| 459 lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret
_op; }} \ | |
| 460 cur = p->buffer; | |
| 461 | |
| 462 #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) | |
| 463 #define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) | |
| 464 | |
| 465 #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBuf
ferSize, p->cutValue | |
| 466 | |
| 467 #define GET_MATCHES_FOOTER(offset, maxLen) \ | |
| 468 offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ | |
| 469 distances + offset, maxLen) - distances); MOVE_POS_RET; | |
| 470 | |
| 471 #define SKIP_FOOTER \ | |
| 472 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; | |
| 473 | |
| 474 static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 475 { | |
| 476 UInt32 offset; | |
| 477 GET_MATCHES_HEADER(2) | |
| 478 HASH2_CALC; | |
| 479 curMatch = p->hash[hashValue]; | |
| 480 p->hash[hashValue] = p->pos; | |
| 481 offset = 0; | |
| 482 GET_MATCHES_FOOTER(offset, 1) | |
| 483 } | |
| 484 | |
| 485 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 486 { | |
| 487 UInt32 offset; | |
| 488 GET_MATCHES_HEADER(3) | |
| 489 HASH_ZIP_CALC; | |
| 490 curMatch = p->hash[hashValue]; | |
| 491 p->hash[hashValue] = p->pos; | |
| 492 offset = 0; | |
| 493 GET_MATCHES_FOOTER(offset, 2) | |
| 494 } | |
| 495 | |
| 496 static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 497 { | |
| 498 UInt32 hash2Value, delta2, maxLen, offset; | |
| 499 GET_MATCHES_HEADER(3) | |
| 500 | |
| 501 HASH3_CALC; | |
| 502 | |
| 503 delta2 = p->pos - p->hash[hash2Value]; | |
| 504 curMatch = p->hash[kFix3HashSize + hashValue]; | |
| 505 | |
| 506 p->hash[hash2Value] = | |
| 507 p->hash[kFix3HashSize + hashValue] = p->pos; | |
| 508 | |
| 509 | |
| 510 maxLen = 2; | |
| 511 offset = 0; | |
| 512 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) | |
| 513 { | |
| 514 for (; maxLen != lenLimit; maxLen++) | |
| 515 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) | |
| 516 break; | |
| 517 distances[0] = maxLen; | |
| 518 distances[1] = delta2 - 1; | |
| 519 offset = 2; | |
| 520 if (maxLen == lenLimit) | |
| 521 { | |
| 522 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); | |
| 523 MOVE_POS_RET; | |
| 524 } | |
| 525 } | |
| 526 GET_MATCHES_FOOTER(offset, maxLen) | |
| 527 } | |
| 528 | |
| 529 static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 530 { | |
| 531 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; | |
| 532 GET_MATCHES_HEADER(4) | |
| 533 | |
| 534 HASH4_CALC; | |
| 535 | |
| 536 delta2 = p->pos - p->hash[ hash2Value]; | |
| 537 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; | |
| 538 curMatch = p->hash[kFix4HashSize + hashValue]; | |
| 539 | |
| 540 p->hash[ hash2Value] = | |
| 541 p->hash[kFix3HashSize + hash3Value] = | |
| 542 p->hash[kFix4HashSize + hashValue] = p->pos; | |
| 543 | |
| 544 maxLen = 1; | |
| 545 offset = 0; | |
| 546 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) | |
| 547 { | |
| 548 distances[0] = maxLen = 2; | |
| 549 distances[1] = delta2 - 1; | |
| 550 offset = 2; | |
| 551 } | |
| 552 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cu
r) | |
| 553 { | |
| 554 maxLen = 3; | |
| 555 distances[offset + 1] = delta3 - 1; | |
| 556 offset += 2; | |
| 557 delta2 = delta3; | |
| 558 } | |
| 559 if (offset != 0) | |
| 560 { | |
| 561 for (; maxLen != lenLimit; maxLen++) | |
| 562 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) | |
| 563 break; | |
| 564 distances[offset - 2] = maxLen; | |
| 565 if (maxLen == lenLimit) | |
| 566 { | |
| 567 SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); | |
| 568 MOVE_POS_RET; | |
| 569 } | |
| 570 } | |
| 571 if (maxLen < 3) | |
| 572 maxLen = 3; | |
| 573 GET_MATCHES_FOOTER(offset, maxLen) | |
| 574 } | |
| 575 | |
| 576 static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 577 { | |
| 578 UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset; | |
| 579 GET_MATCHES_HEADER(4) | |
| 580 | |
| 581 HASH4_CALC; | |
| 582 | |
| 583 delta2 = p->pos - p->hash[ hash2Value]; | |
| 584 delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; | |
| 585 curMatch = p->hash[kFix4HashSize + hashValue]; | |
| 586 | |
| 587 p->hash[ hash2Value] = | |
| 588 p->hash[kFix3HashSize + hash3Value] = | |
| 589 p->hash[kFix4HashSize + hashValue] = p->pos; | |
| 590 | |
| 591 maxLen = 1; | |
| 592 offset = 0; | |
| 593 if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) | |
| 594 { | |
| 595 distances[0] = maxLen = 2; | |
| 596 distances[1] = delta2 - 1; | |
| 597 offset = 2; | |
| 598 } | |
| 599 if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cu
r) | |
| 600 { | |
| 601 maxLen = 3; | |
| 602 distances[offset + 1] = delta3 - 1; | |
| 603 offset += 2; | |
| 604 delta2 = delta3; | |
| 605 } | |
| 606 if (offset != 0) | |
| 607 { | |
| 608 for (; maxLen != lenLimit; maxLen++) | |
| 609 if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) | |
| 610 break; | |
| 611 distances[offset - 2] = maxLen; | |
| 612 if (maxLen == lenLimit) | |
| 613 { | |
| 614 p->son[p->cyclicBufferPos] = curMatch; | |
| 615 MOVE_POS_RET; | |
| 616 } | |
| 617 } | |
| 618 if (maxLen < 3) | |
| 619 maxLen = 3; | |
| 620 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), | |
| 621 distances + offset, maxLen) - (distances)); | |
| 622 MOVE_POS_RET | |
| 623 } | |
| 624 | |
| 625 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances) | |
| 626 { | |
| 627 UInt32 offset; | |
| 628 GET_MATCHES_HEADER(3) | |
| 629 HASH_ZIP_CALC; | |
| 630 curMatch = p->hash[hashValue]; | |
| 631 p->hash[hashValue] = p->pos; | |
| 632 offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), | |
| 633 distances, 2) - (distances)); | |
| 634 MOVE_POS_RET | |
| 635 } | |
| 636 | |
| 637 static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 638 { | |
| 639 do | |
| 640 { | |
| 641 SKIP_HEADER(2) | |
| 642 HASH2_CALC; | |
| 643 curMatch = p->hash[hashValue]; | |
| 644 p->hash[hashValue] = p->pos; | |
| 645 SKIP_FOOTER | |
| 646 } | |
| 647 while (--num != 0); | |
| 648 } | |
| 649 | |
| 650 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 651 { | |
| 652 do | |
| 653 { | |
| 654 SKIP_HEADER(3) | |
| 655 HASH_ZIP_CALC; | |
| 656 curMatch = p->hash[hashValue]; | |
| 657 p->hash[hashValue] = p->pos; | |
| 658 SKIP_FOOTER | |
| 659 } | |
| 660 while (--num != 0); | |
| 661 } | |
| 662 | |
| 663 static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 664 { | |
| 665 do | |
| 666 { | |
| 667 UInt32 hash2Value; | |
| 668 SKIP_HEADER(3) | |
| 669 HASH3_CALC; | |
| 670 curMatch = p->hash[kFix3HashSize + hashValue]; | |
| 671 p->hash[hash2Value] = | |
| 672 p->hash[kFix3HashSize + hashValue] = p->pos; | |
| 673 SKIP_FOOTER | |
| 674 } | |
| 675 while (--num != 0); | |
| 676 } | |
| 677 | |
| 678 static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 679 { | |
| 680 do | |
| 681 { | |
| 682 UInt32 hash2Value, hash3Value; | |
| 683 SKIP_HEADER(4) | |
| 684 HASH4_CALC; | |
| 685 curMatch = p->hash[kFix4HashSize + hashValue]; | |
| 686 p->hash[ hash2Value] = | |
| 687 p->hash[kFix3HashSize + hash3Value] = p->pos; | |
| 688 p->hash[kFix4HashSize + hashValue] = p->pos; | |
| 689 SKIP_FOOTER | |
| 690 } | |
| 691 while (--num != 0); | |
| 692 } | |
| 693 | |
| 694 static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 695 { | |
| 696 do | |
| 697 { | |
| 698 UInt32 hash2Value, hash3Value; | |
| 699 SKIP_HEADER(4) | |
| 700 HASH4_CALC; | |
| 701 curMatch = p->hash[kFix4HashSize + hashValue]; | |
| 702 p->hash[ hash2Value] = | |
| 703 p->hash[kFix3HashSize + hash3Value] = | |
| 704 p->hash[kFix4HashSize + hashValue] = p->pos; | |
| 705 p->son[p->cyclicBufferPos] = curMatch; | |
| 706 MOVE_POS | |
| 707 } | |
| 708 while (--num != 0); | |
| 709 } | |
| 710 | |
| 711 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num) | |
| 712 { | |
| 713 do | |
| 714 { | |
| 715 SKIP_HEADER(3) | |
| 716 HASH_ZIP_CALC; | |
| 717 curMatch = p->hash[hashValue]; | |
| 718 p->hash[hashValue] = p->pos; | |
| 719 p->son[p->cyclicBufferPos] = curMatch; | |
| 720 MOVE_POS | |
| 721 } | |
| 722 while (--num != 0); | |
| 723 } | |
| 724 | |
| 725 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) | |
| 726 { | |
| 727 vTable->Init = (Mf_Init_Func)MatchFinder_Init; | |
| 728 vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte; | |
| 729 vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNu
mAvailableBytes; | |
| 730 vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_G
etPointerToCurrentPos; | |
| 731 if (!p->btMode) | |
| 732 { | |
| 733 vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; | |
| 734 vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; | |
| 735 } | |
| 736 else if (p->numHashBytes == 2) | |
| 737 { | |
| 738 vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; | |
| 739 vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; | |
| 740 } | |
| 741 else if (p->numHashBytes == 3) | |
| 742 { | |
| 743 vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; | |
| 744 vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; | |
| 745 } | |
| 746 else | |
| 747 { | |
| 748 vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; | |
| 749 vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; | |
| 750 } | |
| 751 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 624713003:
Keep only base/extractor.[cc|h]. (Closed)
Base URL: https://chromium.googlesource.com/external/omaha.git@master