diff options
Diffstat (limited to 'LzFind.c')
| -rw-r--r-- | LzFind.c | 1384 |
1 files changed, 628 insertions, 756 deletions
@@ -1,756 +1,628 @@ -/* LzFind.c -- Match finder for LZ algorithms
-2009-04-22 : Igor Pavlov : Public domain */
-
-#define _FILE_OFFSET_BITS 64
-
-#include <stdint.h>
-#include <string.h>
-
-#include "pdlzip.h"
-#include "LzFind.h"
-#include "LzHash.h"
-
-#define kEmptyHashValue 0
-#define kMaxValForNormalize ((UInt32)0xFFFFFFFF)
-#define kNormalizeStepMin (1 << 10) /* it must be power of 2 */
-#define kNormalizeMask (~(kNormalizeStepMin - 1))
-#define kMaxHistorySize ((UInt32)3 << 30)
-
-#define kStartMaxLen 3
-
-static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)
-{
- if (!p->directInput)
- {
- alloc->Free(alloc, p->bufferBase);
- p->bufferBase = 0;
- }
-}
-
-/* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */
-
-static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc)
-{
- UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv;
- if (p->directInput)
- {
- p->blockSize = blockSize;
- return 1;
- }
- if (p->bufferBase == 0 || p->blockSize != blockSize)
- {
- LzInWindow_Free(p, alloc);
- p->blockSize = blockSize;
- p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize);
- }
- return (p->bufferBase != 0);
-}
-
-Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; }
-Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; }
-
-UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
-
-void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
-{
- p->posLimit -= subValue;
- p->pos -= subValue;
- p->streamPos -= subValue;
-}
-
-static void MatchFinder_ReadBlock(CMatchFinder *p)
-{
- if (p->streamEndWasReached || p->result != SZ_OK)
- return;
- if (p->directInput)
- {
- UInt32 curSize = 0xFFFFFFFF - p->streamPos;
- if (curSize > p->directInputRem)
- curSize = (UInt32)p->directInputRem;
- p->directInputRem -= curSize;
- p->streamPos += curSize;
- if (p->directInputRem == 0)
- p->streamEndWasReached = 1;
- return;
- }
- for (;;)
- {
- Byte *dest = p->buffer + (p->streamPos - p->pos);
- size_t size = (p->bufferBase + p->blockSize - dest);
- if (size == 0)
- return;
- p->result = p->stream->Read(p->stream, dest, &size);
- if (p->result != SZ_OK)
- return;
- if (size == 0)
- {
- p->streamEndWasReached = 1;
- return;
- }
- CRC32_update_buf( &p->crc, dest, size );
- p->streamPos += (UInt32)size;
- if (p->streamPos - p->pos > p->keepSizeAfter)
- return;
- }
-}
-
-void MatchFinder_MoveBlock(CMatchFinder *p)
-{
- memmove(p->bufferBase,
- p->buffer - p->keepSizeBefore,
- (size_t)(p->streamPos - p->pos + p->keepSizeBefore));
- p->buffer = p->bufferBase + p->keepSizeBefore;
-}
-
-int MatchFinder_NeedMove(CMatchFinder *p)
-{
- if (p->directInput)
- return 0;
- /* if (p->streamEndWasReached) return 0; */
- return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);
-}
-
-void MatchFinder_ReadIfRequired(CMatchFinder *p)
-{
- if (p->streamEndWasReached)
- return;
- if (p->keepSizeAfter >= p->streamPos - p->pos)
- MatchFinder_ReadBlock(p);
-}
-
-static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
-{
- if (MatchFinder_NeedMove(p))
- MatchFinder_MoveBlock(p);
- MatchFinder_ReadBlock(p);
-}
-
-static void MatchFinder_SetDefaultSettings(CMatchFinder *p)
-{
- p->cutValue = 32;
- p->btMode = 1;
- p->numHashBytes = 4;
- p->bigHash = 0;
-}
-
-
-void MatchFinder_Construct(CMatchFinder *p)
- {
- p->bufferBase = 0;
- p->directInput = 0;
- p->hash = 0;
- MatchFinder_SetDefaultSettings(p);
- p->crc = 0xFFFFFFFFU;
- }
-
-static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
-{
- alloc->Free(alloc, p->hash);
- p->hash = 0;
-}
-
-void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
-{
- MatchFinder_FreeThisClassMemory(p, alloc);
- LzInWindow_Free(p, alloc);
-}
-
-static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)
-{
- size_t sizeInBytes = (size_t)num * sizeof(CLzRef);
- if (sizeInBytes / sizeof(CLzRef) != num)
- return 0;
- return (CLzRef *)alloc->Alloc(alloc, sizeInBytes);
-}
-
-int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
- UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
- ISzAlloc *alloc)
-{
- UInt32 sizeReserv;
- if (historySize > kMaxHistorySize)
- {
- MatchFinder_Free(p, alloc);
- return 0;
- }
- sizeReserv = historySize >> 1;
- if (historySize > ((UInt32)2 << 30))
- sizeReserv = historySize >> 2;
- sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
-
- p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
- p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
- /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
- if (LzInWindow_Create(p, sizeReserv, alloc))
- {
- UInt32 newCyclicBufferSize = historySize + 1;
- UInt32 hs;
- p->matchMaxLen = matchMaxLen;
- {
- p->fixedHashSize = 0;
- if (p->numHashBytes == 2)
- hs = (1 << 16) - 1;
- else
- {
- hs = historySize - 1;
- hs |= (hs >> 1);
- hs |= (hs >> 2);
- hs |= (hs >> 4);
- hs |= (hs >> 8);
- hs >>= 1;
- hs |= 0xFFFF; /* don't change it! It's required for Deflate */
- if (hs > (1 << 24))
- {
- if (p->numHashBytes == 3)
- hs = (1 << 24) - 1;
- else
- hs >>= 1;
- }
- }
- p->hashMask = hs;
- hs++;
- if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;
- if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;
- if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;
- hs += p->fixedHashSize;
- }
-
- {
- UInt32 prevSize = p->hashSizeSum + p->numSons;
- UInt32 newSize;
- p->historySize = historySize;
- p->hashSizeSum = hs;
- p->cyclicBufferSize = newCyclicBufferSize;
- p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
- newSize = p->hashSizeSum + p->numSons;
- if (p->hash != 0 && prevSize == newSize)
- return 1;
- MatchFinder_FreeThisClassMemory(p, alloc);
- p->hash = AllocRefs(newSize, alloc);
- if (p->hash != 0)
- {
- p->son = p->hash + p->hashSizeSum;
- return 1;
- }
- }
- }
- MatchFinder_Free(p, alloc);
- return 0;
-}
-
-static void MatchFinder_SetLimits(CMatchFinder *p)
-{
- UInt32 limit = kMaxValForNormalize - p->pos;
- UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
- if (limit2 < limit)
- limit = limit2;
- limit2 = p->streamPos - p->pos;
- if (limit2 <= p->keepSizeAfter)
- {
- if (limit2 > 0)
- limit2 = 1;
- }
- else
- limit2 -= p->keepSizeAfter;
- if (limit2 < limit)
- limit = limit2;
- {
- UInt32 lenLimit = p->streamPos - p->pos;
- if (lenLimit > p->matchMaxLen)
- lenLimit = p->matchMaxLen;
- p->lenLimit = lenLimit;
- }
- p->posLimit = p->pos + limit;
-}
-
-void MatchFinder_Init(CMatchFinder *p)
-{
- UInt32 i;
- for (i = 0; i < p->hashSizeSum; i++)
- p->hash[i] = kEmptyHashValue;
- p->cyclicBufferPos = 0;
- p->buffer = p->bufferBase;
- p->pos = p->streamPos = p->cyclicBufferSize;
- p->result = SZ_OK;
- p->streamEndWasReached = 0;
- MatchFinder_ReadBlock(p);
- MatchFinder_SetLimits(p);
-}
-
-static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
-{
- return (p->pos - p->historySize - 1) & kNormalizeMask;
-}
-
-void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)
-{
- UInt32 i;
- for (i = 0; i < numItems; i++)
- {
- UInt32 value = items[i];
- if (value <= subValue)
- value = kEmptyHashValue;
- else
- value -= subValue;
- items[i] = value;
- }
-}
-
-static void MatchFinder_Normalize(CMatchFinder *p)
-{
- UInt32 subValue = MatchFinder_GetSubValue(p);
- MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
- MatchFinder_ReduceOffsets(p, subValue);
-}
-
-static void MatchFinder_CheckLimits(CMatchFinder *p)
-{
- if (p->pos == kMaxValForNormalize)
- MatchFinder_Normalize(p);
- if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
- MatchFinder_CheckAndMoveAndRead(p);
- if (p->cyclicBufferPos == p->cyclicBufferSize)
- p->cyclicBufferPos = 0;
- MatchFinder_SetLimits(p);
-}
-
-static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
- UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
- UInt32 *distances, UInt32 maxLen)
-{
- son[_cyclicBufferPos] = curMatch;
- for (;;)
- {
- UInt32 delta = pos - curMatch;
- if (cutValue-- == 0 || delta >= _cyclicBufferSize)
- return distances;
- {
- const Byte *pb = cur - delta;
- curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
- if (pb[maxLen] == cur[maxLen] && *pb == *cur)
- {
- UInt32 len = 0;
- while (++len != lenLimit)
- if (pb[len] != cur[len])
- break;
- if (maxLen < len)
- {
- *distances++ = maxLen = len;
- *distances++ = delta - 1;
- if (len == lenLimit)
- return distances;
- }
- }
- }
- }
-}
-
-UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
- UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
- UInt32 *distances, UInt32 maxLen)
-{
- CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
- CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
- UInt32 len0 = 0, len1 = 0;
- for (;;)
- {
- UInt32 delta = pos - curMatch;
- if (cutValue-- == 0 || delta >= _cyclicBufferSize)
- {
- *ptr0 = *ptr1 = kEmptyHashValue;
- return distances;
- }
- {
- CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
- const Byte *pb = cur - delta;
- UInt32 len = (len0 < len1 ? len0 : len1);
- if (pb[len] == cur[len])
- {
- if (++len != lenLimit && pb[len] == cur[len])
- while (++len != lenLimit)
- if (pb[len] != cur[len])
- break;
- if (maxLen < len)
- {
- *distances++ = maxLen = len;
- *distances++ = delta - 1;
- if (len == lenLimit)
- {
- *ptr1 = pair[0];
- *ptr0 = pair[1];
- return distances;
- }
- }
- }
- if (pb[len] < cur[len])
- {
- *ptr1 = curMatch;
- ptr1 = pair + 1;
- curMatch = *ptr1;
- len1 = len;
- }
- else
- {
- *ptr0 = curMatch;
- ptr0 = pair;
- curMatch = *ptr0;
- len0 = len;
- }
- }
- }
-}
-
-static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
- UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
-{
- CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
- CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
- UInt32 len0 = 0, len1 = 0;
- for (;;)
- {
- UInt32 delta = pos - curMatch;
- if (cutValue-- == 0 || delta >= _cyclicBufferSize)
- {
- *ptr0 = *ptr1 = kEmptyHashValue;
- return;
- }
- {
- CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
- const Byte *pb = cur - delta;
- UInt32 len = (len0 < len1 ? len0 : len1);
- if (pb[len] == cur[len])
- {
- while (++len != lenLimit)
- if (pb[len] != cur[len])
- break;
- {
- if (len == lenLimit)
- {
- *ptr1 = pair[0];
- *ptr0 = pair[1];
- return;
- }
- }
- }
- if (pb[len] < cur[len])
- {
- *ptr1 = curMatch;
- ptr1 = pair + 1;
- curMatch = *ptr1;
- len1 = len;
- }
- else
- {
- *ptr0 = curMatch;
- ptr0 = pair;
- curMatch = *ptr0;
- len0 = len;
- }
- }
- }
-}
-
-#define MOVE_POS \
- ++p->cyclicBufferPos; \
- p->buffer++; \
- if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
-
-#define MOVE_POS_RET MOVE_POS return offset;
-
-static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
-
-#define GET_MATCHES_HEADER2(minLen, ret_op) \
- UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
- lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
- cur = p->buffer;
-
-#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
-#define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue)
-
-#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
-
-#define GET_MATCHES_FOOTER(offset, maxLen) \
- offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
- distances + offset, maxLen) - distances); MOVE_POS_RET;
-
-#define SKIP_FOOTER \
- SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
-
-static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 offset;
- GET_MATCHES_HEADER(2)
- HASH2_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- offset = 0;
- GET_MATCHES_FOOTER(offset, 1)
-}
-
-UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 offset;
- GET_MATCHES_HEADER(3)
- HASH_ZIP_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- offset = 0;
- GET_MATCHES_FOOTER(offset, 2)
-}
-
-static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 hash2Value, delta2, maxLen, offset;
- GET_MATCHES_HEADER(3)
-
- HASH3_CALC;
-
- delta2 = p->pos - p->hash[hash2Value];
- curMatch = p->hash[kFix3HashSize + hashValue];
-
- p->hash[hash2Value] =
- p->hash[kFix3HashSize + hashValue] = p->pos;
-
-
- maxLen = 2;
- offset = 0;
- if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
- {
- for (; maxLen != lenLimit; maxLen++)
- if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
- break;
- distances[0] = maxLen;
- distances[1] = delta2 - 1;
- offset = 2;
- if (maxLen == lenLimit)
- {
- SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
- MOVE_POS_RET;
- }
- }
- GET_MATCHES_FOOTER(offset, maxLen)
-}
-
-static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
- GET_MATCHES_HEADER(4)
-
- HASH4_CALC;
-
- delta2 = p->pos - p->hash[ hash2Value];
- delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
- curMatch = p->hash[kFix4HashSize + hashValue];
-
- p->hash[ hash2Value] =
- p->hash[kFix3HashSize + hash3Value] =
- p->hash[kFix4HashSize + hashValue] = p->pos;
-
- maxLen = 1;
- offset = 0;
- if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
- {
- distances[0] = maxLen = 2;
- distances[1] = delta2 - 1;
- offset = 2;
- }
- if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
- {
- maxLen = 3;
- distances[offset + 1] = delta3 - 1;
- offset += 2;
- delta2 = delta3;
- }
- if (offset != 0)
- {
- for (; maxLen != lenLimit; maxLen++)
- if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
- break;
- distances[offset - 2] = maxLen;
- if (maxLen == lenLimit)
- {
- SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
- MOVE_POS_RET;
- }
- }
- if (maxLen < 3)
- maxLen = 3;
- GET_MATCHES_FOOTER(offset, maxLen)
-}
-
-static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
- GET_MATCHES_HEADER(4)
-
- HASH4_CALC;
-
- delta2 = p->pos - p->hash[ hash2Value];
- delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
- curMatch = p->hash[kFix4HashSize + hashValue];
-
- p->hash[ hash2Value] =
- p->hash[kFix3HashSize + hash3Value] =
- p->hash[kFix4HashSize + hashValue] = p->pos;
-
- maxLen = 1;
- offset = 0;
- if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
- {
- distances[0] = maxLen = 2;
- distances[1] = delta2 - 1;
- offset = 2;
- }
- if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
- {
- maxLen = 3;
- distances[offset + 1] = delta3 - 1;
- offset += 2;
- delta2 = delta3;
- }
- if (offset != 0)
- {
- for (; maxLen != lenLimit; maxLen++)
- if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
- break;
- distances[offset - 2] = maxLen;
- if (maxLen == lenLimit)
- {
- p->son[p->cyclicBufferPos] = curMatch;
- MOVE_POS_RET;
- }
- }
- if (maxLen < 3)
- maxLen = 3;
- offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
- distances + offset, maxLen) - (distances));
- MOVE_POS_RET
-}
-
-UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
-{
- UInt32 offset;
- GET_MATCHES_HEADER(3)
- HASH_ZIP_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
- distances, 2) - (distances));
- MOVE_POS_RET
-}
-
-static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- SKIP_HEADER(2)
- HASH2_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- SKIP_FOOTER
- }
- while (--num != 0);
-}
-
-void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- SKIP_HEADER(3)
- HASH_ZIP_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- SKIP_FOOTER
- }
- while (--num != 0);
-}
-
-static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- UInt32 hash2Value;
- SKIP_HEADER(3)
- HASH3_CALC;
- curMatch = p->hash[kFix3HashSize + hashValue];
- p->hash[hash2Value] =
- p->hash[kFix3HashSize + hashValue] = p->pos;
- SKIP_FOOTER
- }
- while (--num != 0);
-}
-
-static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- UInt32 hash2Value, hash3Value;
- SKIP_HEADER(4)
- HASH4_CALC;
- curMatch = p->hash[kFix4HashSize + hashValue];
- p->hash[ hash2Value] =
- p->hash[kFix3HashSize + hash3Value] = p->pos;
- p->hash[kFix4HashSize + hashValue] = p->pos;
- SKIP_FOOTER
- }
- while (--num != 0);
-}
-
-static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- UInt32 hash2Value, hash3Value;
- SKIP_HEADER(4)
- HASH4_CALC;
- curMatch = p->hash[kFix4HashSize + hashValue];
- p->hash[ hash2Value] =
- p->hash[kFix3HashSize + hash3Value] =
- p->hash[kFix4HashSize + hashValue] = p->pos;
- p->son[p->cyclicBufferPos] = curMatch;
- MOVE_POS
- }
- while (--num != 0);
-}
-
-void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
-{
- do
- {
- SKIP_HEADER(3)
- HASH_ZIP_CALC;
- curMatch = p->hash[hashValue];
- p->hash[hashValue] = p->pos;
- p->son[p->cyclicBufferPos] = curMatch;
- MOVE_POS
- }
- while (--num != 0);
-}
-
-void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
-{
- vTable->Init = (Mf_Init_Func)MatchFinder_Init;
- vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
- vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
- vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
- if (!p->btMode)
- {
- vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
- vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
- }
- else if (p->numHashBytes == 2)
- {
- vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
- vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
- }
- else if (p->numHashBytes == 3)
- {
- vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
- vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
- }
- else
- {
- vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
- vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
- }
-}
+/* LzFind.c -- Match finder for LZ algorithms +2009-04-22 : Igor Pavlov : Public domain */ + +#define _FILE_OFFSET_BITS 64 + +#include <errno.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "clzip.h" +#include "LzFind.h" + +#define kHash2Size (1 << 10) +#define kHash3Size (1 << 16) +#define kHash4Size (1 << 20) + +#define kFix3HashSize (kHash2Size) +#define kFix4HashSize (kHash2Size + kHash3Size) + +#define HASH2_CALC hashValue = cur[0] | ((uint32_t)cur[1] << 8); + +#define HASH3_CALC { \ + uint32_t temp = crc32[cur[0]] ^ cur[1]; \ + hash2Value = temp & (kHash2Size - 1); \ + hashValue = (temp ^ ((uint32_t)cur[2] << 8)) & p->hashMask; } + +#define HASH4_CALC { \ + uint32_t temp = crc32[cur[0]] ^ cur[1]; \ + hash2Value = temp & (kHash2Size - 1); \ + hash3Value = (temp ^ ((uint32_t)cur[2] << 8)) & (kHash3Size - 1); \ + hashValue = (temp ^ ((uint32_t)cur[2] << 8) ^ (crc32[cur[3]] << 5)) & p->hashMask; } + +#define kEmptyHashValue 0 +#define kMaxValForNormalize ((uint32_t)0xFFFFFFFF) +#define kNormalizeStepMin (1 << 10) /* it must be power of 2 */ +#define kNormalizeMask (~(kNormalizeStepMin - 1)) + +#define kStartMaxLen 3 + + +static void Mf_ReadBlock(CMatchFinder *p) +{ + if (p->streamEndWasReached || p->result != SZ_OK) + return; + for (;;) + { + uint8_t * const dest = p->buffer + (p->streamPos - p->pos); + const int size = (p->bufferBase + p->blockSize - dest); + int rd; + if (size == 0) + return; + rd = readblock( p->infd, dest, size ); + if (rd != size && errno) + { p->result = SZ_ERROR_READ; return; } + if (rd == 0) + { + p->streamEndWasReached = true; + return; + } + CRC32_update_buf( &p->crc, dest, rd ); + p->streamPos += rd; + if (p->streamPos - p->pos > p->keepSizeAfter) + return; + } +} + + +static void Mf_CheckAndMoveAndRead(CMatchFinder *p) +{ + if ((uint32_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter) + { + memmove(p->bufferBase, + p->buffer - p->keepSizeBefore, + p->streamPos - p->pos + p->keepSizeBefore); + p->buffer = p->bufferBase + p->keepSizeBefore; + } + Mf_ReadBlock(p); +} + + +void Mf_Free(CMatchFinder *p) +{ + free(p->hash); + p->hash = 0; + free(p->bufferBase); + p->bufferBase = 0; +} + +static CLzRef* AllocRefs(uint32_t num) +{ + uint32_t sizeInBytes = num * sizeof(CLzRef); + if (sizeInBytes / sizeof(CLzRef) != num) + return 0; + return (CLzRef *)malloc(sizeInBytes); +} + +static void Mf_SetLimits(CMatchFinder *p) +{ + uint32_t limit = kMaxValForNormalize - p->pos; + uint32_t limit2 = p->cyclicBufferSize - p->cyclicBufferPos; + if (limit2 < limit) + limit = limit2; + limit2 = p->streamPos - p->pos; + if (limit2 <= p->keepSizeAfter) + { + if (limit2 > 0) + limit2 = 1; + } + else + limit2 -= p->keepSizeAfter; + if (limit2 < limit) + limit = limit2; + { + uint32_t lenLimit = p->streamPos - p->pos; + if (lenLimit > p->matchMaxLen) + lenLimit = p->matchMaxLen; + p->lenLimit = lenLimit; + } + p->posLimit = p->pos + limit; +} + + +int Mf_Init(CMatchFinder *p, const int ifd, const int mc, uint32_t historySize, + uint32_t keepAddBufferBefore, uint32_t matchMaxLen, uint32_t keepAddBufferAfter) +{ + const uint32_t sizeReserv = ( historySize >> 1 ) + + (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19); + + p->hash = 0; + p->cutValue = mc; + p->infd = ifd; + p->btMode = true; + p->numHashBytes = 4; + p->crc = 0xFFFFFFFFU; + p->keepSizeBefore = historySize + keepAddBufferBefore + 1; + p->keepSizeAfter = matchMaxLen + keepAddBufferAfter; + /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */ + /* keepSizeBefore + keepSizeAfter + sizeReserv must be < 4G) */ + p->blockSize = p->keepSizeBefore + p->keepSizeAfter + sizeReserv; + p->buffer = p->bufferBase = (uint8_t *)malloc(p->blockSize); + if( p->bufferBase ) + { + uint32_t newCyclicBufferSize = historySize + 1; + uint32_t hs; + p->matchMaxLen = matchMaxLen; + { + if (p->numHashBytes == 2) + hs = (1 << 16) - 1; + else + { + hs = historySize - 1; + hs |= (hs >> 1); + hs |= (hs >> 2); + hs |= (hs >> 4); + hs |= (hs >> 8); + hs >>= 1; + hs |= 0xFFFF; /* don't change it! It's required for Deflate */ + if (hs > (1 << 24)) + { + if (p->numHashBytes == 3) + hs = (1 << 24) - 1; + else + hs >>= 1; + } + } + p->hashMask = hs; + hs++; + if (p->numHashBytes > 2) hs += kHash2Size; + if (p->numHashBytes > 3) hs += kHash3Size; + if (p->numHashBytes > 4) hs += kHash4Size; + } + + { + uint32_t newSize; + p->historySize = historySize; + p->hashSizeSum = hs; + p->cyclicBufferSize = newCyclicBufferSize; + p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize); + newSize = p->hashSizeSum + p->numSons; + p->hash = AllocRefs(newSize); + if (p->hash != 0) + { + uint32_t i; + p->son = p->hash + p->hashSizeSum; + for (i = 0; i < p->hashSizeSum; i++) + p->hash[i] = kEmptyHashValue; + p->cyclicBufferPos = 0; + p->pos = p->streamPos = p->cyclicBufferSize; + p->result = SZ_OK; + p->streamEndWasReached = false; + Mf_ReadBlock(p); + Mf_SetLimits(p); + return 1; + } + } + } + Mf_Free(p); + return 0; +} + +static void Mf_Normalize3(uint32_t subValue, CLzRef *items, uint32_t numItems) +{ + uint32_t i; + for (i = 0; i < numItems; i++) + { + uint32_t value = items[i]; + if (value <= subValue) + value = kEmptyHashValue; + else + value -= subValue; + items[i] = value; + } +} + +static void Mf_Normalize(CMatchFinder *p) +{ + uint32_t subValue = (p->pos - p->historySize - 1) & kNormalizeMask; + Mf_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons); + p->posLimit -= subValue; + p->pos -= subValue; + p->streamPos -= subValue; +} + +static void Mf_CheckLimits(CMatchFinder *p) +{ + if (p->pos == kMaxValForNormalize) + Mf_Normalize(p); + if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos) + Mf_CheckAndMoveAndRead(p); + if (p->cyclicBufferPos == p->cyclicBufferSize) + p->cyclicBufferPos = 0; + Mf_SetLimits(p); +} + +static uint32_t * Hc_GetMatchesSpec(uint32_t lenLimit, uint32_t curMatch, uint32_t pos, const uint8_t *cur, CLzRef *son, + uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue, + uint32_t *distances, uint32_t maxLen) +{ + son[_cyclicBufferPos] = curMatch; + for (;;) + { + uint32_t delta = pos - curMatch; + if (cutValue-- == 0 || delta >= _cyclicBufferSize) + return distances; + { + const uint8_t *pb = cur - delta; + curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)]; + if (pb[maxLen] == cur[maxLen] && *pb == *cur) + { + uint32_t len = 0; + while (++len != lenLimit) + if (pb[len] != cur[len]) + break; + if (maxLen < len) + { + *distances++ = maxLen = len; + *distances++ = delta - 1; + if (len == lenLimit) + return distances; + } + } + } + } +} + + +static uint32_t * GetMatchesSpec1( uint32_t lenLimit, uint32_t curMatch, + uint32_t pos, const uint8_t *cur, CLzRef *son, + uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue, + uint32_t *distances, uint32_t maxLen ) +{ + CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; + CLzRef *ptr1 = son + (_cyclicBufferPos << 1); + uint32_t len0 = 0, len1 = 0; + for (;;) + { + uint32_t delta = pos - curMatch; + if (cutValue-- == 0 || delta >= _cyclicBufferSize) + { + *ptr0 = *ptr1 = kEmptyHashValue; + return distances; + } + { + CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); + const uint8_t *pb = cur - delta; + uint32_t len = (len0 < len1 ? len0 : len1); + if (pb[len] == cur[len]) + { + if (++len != lenLimit && pb[len] == cur[len]) + while (++len != lenLimit) + if (pb[len] != cur[len]) + break; + if (maxLen < len) + { + *distances++ = maxLen = len; + *distances++ = delta - 1; + if (len == lenLimit) + { + *ptr1 = pair[0]; + *ptr0 = pair[1]; + return distances; + } + } + } + if (pb[len] < cur[len]) + { + *ptr1 = curMatch; + ptr1 = pair + 1; + curMatch = *ptr1; + len1 = len; + } + else + { + *ptr0 = curMatch; + ptr0 = pair; + curMatch = *ptr0; + len0 = len; + } + } + } +} + +static void SkipMatchesSpec(uint32_t lenLimit, uint32_t curMatch, uint32_t pos, const uint8_t *cur, CLzRef *son, + uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue) +{ + CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1; + CLzRef *ptr1 = son + (_cyclicBufferPos << 1); + uint32_t len0 = 0, len1 = 0; + for (;;) + { + uint32_t delta = pos - curMatch; + if (cutValue-- == 0 || delta >= _cyclicBufferSize) + { + *ptr0 = *ptr1 = kEmptyHashValue; + return; + } + { + CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1); + const uint8_t *pb = cur - delta; + uint32_t len = (len0 < len1 ? len0 : len1); + if (pb[len] == cur[len]) + { + while (++len != lenLimit) + if (pb[len] != cur[len]) + break; + { + if (len == lenLimit) + { + *ptr1 = pair[0]; + *ptr0 = pair[1]; + return; + } + } + } + if (pb[len] < cur[len]) + { + *ptr1 = curMatch; + ptr1 = pair + 1; + curMatch = *ptr1; + len1 = len; + } + else + { + *ptr0 = curMatch; + ptr0 = pair; + curMatch = *ptr0; + len0 = len; + } + } + } +} + +#define MOVE_POS \ + ++p->cyclicBufferPos; \ + p->buffer++; \ + if (++p->pos == p->posLimit) Mf_CheckLimits(p); + +#define MOVE_POS_RET MOVE_POS return offset; + +static void Mf_MovePos(CMatchFinder *p) { MOVE_POS; } + +#define GET_MATCHES_HEADER2(minLen, ret_op) \ + uint32_t lenLimit; uint32_t hashValue; const uint8_t *cur; uint32_t curMatch; \ + lenLimit = p->lenLimit; { if (lenLimit < minLen) { Mf_MovePos(p); ret_op; }} \ + cur = p->buffer; + +#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0) +#define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue) + +#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue + +#define GET_MATCHES_FOOTER(offset, maxLen) \ + offset = (uint32_t)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \ + distances + offset, maxLen) - distances); MOVE_POS_RET; + +#define SKIP_FOOTER \ + SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS; + +static uint32_t Bt2_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances) +{ + uint32_t offset; + GET_MATCHES_HEADER(2) + HASH2_CALC; + curMatch = p->hash[hashValue]; + p->hash[hashValue] = p->pos; + offset = 0; + GET_MATCHES_FOOTER(offset, 1) +} + +static uint32_t Bt3_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances) +{ + uint32_t hash2Value, delta2, maxLen, offset; + GET_MATCHES_HEADER(3) + + HASH3_CALC; + + delta2 = p->pos - p->hash[hash2Value]; + curMatch = p->hash[kFix3HashSize + hashValue]; + + p->hash[hash2Value] = + p->hash[kFix3HashSize + hashValue] = p->pos; + + + maxLen = 2; + offset = 0; + if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) + { + for (; maxLen != lenLimit; maxLen++) + if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) + break; + distances[0] = maxLen; + distances[1] = delta2 - 1; + offset = 2; + if (maxLen == lenLimit) + { + SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); + MOVE_POS_RET; + } + } + GET_MATCHES_FOOTER(offset, maxLen) +} + +static uint32_t Bt4_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances) +{ + uint32_t hash2Value, hash3Value, delta2, delta3, maxLen, offset; + GET_MATCHES_HEADER(4) + + HASH4_CALC; + + delta2 = p->pos - p->hash[ hash2Value]; + delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; + curMatch = p->hash[kFix4HashSize + hashValue]; + + p->hash[ hash2Value] = + p->hash[kFix3HashSize + hash3Value] = + p->hash[kFix4HashSize + hashValue] = p->pos; + + maxLen = 1; + offset = 0; + if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) + { + distances[0] = maxLen = 2; + distances[1] = delta2 - 1; + offset = 2; + } + if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) + { + maxLen = 3; + distances[offset + 1] = delta3 - 1; + offset += 2; + delta2 = delta3; + } + if (offset != 0) + { + for (; maxLen != lenLimit; maxLen++) + if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) + break; + distances[offset - 2] = maxLen; + if (maxLen == lenLimit) + { + SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); + MOVE_POS_RET; + } + } + if (maxLen < 3) + maxLen = 3; + GET_MATCHES_FOOTER(offset, maxLen) +} + +static uint32_t Hc4_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances) +{ + uint32_t hash2Value, hash3Value, delta2, delta3, maxLen, offset; + GET_MATCHES_HEADER(4) + + HASH4_CALC; + + delta2 = p->pos - p->hash[ hash2Value]; + delta3 = p->pos - p->hash[kFix3HashSize + hash3Value]; + curMatch = p->hash[kFix4HashSize + hashValue]; + + p->hash[ hash2Value] = + p->hash[kFix3HashSize + hash3Value] = + p->hash[kFix4HashSize + hashValue] = p->pos; + + maxLen = 1; + offset = 0; + if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur) + { + distances[0] = maxLen = 2; + distances[1] = delta2 - 1; + offset = 2; + } + if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur) + { + maxLen = 3; + distances[offset + 1] = delta3 - 1; + offset += 2; + delta2 = delta3; + } + if (offset != 0) + { + for (; maxLen != lenLimit; maxLen++) + if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen]) + break; + distances[offset - 2] = maxLen; + if (maxLen == lenLimit) + { + p->son[p->cyclicBufferPos] = curMatch; + MOVE_POS_RET; + } + } + if (maxLen < 3) + maxLen = 3; + offset = (uint32_t)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p), + distances + offset, maxLen) - (distances)); + MOVE_POS_RET +} + + +static void Bt2_MatchFinder_Skip(CMatchFinder *p, uint32_t num) +{ + do + { + SKIP_HEADER(2) + HASH2_CALC; + curMatch = p->hash[hashValue]; + p->hash[hashValue] = p->pos; + SKIP_FOOTER + } + while (--num != 0); +} + + +static void Bt3_MatchFinder_Skip(CMatchFinder *p, uint32_t num) +{ + do + { + uint32_t hash2Value; + SKIP_HEADER(3) + HASH3_CALC; + curMatch = p->hash[kFix3HashSize + hashValue]; + p->hash[hash2Value] = + p->hash[kFix3HashSize + hashValue] = p->pos; + SKIP_FOOTER + } + while (--num != 0); +} + +static void Bt4_MatchFinder_Skip(CMatchFinder *p, uint32_t num) +{ + do + { + uint32_t hash2Value, hash3Value; + SKIP_HEADER(4) + HASH4_CALC; + curMatch = p->hash[kFix4HashSize + hashValue]; + p->hash[ hash2Value] = + p->hash[kFix3HashSize + hash3Value] = p->pos; + p->hash[kFix4HashSize + hashValue] = p->pos; + SKIP_FOOTER + } + while (--num != 0); +} + +static void Hc4_MatchFinder_Skip(CMatchFinder *p, uint32_t num) +{ + do + { + uint32_t hash2Value, hash3Value; + SKIP_HEADER(4) + HASH4_CALC; + curMatch = p->hash[kFix4HashSize + hashValue]; + p->hash[ hash2Value] = + p->hash[kFix3HashSize + hash3Value] = + p->hash[kFix4HashSize + hashValue] = p->pos; + p->son[p->cyclicBufferPos] = curMatch; + MOVE_POS + } + while (--num != 0); +} + + +void Mf_CreateVTable(CMatchFinder *p, IMatchFinder *vTable) +{ + if (!p->btMode) + { + vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches; + vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip; + } + else if (p->numHashBytes == 2) + { + vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches; + vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip; + } + else if (p->numHashBytes == 3) + { + vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches; + vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip; + } + else + { + vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches; + vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip; + } +} |