nuclear@14: /* LzFind.c -- Match finder for LZ algorithms
nuclear@14: 2008-10-04 : Igor Pavlov : Public domain */
nuclear@14: 
nuclear@14: #include <string.h>
nuclear@14: 
nuclear@14: #include "LzFind.h"
nuclear@14: #include "LzHash.h"
nuclear@14: 
nuclear@14: #define kEmptyHashValue 0
nuclear@14: #define kMaxValForNormalize ((UInt32)0xFFFFFFFF)
nuclear@14: #define kNormalizeStepMin (1 << 10) /* it must be power of 2 */
nuclear@14: #define kNormalizeMask (~(kNormalizeStepMin - 1))
nuclear@14: #define kMaxHistorySize ((UInt32)3 << 30)
nuclear@14: 
nuclear@14: #define kStartMaxLen 3
nuclear@14: 
nuclear@14: static void LzInWindow_Free(CMatchFinder *p, ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   if (!p->directInput)
nuclear@14:   {
nuclear@14:     alloc->Free(alloc, p->bufferBase);
nuclear@14:     p->bufferBase = 0;
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: /* keepSizeBefore + keepSizeAfter + keepSizeReserv must be < 4G) */
nuclear@14: 
nuclear@14: static int LzInWindow_Create(CMatchFinder *p, UInt32 keepSizeReserv, ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   UInt32 blockSize = p->keepSizeBefore + p->keepSizeAfter + keepSizeReserv;
nuclear@14:   if (p->directInput)
nuclear@14:   {
nuclear@14:     p->blockSize = blockSize;
nuclear@14:     return 1;
nuclear@14:   }
nuclear@14:   if (p->bufferBase == 0 || p->blockSize != blockSize)
nuclear@14:   {
nuclear@14:     LzInWindow_Free(p, alloc);
nuclear@14:     p->blockSize = blockSize;
nuclear@14:     p->bufferBase = (Byte *)alloc->Alloc(alloc, (size_t)blockSize);
nuclear@14:   }
nuclear@14:   return (p->bufferBase != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p) { return p->buffer; }
nuclear@14: Byte MatchFinder_GetIndexByte(CMatchFinder *p, Int32 index) { return p->buffer[index]; }
nuclear@14: 
nuclear@14: UInt32 MatchFinder_GetNumAvailableBytes(CMatchFinder *p) { return p->streamPos - p->pos; }
nuclear@14: 
nuclear@14: void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue)
nuclear@14: {
nuclear@14:   p->posLimit -= subValue;
nuclear@14:   p->pos -= subValue;
nuclear@14:   p->streamPos -= subValue;
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_ReadBlock(CMatchFinder *p)
nuclear@14: {
nuclear@14:   if (p->streamEndWasReached || p->result != SZ_OK)
nuclear@14:     return;
nuclear@14:   for (;;)
nuclear@14:   {
nuclear@14:     Byte *dest = p->buffer + (p->streamPos - p->pos);
nuclear@14:     size_t size = (p->bufferBase + p->blockSize - dest);
nuclear@14:     if (size == 0)
nuclear@14:       return;
nuclear@14:     p->result = p->stream->Read(p->stream, dest, &size);
nuclear@14:     if (p->result != SZ_OK)
nuclear@14:       return;
nuclear@14:     if (size == 0)
nuclear@14:     {
nuclear@14:       p->streamEndWasReached = 1;
nuclear@14:       return;
nuclear@14:     }
nuclear@14:     p->streamPos += (UInt32)size;
nuclear@14:     if (p->streamPos - p->pos > p->keepSizeAfter)
nuclear@14:       return;
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_MoveBlock(CMatchFinder *p)
nuclear@14: {
nuclear@14:   memmove(p->bufferBase,
nuclear@14:     p->buffer - p->keepSizeBefore,
nuclear@14:     (size_t)(p->streamPos - p->pos + p->keepSizeBefore));
nuclear@14:   p->buffer = p->bufferBase + p->keepSizeBefore;
nuclear@14: }
nuclear@14: 
nuclear@14: int MatchFinder_NeedMove(CMatchFinder *p)
nuclear@14: {
nuclear@14:   /* if (p->streamEndWasReached) return 0; */
nuclear@14:   return ((size_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter);
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_ReadIfRequired(CMatchFinder *p)
nuclear@14: {
nuclear@14:   if (p->streamEndWasReached)
nuclear@14:     return;
nuclear@14:   if (p->keepSizeAfter >= p->streamPos - p->pos)
nuclear@14:     MatchFinder_ReadBlock(p);
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_CheckAndMoveAndRead(CMatchFinder *p)
nuclear@14: {
nuclear@14:   if (MatchFinder_NeedMove(p))
nuclear@14:     MatchFinder_MoveBlock(p);
nuclear@14:   MatchFinder_ReadBlock(p);
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_SetDefaultSettings(CMatchFinder *p)
nuclear@14: {
nuclear@14:   p->cutValue = 32;
nuclear@14:   p->btMode = 1;
nuclear@14:   p->numHashBytes = 4;
nuclear@14:   /* p->skipModeBits = 0; */
nuclear@14:   p->directInput = 0;
nuclear@14:   p->bigHash = 0;
nuclear@14: }
nuclear@14: 
nuclear@14: #define kCrcPoly 0xEDB88320
nuclear@14: 
nuclear@14: void MatchFinder_Construct(CMatchFinder *p)
nuclear@14: {
nuclear@14:   UInt32 i;
nuclear@14:   p->bufferBase = 0;
nuclear@14:   p->directInput = 0;
nuclear@14:   p->hash = 0;
nuclear@14:   MatchFinder_SetDefaultSettings(p);
nuclear@14: 
nuclear@14:   for (i = 0; i < 256; i++)
nuclear@14:   {
nuclear@14:     UInt32 r = i;
nuclear@14:     int j;
nuclear@14:     for (j = 0; j < 8; j++)
nuclear@14:       r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
nuclear@14:     p->crc[i] = r;
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_FreeThisClassMemory(CMatchFinder *p, ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   alloc->Free(alloc, p->hash);
nuclear@14:   p->hash = 0;
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   MatchFinder_FreeThisClassMemory(p, alloc);
nuclear@14:   LzInWindow_Free(p, alloc);
nuclear@14: }
nuclear@14: 
nuclear@14: static CLzRef* AllocRefs(UInt32 num, ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   size_t sizeInBytes = (size_t)num * sizeof(CLzRef);
nuclear@14:   if (sizeInBytes / sizeof(CLzRef) != num)
nuclear@14:     return 0;
nuclear@14:   return (CLzRef *)alloc->Alloc(alloc, sizeInBytes);
nuclear@14: }
nuclear@14: 
nuclear@14: int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
nuclear@14:     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
nuclear@14:     ISzAlloc *alloc)
nuclear@14: {
nuclear@14:   UInt32 sizeReserv;
nuclear@14:   if (historySize > kMaxHistorySize)
nuclear@14:   {
nuclear@14:     MatchFinder_Free(p, alloc);
nuclear@14:     return 0;
nuclear@14:   }
nuclear@14:   sizeReserv = historySize >> 1;
nuclear@14:   if (historySize > ((UInt32)2 << 30))
nuclear@14:     sizeReserv = historySize >> 2;
nuclear@14:   sizeReserv += (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
nuclear@14: 
nuclear@14:   p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
nuclear@14:   p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
nuclear@14:   /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
nuclear@14:   if (LzInWindow_Create(p, sizeReserv, alloc))
nuclear@14:   {
nuclear@14:     UInt32 newCyclicBufferSize = (historySize /* >> p->skipModeBits */) + 1;
nuclear@14:     UInt32 hs;
nuclear@14:     p->matchMaxLen = matchMaxLen;
nuclear@14:     {
nuclear@14:       p->fixedHashSize = 0;
nuclear@14:       if (p->numHashBytes == 2)
nuclear@14:         hs = (1 << 16) - 1;
nuclear@14:       else
nuclear@14:       {
nuclear@14:         hs = historySize - 1;
nuclear@14:         hs |= (hs >> 1);
nuclear@14:         hs |= (hs >> 2);
nuclear@14:         hs |= (hs >> 4);
nuclear@14:         hs |= (hs >> 8);
nuclear@14:         hs >>= 1;
nuclear@14:         /* hs >>= p->skipModeBits; */
nuclear@14:         hs |= 0xFFFF; /* don't change it! It's required for Deflate */
nuclear@14:         if (hs > (1 << 24))
nuclear@14:         {
nuclear@14:           if (p->numHashBytes == 3)
nuclear@14:             hs = (1 << 24) - 1;
nuclear@14:           else
nuclear@14:             hs >>= 1;
nuclear@14:         }
nuclear@14:       }
nuclear@14:       p->hashMask = hs;
nuclear@14:       hs++;
nuclear@14:       if (p->numHashBytes > 2) p->fixedHashSize += kHash2Size;
nuclear@14:       if (p->numHashBytes > 3) p->fixedHashSize += kHash3Size;
nuclear@14:       if (p->numHashBytes > 4) p->fixedHashSize += kHash4Size;
nuclear@14:       hs += p->fixedHashSize;
nuclear@14:     }
nuclear@14: 
nuclear@14:     {
nuclear@14:       UInt32 prevSize = p->hashSizeSum + p->numSons;
nuclear@14:       UInt32 newSize;
nuclear@14:       p->historySize = historySize;
nuclear@14:       p->hashSizeSum = hs;
nuclear@14:       p->cyclicBufferSize = newCyclicBufferSize;
nuclear@14:       p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
nuclear@14:       newSize = p->hashSizeSum + p->numSons;
nuclear@14:       if (p->hash != 0 && prevSize == newSize)
nuclear@14:         return 1;
nuclear@14:       MatchFinder_FreeThisClassMemory(p, alloc);
nuclear@14:       p->hash = AllocRefs(newSize, alloc);
nuclear@14:       if (p->hash != 0)
nuclear@14:       {
nuclear@14:         p->son = p->hash + p->hashSizeSum;
nuclear@14:         return 1;
nuclear@14:       }
nuclear@14:     }
nuclear@14:   }
nuclear@14:   MatchFinder_Free(p, alloc);
nuclear@14:   return 0;
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_SetLimits(CMatchFinder *p)
nuclear@14: {
nuclear@14:   UInt32 limit = kMaxValForNormalize - p->pos;
nuclear@14:   UInt32 limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
nuclear@14:   if (limit2 < limit)
nuclear@14:     limit = limit2;
nuclear@14:   limit2 = p->streamPos - p->pos;
nuclear@14:   if (limit2 <= p->keepSizeAfter)
nuclear@14:   {
nuclear@14:     if (limit2 > 0)
nuclear@14:       limit2 = 1;
nuclear@14:   }
nuclear@14:   else
nuclear@14:     limit2 -= p->keepSizeAfter;
nuclear@14:   if (limit2 < limit)
nuclear@14:     limit = limit2;
nuclear@14:   {
nuclear@14:     UInt32 lenLimit = p->streamPos - p->pos;
nuclear@14:     if (lenLimit > p->matchMaxLen)
nuclear@14:       lenLimit = p->matchMaxLen;
nuclear@14:     p->lenLimit = lenLimit;
nuclear@14:   }
nuclear@14:   p->posLimit = p->pos + limit;
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_Init(CMatchFinder *p)
nuclear@14: {
nuclear@14:   UInt32 i;
nuclear@14:   for (i = 0; i < p->hashSizeSum; i++)
nuclear@14:     p->hash[i] = kEmptyHashValue;
nuclear@14:   p->cyclicBufferPos = 0;
nuclear@14:   p->buffer = p->bufferBase;
nuclear@14:   p->pos = p->streamPos = p->cyclicBufferSize;
nuclear@14:   p->result = SZ_OK;
nuclear@14:   p->streamEndWasReached = 0;
nuclear@14:   MatchFinder_ReadBlock(p);
nuclear@14:   MatchFinder_SetLimits(p);
nuclear@14: }
nuclear@14: 
nuclear@14: static UInt32 MatchFinder_GetSubValue(CMatchFinder *p)
nuclear@14: {
nuclear@14:   return (p->pos - p->historySize - 1) & kNormalizeMask;
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems)
nuclear@14: {
nuclear@14:   UInt32 i;
nuclear@14:   for (i = 0; i < numItems; i++)
nuclear@14:   {
nuclear@14:     UInt32 value = items[i];
nuclear@14:     if (value <= subValue)
nuclear@14:       value = kEmptyHashValue;
nuclear@14:     else
nuclear@14:       value -= subValue;
nuclear@14:     items[i] = value;
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_Normalize(CMatchFinder *p)
nuclear@14: {
nuclear@14:   UInt32 subValue = MatchFinder_GetSubValue(p);
nuclear@14:   MatchFinder_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
nuclear@14:   MatchFinder_ReduceOffsets(p, subValue);
nuclear@14: }
nuclear@14: 
nuclear@14: static void MatchFinder_CheckLimits(CMatchFinder *p)
nuclear@14: {
nuclear@14:   if (p->pos == kMaxValForNormalize)
nuclear@14:     MatchFinder_Normalize(p);
nuclear@14:   if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
nuclear@14:     MatchFinder_CheckAndMoveAndRead(p);
nuclear@14:   if (p->cyclicBufferPos == p->cyclicBufferSize)
nuclear@14:     p->cyclicBufferPos = 0;
nuclear@14:   MatchFinder_SetLimits(p);
nuclear@14: }
nuclear@14: 
nuclear@14: static UInt32 * Hc_GetMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
nuclear@14:     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
nuclear@14:     UInt32 *distances, UInt32 maxLen)
nuclear@14: {
nuclear@14:   son[_cyclicBufferPos] = curMatch;
nuclear@14:   for (;;)
nuclear@14:   {
nuclear@14:     UInt32 delta = pos - curMatch;
nuclear@14:     if (cutValue-- == 0 || delta >= _cyclicBufferSize)
nuclear@14:       return distances;
nuclear@14:     {
nuclear@14:       const Byte *pb = cur - delta;
nuclear@14:       curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
nuclear@14:       if (pb[maxLen] == cur[maxLen] && *pb == *cur)
nuclear@14:       {
nuclear@14:         UInt32 len = 0;
nuclear@14:         while (++len != lenLimit)
nuclear@14:           if (pb[len] != cur[len])
nuclear@14:             break;
nuclear@14:         if (maxLen < len)
nuclear@14:         {
nuclear@14:           *distances++ = maxLen = len;
nuclear@14:           *distances++ = delta - 1;
nuclear@14:           if (len == lenLimit)
nuclear@14:             return distances;
nuclear@14:         }
nuclear@14:       }
nuclear@14:     }
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
nuclear@14:     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue,
nuclear@14:     UInt32 *distances, UInt32 maxLen)
nuclear@14: {
nuclear@14:   CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
nuclear@14:   CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
nuclear@14:   UInt32 len0 = 0, len1 = 0;
nuclear@14:   for (;;)
nuclear@14:   {
nuclear@14:     UInt32 delta = pos - curMatch;
nuclear@14:     if (cutValue-- == 0 || delta >= _cyclicBufferSize)
nuclear@14:     {
nuclear@14:       *ptr0 = *ptr1 = kEmptyHashValue;
nuclear@14:       return distances;
nuclear@14:     }
nuclear@14:     {
nuclear@14:       CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
nuclear@14:       const Byte *pb = cur - delta;
nuclear@14:       UInt32 len = (len0 < len1 ? len0 : len1);
nuclear@14:       if (pb[len] == cur[len])
nuclear@14:       {
nuclear@14:         if (++len != lenLimit && pb[len] == cur[len])
nuclear@14:           while (++len != lenLimit)
nuclear@14:             if (pb[len] != cur[len])
nuclear@14:               break;
nuclear@14:         if (maxLen < len)
nuclear@14:         {
nuclear@14:           *distances++ = maxLen = len;
nuclear@14:           *distances++ = delta - 1;
nuclear@14:           if (len == lenLimit)
nuclear@14:           {
nuclear@14:             *ptr1 = pair[0];
nuclear@14:             *ptr0 = pair[1];
nuclear@14:             return distances;
nuclear@14:           }
nuclear@14:         }
nuclear@14:       }
nuclear@14:       if (pb[len] < cur[len])
nuclear@14:       {
nuclear@14:         *ptr1 = curMatch;
nuclear@14:         ptr1 = pair + 1;
nuclear@14:         curMatch = *ptr1;
nuclear@14:         len1 = len;
nuclear@14:       }
nuclear@14:       else
nuclear@14:       {
nuclear@14:         *ptr0 = curMatch;
nuclear@14:         ptr0 = pair;
nuclear@14:         curMatch = *ptr0;
nuclear@14:         len0 = len;
nuclear@14:       }
nuclear@14:     }
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: static void SkipMatchesSpec(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *cur, CLzRef *son,
nuclear@14:     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 cutValue)
nuclear@14: {
nuclear@14:   CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
nuclear@14:   CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
nuclear@14:   UInt32 len0 = 0, len1 = 0;
nuclear@14:   for (;;)
nuclear@14:   {
nuclear@14:     UInt32 delta = pos - curMatch;
nuclear@14:     if (cutValue-- == 0 || delta >= _cyclicBufferSize)
nuclear@14:     {
nuclear@14:       *ptr0 = *ptr1 = kEmptyHashValue;
nuclear@14:       return;
nuclear@14:     }
nuclear@14:     {
nuclear@14:       CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
nuclear@14:       const Byte *pb = cur - delta;
nuclear@14:       UInt32 len = (len0 < len1 ? len0 : len1);
nuclear@14:       if (pb[len] == cur[len])
nuclear@14:       {
nuclear@14:         while (++len != lenLimit)
nuclear@14:           if (pb[len] != cur[len])
nuclear@14:             break;
nuclear@14:         {
nuclear@14:           if (len == lenLimit)
nuclear@14:           {
nuclear@14:             *ptr1 = pair[0];
nuclear@14:             *ptr0 = pair[1];
nuclear@14:             return;
nuclear@14:           }
nuclear@14:         }
nuclear@14:       }
nuclear@14:       if (pb[len] < cur[len])
nuclear@14:       {
nuclear@14:         *ptr1 = curMatch;
nuclear@14:         ptr1 = pair + 1;
nuclear@14:         curMatch = *ptr1;
nuclear@14:         len1 = len;
nuclear@14:       }
nuclear@14:       else
nuclear@14:       {
nuclear@14:         *ptr0 = curMatch;
nuclear@14:         ptr0 = pair;
nuclear@14:         curMatch = *ptr0;
nuclear@14:         len0 = len;
nuclear@14:       }
nuclear@14:     }
nuclear@14:   }
nuclear@14: }
nuclear@14: 
nuclear@14: #define MOVE_POS \
nuclear@14:   ++p->cyclicBufferPos; \
nuclear@14:   p->buffer++; \
nuclear@14:   if (++p->pos == p->posLimit) MatchFinder_CheckLimits(p);
nuclear@14: 
nuclear@14: #define MOVE_POS_RET MOVE_POS return offset;
nuclear@14: 
nuclear@14: static void MatchFinder_MovePos(CMatchFinder *p) { MOVE_POS; }
nuclear@14: 
nuclear@14: #define GET_MATCHES_HEADER2(minLen, ret_op) \
nuclear@14:   UInt32 lenLimit; UInt32 hashValue; const Byte *cur; UInt32 curMatch; \
nuclear@14:   lenLimit = p->lenLimit; { if (lenLimit < minLen) { MatchFinder_MovePos(p); ret_op; }} \
nuclear@14:   cur = p->buffer;
nuclear@14: 
nuclear@14: #define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
nuclear@14: #define SKIP_HEADER(minLen)        GET_MATCHES_HEADER2(minLen, continue)
nuclear@14: 
nuclear@14: #define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
nuclear@14: 
nuclear@14: #define GET_MATCHES_FOOTER(offset, maxLen) \
nuclear@14:   offset = (UInt32)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
nuclear@14:   distances + offset, maxLen) - distances); MOVE_POS_RET;
nuclear@14: 
nuclear@14: #define SKIP_FOOTER \
nuclear@14:   SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
nuclear@14: 
nuclear@14: static UInt32 Bt2_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 offset;
nuclear@14:   GET_MATCHES_HEADER(2)
nuclear@14:   HASH2_CALC;
nuclear@14:   curMatch = p->hash[hashValue];
nuclear@14:   p->hash[hashValue] = p->pos;
nuclear@14:   offset = 0;
nuclear@14:   GET_MATCHES_FOOTER(offset, 1)
nuclear@14: }
nuclear@14: 
nuclear@14: UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 offset;
nuclear@14:   GET_MATCHES_HEADER(3)
nuclear@14:   HASH_ZIP_CALC;
nuclear@14:   curMatch = p->hash[hashValue];
nuclear@14:   p->hash[hashValue] = p->pos;
nuclear@14:   offset = 0;
nuclear@14:   GET_MATCHES_FOOTER(offset, 2)
nuclear@14: }
nuclear@14: 
nuclear@14: static UInt32 Bt3_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 hash2Value, delta2, maxLen, offset;
nuclear@14:   GET_MATCHES_HEADER(3)
nuclear@14: 
nuclear@14:   HASH3_CALC;
nuclear@14: 
nuclear@14:   delta2 = p->pos - p->hash[hash2Value];
nuclear@14:   curMatch = p->hash[kFix3HashSize + hashValue];
nuclear@14:   
nuclear@14:   p->hash[hash2Value] =
nuclear@14:   p->hash[kFix3HashSize + hashValue] = p->pos;
nuclear@14: 
nuclear@14: 
nuclear@14:   maxLen = 2;
nuclear@14:   offset = 0;
nuclear@14:   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
nuclear@14:   {
nuclear@14:     for (; maxLen != lenLimit; maxLen++)
nuclear@14:       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
nuclear@14:         break;
nuclear@14:     distances[0] = maxLen;
nuclear@14:     distances[1] = delta2 - 1;
nuclear@14:     offset = 2;
nuclear@14:     if (maxLen == lenLimit)
nuclear@14:     {
nuclear@14:       SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
nuclear@14:       MOVE_POS_RET;
nuclear@14:     }
nuclear@14:   }
nuclear@14:   GET_MATCHES_FOOTER(offset, maxLen)
nuclear@14: }
nuclear@14: 
nuclear@14: static UInt32 Bt4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
nuclear@14:   GET_MATCHES_HEADER(4)
nuclear@14: 
nuclear@14:   HASH4_CALC;
nuclear@14: 
nuclear@14:   delta2 = p->pos - p->hash[                hash2Value];
nuclear@14:   delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
nuclear@14:   curMatch = p->hash[kFix4HashSize + hashValue];
nuclear@14:   
nuclear@14:   p->hash[                hash2Value] =
nuclear@14:   p->hash[kFix3HashSize + hash3Value] =
nuclear@14:   p->hash[kFix4HashSize + hashValue] = p->pos;
nuclear@14: 
nuclear@14:   maxLen = 1;
nuclear@14:   offset = 0;
nuclear@14:   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
nuclear@14:   {
nuclear@14:     distances[0] = maxLen = 2;
nuclear@14:     distances[1] = delta2 - 1;
nuclear@14:     offset = 2;
nuclear@14:   }
nuclear@14:   if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
nuclear@14:   {
nuclear@14:     maxLen = 3;
nuclear@14:     distances[offset + 1] = delta3 - 1;
nuclear@14:     offset += 2;
nuclear@14:     delta2 = delta3;
nuclear@14:   }
nuclear@14:   if (offset != 0)
nuclear@14:   {
nuclear@14:     for (; maxLen != lenLimit; maxLen++)
nuclear@14:       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
nuclear@14:         break;
nuclear@14:     distances[offset - 2] = maxLen;
nuclear@14:     if (maxLen == lenLimit)
nuclear@14:     {
nuclear@14:       SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
nuclear@14:       MOVE_POS_RET;
nuclear@14:     }
nuclear@14:   }
nuclear@14:   if (maxLen < 3)
nuclear@14:     maxLen = 3;
nuclear@14:   GET_MATCHES_FOOTER(offset, maxLen)
nuclear@14: }
nuclear@14: 
nuclear@14: static UInt32 Hc4_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 hash2Value, hash3Value, delta2, delta3, maxLen, offset;
nuclear@14:   GET_MATCHES_HEADER(4)
nuclear@14: 
nuclear@14:   HASH4_CALC;
nuclear@14: 
nuclear@14:   delta2 = p->pos - p->hash[                hash2Value];
nuclear@14:   delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
nuclear@14:   curMatch = p->hash[kFix4HashSize + hashValue];
nuclear@14: 
nuclear@14:   p->hash[                hash2Value] =
nuclear@14:   p->hash[kFix3HashSize + hash3Value] =
nuclear@14:   p->hash[kFix4HashSize + hashValue] = p->pos;
nuclear@14: 
nuclear@14:   maxLen = 1;
nuclear@14:   offset = 0;
nuclear@14:   if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
nuclear@14:   {
nuclear@14:     distances[0] = maxLen = 2;
nuclear@14:     distances[1] = delta2 - 1;
nuclear@14:     offset = 2;
nuclear@14:   }
nuclear@14:   if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
nuclear@14:   {
nuclear@14:     maxLen = 3;
nuclear@14:     distances[offset + 1] = delta3 - 1;
nuclear@14:     offset += 2;
nuclear@14:     delta2 = delta3;
nuclear@14:   }
nuclear@14:   if (offset != 0)
nuclear@14:   {
nuclear@14:     for (; maxLen != lenLimit; maxLen++)
nuclear@14:       if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
nuclear@14:         break;
nuclear@14:     distances[offset - 2] = maxLen;
nuclear@14:     if (maxLen == lenLimit)
nuclear@14:     {
nuclear@14:       p->son[p->cyclicBufferPos] = curMatch;
nuclear@14:       MOVE_POS_RET;
nuclear@14:     }
nuclear@14:   }
nuclear@14:   if (maxLen < 3)
nuclear@14:     maxLen = 3;
nuclear@14:   offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
nuclear@14:     distances + offset, maxLen) - (distances));
nuclear@14:   MOVE_POS_RET
nuclear@14: }
nuclear@14: 
nuclear@14: UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances)
nuclear@14: {
nuclear@14:   UInt32 offset;
nuclear@14:   GET_MATCHES_HEADER(3)
nuclear@14:   HASH_ZIP_CALC;
nuclear@14:   curMatch = p->hash[hashValue];
nuclear@14:   p->hash[hashValue] = p->pos;
nuclear@14:   offset = (UInt32)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
nuclear@14:     distances, 2) - (distances));
nuclear@14:   MOVE_POS_RET
nuclear@14: }
nuclear@14: 
nuclear@14: static void Bt2_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     SKIP_HEADER(2)
nuclear@14:     HASH2_CALC;
nuclear@14:     curMatch = p->hash[hashValue];
nuclear@14:     p->hash[hashValue] = p->pos;
nuclear@14:     SKIP_FOOTER
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     SKIP_HEADER(3)
nuclear@14:     HASH_ZIP_CALC;
nuclear@14:     curMatch = p->hash[hashValue];
nuclear@14:     p->hash[hashValue] = p->pos;
nuclear@14:     SKIP_FOOTER
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: static void Bt3_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     UInt32 hash2Value;
nuclear@14:     SKIP_HEADER(3)
nuclear@14:     HASH3_CALC;
nuclear@14:     curMatch = p->hash[kFix3HashSize + hashValue];
nuclear@14:     p->hash[hash2Value] =
nuclear@14:     p->hash[kFix3HashSize + hashValue] = p->pos;
nuclear@14:     SKIP_FOOTER
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: static void Bt4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     UInt32 hash2Value, hash3Value;
nuclear@14:     SKIP_HEADER(4)
nuclear@14:     HASH4_CALC;
nuclear@14:     curMatch = p->hash[kFix4HashSize + hashValue];
nuclear@14:     p->hash[                hash2Value] =
nuclear@14:     p->hash[kFix3HashSize + hash3Value] = p->pos;
nuclear@14:     p->hash[kFix4HashSize + hashValue] = p->pos;
nuclear@14:     SKIP_FOOTER
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: static void Hc4_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     UInt32 hash2Value, hash3Value;
nuclear@14:     SKIP_HEADER(4)
nuclear@14:     HASH4_CALC;
nuclear@14:     curMatch = p->hash[kFix4HashSize + hashValue];
nuclear@14:     p->hash[                hash2Value] =
nuclear@14:     p->hash[kFix3HashSize + hash3Value] =
nuclear@14:     p->hash[kFix4HashSize + hashValue] = p->pos;
nuclear@14:     p->son[p->cyclicBufferPos] = curMatch;
nuclear@14:     MOVE_POS
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num)
nuclear@14: {
nuclear@14:   do
nuclear@14:   {
nuclear@14:     SKIP_HEADER(3)
nuclear@14:     HASH_ZIP_CALC;
nuclear@14:     curMatch = p->hash[hashValue];
nuclear@14:     p->hash[hashValue] = p->pos;
nuclear@14:     p->son[p->cyclicBufferPos] = curMatch;
nuclear@14:     MOVE_POS
nuclear@14:   }
nuclear@14:   while (--num != 0);
nuclear@14: }
nuclear@14: 
nuclear@14: void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
nuclear@14: {
nuclear@14:   vTable->Init = (Mf_Init_Func)MatchFinder_Init;
nuclear@14:   vTable->GetIndexByte = (Mf_GetIndexByte_Func)MatchFinder_GetIndexByte;
nuclear@14:   vTable->GetNumAvailableBytes = (Mf_GetNumAvailableBytes_Func)MatchFinder_GetNumAvailableBytes;
nuclear@14:   vTable->GetPointerToCurrentPos = (Mf_GetPointerToCurrentPos_Func)MatchFinder_GetPointerToCurrentPos;
nuclear@14:   if (!p->btMode)
nuclear@14:   {
nuclear@14:     vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
nuclear@14:     vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
nuclear@14:   }
nuclear@14:   else if (p->numHashBytes == 2)
nuclear@14:   {
nuclear@14:     vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
nuclear@14:     vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
nuclear@14:   }
nuclear@14:   else if (p->numHashBytes == 3)
nuclear@14:   {
nuclear@14:     vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
nuclear@14:     vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
nuclear@14:   }
nuclear@14:   else
nuclear@14:   {
nuclear@14:     vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
nuclear@14:     vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
nuclear@14:   }
nuclear@14: }