{

int _cyclicBufferPos;

int _cyclicBufferSize = 0;

int _matchMaxLen;

int[] _son;

int[] _hash;

int _cutValue = 0xFF;

int _hashMask;

int _hashSizeSum = 0;

boolean HASH_ARRAY = true;

static final int kHash2Size = 1 << 10;

static final int kHash3Size = 1 << 16;

static final int kBT2HashSize = 1 << 16;

static final int kStartMaxLen = 1;

static final int kHash3Offset = kHash2Size;

static final int kEmptyHashValue = 0;

static final int kMaxValForNormalize = (1 << 30) - 1;

int kNumHashDirectBytes = 0;

int kMinMatchCheck = 4;

int kFixHashSize = kHash2Size + kHash3Size;

public void SetType(int numHashBytes)

{

HASH_ARRAY = (numHashBytes > 2);

if (HASH_ARRAY)

{

kNumHashDirectBytes = 0;

kMinMatchCheck = 4;

kFixHashSize = kHash2Size + kHash3Size;

}

else

{

kNumHashDirectBytes = 2;

kMinMatchCheck = 2 + 1;

kFixHashSize = 0;

}

}

public void Init() throws IOException

{

super.Init();

for (int i = 0; i < _hashSizeSum; i++)

_hash[i] = kEmptyHashValue;

_cyclicBufferPos = 0;

ReduceOffsets(-1);

}

public void MovePos() throws IOException

{

if (++_cyclicBufferPos >= _cyclicBufferSize)

_cyclicBufferPos = 0;

super.MovePos();

if (_pos == kMaxValForNormalize)

Normalize();

}

public boolean Create(int historySize, int keepAddBufferBefore,

int matchMaxLen, int keepAddBufferAfter)

{

if (historySize > kMaxValForNormalize - 256)

return false;

_cutValue = 16 + (matchMaxLen >> 1);

int windowReservSize = (historySize + keepAddBufferBefore +

matchMaxLen + keepAddBufferAfter) / 2 + 256;

super.Create(historySize + keepAddBufferBefore, matchMaxLen + keepAddBufferAfter, windowReservSize);

_matchMaxLen = matchMaxLen;

int cyclicBufferSize = historySize + 1;

if (_cyclicBufferSize != cyclicBufferSize)

_son = new int[(_cyclicBufferSize = cyclicBufferSize) * 2];

int hs = kBT2HashSize;

if (HASH_ARRAY)

{

hs = historySize - 1;

hs |= (hs >> 1);

hs |= (hs >> 2);

hs |= (hs >> 4);

hs |= (hs >> 8);

hs >>= 1;

hs |= 0xFFFF;

if (hs > (1 << 24))

hs >>= 1;

_hashMask = hs;

hs++;

hs += kFixHashSize;

}

if (hs != _hashSizeSum)

_hash = new int [_hashSizeSum = hs];

return true;

}

public int GetMatches(int[] distances) throws IOException

{

int lenLimit;

if (_pos + _matchMaxLen <= _streamPos)

lenLimit = _matchMaxLen;

else

{

lenLimit = _streamPos - _pos;

if (lenLimit < kMinMatchCheck)

{

MovePos();

return 0;

}

}

int offset = 0;

int matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;

int cur = _bufferOffset + _pos;

int maxLen = kStartMaxLen; // to avoid items for len < hashSize;

int hashValue, hash2Value = 0, hash3Value = 0;

if (HASH_ARRAY)

{

int temp = CrcTable[_bufferBase[cur] & 0xFF] ^ (_bufferBase[cur + 1] & 0xFF);

hash2Value = temp & (kHash2Size - 1);

temp ^= ((int)(_bufferBase[cur + 2] & 0xFF) << 8);

hash3Value = temp & (kHash3Size - 1);

hashValue = (temp ^ (CrcTable[_bufferBase[cur + 3] & 0xFF] << 5)) & _hashMask;

}

else

hashValue = ((_bufferBase[cur] & 0xFF) ^ ((int)(_bufferBase[cur + 1] & 0xFF) << 8));

int curMatch = _hash[kFixHashSize + hashValue];

if (HASH_ARRAY)

{

int curMatch2 = _hash[hash2Value];

int curMatch3 = _hash[kHash3Offset + hash3Value];

_hash[hash2Value] = _pos;

_hash[kHash3Offset + hash3Value] = _pos;

if (curMatch2 > matchMinPos)

if (_bufferBase[_bufferOffset + curMatch2] == _bufferBase[cur])

{

distances[offset++] = maxLen = 2;

distances[offset++] = _pos - curMatch2 - 1;

}

if (curMatch3 > matchMinPos)

if (_bufferBase[_bufferOffset + curMatch3] == _bufferBase[cur])

{

if (curMatch3 == curMatch2)

offset -= 2;

distances[offset++] = maxLen = 3;

distances[offset++] = _pos - curMatch3 - 1;

curMatch2 = curMatch3;

}

if (offset != 0 && curMatch2 == curMatch)

{

offset -= 2;

maxLen = kStartMaxLen;

}

}

_hash[kFixHashSize + hashValue] = _pos;

int ptr0 = (_cyclicBufferPos << 1) + 1;

int ptr1 = (_cyclicBufferPos << 1);

int len0, len1;

len0 = len1 = kNumHashDirectBytes;

if (kNumHashDirectBytes != 0)

{

if (curMatch > matchMinPos)

{

if (_bufferBase[_bufferOffset + curMatch + kNumHashDirectBytes] !=

_bufferBase[cur + kNumHashDirectBytes])

{

distances[offset++] = maxLen = kNumHashDirectBytes;

distances[offset++] = _pos - curMatch - 1;

}

}

}

int count = _cutValue;

while (true)

{

if (curMatch <= matchMinPos || count-- == 0)

{

_son[ptr0] = _son[ptr1] = kEmptyHashValue;

break;

}

int delta = _pos - curMatch;

int cyclicPos = ((delta <= _cyclicBufferPos) ?

(_cyclicBufferPos - delta) :

(_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;

int pby1 = _bufferOffset + curMatch;

int len = Math.min(len0, len1);

if (_bufferBase[pby1 + len] == _bufferBase[cur + len])

{

while(++len != lenLimit)

if (_bufferBase[pby1 + len] != _bufferBase[cur + len])

break;

if (maxLen < len)

{

distances[offset++] = maxLen = len;

distances[offset++] = delta - 1;

if (len == lenLimit)

{

_son[ptr1] = _son[cyclicPos];

_son[ptr0] = _son[cyclicPos + 1];

break;

}

}

}

if ((_bufferBase[pby1 + len] & 0xFF) < (_bufferBase[cur + len] & 0xFF))

{

_son[ptr1] = curMatch;

ptr1 = cyclicPos + 1;

curMatch = _son[ptr1];

len1 = len;

}

else

{

_son[ptr0] = curMatch;

ptr0 = cyclicPos;

curMatch = _son[ptr0];

len0 = len;

}

}

MovePos();

return offset;

}

public void Skip(int num) throws IOException

{

do

{

int lenLimit;

if (_pos + _matchMaxLen <= _streamPos)

lenLimit = _matchMaxLen;

else

{

lenLimit = _streamPos - _pos;

if (lenLimit < kMinMatchCheck)

{

MovePos();

continue;

}

}

int matchMinPos = (_pos > _cyclicBufferSize) ? (_pos - _cyclicBufferSize) : 0;

int cur = _bufferOffset + _pos;

int hashValue;

if (HASH_ARRAY)

{

int temp = CrcTable[_bufferBase[cur] & 0xFF] ^ (_bufferBase[cur + 1] & 0xFF);

int hash2Value = temp & (kHash2Size - 1);

_hash[hash2Value] = _pos;

temp ^= ((int)(_bufferBase[cur + 2] & 0xFF) << 8);

int hash3Value = temp & (kHash3Size - 1);

_hash[kHash3Offset + hash3Value] = _pos;

hashValue = (temp ^ (CrcTable[_bufferBase[cur + 3] & 0xFF] << 5)) & _hashMask;

}

else

hashValue = ((_bufferBase[cur] & 0xFF) ^ ((int)(_bufferBase[cur + 1] & 0xFF) << 8));

int curMatch = _hash[kFixHashSize + hashValue];

_hash[kFixHashSize + hashValue] = _pos;

int ptr0 = (_cyclicBufferPos << 1) + 1;

int ptr1 = (_cyclicBufferPos << 1);

int len0, len1;

len0 = len1 = kNumHashDirectBytes;

int count = _cutValue;

while (true)

{

if (curMatch <= matchMinPos || count-- == 0)

{

_son[ptr0] = _son[ptr1] = kEmptyHashValue;

break;

}

int delta = _pos - curMatch;

int cyclicPos = ((delta <= _cyclicBufferPos) ?

(_cyclicBufferPos - delta) :

(_cyclicBufferPos - delta + _cyclicBufferSize)) << 1;

int pby1 = _bufferOffset + curMatch;

int len = Math.min(len0, len1);

if (_bufferBase[pby1 + len] == _bufferBase[cur + len])

{

while (++len != lenLimit)

if (_bufferBase[pby1 + len] != _bufferBase[cur + len])

break;

if (len == lenLimit)

{

_son[ptr1] = _son[cyclicPos];

_son[ptr0] = _son[cyclicPos + 1];

break;

}

}

if ((_bufferBase[pby1 + len] & 0xFF) < (_bufferBase[cur + len] & 0xFF))

{

_son[ptr1] = curMatch;

ptr1 = cyclicPos + 1;

curMatch = _son[ptr1];

len1 = len;

}

else

{

_son[ptr0] = curMatch;

ptr0 = cyclicPos;

curMatch = _son[ptr0];

len0 = len;

}

}

MovePos();

}

while (--num != 0);

}

void NormalizeLinks(int[] items, int numItems, int subValue)

{

for (int i = 0; i < numItems; i++)

{

int value = items[i];

if (value <= subValue)

value = kEmptyHashValue;

else

value -= subValue;

items[i] = value;

}

}

void Normalize()

{

int subValue = _pos - _cyclicBufferSize;

NormalizeLinks(_son, _cyclicBufferSize * 2, subValue);

NormalizeLinks(_hash, _hashSizeSum, subValue);

ReduceOffsets(subValue);

}

public void SetCutValue(int cutValue) { _cutValue = cutValue; }

private static final int[] CrcTable = new int[256];

static

{

for (int i = 0; i < 256; i++)

{

int r = i;

for (int j = 0; j < 8; j++)

if ((r & 1) != 0)

r = (r >>> 1) ^ 0xEDB88320;

else

r >>>= 1;

CrcTable[i] = r;

}

}