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// LZ.BinTree↩
↩
package SevenZip.Compression.LZ;↩
import java.io.IOException;↩
↩
↩
public class BinTree extends InWindow↩
{↩
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;↩
}↩
}↩
}↩