Source code
Revision control
Copy as Markdown
Other Tools
// LZ.InWindow↩
↩
package SevenZip.Compression.LZ;↩
↩
import java.io.IOException;↩
↩
public class InWindow↩
{↩
public byte[] _bufferBase; // pointer to buffer with data↩
java.io.InputStream _stream;↩
int _posLimit; // offset (from _buffer) of first byte when new block reading must be done↩
boolean _streamEndWasReached; // if (true) then _streamPos shows real end of stream↩
↩
int _pointerToLastSafePosition;↩
↩
public int _bufferOffset;↩
↩
public int _blockSize; // Size of Allocated memory block↩
public int _pos; // offset (from _buffer) of curent byte↩
int _keepSizeBefore; // how many BYTEs must be kept in buffer before _pos↩
int _keepSizeAfter; // how many BYTEs must be kept buffer after _pos↩
public int _streamPos; // offset (from _buffer) of first not read byte from Stream↩
↩
public void MoveBlock()↩
{↩
int offset = _bufferOffset + _pos - _keepSizeBefore;↩
// we need one additional byte, since MovePos moves on 1 byte.↩
if (offset > 0)↩
offset--;↩
↩
int numBytes = _bufferOffset + _streamPos - offset;↩
↩
// check negative offset ????↩
for (int i = 0; i < numBytes; i++)↩
_bufferBase[i] = _bufferBase[offset + i];↩
_bufferOffset -= offset;↩
}↩
↩
public void ReadBlock() throws IOException↩
{↩
if (_streamEndWasReached)↩
return;↩
while (true)↩
{↩
int size = (0 - _bufferOffset) + _blockSize - _streamPos;↩
if (size == 0)↩
return;↩
int numReadBytes = _stream.read(_bufferBase, _bufferOffset + _streamPos, size);↩
if (numReadBytes == -1)↩
{↩
_posLimit = _streamPos;↩
int pointerToPostion = _bufferOffset + _posLimit;↩
if (pointerToPostion > _pointerToLastSafePosition)↩
_posLimit = _pointerToLastSafePosition - _bufferOffset;↩
↩
_streamEndWasReached = true;↩
return;↩
}↩
_streamPos += numReadBytes;↩
if (_streamPos >= _pos + _keepSizeAfter)↩
_posLimit = _streamPos - _keepSizeAfter;↩
}↩
}↩
↩
void Free() { _bufferBase = null; }↩
↩
public void Create(int keepSizeBefore, int keepSizeAfter, int keepSizeReserv)↩
{↩
_keepSizeBefore = keepSizeBefore;↩
_keepSizeAfter = keepSizeAfter;↩
int blockSize = keepSizeBefore + keepSizeAfter + keepSizeReserv;↩
if (_bufferBase == null || _blockSize != blockSize)↩
{↩
Free();↩
_blockSize = blockSize;↩
_bufferBase = new byte[_blockSize];↩
}↩
_pointerToLastSafePosition = _blockSize - keepSizeAfter;↩
}↩
↩
public void SetStream(java.io.InputStream stream) { _stream = stream; }↩
public void ReleaseStream() { _stream = null; }↩
↩
public void Init() throws IOException↩
{↩
_bufferOffset = 0;↩
_pos = 0;↩
_streamPos = 0;↩
_streamEndWasReached = false;↩
ReadBlock();↩
}↩
↩
public void MovePos() throws IOException↩
{↩
_pos++;↩
if (_pos > _posLimit)↩
{↩
int pointerToPostion = _bufferOffset + _pos;↩
if (pointerToPostion > _pointerToLastSafePosition)↩
MoveBlock();↩
ReadBlock();↩
}↩
}↩
↩
public byte GetIndexByte(int index) { return _bufferBase[_bufferOffset + _pos + index]; }↩
↩
// index + limit have not to exceed _keepSizeAfter;↩
public int GetMatchLen(int index, int distance, int limit)↩
{↩
if (_streamEndWasReached)↩
if ((_pos + index) + limit > _streamPos)↩
limit = _streamPos - (_pos + index);↩
distance++;↩
// Byte *pby = _buffer + (size_t)_pos + index;↩
int pby = _bufferOffset + _pos + index;↩
↩
int i;↩
for (i = 0; i < limit && _bufferBase[pby + i] == _bufferBase[pby + i - distance]; i++);↩
return i;↩
}↩
↩
public int GetNumAvailableBytes() { return _streamPos - _pos; }↩
↩
public void ReduceOffsets(int subValue)↩
{↩
_bufferOffset += subValue;↩
_posLimit -= subValue;↩
_pos -= subValue;↩
_streamPos -= subValue;↩
}↩
}↩