diff options
Diffstat (limited to '3rdparty/lzma/Java/SevenZip/Compression/LZ/InWindow.java')
-rw-r--r-- | 3rdparty/lzma/Java/SevenZip/Compression/LZ/InWindow.java | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/3rdparty/lzma/Java/SevenZip/Compression/LZ/InWindow.java b/3rdparty/lzma/Java/SevenZip/Compression/LZ/InWindow.java new file mode 100644 index 00000000000..c9efe601fae --- /dev/null +++ b/3rdparty/lzma/Java/SevenZip/Compression/LZ/InWindow.java @@ -0,0 +1,131 @@ +// 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; + } +} |