diff options
Diffstat (limited to 'other-licenses/7zstub/src/Java/SevenZip/Compression/LZ/InWindow.java')
-rw-r--r-- | other-licenses/7zstub/src/Java/SevenZip/Compression/LZ/InWindow.java | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/Java/SevenZip/Compression/LZ/InWindow.java b/other-licenses/7zstub/src/Java/SevenZip/Compression/LZ/InWindow.java new file mode 100644 index 000000000..5f3f0b4d0 --- /dev/null +++ b/other-licenses/7zstub/src/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;
+ }
+}
|