diff options
Diffstat (limited to 'util/cbfstool/tools/lzma/C/7zip/Compress/LZ/LZInWindow.h')
-rw-r--r-- | util/cbfstool/tools/lzma/C/7zip/Compress/LZ/LZInWindow.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/util/cbfstool/tools/lzma/C/7zip/Compress/LZ/LZInWindow.h b/util/cbfstool/tools/lzma/C/7zip/Compress/LZ/LZInWindow.h new file mode 100644 index 0000000000..87cb8e94fa --- /dev/null +++ b/util/cbfstool/tools/lzma/C/7zip/Compress/LZ/LZInWindow.h @@ -0,0 +1,87 @@ +// LZInWindow.h
+
+#ifndef __LZ_IN_WINDOW_H
+#define __LZ_IN_WINDOW_H
+
+#include "../../IStream.h"
+
+class CLZInWindow
+{
+ Byte *_bufferBase; // pointer to buffer with data
+ ISequentialInStream *_stream;
+ UInt32 _posLimit; // offset (from _buffer) when new block reading must be done
+ bool _streamEndWasReached; // if (true) then _streamPos shows real end of stream
+ const Byte *_pointerToLastSafePosition;
+protected:
+ Byte *_buffer; // Pointer to virtual Buffer begin
+ UInt32 _blockSize; // Size of Allocated memory block
+ UInt32 _pos; // offset (from _buffer) of curent byte
+ UInt32 _keepSizeBefore; // how many BYTEs must be kept in buffer before _pos
+ UInt32 _keepSizeAfter; // how many BYTEs must be kept buffer after _pos
+ UInt32 _streamPos; // offset (from _buffer) of first not read byte from Stream
+
+ void MoveBlock();
+ HRESULT ReadBlock();
+ void Free();
+public:
+ CLZInWindow(): _bufferBase(0) {}
+ virtual ~CLZInWindow() { Free(); }
+
+ // keepSizeBefore + keepSizeAfter + keepSizeReserv < 4G)
+ bool Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, UInt32 keepSizeReserv = (1<<17));
+
+ void SetStream(ISequentialInStream *stream);
+ HRESULT Init();
+ // void ReleaseStream();
+
+ Byte *GetBuffer() const { return _buffer; }
+
+ const Byte *GetPointerToCurrentPos() const { return _buffer + _pos; }
+
+ HRESULT MovePos()
+ {
+ _pos++;
+ if (_pos > _posLimit)
+ {
+ const Byte *pointerToPostion = _buffer + _pos;
+ if(pointerToPostion > _pointerToLastSafePosition)
+ MoveBlock();
+ return ReadBlock();
+ }
+ else
+ return S_OK;
+ }
+ Byte GetIndexByte(Int32 index) const { return _buffer[(size_t)_pos + index]; }
+
+ // index + limit have not to exceed _keepSizeAfter;
+ // -2G <= index < 2G
+ UInt32 GetMatchLen(Int32 index, UInt32 distance, UInt32 limit) const
+ {
+ if(_streamEndWasReached)
+ if ((_pos + index) + limit > _streamPos)
+ limit = _streamPos - (_pos + index);
+ distance++;
+ const Byte *pby = _buffer + (size_t)_pos + index;
+ UInt32 i;
+ for(i = 0; i < limit && pby[i] == pby[(size_t)i - distance]; i++);
+ return i;
+ }
+
+ UInt32 GetNumAvailableBytes() const { return _streamPos - _pos; }
+
+ void ReduceOffsets(Int32 subValue)
+ {
+ _buffer += subValue;
+ _posLimit -= subValue;
+ _pos -= subValue;
+ _streamPos -= subValue;
+ }
+
+ bool NeedMove(UInt32 numCheckBytes)
+ {
+ UInt32 reserv = _pointerToLastSafePosition - (_buffer + _pos);
+ return (reserv <= numCheckBytes);
+ }
+};
+
+#endif
|