1 files changed, 14 insertions, 11 deletions
diff --git a/7zip/Compress/LZ/LZInWindow.h b/7zip/Compress/LZ/LZInWindow.h
index a9cb7320..54f2cb7b 100755
--- a/7zip/Compress/LZ/LZInWindow.h
+++ b/7zip/Compress/LZ/LZInWindow.h
@@ -9,7 +9,7 @@ class CLZInWindow
 {
   Byte *_bufferBase; // pointer to buffer with data
   ISequentialInStream *_stream;
-  UInt32 _posLimit;  // offset (from _buffer) of first byte when new block reading must be done
+  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:
@@ -18,22 +18,20 @@ protected:
   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 _keepSizeReserv;  // how many BYTEs must be kept as reserv
   UInt32 _streamPos;   // offset (from _buffer) of first not read byte from Stream
 
-  virtual void BeforeMoveBlock() {};
-  virtual void AfterMoveBlock() {};
   void MoveBlock();
-  virtual HRESULT ReadBlock();
+  HRESULT ReadBlock();
   void Free();
 public:
   CLZInWindow(): _bufferBase(0) {}
   virtual ~CLZInWindow() { Free(); }
 
-  bool Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, 
-      UInt32 keepSizeReserv = (1<<17));
+  // keepSizeBefore + keepSizeAfter + keepSizeReserv < 4G)
+  bool Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, UInt32 keepSizeReserv = (1<<17));
 
-  HRESULT Init(ISequentialInStream *stream);
+  void SetStream(ISequentialInStream *stream);
+  HRESULT Init();
   // void ReleaseStream();
 
   Byte *GetBuffer() const { return _buffer; }
@@ -53,17 +51,17 @@ public:
     else
       return S_OK;
   }
-  Byte GetIndexByte(Int32 index)const
-    {  return _buffer[(size_t)_pos + index]; }
+  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++;
-    Byte *pby = _buffer + (size_t)_pos + index;
+    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;
@@ -79,6 +77,11 @@ public:
     _streamPos -= subValue;
   }
 
+  bool NeedMove(UInt32 numCheckBytes)
+  {
+    UInt32 reserv = _pointerToLastSafePosition - (_buffer + _pos);
+    return (reserv <= numCheckBytes);
+  }
 };
 
 #endif