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+/******************************************************************************
+ *  lzsscomprs.h   - definition of Class SWCompress used for data compression
+ *
+ * $Id: lzsscomprs.h,v 1.3 2001/02/09 15:38:51 jansorg Exp $
+ *
+ * Copyright 1998 CrossWire Bible Society (http://www.crosswire.org)
+ *	CrossWire Bible Society
+ *	P. O. Box 2528
+ *	Tempe, AZ  85280-2528
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#ifndef LZSSCOMPRS_H
+#define LZSSCOMPRS_H
+
+#include <swcomprs.h>
+
+#include <defs.h>
+
+// The following are constant sizes used by the compression algorithm.
+//
+//  N         - This is the size of the ring buffer.  It is set
+//              to 4K.  It is important to note that a position
+//              within the ring buffer requires 12 bits.  
+//
+//  F         - This is the maximum length of a character sequence
+//              that can be taken from the ring buffer.  It is set
+//              to 18.  Note that a length must be 3 before it is
+//              worthwhile to store a position/length pair, so the
+//              length can be encoded in only 4 bits.  Or, put yet
+//              another way, it is not necessary to encode a length
+//              of 0-18, it is necessary to encode a length of
+//              3-18, which requires 4 bits.
+//              
+//  THRESHOLD - It takes 2 bytes to store an offset and
+//              a length.  If a character sequence only
+//              requires 1 or 2 characters to store 
+//              uncompressed, then it is better to store
+//              it uncompressed than as an offset into
+//              the ring buffer.
+//
+// Note that the 12 bits used to store the position and the 4 bits
+// used to store the length equal a total of 16 bits, or 2 bytes.
+
+#define N		4096
+#define F		18
+#define THRESHOLD	3
+#define NOT_USED	N
+
+
+
+class SWDLLEXPORT LZSSCompress:public SWCompress
+{
+  static unsigned char m_ring_buffer[N + F - 1];
+  static short int m_match_position;
+  static short int m_match_length;
+  static short int m_lson[N + 1];
+  static short int m_rson[N + 257];
+  static short int m_dad[N + 1];
+  void InitTree ();
+  void InsertNode (short int Pos);
+  void DeleteNode (short int Node);
+public:
+    LZSSCompress ();
+    virtual ~ LZSSCompress ();
+  virtual void Encode (void);
+  virtual void Decode (void);
+};
+
+#endif