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Diffstat (limited to 'include/lzsscomprs.h')
| -rw-r--r-- | include/lzsscomprs.h | 82 |
1 files changed, 0 insertions, 82 deletions
diff --git a/include/lzsscomprs.h b/include/lzsscomprs.h deleted file mode 100644 index d972f88..0000000 --- a/include/lzsscomprs.h +++ /dev/null @@ -1,82 +0,0 @@ -/****************************************************************************** - * lzsscomprs.h - definition of Class SWCompress used for data compression - * - * $Id: lzsscomprs.h,v 1.4 2002/10/01 19:52:40 dglassey 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> - -SWORD_NAMESPACE_START - -// 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); -}; - -SWORD_NAMESPACE_END -#endif |