mcmartin
a82bcf1338
git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@2661 8092fc87-c524-0410-9efc-e669fe64eaf9
75 lines
2.1 KiB
C
75 lines
2.1 KiB
C
/**************************************************************
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lzhuf.h
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Lib-like reentrant definition of lzhuf.c
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Please see lzhuf.c for authorship info
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**************************************************************/
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#ifndef LZHUF_H_INCL_
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#define LZHUF_H_INCL_
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/********** LZSS compression **********/
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#define LZHUF_N 4096 /* buffer size */
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#define LZHUF_F 60 /* lookahead buffer size */
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#define LZHUF_THRESHOLD 2
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#define LZHUF_NIL LZHUF_N /* leaf of tree */
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/* Huffman coding */
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#define LZHUF_N_CHAR (256 - LZHUF_THRESHOLD + LZHUF_F)
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/* kinds of characters (character code = 0..LZHUF_N_CHAR-1) */
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#define LZHUF_T (LZHUF_N_CHAR * 2 - 1) /* size of table */
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#define LZHUF_R (LZHUF_T - 1) /* position of root */
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#define LZHUF_MAX_FREQ 0x8000 /* updates tree when the */
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typedef void* lzhuf_handle_t;
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typedef struct
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{
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unsigned long int codesize;
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unsigned char text_buf[LZHUF_N + LZHUF_F - 1];
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int match_position;
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int match_length;
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int lson[LZHUF_N + 1];
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int rson[LZHUF_N + 257];
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int dad[LZHUF_N + 1];
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unsigned freq[LZHUF_T + 1]; /* frequency table */
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int prnt[LZHUF_T + LZHUF_N_CHAR]; /* pointers to parent nodes, except for the */
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/* elements [LZHUF_T..LZHUF_T + LZHUF_N_CHAR - 1] which are used to get */
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/* the positions of leaves corresponding to the codes. */
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int son[LZHUF_T]; /* pointers to child nodes (son[], son[] + 1) */
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unsigned getbuf;
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unsigned char getlen;
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unsigned putbuf;
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unsigned char putlen;
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/* user-settable data */
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void* userdata;
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lzhuf_handle_t infile;
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lzhuf_handle_t outfile;
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size_t (* read)(void*, size_t, size_t, lzhuf_handle_t);
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size_t (* write)(const void*, size_t, size_t, lzhuf_handle_t);
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int (* seek)(lzhuf_handle_t, long, int);
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long (* tell)(lzhuf_handle_t);
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} lzhuf_session_t;
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#define LZHUF_STDIO 1
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void lzhuf_startSession(lzhuf_session_t *, int bStdIO);
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void lzhuf_endSession(lzhuf_session_t *);
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int lzhuf_encode(lzhuf_session_t *); /* compression */
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int lzhuf_decode(lzhuf_session_t *); /* recover */
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#endif /* LZHUF_H_INCL_ */
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