/* Copyright (C) 1994, 1995 artofcode LLC.  All rights reserved.
  
  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; either version 2 of the License, or (at your
  option) any later version.

  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.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.

*/

/*$Id: sbwbs.h,v 1.2.6.1.2.1 2003/01/17 00:49:05 giles Exp $ */
/* Definitions for BWBlockSort (Burroughs-Wheeler) filters */
/* Requires scommon.h; strimpl.h if any templates are referenced */

#ifndef sbwbs_INCLUDED
#  define sbwbs_INCLUDED

/* Common framework for streams that buffer a block for processing */
#define stream_buffered_state_common\
	stream_state_common;\
		/* The client may set the following before initialization, */\
		/* or the stream may set it later. */\
	int BlockSize;\
		/* The init procedure sets the following, */\
		/* if BlockSize has been set. */\
	byte *buffer;		/* [BlockSize] */\
		/* The following are updated dynamically. */\
	bool filling;		/* true if filling buffer, */\
				/* false if emptying */\
	int bsize;		/* size of current block (<= BlockSize) */\
	int bpos		/* current index within buffer */
typedef struct stream_buffered_state_s {
    stream_buffered_state_common;
} stream_buffered_state;

#define private_st_buffered_state()	/* in sbwbs.c */\
  gs_private_st_ptrs1(st_buffered_state, stream_buffered_state,\
    "stream_buffered state", sbuf_enum_ptrs, sbuf_reloc_ptrs, buffer)

/* BWBlockSortEncode/Decode */
typedef struct of_ {
    uint v[256];
} offsets_full;
typedef struct stream_BWBS_state_s {
    stream_buffered_state_common;
    /* The init procedure sets the following. */
    void *offsets;		/* permutation indices when writing, */
    /* multi-level indices when reading */
    /* The following are updated dynamically. */
    int N;			/* actual length of block */
    /* The following are only used when decoding. */
    int I;			/* index of unrotated string */
    int i;			/* next index in encoded string */
} stream_BWBS_state;
typedef stream_BWBS_state stream_BWBSE_state;
typedef stream_BWBS_state stream_BWBSD_state;

#define private_st_BWBS_state()	/* in sbwbs.c */\
  gs_private_st_suffix_add1(st_BWBS_state, stream_BWBS_state,\
    "BWBlockSortEncode/Decode state", bwbs_enum_ptrs, bwbs_reloc_ptrs,\
    st_buffered_state, offsets)
extern const stream_template s_BWBSE_template;
extern const stream_template s_BWBSD_template;

#endif /* sbwbs_INCLUDED */