1 /* Copyright (C) 1994, 1995 Aladdin Enterprises. All rights reserved. 2 3 This software is provided AS-IS with no warranty, either express or 4 implied. 5 6 This software is distributed under license and may not be copied, 7 modified or distributed except as expressly authorized under the terms 8 of the license contained in the file LICENSE in this distribution. 9 10 For more information about licensing, please refer to 11 http://www.ghostscript.com/licensing/. For information on 12 commercial licensing, go to http://www.artifex.com/licensing/ or 13 contact Artifex Software, Inc., 101 Lucas Valley Road #110, 14 San Rafael, CA 94903, U.S.A., +1(415)492-9861. 15 */ 16 17 /* $Id: sbwbs.h,v 1.4 2002/02/21 22:24:53 giles Exp $ */ 18 /* Definitions for BWBlockSort (Burroughs-Wheeler) filters */ 19 /* Requires scommon.h; strimpl.h if any templates are referenced */ 20 21 #ifndef sbwbs_INCLUDED 22 # define sbwbs_INCLUDED 23 24 /* Common framework for streams that buffer a block for processing */ 25 #define stream_buffered_state_common\ 26 stream_state_common;\ 27 /* The client may set the following before initialization, */\ 28 /* or the stream may set it later. */\ 29 int BlockSize;\ 30 /* The init procedure sets the following, */\ 31 /* if BlockSize has been set. */\ 32 byte *buffer; /* [BlockSize] */\ 33 /* The following are updated dynamically. */\ 34 bool filling; /* true if filling buffer, */\ 35 /* false if emptying */\ 36 int bsize; /* size of current block (<= BlockSize) */\ 37 int bpos /* current index within buffer */ 38 typedef struct stream_buffered_state_s { 39 stream_buffered_state_common; 40 } stream_buffered_state; 41 42 #define private_st_buffered_state() /* in sbwbs.c */\ 43 gs_private_st_ptrs1(st_buffered_state, stream_buffered_state,\ 44 "stream_buffered state", sbuf_enum_ptrs, sbuf_reloc_ptrs, buffer) 45 46 /* BWBlockSortEncode/Decode */ 47 typedef struct of_ { 48 uint v[256]; 49 } offsets_full; 50 typedef struct stream_BWBS_state_s { 51 stream_buffered_state_common; 52 /* The init procedure sets the following. */ 53 void *offsets; /* permutation indices when writing, */ 54 /* multi-level indices when reading */ 55 /* The following are updated dynamically. */ 56 int N; /* actual length of block */ 57 /* The following are only used when decoding. */ 58 int I; /* index of unrotated string */ 59 int i; /* next index in encoded string */ 60 } stream_BWBS_state; 61 typedef stream_BWBS_state stream_BWBSE_state; 62 typedef stream_BWBS_state stream_BWBSD_state; 63 64 #define private_st_BWBS_state() /* in sbwbs.c */\ 65 gs_private_st_suffix_add1(st_BWBS_state, stream_BWBS_state,\ 66 "BWBlockSortEncode/Decode state", bwbs_enum_ptrs, bwbs_reloc_ptrs,\ 67 st_buffered_state, offsets) 68 extern const stream_template s_BWBSE_template; 69 extern const stream_template s_BWBSD_template; 70 71 #endif /* sbwbs_INCLUDED */ 72