source: trunk/gsdl3/src/packages/mg/lib/bitio_m_mem.h@ 3745

Last change on this file since 3745 was 3745, checked in by mdewsnip, 21 years ago

Addition of MG package for search and retrieval
  • Property svn:executable set to *
  • Property svn:keywords set to Author Date Id Revision
File size: 5.3 KB
Line 
1/**************************************************************************
2 *
3 * bitio_m_mem.h -- Macros for bitio to memory
4 * Copyright (C) 1994 Neil Sharman
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 * $Id: bitio_m_mem.h 3745 2003-02-20 21:20:24Z mdewsnip $
21 *
22 **************************************************************************
23 *
24 * This file contains macros for doing bitwise input and output on an array
25 * of chars. These routines are faster than the ones in "mems" files. But
26 * with these routines you cannot mix reads and writes on the array of chars,
27 * or multiple write, at the same time and guarantee them to work, also you
28 * cannot seek to a point and do a write. The decode routine can detect when
29 * you run off the end of the array and will produce an approate error
30 * message, and the encode routine will stop when it gets to the end of the
31 * character array.
32 *
33 **************************************************************************/
34
35#ifndef H_BITIO_M_MEM
36#define H_BITIO_M_MEM
37
38typedef struct mem_bitio_state
39 {
40 unsigned char *Base;
41 unsigned char *Pos;
42 int Remaining;
43 unsigned char Buff;
44 unsigned char Btg;
45 }
46mem_bitio_state;
47
48
49
50
51#ifndef DECODE_ERROR
52#define DECODE_ERROR (fprintf(stderr,"Unexpected EOF in \"%s\" on line %d\n",\
53 __FILE__, __LINE__), exit(1))
54#endif
55
56
57
58#define ENCODE_START(p,r) \
59 { \
60 register unsigned char *__pos = p; \
61 register unsigned char *__base = p; \
62 register int __remaining = r; \
63 register unsigned char __buff = 0; \
64 register unsigned char __btg = sizeof(__buff)*8;
65
66#define ENCODE_CONTINUE(b) \
67 { \
68 register unsigned char *__pos = (b).Pos; \
69 register unsigned char *__base = (b).Base; \
70 register int __remaining = (b).Remaining; \
71 register unsigned char __buff = (b).Buff; \
72 register unsigned char __btg = (b).Btg;
73
74#define ENCODE_BIT(b) \
75 do { \
76 __btg--; \
77 if (b) __buff |= (1 << __btg); \
78 if (!__btg) \
79 { \
80 if (__remaining) \
81 { \
82 *__pos++ = __buff; \
83 __remaining--; \
84 } \
85 __buff = 0; \
86 __btg = sizeof(__buff)*8; \
87 } \
88 } while(0)
89
90#define ENCODE_PAUSE(b) \
91 (b).Pos = __pos; \
92 (b).Base = __base; \
93 (b).Remaining = __remaining; \
94 (b).Buff = __buff; \
95 (b).Btg = __btg; \
96 }
97
98#define ENCODE_FLUSH \
99 do { \
100 if (__btg != sizeof(__buff)*8) \
101 if (__remaining) \
102 { \
103 *__pos++ = __buff; \
104 __remaining--; \
105 } \
106 __btg = sizeof(__buff)*8; \
107 } while (0)
108
109#define ENCODE_DONE \
110 ENCODE_FLUSH; \
111 }
112
113
114#define DECODE_START(p,r) \
115 { \
116 register unsigned char *__pos = p; \
117 register unsigned char *__base = p; \
118 register int __remaining = r; \
119 register unsigned char __buff = 0; \
120 register unsigned char __btg = 0;
121
122#define DECODE_CONTINUE(b) \
123 { \
124 register unsigned char *__pos = (b).Pos; \
125 register unsigned char *__base = (b).Base; \
126 register int __remaining = (b).Remaining; \
127 register unsigned char __buff = (b).Buff; \
128 register unsigned char __btg = (b).Btg;
129
130#define DECODE_ADD_FF(b) \
131 do { \
132 if (!__btg) \
133 { \
134 if (__remaining) \
135 { \
136 __buff = *__pos++; \
137 __remaining--; \
138 } \
139 else \
140 __buff = 0xff; \
141 __btg = sizeof(__buff)*8; \
142 } \
143 (b) += (b) + ((__buff >> --__btg) & 1); \
144 } while(0)
145
146#define DECODE_ADD_00(b) \
147 do { \
148 if (!__btg) \
149 { \
150 if (__remaining) \
151 { \
152 __buff = *__pos++; \
153 __remaining--; \
154 } \
155 else \
156 __buff = 0x00; \
157 __btg = sizeof(__buff)*8; \
158 } \
159 (b) += (b) + ((__buff >> --__btg) & 1); \
160 } while(0)
161
162#define DECODE_BIT (__btg ? (__buff >> --__btg) & 1 : \
163 (!__remaining ? \
164 (DECODE_ERROR, 0) : \
165 (__buff = *__pos++, __remaining--, __btg = sizeof(__buff)*8, \
166 (__buff >> --__btg) & 1)))
167
168#define DECODE_DONE ; \
169 }
170
171#define DECODE_PAUSE(b) \
172 (b).Pos = __pos; \
173 (b).Base = __base; \
174 (b).Remaining = __remaining; \
175 (b).Buff = __buff; \
176 (b).Btg = __btg; \
177 }
178
179#define DECODE_SEEK(pos) \
180 do { \
181 register long __new_pos = (pos); \
182 __pos = __base + (__new_pos >> 3); \
183 __buff = *__pos++; \
184 __btg = 8 - (__new_pos&7); \
185 } \
186 while(0)
187
188
189
190
191#endif
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