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More sophisticated and excessive signal and alarm handling.
[mLib] / sym.h
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0875b58f 1/* -*-c-*-
2 *
d4d7a053 3 * $Id: sym.h,v 1.7 1999/06/01 09:49:33 mdw Exp $
0875b58f 4 *
5 * Symbol table management
6 *
7 * (c) 1998 Straylight/Edgeware
8 */
9
c846879c 10/*----- Licensing notice --------------------------------------------------*
0875b58f 11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
c846879c 15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
0875b58f 19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
c846879c 22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
0bd98442 25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
0875b58f 28 */
29
30/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: sym.h,v $
d4d7a053 33 * Revision 1.7 1999/06/01 09:49:33 mdw
34 * Allow things to be looked up by just their caller-supplied hashes. This
35 * actually needs to be thought through better.
36 *
34b97201 37 * Revision 1.6 1999/05/26 21:08:31 mdw
38 * Rename symbols in line with newer conventions.
39 *
8c6d948b 40 * Revision 1.5 1999/05/13 22:48:37 mdw
41 * Change `-ise' to `-ize' throughout.
42 *
0bd98442 43 * Revision 1.4 1999/05/06 19:51:35 mdw
44 * Reformatted the LGPL notice a little bit.
45 *
c846879c 46 * Revision 1.3 1999/05/05 18:50:31 mdw
47 * Change licensing conditions to LGPL.
48 *
a5d14ede 49 * Revision 1.2 1998/11/26 19:27:34 mdw
50 * Move SYM_NAME into the header file. Fix bugs.
51 *
52 * Revision 1.1.1.1 1998/06/17 23:44:42 mdw
53 * Initial version of mLib
0875b58f 54 *
55 */
56
57#ifndef SYM_H
58#define SYM_H
59
60#ifdef __cplusplus
61 extern "C" {
62#endif
63
64/*----- Required headers --------------------------------------------------*/
65
66#include <stddef.h>
67
d4d7a053 68#ifndef BITS_H
69# include "bits.h"
70#endif
71
0875b58f 72/*----- Type definitions --------------------------------------------------*/
73
74/* --- Symbol table --- *
75 *
76 * A @sym_table@ contains the information needed to manage a symbol table.
77 * Users shouldn't fiddle with this information directly, but it needs to be
78 * here so that objects of the correct type can be created.
79 */
80
81typedef struct sym_table {
82 unsigned long mask; /* Bit mask for hashing purposes */
83 size_t c; /* Down counter for growing table */
84 struct sym_base **a; /* Array of hash bins */
85} sym_table;
86
87/* --- A symbol table entry --- *
88 *
89 * I don't care what actually gets stored in symbol entries because I don't
90 * create them: that's the responsibility of my client. All I care about
91 * here is that whatever gets passed to me is a structure whose first member
92 * is a @sym_base@. The ANSI guarantees about structure layout are
93 * sufficient to allow me to manipulate such objects.
94 */
95
96#define SYM_BUFSZ 16 /* Size of local string buffer */
97
98typedef struct sym_base {
99 struct sym_base *next; /* Next symbol in hash bin */
d4d7a053 100 uint32 hash; /* Hash value for symbol's name */
0875b58f 101 union {
102 char *p; /* Pointer to name string */
103 char b[SYM_BUFSZ]; /* Buffer containing a short name */
104 } name; /* Name of this symbol */
105 size_t len; /* Length of the symbol's name */
106} sym_base;
107
a5d14ede 108/* --- A macro to pick a symbol's name out from the mess --- */
109
110#define SYM_NAME(sy) \
111 (((sym_base *)(sy))->len > SYM_BUFSZ ? \
112 ((sym_base *)(sy))->name.p : \
113 ((sym_base *)(sy))->name.b)
114
0875b58f 115/* --- An iterator block --- */
116
117typedef struct sym_iter {
118 sym_table *t; /* Symbol table being iterated */
119 sym_base *n; /* Address of next item to return */
120 size_t i; /* Index of next hash bin to use */
121} sym_iter;
122
123/*----- External functions ------------------------------------------------*/
124
34b97201 125/* --- @sym_create@ --- *
0875b58f 126 *
8c6d948b 127 * Arguments: @sym_table *t@ = symbol table to initialize
0875b58f 128 *
129 * Returns: ---
130 *
8c6d948b 131 * Use: Initializes the given symbol table. Raises @EXC_NOMEM@ if
0875b58f 132 * there isn't enough memory.
133 */
134
34b97201 135extern void sym_create(sym_table */*t*/);
0875b58f 136
34b97201 137/* --- @sym_destroy@ --- *
0875b58f 138 *
139 * Arguments: @sym_table *t@ = pointer to symbol table in question
140 *
141 * Returns: ---
142 *
143 * Use: Destroys a symbol table, freeing all the memory it used to
144 * occupy.
145 */
146
34b97201 147extern void sym_destroy(sym_table */*t*/);
0875b58f 148
149/* --- @sym_find@ --- *
150 *
151 * Arguments: @sym_table *t@ = pointer to symbol table in question
152 * @const char *n@ = pointer to symbol table to look up
153 * @long l@ = length of the name string or negative to measure
154 * @size_t sz@ = size of desired symbol object, or zero
155 * @unsigned *f@ = pointer to a flag, or null.
156 *
157 * Returns: The address of a @sym_base@ structure, or null if not found
158 * and @sz@ is zero.
159 *
160 * Use: Looks up a symbol in a given symbol table. The name is
161 * passed by the address of its first character. The length
162 * may be given, in which case the name may contain arbitrary
163 * binary data, or it may be given as a negative number, in
164 * which case the length of the name is calculated as
d4d7a053 165 * @strlen(n) + 1@. The name pointer @n@ may also be zero; in
166 * this case, @l@ is taken to be a raw hash, and any element
167 * with a matching hash is taken to be the one wanted.
0875b58f 168 *
169 * The return value is the address of a pointer to a @sym_base@
170 * block (which may have other things on the end, as above). If
171 * the symbol could be found, the return value points to the
172 * symbol block. If the symbol wasn't there, then if @sz@ is
173 * nonzero, a new symbol is created and its address is returned;
174 * otherwise a null pointer is returned. The exception
175 * @EXC_NOMEM@ is raised if the block can't be allocated.
176 *
177 * The value of @*f@ indicates whether a new symbol entry was
178 * created: a nonzero value indicates that an old value was
179 * found.
180 */
181
182extern void *sym_find(sym_table */*t*/, const char */*n*/, long /*l*/,
183 size_t /*sz*/, unsigned */*f*/);
184
185/* --- @sym_remove@ --- *
186 *
187 * Arguments: @sym_table *i@ = pointer to a symbol table object
188 * @void *b@ = pointer to symbol table entry
189 *
190 * Returns: ---
191 *
192 * Use: Removes the object from the symbol table. The space occupied
193 * by the object and its name is freed; anything else attached
194 * to the entry should already be gone by this point.
195 */
196
197extern void sym_remove(sym_table */*t*/, void */*b*/);
198
34b97201 199/* --- @sym_mkiter@ --- *
0875b58f 200 *
201 * Arguments: @sym_iter *i@ = pointer to an iterator object
202 * @sym_table *t@ = pointer to a symbol table object
203 *
204 * Returns: ---
205 *
206 * Use: Creates a new symbol table iterator which may be used to
207 * iterate through a symbol table.
208 */
209
34b97201 210extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/);
0875b58f 211
212/* --- @sym_next@ --- *
213 *
214 * Arguments: @sym_iter *i@ = pointer to iterator object
215 *
216 * Returns: Pointer to the next symbol found, or null when finished.
217 *
218 * Use: Returns the next symbol from the table. Symbols are not
219 * returned in any particular order.
220 */
221
222extern void *sym_next(sym_iter */*i*/);
223
224/*----- That's all, folks -------------------------------------------------*/
225
226#ifdef __cplusplus
227 }
228#endif
229
230#endif