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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: assoc.h,v 1.2 2001/01/25 21:12:22 mdw Exp $ |
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4 | * |
5 | * Assocation tables |
6 | * |
7 | * (c) 2000 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
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 | * |
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 |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
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. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: assoc.h,v $ |
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33 | * Revision 1.2 2001/01/25 21:12:22 mdw |
34 | * Add new macro to find an association's atom key. |
35 | * |
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36 | * Revision 1.1 2001/01/20 11:50:58 mdw |
37 | * Hash tables indexed by atoms, to avoid expense of hashing keys on each |
38 | * lookup, and to reduce storage used by key texts. |
39 | * |
40 | */ |
41 | |
42 | #ifndef MLIB_ASSOC_H |
43 | #define MLIB_ASSOC_H |
44 | |
45 | #ifdef __cplusplus |
46 | extern "C" { |
47 | #endif |
48 | |
49 | /*----- Header files ------------------------------------------------------*/ |
50 | |
51 | #ifndef MLIB_ATOM_H |
52 | # include "atom.h" |
53 | #endif |
54 | |
55 | #ifndef MLIB_HASH_H |
56 | # include "hash.h" |
57 | #endif |
58 | |
59 | /*----- Data structures ---------------------------------------------------*/ |
60 | |
61 | typedef struct assoc_table { |
62 | hash_table t; |
63 | size_t load; |
64 | } assoc_table; |
65 | |
66 | typedef struct assoc_base { |
67 | hash_base b; |
68 | atom *a; |
69 | } assoc_base; |
70 | |
71 | typedef struct { hash_iter i; } assoc_iter; |
72 | |
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73 | #define ASSOC_ATOM(p) (((assoc_base *)(p))->a + 0) |
74 | |
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75 | /*----- Functions provided ------------------------------------------------*/ |
76 | |
77 | /* --- @assoc_create@ --- * |
78 | * |
79 | * Arguments: @assoc_table *t@ = pointer to an association table |
80 | * |
81 | * Returns: --- |
82 | * |
83 | * Use: Creates a new association table. |
84 | */ |
85 | |
86 | extern void assoc_create(assoc_table */*t*/); |
87 | |
88 | /* --- @assoc_destroy@ --- * |
89 | * |
90 | * Arguments: @assoc_table *t@ = pointer to an association table |
91 | * |
92 | * Returns: --- |
93 | * |
94 | * Use: Destroys an association table. |
95 | */ |
96 | |
97 | extern void assoc_destroy(assoc_table */*t*/); |
98 | |
99 | /* --- @assoc_find@ --- * |
100 | * |
101 | * Arguments: @assoc_table *t@ = pointer to an association table |
102 | * @atom *a@ = an atom to label the item |
103 | * @size_t sz@ = size of block to allocate |
104 | * @unsigned *f@ = pointer to `found' flag |
105 | * |
106 | * Returns: A pointer to the item located or null. |
107 | * |
108 | * Use: Looks up an atom in an association table. If the atom is |
109 | * found, the association is returned. If not, and @sz@ is |
110 | * zero, a null pointer is returned. Otherwise, a block of size |
111 | * @sz@ is allocated, its @assoc_base@ header is filled in, and |
112 | * the pointer returned. The flag @*f@ is cleared if the item |
113 | * couldn't be found, or set if it was. |
114 | * |
115 | * All the atoms used in a particular table should |
116 | */ |
117 | |
118 | extern void *assoc_find(assoc_table */*t*/, atom */*a*/, |
119 | size_t /*sz*/, unsigned */*f*/); |
120 | |
121 | /* --- @assoc_remove@ --- * |
122 | * |
123 | * Arguments: @assoc_table *t@ = pointer to an association table |
124 | * @void *p@ = pointer to a block to remove |
125 | * |
126 | * Returns: --- |
127 | * |
128 | * Use: Removes an association from a table. |
129 | */ |
130 | |
131 | extern void assoc_remove(assoc_table */*t*/, void */*p*/); |
132 | |
133 | /* --- @assoc_mkiter@, @assoc_next@ --- * |
134 | * |
135 | * Arguments: @assoc_iter *i@ = pointer to an iterator |
136 | * @assoc_table *t@ = pointer to an association table |
137 | * |
138 | * Returns: Next association, or null, for @assoc_next@; nothing for |
139 | * @assoc_mkiter@. |
140 | * |
141 | * Use: Iterates over the associations in a table. |
142 | */ |
143 | |
144 | #define ASSOC_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t) |
145 | |
146 | #define ASSOC_NEXT(i_, p) do { \ |
147 | hash_base *_q; \ |
148 | HASH_NEXT(&(i_)->i, _q); \ |
149 | (p) = (void *)_q; \ |
150 | } while (0) |
151 | |
152 | extern void assoc_mkiter(assoc_iter */*i*/, assoc_table */*t*/); |
153 | extern void *assoc_next(assoc_iter */*i*/); |
154 | |
155 | /*----- That's all, folks -------------------------------------------------*/ |
156 | |
157 | #ifdef __cplusplus |
158 | } |
159 | #endif |
160 | |
161 | #endif |