dcda5944 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: assoc.h,v 1.1 2001/01/20 11:50:58 mdw Exp $ |
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 $ |
33 | * Revision 1.1 2001/01/20 11:50:58 mdw |
34 | * Hash tables indexed by atoms, to avoid expense of hashing keys on each |
35 | * lookup, and to reduce storage used by key texts. |
36 | * |
37 | */ |
38 | |
39 | #ifndef MLIB_ASSOC_H |
40 | #define MLIB_ASSOC_H |
41 | |
42 | #ifdef __cplusplus |
43 | extern "C" { |
44 | #endif |
45 | |
46 | /*----- Header files ------------------------------------------------------*/ |
47 | |
48 | #ifndef MLIB_ATOM_H |
49 | # include "atom.h" |
50 | #endif |
51 | |
52 | #ifndef MLIB_HASH_H |
53 | # include "hash.h" |
54 | #endif |
55 | |
56 | /*----- Data structures ---------------------------------------------------*/ |
57 | |
58 | typedef struct assoc_table { |
59 | hash_table t; |
60 | size_t load; |
61 | } assoc_table; |
62 | |
63 | typedef struct assoc_base { |
64 | hash_base b; |
65 | atom *a; |
66 | } assoc_base; |
67 | |
68 | typedef struct { hash_iter i; } assoc_iter; |
69 | |
70 | /*----- Functions provided ------------------------------------------------*/ |
71 | |
72 | /* --- @assoc_create@ --- * |
73 | * |
74 | * Arguments: @assoc_table *t@ = pointer to an association table |
75 | * |
76 | * Returns: --- |
77 | * |
78 | * Use: Creates a new association table. |
79 | */ |
80 | |
81 | extern void assoc_create(assoc_table */*t*/); |
82 | |
83 | /* --- @assoc_destroy@ --- * |
84 | * |
85 | * Arguments: @assoc_table *t@ = pointer to an association table |
86 | * |
87 | * Returns: --- |
88 | * |
89 | * Use: Destroys an association table. |
90 | */ |
91 | |
92 | extern void assoc_destroy(assoc_table */*t*/); |
93 | |
94 | /* --- @assoc_find@ --- * |
95 | * |
96 | * Arguments: @assoc_table *t@ = pointer to an association table |
97 | * @atom *a@ = an atom to label the item |
98 | * @size_t sz@ = size of block to allocate |
99 | * @unsigned *f@ = pointer to `found' flag |
100 | * |
101 | * Returns: A pointer to the item located or null. |
102 | * |
103 | * Use: Looks up an atom in an association table. If the atom is |
104 | * found, the association is returned. If not, and @sz@ is |
105 | * zero, a null pointer is returned. Otherwise, a block of size |
106 | * @sz@ is allocated, its @assoc_base@ header is filled in, and |
107 | * the pointer returned. The flag @*f@ is cleared if the item |
108 | * couldn't be found, or set if it was. |
109 | * |
110 | * All the atoms used in a particular table should |
111 | */ |
112 | |
113 | extern void *assoc_find(assoc_table */*t*/, atom */*a*/, |
114 | size_t /*sz*/, unsigned */*f*/); |
115 | |
116 | /* --- @assoc_remove@ --- * |
117 | * |
118 | * Arguments: @assoc_table *t@ = pointer to an association table |
119 | * @void *p@ = pointer to a block to remove |
120 | * |
121 | * Returns: --- |
122 | * |
123 | * Use: Removes an association from a table. |
124 | */ |
125 | |
126 | extern void assoc_remove(assoc_table */*t*/, void */*p*/); |
127 | |
128 | /* --- @assoc_mkiter@, @assoc_next@ --- * |
129 | * |
130 | * Arguments: @assoc_iter *i@ = pointer to an iterator |
131 | * @assoc_table *t@ = pointer to an association table |
132 | * |
133 | * Returns: Next association, or null, for @assoc_next@; nothing for |
134 | * @assoc_mkiter@. |
135 | * |
136 | * Use: Iterates over the associations in a table. |
137 | */ |
138 | |
139 | #define ASSOC_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t) |
140 | |
141 | #define ASSOC_NEXT(i_, p) do { \ |
142 | hash_base *_q; \ |
143 | HASH_NEXT(&(i_)->i, _q); \ |
144 | (p) = (void *)_q; \ |
145 | } while (0) |
146 | |
147 | extern void assoc_mkiter(assoc_iter */*i*/, assoc_table */*t*/); |
148 | extern void *assoc_next(assoc_iter */*i*/); |
149 | |
150 | /*----- That's all, folks -------------------------------------------------*/ |
151 | |
152 | #ifdef __cplusplus |
153 | } |
154 | #endif |
155 | |
156 | #endif |