Line data Source code
1 : /* ccparray.c - A simple dynamic array for character pointer.
2 : * Copyright (C) 2016 g10 Code GmbH
3 : *
4 : * This file is part of GnuPG.
5 : *
6 : * This file is free software; you can redistribute it and/or modify
7 : * it under the terms of either
8 : *
9 : * - the GNU Lesser General Public License as published by the Free
10 : * Software Foundation; either version 3 of the License, or (at
11 : * your option) any later version.
12 : *
13 : * or
14 : *
15 : * - the GNU General Public License as published by the Free
16 : * Software Foundation; either version 2 of the License, or (at
17 : * your option) any later version.
18 : *
19 : * or both in parallel, as here.
20 : *
21 : * This file is distributed in the hope that it will be useful,
22 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 : * GNU General Public License for more details.
25 : *
26 : * You should have received a copy of the GNU General Public License
27 : * along with this program; if not, see <http://www.gnu.org/licenses/>.
28 : */
29 :
30 : #include <config.h>
31 : #include <stdlib.h>
32 : #include <errno.h>
33 : #include <stdarg.h>
34 :
35 : #include "util.h"
36 : #include "ccparray.h"
37 :
38 :
39 : /* A simple implementation of a dynamic array of const char pointers.
40 : * The example code:
41 : *
42 : * ccparray_t ccp;
43 : * const char **argv;
44 : * int i;
45 : *
46 : * ccparray_init (&ccp, 0);
47 : * ccparray_put (&ccp, "First arg");
48 : * ccparray_put (&ccp, "Second arg");
49 : * ccparray_put (&ccp, NULL);
50 : * ccparray_put (&ccp, "Fourth arg");
51 : * argv = ccparray_get (&ccp, NULL);
52 : * if (!argv)
53 : * die ("error building array: %s\n", strerror (errno));
54 : * for (i=0; argv[i]; i++)
55 : * printf ("[%d] = '%s'\n", i, argv[i]);
56 : * xfree (argv);
57 : *
58 : * will result in this output:
59 : *
60 : * [0] = 'First arg'
61 : * [1] = 'Second arg'
62 : *
63 : * Note that allocation errors are detected but only returned with the
64 : * final ccparray_get(); this helps not to clutter the code with out
65 : * of core checks.
66 : */
67 :
68 : void
69 24 : ccparray_init (ccparray_t *cpa, unsigned int initialsize)
70 : {
71 24 : if (!initialsize)
72 24 : cpa->size = 16;
73 0 : else if (initialsize < (1<<16))
74 0 : cpa->size = initialsize;
75 : else
76 0 : cpa->size = (1<<16);
77 :
78 24 : cpa->count = 0;
79 24 : cpa->out_of_core = 0;
80 24 : cpa->array = xtrycalloc (cpa->size, sizeof *cpa->array);
81 24 : if (!cpa->array)
82 0 : cpa->out_of_core = errno;
83 24 : }
84 :
85 :
86 : void
87 4221 : ccparray_put (ccparray_t *cpa, const char *value)
88 : {
89 4221 : if (cpa->out_of_core)
90 0 : return;
91 :
92 4221 : if (cpa->count + 1 >= cpa->size)
93 : {
94 : const char **newarray;
95 : size_t n, newsize;
96 :
97 9 : if (cpa->size < 8)
98 0 : newsize = 16;
99 9 : else if (cpa->size < 4096)
100 8 : newsize = 2 * cpa->size;
101 1 : else if (cpa->size < (1<<16))
102 1 : newsize = cpa->size + 2048;
103 : else
104 : {
105 0 : cpa->out_of_core = ENOMEM;
106 0 : return;
107 : }
108 :
109 9 : newarray = xtrycalloc (newsize, sizeof *newarray);
110 9 : if (!newarray)
111 : {
112 0 : cpa->out_of_core = errno ? errno : ENOMEM;
113 0 : return;
114 : }
115 8185 : for (n=0; n < cpa->size; n++)
116 8176 : newarray[n] = cpa->array[n];
117 9 : xfree (cpa->array);
118 9 : cpa->array = newarray;
119 9 : cpa->size = newsize;
120 :
121 : }
122 4221 : cpa->array[cpa->count++] = value;
123 : }
124 :
125 :
126 : const char **
127 24 : ccparray_get (ccparray_t *cpa, size_t *r_count)
128 : {
129 : const char **result;
130 :
131 24 : if (cpa->out_of_core)
132 : {
133 0 : if (cpa->array)
134 : {
135 0 : xfree (cpa->array);
136 0 : cpa->array = NULL;
137 : }
138 0 : gpg_err_set_errno (cpa->out_of_core);
139 0 : return NULL;
140 : }
141 :
142 24 : result= cpa->array;
143 24 : if (r_count)
144 6 : *r_count = cpa->count;
145 24 : cpa->array = NULL;
146 24 : cpa->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */
147 24 : return result;
148 : }
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