1 /*
2 chronyd/chronyc - Programs for keeping computer clocks accurate.
3
4 **********************************************************************
5 * Copyright (C) Miroslav Lichvar 2014
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of version 2 of the GNU General Public License as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 *
20 **********************************************************************
21
22 =======================================================================
23
24 Functions implementing an array with automatic memory allocation.
25
26 */
27
28 #include "config.h"
29
30 #include "sysincl.h"
31
32 #include "array.h"
33 #include "memory.h"
34
35 struct ARR_Instance_Record {
36 void *data;
37 unsigned int elem_size;
38 unsigned int used;
39 unsigned int allocated;
40 };
41
42 ARR_Instance
ARR_CreateInstance(unsigned int elem_size)43 ARR_CreateInstance(unsigned int elem_size)
44 {
45 ARR_Instance array;
46
47 assert(elem_size > 0);
48
49 array = MallocNew(struct ARR_Instance_Record);
50
51 array->data = NULL;
52 array->elem_size = elem_size;
53 array->used = 0;
54 array->allocated = 0;
55
56 return array;
57 }
58
59 void
ARR_DestroyInstance(ARR_Instance array)60 ARR_DestroyInstance(ARR_Instance array)
61 {
62 Free(array->data);
63 Free(array);
64 }
65
66 static void
realloc_array(ARR_Instance array,unsigned int min_size)67 realloc_array(ARR_Instance array, unsigned int min_size)
68 {
69 assert(min_size <= 2 * min_size);
70 if (array->allocated >= min_size && array->allocated <= 2 * min_size)
71 return;
72
73 if (array->allocated < min_size) {
74 while (array->allocated < min_size)
75 array->allocated = array->allocated ? 2 * array->allocated : 1;
76 } else {
77 array->allocated = min_size;
78 }
79
80 array->data = Realloc2(array->data, array->allocated, array->elem_size);
81 }
82
83 void *
ARR_GetNewElement(ARR_Instance array)84 ARR_GetNewElement(ARR_Instance array)
85 {
86 array->used++;
87 realloc_array(array, array->used);
88 return ARR_GetElement(array, array->used - 1);
89 }
90
91 void *
ARR_GetElement(ARR_Instance array,unsigned int index)92 ARR_GetElement(ARR_Instance array, unsigned int index)
93 {
94 assert(index < array->used);
95 return (void *)((char *)array->data + (size_t)index * array->elem_size);
96 }
97
98 void *
ARR_GetElements(ARR_Instance array)99 ARR_GetElements(ARR_Instance array)
100 {
101 /* Return a non-NULL pointer when the array has zero size */
102 if (!array->data) {
103 assert(!array->used);
104 return array;
105 }
106
107 return array->data;
108 }
109
110 void
ARR_AppendElement(ARR_Instance array,void * element)111 ARR_AppendElement(ARR_Instance array, void *element)
112 {
113 void *e;
114
115 e = ARR_GetNewElement(array);
116 memcpy(e, element, array->elem_size);
117 }
118
119 void
ARR_SetSize(ARR_Instance array,unsigned int size)120 ARR_SetSize(ARR_Instance array, unsigned int size)
121 {
122 realloc_array(array, size);
123 array->used = size;
124 }
125
126 unsigned int
ARR_GetSize(ARR_Instance array)127 ARR_GetSize(ARR_Instance array)
128 {
129 return array->used;
130 }
131