Line data Source code
1 : /*
2 : * Copyright (c) 2013, Andrea Mazzoleni. All rights reserved.
3 : *
4 : * Redistribution and use in source and binary forms, with or without
5 : * modification, are permitted provided that the following conditions
6 : * are met:
7 : *
8 : * 1. Redistributions of source code must retain the above copyright
9 : * notice, this list of conditions and the following disclaimer.
10 : *
11 : * 2. Redistributions in binary form must reproduce the above copyright
12 : * notice, this list of conditions and the following disclaimer in the
13 : * documentation and/or other materials provided with the distribution.
14 : *
15 : * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 : * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 : * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19 : * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 : * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 : * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 : * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 : * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 : * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 : * POSSIBILITY OF SUCH DAMAGE.
26 : */
27 :
28 : /** \file
29 : * Dynamic array based on blocks of fixed size.
30 : *
31 : * This array is able to grow dynamically upon request, without any reallocation.
32 : *
33 : * The grow operation involves an allocation of a new array block, without reallocating
34 : * the already used memory, and then not increasing the heap fragmentation,
35 : * and minimize the space occupation.
36 : * This also implies that the address of the stored elements never change.
37 : *
38 : * Allocated blocks are always of the same fixed size of 4 Ki pointers.
39 : */
40 :
41 : #ifndef __TOMMYARRAYBLK_H
42 : #define __TOMMYARRAYBLK_H
43 :
44 : #include "tommytypes.h"
45 : #include "tommyarray.h"
46 :
47 : #include <assert.h> /* for assert */
48 :
49 : /******************************************************************************/
50 : /* array */
51 :
52 : /**
53 : * Elements for each block.
54 : */
55 : #define TOMMY_ARRAYBLK_SIZE (4 * 1024)
56 :
57 : /**
58 : * Array container type.
59 : * \note Don't use internal fields directly, but access the container only using functions.
60 : */
61 : typedef struct tommy_arrayblk_struct {
62 : tommy_array block; /**< Array of blocks. */
63 : tommy_size_t count; /**< Number of initialized elements in the array. */
64 : } tommy_arrayblk;
65 :
66 : /**
67 : * Initializes the array.
68 : */
69 : void tommy_arrayblk_init(tommy_arrayblk* array);
70 :
71 : /**
72 : * Deinitializes the array.
73 : */
74 : void tommy_arrayblk_done(tommy_arrayblk* array);
75 :
76 : /**
77 : * Grows the size up to the specified value.
78 : * All the new elements in the array are initialized with the 0 value.
79 : */
80 : void tommy_arrayblk_grow(tommy_arrayblk* array, tommy_size_t size);
81 :
82 : /**
83 : * Gets a reference of the element at the specified position.
84 : * You must be sure that space for this position is already
85 : * allocated calling tommy_arrayblk_grow().
86 : */
87 150000000 : tommy_inline void** tommy_arrayblk_ref(tommy_arrayblk* array, tommy_size_t pos)
88 : {
89 : void** ptr;
90 :
91 150000000 : assert(pos < array->count);
92 :
93 150000000 : ptr = tommy_cast(void**, tommy_array_get(&array->block, pos / TOMMY_ARRAYBLK_SIZE));
94 :
95 150000000 : return &ptr[pos % TOMMY_ARRAYBLK_SIZE];
96 : }
97 :
98 : /**
99 : * Sets the element at the specified position.
100 : * You must be sure that space for this position is already
101 : * allocated calling tommy_arrayblk_grow().
102 : */
103 50000000 : tommy_inline void tommy_arrayblk_set(tommy_arrayblk* array, tommy_size_t pos, void* element)
104 : {
105 50000000 : *tommy_arrayblk_ref(array, pos) = element;
106 50000000 : }
107 :
108 : /**
109 : * Gets the element at the specified position.
110 : * You must be sure that space for this position is already
111 : * allocated calling tommy_arrayblk_grow().
112 : */
113 100000000 : tommy_inline void* tommy_arrayblk_get(tommy_arrayblk* array, tommy_size_t pos)
114 : {
115 100000000 : return *tommy_arrayblk_ref(array, pos);
116 : }
117 :
118 : /**
119 : * Grows and inserts a new element at the end of the array.
120 : */
121 : tommy_inline void tommy_arrayblk_insert(tommy_arrayblk* array, void* element)
122 : {
123 : tommy_size_t pos = array->count;
124 :
125 : tommy_arrayblk_grow(array, pos + 1);
126 :
127 : tommy_arrayblk_set(array, pos, element);
128 : }
129 :
130 : /**
131 : * Gets the initialized size of the array.
132 : */
133 : tommy_inline tommy_size_t tommy_arrayblk_size(tommy_arrayblk* array)
134 : {
135 : return array->count;
136 : }
137 :
138 : /**
139 : * Gets the size of allocated memory.
140 : */
141 : tommy_size_t tommy_arrayblk_memory_usage(tommy_arrayblk* array);
142 :
143 : #endif
144 :
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