Line data Source code
1 : /*
2 : * Copyright (c) 2011, 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 segments of exponential growing 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 segment, without reallocating
34 : * the already used memory, and then not increasing the heap fragmentation.
35 : * This also implies that the address of the stored elements never change.
36 : *
37 : * Allocated segments grow in size exponentially.
38 : */
39 :
40 : #ifndef __TOMMYARRAY_H
41 : #define __TOMMYARRAY_H
42 :
43 : #include "tommytypes.h"
44 :
45 : #include <assert.h> /* for assert */
46 :
47 : /******************************************************************************/
48 : /* array */
49 :
50 : /**
51 : * Initial and minimal size of the array expressed as a power of 2.
52 : * The initial size is 2^TOMMY_ARRAY_BIT.
53 : */
54 : #define TOMMY_ARRAY_BIT 6
55 :
56 : /** \internal
57 : * Max number of elements as a power of 2.
58 : */
59 : #define TOMMY_ARRAY_BIT_MAX 32
60 :
61 : /**
62 : * Array container type.
63 : * \note Don't use internal fields directly, but access the container only using functions.
64 : */
65 : typedef struct tommy_array_struct {
66 : void** bucket[TOMMY_ARRAY_BIT_MAX]; /**< Dynamic array of buckets. */
67 : tommy_uint_t bucket_bit; /**< Bits used in the bit mask. */
68 : tommy_count_t bucket_max; /**< Number of buckets. */
69 : tommy_count_t count; /**< Number of initialized elements in the array. */
70 : } tommy_array;
71 :
72 : /**
73 : * Initializes the array.
74 : */
75 : void tommy_array_init(tommy_array* array);
76 :
77 : /**
78 : * Deinitializes the array.
79 : */
80 : void tommy_array_done(tommy_array* array);
81 :
82 : /**
83 : * Grows the size up to the specified value.
84 : * All the new elements in the array are initialized with the 0 value.
85 : */
86 : void tommy_array_grow(tommy_array* array, tommy_count_t size);
87 :
88 : /**
89 : * Gets a reference of the element at the specified position.
90 : * You must be sure that space for this position is already
91 : * allocated calling tommy_array_grow().
92 : */
93 10268423 : tommy_inline void** tommy_array_ref(tommy_array* array, tommy_count_t pos)
94 : {
95 : tommy_uint_t bsr;
96 :
97 10268423 : assert(pos < array->count);
98 :
99 : /* get the highest bit set, in case of all 0, return 0 */
100 10268423 : bsr = tommy_ilog2_u32(pos | 1);
101 :
102 10268423 : return &array->bucket[bsr][pos];
103 : }
104 :
105 : /**
106 : * Sets the element at the specified position.
107 : * You must be sure that space for this position is already
108 : * allocated calling tommy_array_grow().
109 : */
110 2214 : tommy_inline void tommy_array_set(tommy_array* array, tommy_count_t pos, void* element)
111 : {
112 2214 : *tommy_array_ref(array, pos) = element;
113 2214 : }
114 :
115 : /**
116 : * Gets the element at the specified position.
117 : * You must be sure that space for this position is already
118 : * allocated calling tommy_array_grow().
119 : */
120 10266209 : tommy_inline void* tommy_array_get(tommy_array* array, tommy_count_t pos)
121 : {
122 10266209 : return *tommy_array_ref(array, pos);
123 : }
124 :
125 : /**
126 : * Grows and inserts a new element at the end of the array.
127 : */
128 256 : tommy_inline void tommy_array_insert(tommy_array* array, void* element)
129 : {
130 256 : tommy_count_t pos = array->count;
131 :
132 256 : tommy_array_grow(array, pos + 1);
133 :
134 256 : tommy_array_set(array, pos, element);
135 256 : }
136 :
137 : /**
138 : * Gets the initialized size of the array.
139 : */
140 1575778 : tommy_inline tommy_count_t tommy_array_size(tommy_array* array)
141 : {
142 1575778 : return array->count;
143 : }
144 :
145 : /**
146 : * Gets the size of allocated memory.
147 : */
148 : tommy_size_t tommy_array_memory_usage(tommy_array* array);
149 :
150 : #endif
151 :
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