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 : /**
57 : * Array container type.
58 : * \note Don't use internal fields directly, but access the container only using functions.
59 : */
60 : typedef struct tommy_array_struct {
61 : void** bucket[TOMMY_SIZE_BIT]; /**< Dynamic array of buckets. */
62 : tommy_size_t bucket_max; /**< Number of buckets. */
63 : tommy_size_t count; /**< Number of initialized elements in the array. */
64 : tommy_uint_t bucket_bit; /**< Bits used in the bit mask. */
65 : } tommy_array;
66 :
67 : /**
68 : * Initializes the array.
69 : */
70 : void tommy_array_init(tommy_array* array);
71 :
72 : /**
73 : * Deinitializes the array.
74 : */
75 : void tommy_array_done(tommy_array* array);
76 :
77 : /**
78 : * Grows the size up to the specified value.
79 : * All the new elements in the array are initialized with the 0 value.
80 : */
81 : void tommy_array_grow(tommy_array* array, tommy_size_t size);
82 :
83 : /**
84 : * Gets a reference of the element at the specified position.
85 : * You must be sure that space for this position is already
86 : * allocated calling tommy_array_grow().
87 : */
88 450048832 : tommy_inline void** tommy_array_ref(tommy_array* array, tommy_size_t pos)
89 : {
90 : tommy_uint_t bsr;
91 :
92 450048832 : assert(pos < array->count);
93 :
94 : /* get the highest bit set, in case of all 0, return 0 */
95 450048832 : bsr = tommy_ilog2(pos | 1);
96 :
97 450048832 : return &array->bucket[bsr][pos];
98 : }
99 :
100 : /**
101 : * Sets the element at the specified position.
102 : * You must be sure that space for this position is already
103 : * allocated calling tommy_array_grow().
104 : */
105 50024416 : tommy_inline void tommy_array_set(tommy_array* array, tommy_size_t pos, void* element)
106 : {
107 50024416 : *tommy_array_ref(array, pos) = element;
108 50024416 : }
109 :
110 : /**
111 : * Gets the element at the specified position.
112 : * You must be sure that space for this position is already
113 : * allocated calling tommy_array_grow().
114 : */
115 400024416 : tommy_inline void* tommy_array_get(tommy_array* array, tommy_size_t pos)
116 : {
117 400024416 : return *tommy_array_ref(array, pos);
118 : }
119 :
120 : /**
121 : * Grows and inserts a new element at the end of the array.
122 : */
123 : tommy_inline void tommy_array_insert(tommy_array* array, void* element)
124 : {
125 : tommy_size_t pos = array->count;
126 :
127 : tommy_array_grow(array, pos + 1);
128 :
129 : tommy_array_set(array, pos, element);
130 : }
131 :
132 : /**
133 : * Gets the initialized size of the array.
134 : */
135 100024420 : tommy_inline tommy_size_t tommy_array_size(tommy_array* array)
136 : {
137 100024420 : return array->count;
138 : }
139 :
140 : /**
141 : * Gets the size of allocated memory.
142 : */
143 : tommy_size_t tommy_array_memory_usage(tommy_array* array);
144 :
145 : #endif
146 :
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