Clean-up: tests: notification-client: unused assignment
[lttng-tools.git] / src / common / dynamic-array.h
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2c5ff4e4 1/*
ab5be9fa 2 * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
2c5ff4e4 3 *
ab5be9fa 4 * SPDX-License-Identifier: LGPL-2.1-only
2c5ff4e4 5 *
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6 */
7
8#ifndef LTTNG_DYNAMIC_ARRAY_H
9#define LTTNG_DYNAMIC_ARRAY_H
10
11#include <common/dynamic-buffer.h>
12#include <assert.h>
13
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14typedef void (*lttng_dynamic_array_element_destructor)(void *element);
15typedef void (*lttng_dynamic_pointer_array_destructor)(void *ptr);
16
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17struct lttng_dynamic_array {
18 struct lttng_dynamic_buffer buffer;
19 size_t element_size;
20 size_t size;
93bed9fe 21 lttng_dynamic_array_element_destructor destructor;
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22};
23
24struct lttng_dynamic_pointer_array {
25 struct lttng_dynamic_array array;
26};
27
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28/*
29 * Initialize a resizable array of fixed-size elements. This performs no
30 * allocation and can't fail.
31 */
32LTTNG_HIDDEN
33void lttng_dynamic_array_init(struct lttng_dynamic_array *array,
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34 size_t element_size,
35 lttng_dynamic_array_element_destructor destructor);
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36
37/*
38 * Returns the number of elements in the dynamic array.
39 */
40static inline
41size_t lttng_dynamic_array_get_count(
42 const struct lttng_dynamic_array *array)
43{
44 return array->size;
45}
46
47/*
48 * Returns a pointer to the element. Mutating operations on the array invalidate
49 * the returned pointer.
50 */
51static inline
52void *lttng_dynamic_array_get_element(const struct lttng_dynamic_array *array,
53 size_t element_index)
54{
55 assert(element_index < array->size);
56 return array->buffer.data + (element_index * array->element_size);
57}
58
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59/*
60 * Set the array's element count to new_element_count. Any added element will
61 * be zeroed.
62 *
63 * Be careful to expand the array's element count _before_ calling out external
64 * APIs (e.g. read(3)) which may populate the buffer as setting the element
65 * count after will zero-out the result of the operation.
66 *
67 * Shrinking an array does not zero the old content. If the buffer may contain
68 * sensititve information, it must be cleared manually _before_ changing the
69 * size.
70 *
71 * NOTE: It is striclty _invalid_ to access memory after _size_, regardless
72 * of prior calls to set_capacity().
73 */
74LTTNG_HIDDEN
75int lttng_dynamic_array_set_count(struct lttng_dynamic_array *array,
76 size_t new_element_count);
77
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78/*
79 * Add an element to the end of a dynamic array. The array's element count is
80 * increased by one and its underlying capacity is adjusted automatically.
81 *
82 * element is a pointer to the element to add (copy) to the array.
83 */
84LTTNG_HIDDEN
85int lttng_dynamic_array_add_element(struct lttng_dynamic_array *array,
86 const void *element);
87
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88/*
89 * Remove an element from the dynamic array. The array's element count is
90 * decreased by one and the following elements are shifted to take its place
91 * (when applicable).
92 */
93LTTNG_HIDDEN
94int lttng_dynamic_array_remove_element(struct lttng_dynamic_array *array,
95 size_t element_index);
96
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97/* Release any memory used by the dynamic array. */
98LTTNG_HIDDEN
93bed9fe 99void lttng_dynamic_array_reset(struct lttng_dynamic_array *array);
2c5ff4e4 100
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101/* Remove all elements from the dynamic array. */
102LTTNG_HIDDEN
103void lttng_dynamic_array_clear(struct lttng_dynamic_array *array);
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104
105/*
106 * Specialization of lttng_dynamic_array for pointers. This utility
107 * is built under the assumption that pointer sizes are equal
108 * for all data types on supported architectures. Revisit this in the event
109 * of a port to an Harvard architecture.
110 */
111
112/*
113 * Initialize a resizable array of fixed-size elements. This performs no
114 * allocation and can't fail.
115 */
116LTTNG_HIDDEN
117void lttng_dynamic_pointer_array_init(
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118 struct lttng_dynamic_pointer_array *array,
119 lttng_dynamic_pointer_array_destructor destructor);
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120
121/*
122 * Returns the number of pointers in the dynamic pointer array.
123 */
124static inline
125size_t lttng_dynamic_pointer_array_get_count(
126 const struct lttng_dynamic_pointer_array *array)
127{
128 return lttng_dynamic_array_get_count(&array->array);
129}
130
131/*
14c4262b 132 * Returns the pointer at index `index`.
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133 */
134static inline
135void *lttng_dynamic_pointer_array_get_pointer(
136 const struct lttng_dynamic_pointer_array *array, size_t index)
137{
138 void **element = lttng_dynamic_array_get_element(&array->array, index);
139
140 return *element;
141}
142
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143/*
144 * Returns the pointer at index `index`, sets the array slot to NULL. Does not
145 * run the destructor.
146 */
147
148static inline
149void *lttng_dynamic_pointer_array_steal_pointer(
150 struct lttng_dynamic_pointer_array *array, size_t index)
151{
152 void **p_element = lttng_dynamic_array_get_element(&array->array, index);
153 void *element = *p_element;
154
155 *p_element = NULL;
156
157 return element;
158}
159
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160/*
161 * Add a pointer to the end of a dynamic pointer array. The array's element
162 * count is increased by one and its underlying capacity is adjusted
163 * automatically.
164 */
165static inline
166int lttng_dynamic_pointer_array_add_pointer(
167 struct lttng_dynamic_pointer_array *array, void *pointer)
168{
169 return lttng_dynamic_array_add_element(&array->array, &pointer);
170}
171
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172/*
173 * Remove a pointer from a dynamic pointer array. The array's element
174 * count is decreased by one and the following pointers are shifted to
175 * take the place of the removed pointer (if applicable).
176 */
0186592a 177LTTNG_HIDDEN
93bed9fe 178int lttng_dynamic_pointer_array_remove_pointer(
0186592a 179 struct lttng_dynamic_pointer_array *array, size_t index);
93bed9fe 180
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181/* Release any memory used by the dynamic array. */
182LTTNG_HIDDEN
183void lttng_dynamic_pointer_array_reset(
93bed9fe 184 struct lttng_dynamic_pointer_array *array);
2c5ff4e4 185
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186/* Remove all elements from the dynamic pointer array. */
187LTTNG_HIDDEN
188void lttng_dynamic_pointer_array_clear(
189 struct lttng_dynamic_pointer_array *array);
190
2c5ff4e4 191#endif /* LTTNG_DYNAMIC_ARRAY_H */
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