src/common/dynamic-array.h

   1 /*
   2  * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef LTTNG_DYNAMIC_ARRAY_H
  19 #define LTTNG_DYNAMIC_ARRAY_H
  20
  21 #include <common/dynamic-buffer.h>
  22 #include <assert.h>
  23
  24 typedef void (*lttng_dynamic_array_element_destructor)(void *element);
  25 typedef void (*lttng_dynamic_pointer_array_destructor)(void *ptr);
  26
  27 struct lttng_dynamic_array {
  28         struct lttng_dynamic_buffer buffer;
  29         size_t element_size;
  30         size_t size;
  31         lttng_dynamic_array_element_destructor destructor;
  32 };
  33
  34 struct lttng_dynamic_pointer_array {
  35         struct lttng_dynamic_array array;
  36 };
  37
  38 /*
  39  * Initialize a resizable array of fixed-size elements. This performs no
  40  * allocation and can't fail.
  41  */
  42 LTTNG_HIDDEN
  43 void lttng_dynamic_array_init(struct lttng_dynamic_array *array,
  44                 size_t element_size,
  45                 lttng_dynamic_array_element_destructor destructor);
  46
  47 /*
  48  * Returns the number of elements in the dynamic array.
  49  */
  50 static inline
  51 size_t lttng_dynamic_array_get_count(
  52                 const struct lttng_dynamic_array *array)
  53 {
  54         return array->size;
  55 }
  56
  57 /*
  58  * Returns a pointer to the element. Mutating operations on the array invalidate
  59  * the returned pointer.
  60  */
  61 static inline
  62 void *lttng_dynamic_array_get_element(const struct lttng_dynamic_array *array,
  63                 size_t element_index)
  64 {
  65         assert(element_index < array->size);
  66         return array->buffer.data + (element_index * array->element_size);
  67 }
  68
  69 /*
  70  * Add an element to the end of a dynamic array. The array's element count is
  71  * increased by one and its underlying capacity is adjusted automatically.
  72  *
  73  * element is a pointer to the element to add (copy) to the array.
  74  */
  75 LTTNG_HIDDEN
  76 int lttng_dynamic_array_add_element(struct lttng_dynamic_array *array,
  77                 const void *element);
  78
  79 /*
  80  * Remove an element from the dynamic array. The array's element count is
  81  * decreased by one and the following elements are shifted to take its place
  82  * (when applicable).
  83  */
  84 LTTNG_HIDDEN
  85 int lttng_dynamic_array_remove_element(struct lttng_dynamic_array *array,
  86                 size_t element_index);
  87
  88 /* Release any memory used by the dynamic array. */
  89 LTTNG_HIDDEN
  90 void lttng_dynamic_array_reset(struct lttng_dynamic_array *array);
  91
  92
  93 /*
  94  * Specialization of lttng_dynamic_array for pointers. This utility
  95  * is built under the assumption that pointer sizes are equal
  96  * for all data types on supported architectures. Revisit this in the event
  97  * of a port to an Harvard architecture.
  98  */
  99
 100 /*
 101  * Initialize a resizable array of fixed-size elements. This performs no
 102  * allocation and can't fail.
 103  */
 104 LTTNG_HIDDEN
 105 void lttng_dynamic_pointer_array_init(
 106                 struct lttng_dynamic_pointer_array *array,
 107                 lttng_dynamic_pointer_array_destructor destructor);
 108
 109 /*
 110  * Returns the number of pointers in the dynamic pointer array.
 111  */
 112 static inline
 113 size_t lttng_dynamic_pointer_array_get_count(
 114                 const struct lttng_dynamic_pointer_array *array)
 115 {
 116         return lttng_dynamic_array_get_count(&array->array);
 117 }
 118
 119 /*
 120  * Returns the pointer at index `index`.
 121  */
 122 static inline
 123 void *lttng_dynamic_pointer_array_get_pointer(
 124                 const struct lttng_dynamic_pointer_array *array, size_t index)
 125 {
 126         void **element = lttng_dynamic_array_get_element(&array->array, index);
 127
 128         return *element;
 129 }
 130
 131 /*
 132  * Add a pointer to the end of a dynamic pointer array. The array's element
 133  * count is increased by one and its underlying capacity is adjusted
 134  * automatically.
 135  */
 136 static inline
 137 int lttng_dynamic_pointer_array_add_pointer(
 138                 struct lttng_dynamic_pointer_array *array, void *pointer)
 139 {
 140         return lttng_dynamic_array_add_element(&array->array, &pointer);
 141 }
 142
 143 /*
 144  * Remove a pointer from a dynamic pointer array. The array's element
 145  * count is decreased by one and the following pointers are shifted to
 146  * take the place of the removed pointer (if applicable).
 147  */
 148 LTTNG_HIDDEN
 149 int lttng_dynamic_pointer_array_remove_pointer(
 150                 struct lttng_dynamic_pointer_array *array, size_t index);
 151
 152 /* Release any memory used by the dynamic array. */
 153 LTTNG_HIDDEN
 154 void lttng_dynamic_pointer_array_reset(
 155                 struct lttng_dynamic_pointer_array *array);
 156
 157 #endif /* LTTNG_DYNAMIC_ARRAY_H */