shared/array.c

   1 /*
   2  * libkmod - interface to kernel module operations
   3  *
   4  * Copyright (C) 2011-2013  ProFUSION embedded systems
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #include <assert.h>
  22 #include <errno.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <shared/array.h>
  27
  28 #include <libkmod.h>
  29
  30 /* basic pointer array growing in steps */
  31
  32
  33 static int array_realloc(struct array *array, size_t new_total)
  34 {
  35         void *tmp = realloc(array->array, sizeof(void *) * new_total);
  36         if (tmp == NULL)
  37                 return -ENOMEM;
  38         array->array = tmp;
  39         array->total = new_total;
  40         return 0;
  41 }
  42
  43 void array_init(struct array *array, size_t step)
  44 {
  45         assert(step > 0);
  46         array->array = NULL;
  47         array->count = 0;
  48         array->total = 0;
  49         array->step = step;
  50 }
  51
  52 int array_append(struct array *array, const void *element)
  53 {
  54         size_t idx;
  55
  56         if (array->count + 1 >= array->total) {
  57                 int r = array_realloc(array, array->total + array->step);
  58                 if (r < 0)
  59                         return r;
  60         }
  61         idx = array->count;
  62         array->array[idx] = (void *)element;
  63         array->count++;
  64         return idx;
  65 }
  66
  67 int array_append_unique(struct array *array, const void *element)
  68 {
  69         void **itr = array->array;
  70         void **itr_end = itr + array->count;
  71         for (; itr < itr_end; itr++)
  72                 if (*itr == element)
  73                         return -EEXIST;
  74         return array_append(array, element);
  75 }
  76
  77 void array_pop(struct array *array) {
  78         array->count--;
  79         if (array->count + array->step < array->total) {
  80                 int r = array_realloc(array, array->total - array->step);
  81                 if (r < 0)
  82                         return;
  83         }
  84 }
  85
  86 void array_free_array(struct array *array) {
  87         free(array->array);
  88         array->count = 0;
  89         array->total = 0;
  90 }
  91
  92
  93 void array_sort(struct array *array, int (*cmp)(const void *a, const void *b))
  94 {
  95         qsort(array->array, array->count, sizeof(void *), cmp);
  96 }
  97
  98 int array_remove_at(struct array *array, unsigned int pos)
  99 {
 100         if (array->count <= pos)
 101                 return -ENOENT;
 102
 103         array->count--;
 104         if (pos < array->count)
 105                 memmove(array->array + pos, array->array + pos + 1,
 106                         sizeof(void *) * (array->count - pos));
 107
 108         if (array->count + array->step < array->total) {
 109                 int r = array_realloc(array, array->total - array->step);
 110                 /* ignore error */
 111                 if (r < 0)
 112                         return 0;
 113         }
 114
 115         return 0;
 116 }