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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <shared/array.h>
  26
  27 /* basic pointer array growing in steps */
  28
  29
  30 static int array_realloc(struct array *array, size_t new_total)
  31 {
  32         void *tmp = realloc(array->array, sizeof(void *) * new_total);
  33         if (tmp == NULL)
  34                 return -ENOMEM;
  35         array->array = tmp;
  36         array->total = new_total;
  37         return 0;
  38 }
  39
  40 void array_init(struct array *array, size_t step)
  41 {
  42         assert(step > 0);
  43         array->array = NULL;
  44         array->count = 0;
  45         array->total = 0;
  46         array->step = step;
  47 }
  48
  49 int array_append(struct array *array, const void *element)
  50 {
  51         size_t idx;
  52
  53         if (array->count + 1 >= array->total) {
  54                 int r = array_realloc(array, array->total + array->step);
  55                 if (r < 0)
  56                         return r;
  57         }
  58         idx = array->count;
  59         array->array[idx] = (void *)element;
  60         array->count++;
  61         return idx;
  62 }
  63
  64 int array_append_unique(struct array *array, const void *element)
  65 {
  66         void **itr = array->array;
  67         void **itr_end = itr + array->count;
  68         for (; itr < itr_end; itr++)
  69                 if (*itr == element)
  70                         return -EEXIST;
  71         return array_append(array, element);
  72 }
  73
  74 void array_pop(struct array *array) {
  75         array->count--;
  76         if (array->count + array->step < array->total) {
  77                 int r = array_realloc(array, array->total - array->step);
  78                 if (r < 0)
  79                         return;
  80         }
  81 }
  82
  83 void array_free_array(struct array *array) {
  84         free(array->array);
  85         array->count = 0;
  86         array->total = 0;
  87 }
  88
  89
  90 void array_sort(struct array *array, int (*cmp)(const void *a, const void *b))
  91 {
  92         qsort(array->array, array->count, sizeof(void *), cmp);
  93 }
  94
  95 int array_remove_at(struct array *array, unsigned int pos)
  96 {
  97         if (array->count <= pos)
  98                 return -ENOENT;
  99
 100         array->count--;
 101         if (pos < array->count)
 102                 memmove(array->array + pos, array->array + pos + 1,
 103                         sizeof(void *) * (array->count - pos));
 104
 105         if (array->count + array->step < array->total) {
 106                 int r = array_realloc(array, array->total - array->step);
 107                 /* ignore error */
 108                 if (r < 0)
 109                         return 0;
 110         }
 111
 112         return 0;
 113 }