src/util-slist.c

   1 /*
   2     Copyright (C) 2012
   3     Ben Kibbey <bjk@luxsci.net>
   4
   5     This file is part of pwmd.
   6
   7     Pwmd is free software: you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation, either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     Pwmd is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with Pwmd.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include "util-slist.h"
  26 #include "mem.h"
  27
  28 unsigned slist_length(struct slist_s *list)
  29 {
  30     struct slist_s *cur;
  31     unsigned n = 0;
  32
  33     for (cur = list; cur; cur = cur->next)
  34         n++;
  35
  36     return n;
  37 }
  38
  39 void *slist_nth_data(struct slist_s *list, unsigned n)
  40 {
  41     struct slist_s *cur;
  42     unsigned i;
  43
  44     for (i = 0, cur = list; cur; cur = cur->next, i++) {
  45         if (i == n)
  46             return cur->data;
  47     }
  48
  49     return NULL;
  50 }
  51
  52 struct slist_s *slist_append(struct slist_s *list, void *data)
  53 {
  54     struct slist_s *cur;
  55
  56     if (!list) {
  57         cur = xcalloc(1, sizeof(struct slist_s));
  58         cur->data = data;
  59         return cur;
  60     }
  61
  62     for (cur = list; cur; cur = cur->next) {
  63         if (!cur->next)
  64             break;
  65     }
  66
  67     cur->next = xcalloc(1, sizeof(struct slist_s));
  68     cur->next->data = data;
  69     return list;
  70 }
  71
  72 static struct slist_s *free_once(struct slist_s *cur)
  73 {
  74     struct slist_s *next = cur ? cur->next : NULL;
  75
  76     xfree(cur);
  77     return next;
  78 }
  79
  80 void slist_free(struct slist_s *list)
  81 {
  82     while (list)
  83         list = free_once(list);
  84 }
  85
  86 struct slist_s *slist_remove(struct slist_s *list, void *data)
  87 {
  88     struct slist_s *prev, *cur;
  89
  90     for (cur = prev = list; cur; prev = cur, cur = cur->next) {
  91         if (cur->data == data) {
  92             struct slist_s *next = free_once(cur);
  93
  94             if (cur != list)
  95                 prev->next = next;
  96             else
  97                 list = next;
  98             break;
  99         }
 100     }
 101
 102     return list;
 103 }