release/src/router/busybox/libbb/llist.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * linked list helper functions.
   4  *
   5  * Copyright (C) 2003 Glenn McGrath
   6  * Copyright (C) 2005 Vladimir Oleynik
   7  * Copyright (C) 2005 Bernhard Reutner-Fischer
   8  * Copyright (C) 2006 Rob Landley <rob@landley.net>
   9  *
  10  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  11  */
  12
  13 #include "libbb.h"
  14
  15 /* Add data to the start of the linked list.  */
  16 void FAST_FUNC llist_add_to(llist_t **old_head, void *data)
  17 {
  18         llist_t *new_head = xmalloc(sizeof(llist_t));
  19
  20         new_head->data = data;
  21         new_head->link = *old_head;
  22         *old_head = new_head;
  23 }
  24
  25 /* Add data to the end of the linked list.  */
  26 void FAST_FUNC llist_add_to_end(llist_t **list_head, void *data)
  27 {
  28         while (*list_head)
  29                 list_head = &(*list_head)->link;
  30         *list_head = xzalloc(sizeof(llist_t));
  31         (*list_head)->data = data;
  32         /*(*list_head)->link = NULL;*/
  33 }
  34
  35 /* Remove first element from the list and return it */
  36 void* FAST_FUNC llist_pop(llist_t **head)
  37 {
  38         void *data = NULL;
  39         llist_t *temp = *head;
  40
  41         if (temp) {
  42                 data = temp->data;
  43                 *head = temp->link;
  44                 free(temp);
  45         }
  46         return data;
  47 }
  48
  49 /* Unlink arbitrary given element from the list */
  50 void FAST_FUNC llist_unlink(llist_t **head, llist_t *elm)
  51 {
  52         if (!elm)
  53                 return;
  54         while (*head) {
  55                 if (*head == elm) {
  56                         *head = (*head)->link;
  57                         break;
  58                 }
  59                 head = &(*head)->link;
  60         }
  61 }
  62
  63 /* Recursively free all elements in the linked list.  If freeit != NULL
  64  * call it on each datum in the list */
  65 void FAST_FUNC llist_free(llist_t *elm, void (*freeit)(void *data))
  66 {
  67         while (elm) {
  68                 void *data = llist_pop(&elm);
  69
  70                 if (freeit)
  71                         freeit(data);
  72         }
  73 }
  74
  75 /* Reverse list order. */
  76 llist_t* FAST_FUNC llist_rev(llist_t *list)
  77 {
  78         llist_t *rev = NULL;
  79
  80         while (list) {
  81                 llist_t *next = list->link;
  82
  83                 list->link = rev;
  84                 rev = list;
  85                 list = next;
  86         }
  87         return rev;
  88 }
  89
  90 llist_t* FAST_FUNC llist_find_str(llist_t *list, const char *str)
  91 {
  92         while (list) {
  93                 if (strcmp(list->data, str) == 0)
  94                         break;
  95                 list = list->link;
  96         }
  97         return list;
  98 }