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  1. /*
  2.  * Copyright (c) 2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup libc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <adt/list.h>
  36.  
  37.  
  38. /** Check for membership
  39.  *
  40.  * Check whether link is contained in the list head.
  41.  * The membership is defined as pointer equivalence.
  42.  *
  43.  * @param link Item to look for.
  44.  * @param head List to look in.
  45.  *
  46.  * @return true if link is contained in head, false otherwise.
  47.  *
  48.  */
  49. int list_member(const link_t *link, const link_t *head)
  50. {
  51.     int found = 0;
  52.     link_t *hlp = head->next;
  53.    
  54.     while (hlp != head) {
  55.         if (hlp == link) {
  56.             found = 1;
  57.             break;
  58.         }
  59.         hlp = hlp->next;
  60.     }
  61.    
  62.     return found;
  63. }
  64.  
  65.  
  66. /** Concatenate two lists
  67.  *
  68.  * Concatenate lists head1 and head2, producing a single
  69.  * list head1 containing items from both (in head1, head2
  70.  * order) and empty list head2.
  71.  *
  72.  * @param head1 First list and concatenated output
  73.  * @param head2 Second list and empty output.
  74.  *
  75.  */
  76. void list_concat(link_t *head1, link_t *head2)
  77. {
  78.     if (list_empty(head2))
  79.         return;
  80.    
  81.     head2->next->prev = head1->prev;
  82.     head2->prev->next = head1;
  83.     head1->prev->next = head2->next;
  84.     head1->prev = head2->prev;
  85.     list_initialize(head2);
  86. }
  87.  
  88.  
  89. /** Count list items
  90.  *
  91.  * Return the number of items in the list.
  92.  *
  93.  * @param link List to count.
  94.  *
  95.  * @return Number of items in the list.
  96.  *
  97.  */
  98. unsigned int list_count(const link_t *link)
  99. {
  100.     unsigned int count = 0;
  101.     link_t *hlp = link->next;
  102.    
  103.     while (hlp != link) {
  104.         count++;
  105.         hlp = hlp->next;
  106.     }
  107.    
  108.     return count;
  109. }
  110.  
  111. /** @}
  112.  */
  113.