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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 genericadt
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Functions completing doubly linked circular list implementaion.
  36.  *
  37.  * This file contains some of the functions implementing doubly linked circular lists.
  38.  * However, this ADT is mostly implemented in @ref list.h.
  39.  */
  40.  
  41. #include <adt/list.h>
  42.  
  43. /** Check for membership
  44.  *
  45.  * Check whether link is contained in the list head.
  46.  * The membership is defined as pointer equivalence.
  47.  *
  48.  * @param link Item to look for.
  49.  * @param head List to look in.
  50.  *
  51.  * @return true if link is contained in head, false otherwise.
  52.  *
  53.  */
  54. bool list_member(const link_t *link, const link_t *head)
  55. {
  56.     bool found = false;
  57.     link_t *hlp = head->next;
  58.    
  59.     while (hlp != head) {
  60.         if (hlp == link) {
  61.             found = true;
  62.             break;
  63.         }
  64.         hlp = hlp->next;
  65.     }
  66.    
  67.     return found;
  68. }
  69.  
  70.  
  71. /** Concatenate two lists
  72.  *
  73.  * Concatenate lists head1 and head2, producing a single
  74.  * list head1 containing items from both (in head1, head2
  75.  * order) and empty list head2.
  76.  *
  77.  * @param head1 First list and concatenated output
  78.  * @param head2 Second list and empty output.
  79.  *
  80.  */
  81. void list_concat(link_t *head1, link_t *head2)
  82. {
  83.     if (list_empty(head2))
  84.         return;
  85.  
  86.     head2->next->prev = head1->prev;
  87.     head2->prev->next = head1; 
  88.     head1->prev->next = head2->next;
  89.     head1->prev = head2->prev;
  90.     list_initialize(head2);
  91. }
  92.  
  93. /** @}
  94.  */
  95.