API/tests/NodeList.c

   1 /*
   2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "NodeList.h"
  27
  28 #include <stdlib.h>
  29
  30 extern NodeList* NodeList_new(Node* parentNode)
  31 {
  32     Node_ref(parentNode);
  33
  34     NodeList* nodeList = (NodeList*)malloc(sizeof(NodeList));
  35     nodeList->parentNode = parentNode;
  36     nodeList->refCount = 0;
  37     return nodeList;
  38 }
  39
  40 extern unsigned NodeList_length(NodeList* nodeList)
  41 {
  42     /* Linear count from tail -- good enough for our purposes here */
  43     unsigned i = 0;
  44     NodeLink* n = nodeList->parentNode->childNodesTail;
  45     while (n) {
  46         n = n->prev;
  47         ++i;
  48     }
  49
  50     return i;
  51 }
  52
  53 extern Node* NodeList_item(NodeList* nodeList, unsigned index)
  54 {
  55     unsigned length = NodeList_length(nodeList);
  56     if (index >= length)
  57         return NULL;
  58
  59     /* Linear search from tail -- good enough for our purposes here */
  60     NodeLink* n = nodeList->parentNode->childNodesTail;
  61     unsigned i = 0;
  62     unsigned count = length - 1 - index;
  63     while (i < count) {
  64         ++i;
  65         n = n->prev;
  66     }
  67     return n->node;
  68 }
  69
  70 extern void NodeList_ref(NodeList* nodeList)
  71 {
  72     ++nodeList->refCount;
  73 }
  74
  75 extern void NodeList_deref(NodeList* nodeList)
  76 {
  77     if (--nodeList->refCount == 0) {
  78         Node_deref(nodeList->parentNode);
  79         free(nodeList);
  80     }
  81 }