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/* $Id: kAvlGet.h 29 2009-07-01 20:30:29Z bird $ */
/** @file
* kAvlTmpl - Templated AVL Trees, Get a Node.
*/
/*
* Copyright (c) 1999-2009 Knut St. Osmundsen <bird-kStuff-spamix@anduin.net>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* Gets a node from the tree (does not remove it!)
*
* @returns Pointer to the node holding the given key.
* @param pRoot Pointer to the AVL-tree root structure.
* @param Key Key value of the node which is to be found.
*/
KAVL_DECL(KAVLNODE *) KAVL_FN(Get)(KAVLROOT *pRoot, KAVLKEY Key)
{
KAVLNODE *pNode;
#ifdef KAVL_LOOKTHRU_CACHE
KAVLTREEPTR *ppEntry;
#endif
KAVL_READ_LOCK(pRoot);
if (pRoot->mpRoot == KAVL_NULL)
{
KAVL_READ_UNLOCK(pRoot);
return NULL;
}
#ifdef KAVL_LOOKTHRU_CACHE
ppEntry = &pRoot->maLookthru[KAVL_LOOKTHRU_HASH(Key)];
pNode = KAVL_GET_POINTER_NULL(ppEntry);
if (!pNode || KAVL_NE(pNode->mKey, Key))
#endif
{
pNode = KAVL_GET_POINTER(&pRoot->mpRoot);
while (KAVL_NE(pNode->mKey, Key))
{
if (KAVL_G(pNode->mKey, Key))
{
if (pNode->mpLeft == KAVL_NULL)
{
KAVL_READ_UNLOCK(pRoot);
return NULL;
}
pNode = KAVL_GET_POINTER(&pNode->mpLeft);
}
else
{
if (pNode->mpRight == KAVL_NULL)
{
KAVL_READ_UNLOCK(pRoot);
return NULL;
}
pNode = KAVL_GET_POINTER(&pNode->mpRight);
}
}
#ifdef KAVL_LOOKTHRU_CACHE
KAVL_SET_POINTER(ppEntry, pNode);
#endif
}
KAVL_READ_UNLOCK(pRoot);
return pNode;
}
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