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/* $Id: kAvlDestroy.h 29 2009-07-01 20:30:29Z bird $ */
/** @file
* kAvlTmpl - Templated AVL Trees, Destroy the tree.
*/
/*
* 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.
*/
/**
* Destroys the specified tree, starting with the root node and working our way down.
*
* @returns 0 on success.
* @returns Return value from callback on failure. On failure, the tree will be in
* an unbalanced condition and only further calls to the Destroy should be
* made on it. Note that the node we fail on will be considered dead and
* no action is taken to link it back into the tree.
* @param pRoot Pointer to the AVL-tree root structure.
* @param pfnCallBack Pointer to callback function.
* @param pvUser User parameter passed on to the callback function.
*/
KAVL_DECL(int) KAVL_FN(Destroy)(KAVLROOT *pRoot, KAVL_TYPE(PFN,CALLBACK) pfnCallBack, void *pvUser)
{
#ifdef KAVL_LOOKTHRU
unsigned i;
#endif
unsigned cEntries;
KAVLNODE *apEntries[KAVL_MAX_STACK];
int rc;
KAVL_WRITE_LOCK(pRoot);
if (pRoot->mpRoot == KAVL_NULL)
{
KAVL_WRITE_UNLOCK(pRoot);
return 0;
}
#ifdef KAVL_LOOKTHRU
/*
* Kill the lookthru cache.
*/
for (i = 0; i < (KAVL_LOOKTHRU); i++)
pRoot->maLookthru[i] = KAVL_NULL;
#endif
cEntries = 1;
apEntries[0] = KAVL_GET_POINTER(&pRoot->mpRoot);
while (cEntries > 0)
{
/*
* Process the subtrees first.
*/
KAVLNODE *pNode = apEntries[cEntries - 1];
if (pNode->mpLeft != KAVL_NULL)
apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->mpLeft);
else if (pNode->mpRight != KAVL_NULL)
apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->mpRight);
else
{
#ifdef KAVL_EQUAL_ALLOWED
/*
* Process nodes with the same key.
*/
while (pNode->pList != KAVL_NULL)
{
KAVLNODE *pEqual = KAVL_GET_POINTER(&pNode->pList);
KAVL_SET_POINTER(&pNode->pList, KAVL_GET_POINTER_NULL(&pEqual->pList));
pEqual->pList = KAVL_NULL;
rc = pfnCallBack(pEqual, pvUser);
if (rc)
{
KAVL_WRITE_UNLOCK(pRoot);
return rc;
}
}
#endif
/*
* Unlink the node.
*/
if (--cEntries > 0)
{
KAVLNODE *pParent = apEntries[cEntries - 1];
if (KAVL_GET_POINTER(&pParent->mpLeft) == pNode)
pParent->mpLeft = KAVL_NULL;
else
pParent->mpRight = KAVL_NULL;
}
else
pRoot->mpRoot = KAVL_NULL;
kHlpAssert(pNode->mpLeft == KAVL_NULL);
kHlpAssert(pNode->mpRight == KAVL_NULL);
rc = pfnCallBack(pNode, pvUser);
if (rc)
{
KAVL_WRITE_UNLOCK(pRoot);
return rc;
}
}
} /* while */
kHlpAssert(pRoot->mpRoot == KAVL_NULL);
KAVL_WRITE_UNLOCK(pRoot);
return 0;
}
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