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/* $Id: avl_Destroy.cpp.h $ */
/** @file
* kAVLDestroy - Walk the tree calling a callback to destroy all the nodes.
*/
/*
* Copyright (C) 2006-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
* in the VirtualBox distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*
* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
*/
#ifndef _kAVLDestroy_h_
#define _kAVLDestroy_h_
/**
* 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 ppTree Pointer to the AVL-tree root node pointer.
* @param pfnCallBack Pointer to callback function.
* @param pvUser User parameter passed on to the callback function.
*/
KAVL_DECL(int) KAVL_FN(Destroy)(PPKAVLNODECORE ppTree, PKAVLCALLBACK pfnCallBack, void *pvUser)
{
unsigned cEntries;
PKAVLNODECORE apEntries[KAVL_MAX_STACK];
int rc;
if (*ppTree == KAVL_NULL)
return VINF_SUCCESS;
cEntries = 1;
apEntries[0] = KAVL_GET_POINTER(ppTree);
while (cEntries > 0)
{
/*
* Process the subtrees first.
*/
PKAVLNODECORE pNode = apEntries[cEntries - 1];
if (pNode->pLeft != KAVL_NULL)
apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->pLeft);
else if (pNode->pRight != KAVL_NULL)
apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->pRight);
else
{
#ifdef KAVL_EQUAL_ALLOWED
/*
* Process nodes with the same key.
*/
while (pNode->pList != KAVL_NULL)
{
PKAVLNODECORE 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 != VINF_SUCCESS)
return rc;
}
#endif
/*
* Unlink the node.
*/
if (--cEntries > 0)
{
PKAVLNODECORE pParent = apEntries[cEntries - 1];
if (KAVL_GET_POINTER(&pParent->pLeft) == pNode)
pParent->pLeft = KAVL_NULL;
else
pParent->pRight = KAVL_NULL;
}
else
*ppTree = KAVL_NULL;
kASSERT(pNode->pLeft == KAVL_NULL);
kASSERT(pNode->pRight == KAVL_NULL);
rc = pfnCallBack(pNode, pvUser);
if (rc != VINF_SUCCESS)
return rc;
}
} /* while */
kASSERT(*ppTree == KAVL_NULL);
return VINF_SUCCESS;
}
#endif
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