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Diffstat (limited to 'src/VBox/Runtime/common/table/avl_GetBestFit.cpp.h')
| -rw-r--r-- | src/VBox/Runtime/common/table/avl_GetBestFit.cpp.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/table/avl_GetBestFit.cpp.h b/src/VBox/Runtime/common/table/avl_GetBestFit.cpp.h new file mode 100644 index 00000000..d8438456 --- /dev/null +++ b/src/VBox/Runtime/common/table/avl_GetBestFit.cpp.h @@ -0,0 +1,113 @@ +/* $Id: avl_GetBestFit.cpp.h $ */ +/** @file + * kAVLGetBestFit - Get Best Fit routine for AVL trees. + * Intended specially on heaps. The tree should allow duplicate keys. + * + */ + +/* + * 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 _kAVLGetBestFit_h_ +#define _kAVLGetBestFit_h_ + + +/** + * Finds the best fitting node in the tree for the given Key value. + * @returns Pointer to the best fitting node found. + * @param ppTree Pointer to Pointer to the tree root node. + * @param Key The Key of which is to be found a best fitting match for.. + * @param fAbove TRUE: Returned node is have the closest key to Key from above. + * FALSE: Returned node is have the closest key to Key from below. + * @sketch The best fitting node is always located in the searchpath above you. + * >= (above): The node where you last turned left. + * <= (below): the node where you last turned right. + */ +KAVL_DECL(PKAVLNODECORE) KAVL_FN(GetBestFit)(PPKAVLNODECORE ppTree, KAVLKEY Key, bool fAbove) +{ + PKAVLNODECORE pNode = KAVL_GET_POINTER_NULL(ppTree); + if (pNode) + { + PKAVLNODECORE pNodeLast = NULL; + if (fAbove) + { /* pNode->Key >= Key */ + while (KAVL_NE(pNode->Key, Key)) + { + if (KAVL_G(pNode->Key, Key)) + { + if (pNode->pLeft != KAVL_NULL) + { + pNodeLast = pNode; + pNode = KAVL_GET_POINTER(&pNode->pLeft); + } + else + return pNode; + } + else + { + if (pNode->pRight != KAVL_NULL) + pNode = KAVL_GET_POINTER(&pNode->pRight); + else + return pNodeLast; + } + } + } + else + { /* pNode->Key <= Key */ + while (KAVL_NE(pNode->Key, Key)) + { + if (KAVL_G(pNode->Key, Key)) + { + if (pNode->pLeft != KAVL_NULL) + pNode = KAVL_GET_POINTER(&pNode->pLeft); + else + return pNodeLast; + } + else + { + if (pNode->pRight != KAVL_NULL) + { + pNodeLast = pNode; + pNode = KAVL_GET_POINTER(&pNode->pRight); + } + else + return pNode; + } + } + } + } + + /* perfect match or nothing. */ + return pNode; +} + + +#endif |