| 1 | /* $Id: kAvlRemoveBestFit.h 29 2009-07-01 20:30:29Z bird $ */
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| 2 | /** @file
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| 3 | * kAvlTmpl - Templated AVL Trees, Remove Best Fitting Node.
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| 4 | */
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| 5 |
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| 6 | /*
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| 7 | * Copyright (c) 1999-2009 Knut St. Osmundsen <bird-kStuff-spamix@anduin.net>
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| 8 | *
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| 9 | * Permission is hereby granted, free of charge, to any person
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| 10 | * obtaining a copy of this software and associated documentation
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| 11 | * files (the "Software"), to deal in the Software without
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| 12 | * restriction, including without limitation the rights to use,
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| 13 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
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| 14 | * copies of the Software, and to permit persons to whom the
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| 15 | * Software is furnished to do so, subject to the following
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| 16 | * conditions:
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| 17 | *
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| 18 | * The above copyright notice and this permission notice shall be
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| 19 | * included in all copies or substantial portions of the Software.
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| 20 | *
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| 21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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| 22 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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| 23 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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| 24 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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| 25 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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| 26 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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| 27 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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| 28 | * OTHER DEALINGS IN THE SOFTWARE.
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| 29 | */
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| 30 |
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| 31 | /**
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| 32 | * Finds the best fitting node in the tree for the given Key value and removes the node.
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| 33 | *
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| 34 | * @returns Pointer to the removed node.
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| 35 | * @param pRoot Pointer to the AVL-tree root structure.
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| 36 | * @param Key The Key of which is to be found a best fitting match for..
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| 37 | * @param fAbove K_TRUE: Returned node is have the closest key to Key from above.
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| 38 | * K_FALSE: Returned node is have the closest key to Key from below.
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| 39 | *
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| 40 | * @remark This implementation uses GetBestFit and then Remove and might therefore
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| 41 | * not be the most optimal kind of implementation, but it reduces the complexity
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| 42 | * code size, and the likelyhood for bugs.
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| 43 | */
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| 44 | KAVL_DECL(KAVLNODE *) KAVL_FN(RemoveBestFit)(KAVLROOT *pRoot, KAVLKEY Key, KBOOL fAbove)
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| 45 | {
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| 46 | /*
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| 47 | * If we find anything we'll have to remove the node and return it.
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| 48 | * Now, if duplicate keys are allowed we'll remove a duplicate before
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| 49 | * removing the in-tree node as this is way cheaper.
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| 50 | */
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| 51 | KAVLNODE *pNode = KAVL_FN(GetBestFit)(pRoot, Key, fAbove);
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| 52 | if (pNode != NULL)
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| 53 | {
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| 54 | #ifdef KAVL_EQUAL_ALLOWED
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| 55 | KAVL_WRITE_LOCK(pRoot); /** @todo the locking isn't quite sane here. :-/ */
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| 56 | if (pNode->mpList != KAVL_NULL)
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| 57 | {
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| 58 | KAVLNODE *pRet = KAVL_GET_POINTER(&pNode->mpList);
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| 59 | KAVL_SET_POINTER_NULL(&pNode->mpList, &pRet->mpList);
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| 60 | KAVL_LOOKTHRU_INVALIDATE_NODE(pRoot, pNode, pNode->mKey);
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| 61 | KAVL_WRITE_UNLOCK(pRoot);
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| 62 | return pRet;
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| 63 | }
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| 64 | KAVL_WRITE_UNLOCK(pRoot);
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| 65 | #endif
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| 66 | pNode = KAVL_FN(Remove)(pRoot, pNode->mKey);
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| 67 | }
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| 68 | return pNode;
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| 69 | }
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| 70 |
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