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Diffstat (limited to 'src/lib/kStuff/include/k/kRbTmpl/kRbRemoveBestFit.h')
| -rw-r--r-- | src/lib/kStuff/include/k/kRbTmpl/kRbRemoveBestFit.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/lib/kStuff/include/k/kRbTmpl/kRbRemoveBestFit.h b/src/lib/kStuff/include/k/kRbTmpl/kRbRemoveBestFit.h new file mode 100644 index 0000000..17fc66d --- /dev/null +++ b/src/lib/kStuff/include/k/kRbTmpl/kRbRemoveBestFit.h @@ -0,0 +1,70 @@ +/* $Id: kRbRemoveBestFit.h 35 2009-11-08 19:39:03Z bird $ */ +/** @file + * kRbTmpl - Templated Red-Black Trees, Remove Best Fitting 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. + */ + +/** + * Finds the best fitting node in the tree for the given Key value and removes the node. + * + * @returns Pointer to the removed node. + * @param pRoot Pointer to the Red-Back tree's root structure. + * @param Key The Key of which is to be found a best fitting match for.. + * @param fAbove K_TRUE: Returned node is have the closest key to Key from above. + * K_FALSE: Returned node is have the closest key to Key from below. + * + * @remark This implementation uses GetBestFit and then Remove and might therefore + * not be the most optimal kind of implementation, but it reduces the complexity + * code size, and the likelyhood for bugs. + */ +KRB_DECL(KRBNODE *) KRB_FN(RemoveBestFit)(KRBROOT *pRoot, KRBKEY Key, KBOOL fAbove) +{ + /* + * If we find anything we'll have to remove the node and return it. + * Now, if duplicate keys are allowed we'll remove a duplicate before + * removing the in-tree node as this is way cheaper. + */ + KRBNODE *pNode = KRB_FN(GetBestFit)(pRoot, Key, fAbove); + if (pNode != NULL) + { +#ifdef KRB_EQUAL_ALLOWED + KRB_WRITE_LOCK(pRoot); /** @todo the locking isn't quite sane here. :-/ */ + if (pNode->mpList != KRB_NULL) + { + KRBNODE *pRet = KRB_GET_POINTER(&pNode->mpList); + KRB_SET_POINTER_NULL(&pNode->mpList, &pRet->mpList); + KRB_CACHE_INVALIDATE_NODE(pRoot, pNode, pNode->mKey); + KRB_WRITE_UNLOCK(pRoot); + return pRet; + } + KRB_WRITE_UNLOCK(pRoot); +#endif + pNode = KRB_FN(Remove)(pRoot, pNode->mKey); + } + return pNode; +} + |