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Diffstat (limited to 'src/lib/kStuff/include/k/kAvlTmpl/kAvlDestroy.h')
| -rw-r--r-- | src/lib/kStuff/include/k/kAvlTmpl/kAvlDestroy.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/lib/kStuff/include/k/kAvlTmpl/kAvlDestroy.h b/src/lib/kStuff/include/k/kAvlTmpl/kAvlDestroy.h new file mode 100644 index 0000000..17115f3 --- /dev/null +++ b/src/lib/kStuff/include/k/kAvlTmpl/kAvlDestroy.h @@ -0,0 +1,129 @@ +/* $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; +} + |