| 1 | /* $Id: avl_Destroy.cpp.h 4687 2007-09-11 09:13:32Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * kAVLDestroy - Walk the tree calling a callback to destroy all the nodes.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 1999-2007 knut st. osmundsen ([email protected])
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License as published by the Free Software Foundation,
|
|---|
| 13 | * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
|
|---|
| 14 | * distribution. VirtualBox OSE is distributed in the hope that it will
|
|---|
| 15 | * be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | */
|
|---|
| 17 |
|
|---|
| 18 | #ifndef _kAVLDestroy_h_
|
|---|
| 19 | #define _kAVLDestroy_h_
|
|---|
| 20 |
|
|---|
| 21 |
|
|---|
| 22 | /**
|
|---|
| 23 | * Destroys the specified tree, starting with the root node and working our way down.
|
|---|
| 24 | *
|
|---|
| 25 | * @returns 0 on success.
|
|---|
| 26 | * @returns Return value from callback on failure. On failure, the tree will be in
|
|---|
| 27 | * an unbalanced condition and only further calls to the Destroy should be
|
|---|
| 28 | * made on it. Note that the node we fail on will be considered dead and
|
|---|
| 29 | * no action is taken to link it back into the tree.
|
|---|
| 30 | * @param ppTree Pointer to the AVL-tree root node pointer.
|
|---|
| 31 | * @param pfnCallBack Pointer to callback function.
|
|---|
| 32 | * @param pvUser User parameter passed on to the callback function.
|
|---|
| 33 | */
|
|---|
| 34 | RTDECL(int) KAVL_FN(Destroy)(PPKAVLNODECORE ppTree, PKAVLCALLBACK pfnCallBack, void *pvUser)
|
|---|
| 35 | {
|
|---|
| 36 | unsigned cEntries;
|
|---|
| 37 | PKAVLNODECORE apEntries[KAVL_MAX_STACK];
|
|---|
| 38 | int rc;
|
|---|
| 39 |
|
|---|
| 40 | if (*ppTree == KAVL_NULL)
|
|---|
| 41 | return 0;
|
|---|
| 42 |
|
|---|
| 43 | cEntries = 1;
|
|---|
| 44 | apEntries[0] = KAVL_GET_POINTER(ppTree);
|
|---|
| 45 | while (cEntries > 0)
|
|---|
| 46 | {
|
|---|
| 47 | /*
|
|---|
| 48 | * Process the subtrees first.
|
|---|
| 49 | */
|
|---|
| 50 | PKAVLNODECORE pNode = apEntries[cEntries - 1];
|
|---|
| 51 | if (pNode->pLeft != KAVL_NULL)
|
|---|
| 52 | apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->pLeft);
|
|---|
| 53 | else if (pNode->pRight != KAVL_NULL)
|
|---|
| 54 | apEntries[cEntries++] = KAVL_GET_POINTER(&pNode->pRight);
|
|---|
| 55 | else
|
|---|
| 56 | {
|
|---|
| 57 | #ifdef KAVL_EQUAL_ALLOWED
|
|---|
| 58 | /*
|
|---|
| 59 | * Process nodes with the same key.
|
|---|
| 60 | */
|
|---|
| 61 | while (pNode->pList != KAVL_NULL)
|
|---|
| 62 | {
|
|---|
| 63 | PKAVLNODECORE pEqual = KAVL_GET_POINTER(&pNode->pList);
|
|---|
| 64 | KAVL_SET_POINTER(&pNode->pList, KAVL_GET_POINTER_NULL(&pEqual->pList));
|
|---|
| 65 | pEqual->pList = KAVL_NULL;
|
|---|
| 66 |
|
|---|
| 67 | rc = pfnCallBack(pEqual, pvUser);
|
|---|
| 68 | if (rc)
|
|---|
| 69 | return rc;
|
|---|
| 70 | }
|
|---|
| 71 | #endif
|
|---|
| 72 |
|
|---|
| 73 | /*
|
|---|
| 74 | * Unlink the node.
|
|---|
| 75 | */
|
|---|
| 76 | if (--cEntries > 0)
|
|---|
| 77 | {
|
|---|
| 78 | PKAVLNODECORE pParent = apEntries[cEntries - 1];
|
|---|
| 79 | if (KAVL_GET_POINTER(&pParent->pLeft) == pNode)
|
|---|
| 80 | pParent->pLeft = KAVL_NULL;
|
|---|
| 81 | else
|
|---|
| 82 | pParent->pRight = KAVL_NULL;
|
|---|
| 83 | }
|
|---|
| 84 | else
|
|---|
| 85 | *ppTree = KAVL_NULL;
|
|---|
| 86 |
|
|---|
| 87 | kASSERT(pNode->pLeft == KAVL_NULL);
|
|---|
| 88 | kASSERT(pNode->pRight == KAVL_NULL);
|
|---|
| 89 | rc = pfnCallBack(pNode, pvUser);
|
|---|
| 90 | if (rc)
|
|---|
| 91 | return rc;
|
|---|
| 92 | }
|
|---|
| 93 | } /* while */
|
|---|
| 94 |
|
|---|
| 95 | kASSERT(*ppTree == KAVL_NULL);
|
|---|
| 96 |
|
|---|
| 97 | return 0;
|
|---|
| 98 | }
|
|---|
| 99 |
|
|---|
| 100 | #endif
|
|---|
| 101 |
|
|---|
| 102 |
|
|---|
