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|
/** @file
* IPRT - Hardened AVL tree, unique key ranges.
*/
/*
* Copyright (C) 2022-2025 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 IPRT_INCLUDED_cpp_hardavlrange_h
#define IPRT_INCLUDED_cpp_hardavlrange_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif
#include <iprt/cpp/hardavlslaballocator.h>
/** @defgroup grp_rt_cpp_hardavl Hardened AVL Trees
* @ingroup grp_rt_cpp
* @{
*/
/**
* Check that the tree heights make sense for the current node.
*
* This is a RT_STRICT test as it's expensive and we should have sufficient
* other checks to ensure safe AVL tree operation.
*
* @note the a_cStackEntries parameter is a hack to avoid running into gcc's
* "the address of 'AVLStack' will never be NULL" errors.
*/
#ifdef RT_STRICT
# define RTHARDAVL_STRICT_CHECK_HEIGHTS(a_pNode, a_pAvlStack, a_cStackEntries) do { \
NodeType * const pLeftNodeX = a_pAllocator->ptrFromInt(readIdx(&(a_pNode)->idxLeft)); \
AssertReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNodeX), m_cErrors++, a_pAllocator->ptrErrToStatus((a_pNode))); \
NodeType * const pRightNodeX = a_pAllocator->ptrFromInt(readIdx(&(a_pNode)->idxRight)); \
AssertReturnStmt(a_pAllocator->isPtrRetOkay(pRightNodeX), m_cErrors++, a_pAllocator->ptrErrToStatus((a_pNode))); \
uint8_t const cLeftHeightX = pLeftNodeX ? pLeftNodeX->cHeight : 0; \
uint8_t const cRightHeightX = pRightNodeX ? pRightNodeX->cHeight : 0; \
if (RT_LIKELY((a_pNode)->cHeight == RT_MAX(cLeftHeightX, cRightHeightX) + 1)) { /*likely*/ } \
else \
{ \
RTAssertMsg2("line %u: %u l=%u r=%u\n", __LINE__, (a_pNode)->cHeight, cLeftHeightX, cRightHeightX); \
if ((a_cStackEntries)) dumpStack(a_pAllocator, (a_pAvlStack)); \
AssertMsgReturnStmt((a_pNode)->cHeight == RT_MAX(cLeftHeightX, cRightHeightX) + 1, \
("%u l=%u r=%u\n", (a_pNode)->cHeight, cLeftHeightX, cRightHeightX), \
m_cErrors++, VERR_HARDAVL_BAD_HEIGHT); \
} \
AssertMsgReturnStmt(RT_ABS(cLeftHeightX - cRightHeightX) <= 1, ("l=%u r=%u\n", cLeftHeightX, cRightHeightX), \
m_cErrors++, VERR_HARDAVL_UNBALANCED); \
Assert(!pLeftNodeX || pLeftNodeX->Key < (a_pNode)->Key); \
Assert(!pRightNodeX || pRightNodeX->Key > (a_pNode)->Key); \
} while (0)
#else
# define RTHARDAVL_STRICT_CHECK_HEIGHTS(a_pNode, a_pAvlStack, a_cStackEntries) do { } while (0)
#endif
/**
* Hardened AVL tree for nodes with key ranges.
*
* This is very crude and therefore expects the NodeType to feature:
* - Key and KeyLast members of KeyType.
* - idxLeft and idxRight members with type uint32_t.
* - cHeight members of type uint8_t.
*
* The code is very C-ish because of it's sources and initial use (ring-0
* without C++ exceptions enabled).
*/
template<typename NodeType, typename KeyType>
struct RTCHardAvlRangeTree
{
/** The root index. */
uint32_t m_idxRoot;
/** The error count. */
uint32_t m_cErrors;
/** @name Statistics
* @{ */
uint64_t m_cInserts;
uint64_t m_cRemovals;
uint64_t m_cRebalancingOperations;
/** @} */
/** The max stack depth. */
enum { kMaxStack = 28 };
/** The max height value we allow. */
enum { kMaxHeight = kMaxStack + 1 };
/** A stack used internally to avoid recursive calls.
* This is used with operations invoking i_rebalance(). */
typedef struct HardAvlStack
{
/** Number of entries on the stack. */
unsigned cEntries;
/** The stack. */
uint32_t *apidxEntries[kMaxStack];
} HardAvlStack;
/** @name Key comparisons
* @{ */
static inline int areKeyRangesIntersecting(KeyType a_Key1First, KeyType a_Key2First,
KeyType a_Key1Last, KeyType a_Key2Last) RT_NOEXCEPT
{
return a_Key1First <= a_Key2Last && a_Key1Last >= a_Key2First;
}
static inline int isKeyInRange(KeyType a_Key, KeyType a_KeyFirst, KeyType a_KeyLast) RT_NOEXCEPT
{
return a_Key <= a_KeyLast && a_Key >= a_KeyFirst;
}
static inline int isKeyGreater(KeyType a_Key1, KeyType a_Key2) RT_NOEXCEPT
{
return a_Key1 > a_Key2;
}
/** @} */
/**
* Read an index value trying to prevent the compiler from re-reading it.
*/
DECL_FORCE_INLINE(uint32_t) readIdx(uint32_t volatile *pidx) RT_NOEXCEPT
{
uint32_t idx = *pidx;
ASMCompilerBarrier();
return idx;
}
RTCHardAvlRangeTree() RT_NOEXCEPT
: m_idxRoot(0)
, m_cErrors(0)
{ }
RTCHardAvlRangeTree(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator) RT_NOEXCEPT
{
initWithAllocator(a_pAllocator);
}
void initWithAllocator(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator) RT_NOEXCEPT
{
m_idxRoot = a_pAllocator->kNilIndex;
m_cErrors = 0;
}
/**
* Inserts a node into the AVL-tree.
*
* @returns IPRT status code.
* @retval VERR_ALREADY_EXISTS if a node with overlapping key range exists.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_pNode Pointer to the node which is to be added.
*
* @code
* Find the location of the node (using binary tree algorithm.):
* LOOP until KAVL_NULL leaf pointer
* BEGIN
* Add node pointer pointer to the AVL-stack.
* IF new-node-key < node key THEN
* left
* ELSE
* right
* END
* Fill in leaf node and insert it.
* Rebalance the tree.
* @endcode
*/
int insert(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, NodeType *a_pNode) RT_NOEXCEPT
{
KeyType const Key = a_pNode->Key;
KeyType const KeyLast = a_pNode->KeyLast;
AssertMsgReturn(Key <= KeyLast, ("Key=%#RX64 KeyLast=%#RX64\n", (uint64_t)Key, (uint64_t)KeyLast),
VERR_HARDAVL_INSERT_INVALID_KEY_RANGE);
uint32_t *pidxCurNode = &m_idxRoot;
HardAvlStack AVLStack;
AVLStack.cEntries = 0;
for (;;)
{
NodeType *pCurNode = a_pAllocator->ptrFromInt(readIdx(pidxCurNode));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pCurNode), ("*pidxCurNode=%#x pCurNode=%p\n", *pidxCurNode, pCurNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pCurNode));
if (!pCurNode)
break;
unsigned const cEntries = AVLStack.cEntries;
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(AVLStack.apidxEntries),
("%p[%#x/%p] %p[%#x] %p[%#x] %p[%#x] %p[%#x] %p[%#x]\n", pidxCurNode, *pidxCurNode, pCurNode,
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
AVLStack.apidxEntries[cEntries] = pidxCurNode;
AVLStack.cEntries = cEntries + 1;
RTHARDAVL_STRICT_CHECK_HEIGHTS(pCurNode, &AVLStack, AVLStack.cEntries);
/* Range check: */
if (areKeyRangesIntersecting(pCurNode->Key, Key, pCurNode->KeyLast, KeyLast))
return VERR_ALREADY_EXISTS;
/* Descend: */
if (isKeyGreater(pCurNode->Key, Key))
pidxCurNode = &pCurNode->idxLeft;
else
pidxCurNode = &pCurNode->idxRight;
}
a_pNode->idxLeft = a_pAllocator->kNilIndex;
a_pNode->idxRight = a_pAllocator->kNilIndex;
a_pNode->cHeight = 1;
uint32_t const idxNode = a_pAllocator->ptrToInt(a_pNode);
AssertMsgReturn(a_pAllocator->isIdxRetOkay(idxNode), ("pNode=%p idxNode=%#x\n", a_pNode, idxNode),
a_pAllocator->idxErrToStatus(idxNode));
*pidxCurNode = idxNode;
m_cInserts++;
return i_rebalance(a_pAllocator, &AVLStack);
}
/**
* Removes a node from the AVL-tree by a key value.
*
* @returns IPRT status code.
* @retval VERR_NOT_FOUND if not found.
* @param a_pAllocator Pointer to the allocator.
* @param a_Key A key value in the range of the node to be removed.
* @param a_ppRemoved Where to return the pointer to the removed node.
*
* @code
* Find the node which is to be removed:
* LOOP until not found
* BEGIN
* Add node pointer pointer to the AVL-stack.
* IF the keys matches THEN break!
* IF remove key < node key THEN
* left
* ELSE
* right
* END
* IF found THEN
* BEGIN
* IF left node not empty THEN
* BEGIN
* Find the right most node in the left tree while adding the pointer to the pointer to it's parent to the stack:
* Start at left node.
* LOOP until right node is empty
* BEGIN
* Add to stack.
* go right.
* END
* Link out the found node.
* Replace the node which is to be removed with the found node.
* Correct the stack entry for the pointer to the left tree.
* END
* ELSE
* BEGIN
* Move up right node.
* Remove last stack entry.
* END
* Balance tree using stack.
* END
* return pointer to the removed node (if found).
* @endcode
*/
int remove(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, KeyType a_Key, NodeType **a_ppRemoved) RT_NOEXCEPT
{
*a_ppRemoved = NULL;
/*
* Walk the tree till we locate the node that is to be deleted.
*/
uint32_t *pidxDeleteNode = &m_idxRoot;
NodeType *pDeleteNode;
HardAvlStack AVLStack;
AVLStack.cEntries = 0;
for (;;)
{
pDeleteNode = a_pAllocator->ptrFromInt(readIdx(pidxDeleteNode));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pDeleteNode),
("*pidxCurNode=%#x pDeleteNode=%p\n", *pidxDeleteNode, pDeleteNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pDeleteNode));
if (pDeleteNode)
{ /*likely*/ }
else
return VERR_NOT_FOUND;
unsigned const cEntries = AVLStack.cEntries;
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(AVLStack.apidxEntries),
("%p[%#x/%p] %p[%#x] %p[%#x] %p[%#x] %p[%#x] %p[%#x]\n",
pidxDeleteNode, *pidxDeleteNode, pDeleteNode,
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
AVLStack.apidxEntries[cEntries] = pidxDeleteNode;
AVLStack.cEntries = cEntries + 1;
RTHARDAVL_STRICT_CHECK_HEIGHTS(pDeleteNode, &AVLStack, AVLStack.cEntries);
/* Range check: */
if (isKeyInRange(a_Key, pDeleteNode->Key, pDeleteNode->KeyLast))
break;
/* Descend: */
if (isKeyGreater(pDeleteNode->Key, a_Key))
pidxDeleteNode = &pDeleteNode->idxLeft;
else
pidxDeleteNode = &pDeleteNode->idxRight;
}
/*
* Do the deletion.
*/
uint32_t const idxDeleteLeftNode = readIdx(&pDeleteNode->idxLeft);
if (idxDeleteLeftNode != a_pAllocator->kNilIndex)
{
/*
* Replace the deleted node with the rightmost node in the left subtree.
*/
NodeType * const pDeleteLeftNode = a_pAllocator->ptrFromInt(idxDeleteLeftNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pDeleteLeftNode),
("idxDeleteLeftNode=%#x pDeleteLeftNode=%p\n", idxDeleteLeftNode, pDeleteLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pDeleteLeftNode));
uint32_t const idxDeleteRightNode = readIdx(&pDeleteNode->idxRight);
AssertReturnStmt(a_pAllocator->isIntValid(idxDeleteRightNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
const unsigned iStackEntry = AVLStack.cEntries;
uint32_t *pidxLeftBiggest = &pDeleteNode->idxLeft;
uint32_t idxLeftBiggestNode = idxDeleteLeftNode;
NodeType *pLeftBiggestNode = pDeleteLeftNode;
RTHARDAVL_STRICT_CHECK_HEIGHTS(pLeftBiggestNode, &AVLStack, AVLStack.cEntries);
uint32_t idxRightTmp;
while ((idxRightTmp = readIdx(&pLeftBiggestNode->idxRight)) != a_pAllocator->kNilIndex)
{
unsigned const cEntries = AVLStack.cEntries;
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(AVLStack.apidxEntries),
("%p[%#x/%p] %p[%#x] %p[%#x] %p[%#x] %p[%#x] %p[%#x]\n",
pidxLeftBiggest, *pidxLeftBiggest, pLeftBiggestNode,
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 1],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 2],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 3],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 4],
AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5], *AVLStack.apidxEntries[RT_ELEMENTS(AVLStack.apidxEntries) - 5]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
AVLStack.apidxEntries[cEntries] = pidxLeftBiggest;
AVLStack.cEntries = cEntries + 1;
pidxLeftBiggest = &pLeftBiggestNode->idxRight;
idxLeftBiggestNode = idxRightTmp;
pLeftBiggestNode = a_pAllocator->ptrFromInt(idxRightTmp);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftBiggestNode),
("idxLeftBiggestNode=%#x pLeftBiggestNode=%p\n", idxLeftBiggestNode, pLeftBiggestNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftBiggestNode));
RTHARDAVL_STRICT_CHECK_HEIGHTS(pLeftBiggestNode, &AVLStack, AVLStack.cEntries);
}
uint32_t const idxLeftBiggestLeftNode = readIdx(&pLeftBiggestNode->idxLeft);
AssertReturnStmt(a_pAllocator->isIntValid(idxLeftBiggestLeftNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
/* link out pLeftBiggestNode */
*pidxLeftBiggest = idxLeftBiggestLeftNode;
/* link it in place of the deleted node. */
if (idxDeleteLeftNode != idxLeftBiggestNode)
pLeftBiggestNode->idxLeft = idxDeleteLeftNode;
pLeftBiggestNode->idxRight = idxDeleteRightNode;
pLeftBiggestNode->cHeight = AVLStack.cEntries > iStackEntry ? pDeleteNode->cHeight : 0;
*pidxDeleteNode = idxLeftBiggestNode;
if (AVLStack.cEntries > iStackEntry)
AVLStack.apidxEntries[iStackEntry] = &pLeftBiggestNode->idxLeft;
}
else
{
/* No left node, just pull up the right one. */
uint32_t const idxDeleteRightNode = readIdx(&pDeleteNode->idxRight);
AssertReturnStmt(a_pAllocator->isIntValid(idxDeleteRightNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
*pidxDeleteNode = idxDeleteRightNode;
AVLStack.cEntries--;
}
*a_ppRemoved = pDeleteNode;
m_cRemovals++;
return i_rebalance(a_pAllocator, &AVLStack);
}
/**
* Looks up a node from the tree.
*
* @returns IPRT status code.
* @retval VERR_NOT_FOUND if not found.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_Key A key value in the range of the desired node.
* @param a_ppFound Where to return the pointer to the node.
*/
int lookup(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, KeyType a_Key, NodeType **a_ppFound) RT_NOEXCEPT
{
*a_ppFound = NULL;
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
#ifdef RT_STRICT
HardAvlStack AVLStack;
AVLStack.apidxEntries[0] = &m_idxRoot;
AVLStack.cEntries = 1;
#endif
unsigned cDepth = 0;
while (pNode)
{
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, &AVLStack, AVLStack.cEntries);
AssertReturn(cDepth <= kMaxHeight, VERR_HARDAVL_LOOKUP_TOO_DEEP);
cDepth++;
if (isKeyInRange(a_Key, pNode->Key, pNode->KeyLast))
{
*a_ppFound = pNode;
return VINF_SUCCESS;
}
if (isKeyGreater(pNode->Key, a_Key))
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxLeft;
#endif
uint32_t const idxLeft = readIdx(&pNode->idxLeft);
pNode = a_pAllocator->ptrFromInt(idxLeft);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("idxLeft=%#x pNode=%p\n", idxLeft, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
}
else
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxRight;
#endif
uint32_t const idxRight = readIdx(&pNode->idxRight);
pNode = a_pAllocator->ptrFromInt(idxRight);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("idxRight=%#x pNode=%p\n", idxRight, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
}
}
return VERR_NOT_FOUND;
}
/**
* Looks up node matching @a a_Key or if no exact match the closest smaller than it.
*
* @returns IPRT status code.
* @retval VERR_NOT_FOUND if not found.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_Key A key value in the range of the desired node.
* @param a_ppFound Where to return the pointer to the node.
*/
int lookupMatchingOrBelow(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, KeyType a_Key,
NodeType **a_ppFound) RT_NOEXCEPT
{
*a_ppFound = NULL;
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
#ifdef RT_STRICT
HardAvlStack AVLStack;
AVLStack.apidxEntries[0] = &m_idxRoot;
AVLStack.cEntries = 1;
#endif
unsigned cDepth = 0;
NodeType *pNodeLast = NULL;
while (pNode)
{
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, &AVLStack, AVLStack.cEntries);
AssertReturn(cDepth <= kMaxHeight, VERR_HARDAVL_LOOKUP_TOO_DEEP);
cDepth++;
if (isKeyInRange(a_Key, pNode->Key, pNode->KeyLast))
{
*a_ppFound = pNode;
return VINF_SUCCESS;
}
if (isKeyGreater(pNode->Key, a_Key))
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxLeft;
#endif
uint32_t const idxLeft = readIdx(&pNode->idxLeft);
NodeType *pLeftNode = a_pAllocator->ptrFromInt(idxLeft);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode), ("idxLeft=%#x pLeftNode=%p\n", idxLeft, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
if (pLeftNode)
pNode = pLeftNode;
else if (!pNodeLast)
break;
else
{
*a_ppFound = pNodeLast;
return VINF_SUCCESS;
}
}
else
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxRight;
#endif
uint32_t const idxRight = readIdx(&pNode->idxRight);
NodeType *pRightNode = a_pAllocator->ptrFromInt(idxRight);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode), ("idxRight=%#x pRightNode=%p\n", idxRight, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
if (pRightNode)
{
pNodeLast = pNode;
pNode = pRightNode;
}
else
{
*a_ppFound = pNode;
return VINF_SUCCESS;
}
}
}
return VERR_NOT_FOUND;
}
/**
* Looks up node matching @a a_Key or if no exact match the closest larger than it.
*
* @returns IPRT status code.
* @retval VERR_NOT_FOUND if not found.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_Key A key value in the range of the desired node.
* @param a_ppFound Where to return the pointer to the node.
*/
int lookupMatchingOrAbove(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, KeyType a_Key,
NodeType **a_ppFound) RT_NOEXCEPT
{
*a_ppFound = NULL;
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
#ifdef RT_STRICT
HardAvlStack AVLStack;
AVLStack.apidxEntries[0] = &m_idxRoot;
AVLStack.cEntries = 1;
#endif
unsigned cDepth = 0;
NodeType *pNodeLast = NULL;
while (pNode)
{
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, &AVLStack, AVLStack.cEntries);
AssertReturn(cDepth <= kMaxHeight, VERR_HARDAVL_LOOKUP_TOO_DEEP);
cDepth++;
if (isKeyInRange(a_Key, pNode->Key, pNode->KeyLast))
{
*a_ppFound = pNode;
return VINF_SUCCESS;
}
if (isKeyGreater(pNode->Key, a_Key))
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxLeft;
#endif
uint32_t const idxLeft = readIdx(&pNode->idxLeft);
NodeType *pLeftNode = a_pAllocator->ptrFromInt(idxLeft);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode), ("idxLeft=%#x pLeftNode=%p\n", idxLeft, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
if (pLeftNode)
{
pNodeLast = pNode;
pNode = pLeftNode;
}
else
{
*a_ppFound = pNode;
return VINF_SUCCESS;
}
}
else
{
#ifdef RT_STRICT
AVLStack.apidxEntries[AVLStack.cEntries++] = &pNode->idxRight;
#endif
uint32_t const idxRight = readIdx(&pNode->idxRight);
NodeType *pRightNode = a_pAllocator->ptrFromInt(idxRight);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode), ("idxRight=%#x pRightNode=%p\n", idxRight, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
if (pRightNode)
pNode = pRightNode;
else if (!pNodeLast)
break;
else
{
*a_ppFound = pNodeLast;
return VINF_SUCCESS;
}
}
}
return VERR_NOT_FOUND;
}
/**
* A callback for doWithAllFromLeft and doWithAllFromRight.
*
* @returns IPRT status code. Any non-zero status causes immediate return from
* the enumeration function.
* @param pNode The current node.
* @param pvUser The user argument.
*/
typedef DECLCALLBACKTYPE(int, FNCALLBACK,(NodeType *pNode, void *pvUser));
/** Pointer to a callback for doWithAllFromLeft and doWithAllFromRight. */
typedef FNCALLBACK *PFNCALLBACK;
/**
* Iterates thru all nodes in the tree from left (smaller) to right.
*
* @returns IPRT status code.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_pfnCallBack Pointer to callback function.
* @param a_pvUser Callback user argument.
*
* @note This is very similar code to doWithAllFromRight() and destroy().
*/
int doWithAllFromLeft(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator,
PFNCALLBACK a_pfnCallBack, void *a_pvUser) RT_NOEXCEPT
{
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
if (!pNode)
return VINF_SUCCESS;
/*
* We simulate recursive calling here. For safety reasons, we do not
* pop before going down the right tree like the original code did.
*/
uint32_t cNodesLeft = a_pAllocator->m_cNodes;
NodeType *apEntries[kMaxStack];
uint8_t abState[kMaxStack];
unsigned cEntries = 1;
abState[0] = 0;
apEntries[0] = pNode;
while (cEntries > 0)
{
pNode = apEntries[cEntries - 1];
switch (abState[cEntries - 1])
{
/* Go left. */
case 0:
{
abState[cEntries - 1] = 1;
NodeType * const pLeftNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxLeft));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode),
("idxLeft=%#x pLeftNode=%p\n", pNode->idxLeft, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
if (pLeftNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pLeftNode, pNode->idxLeft, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pLeftNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
/* center then right. */
case 1:
{
abState[cEntries - 1] = 2;
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, NULL, 0);
int rc = a_pfnCallBack(pNode, a_pvUser);
if (rc != VINF_SUCCESS)
return rc;
NodeType * const pRightNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxRight));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode),
("idxRight=%#x pRightNode=%p\n", pNode->idxRight, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
if (pRightNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pRightNode, pNode->idxRight, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pRightNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
default:
/* pop it. */
cEntries -= 1;
break;
}
}
return VINF_SUCCESS;
}
/**
* Iterates thru all nodes in the tree from right (larger) to left (smaller).
*
* @returns IPRT status code.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_pfnCallBack Pointer to callback function.
* @param a_pvUser Callback user argument.
*
* @note This is very similar code to doWithAllFromLeft() and destroy().
*/
int doWithAllFromRight(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator,
PFNCALLBACK a_pfnCallBack, void *a_pvUser) RT_NOEXCEPT
{
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
if (!pNode)
return VINF_SUCCESS;
/*
* We simulate recursive calling here. For safety reasons, we do not
* pop before going down the right tree like the original code did.
*/
uint32_t cNodesLeft = a_pAllocator->m_cNodes;
NodeType *apEntries[kMaxStack];
uint8_t abState[kMaxStack];
unsigned cEntries = 1;
abState[0] = 0;
apEntries[0] = pNode;
while (cEntries > 0)
{
pNode = apEntries[cEntries - 1];
switch (abState[cEntries - 1])
{
/* Go right. */
case 0:
{
abState[cEntries - 1] = 1;
NodeType * const pRightNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxRight));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode),
("idxRight=%#x pRightNode=%p\n", pNode->idxRight, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
if (pRightNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pRightNode, pNode->idxRight, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pRightNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
/* center then left. */
case 1:
{
abState[cEntries - 1] = 2;
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, NULL, 0);
int rc = a_pfnCallBack(pNode, a_pvUser);
if (rc != VINF_SUCCESS)
return rc;
NodeType * const pLeftNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxLeft));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode),
("idxLeft=%#x pLeftNode=%p\n", pNode->idxLeft, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
if (pLeftNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pLeftNode, pNode->idxLeft, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pLeftNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
default:
/* pop it. */
cEntries -= 1;
break;
}
}
return VINF_SUCCESS;
}
/**
* A callback for destroy to do additional cleanups before the node is freed.
*
* @param pNode The current node.
* @param pvUser The user argument.
*/
typedef DECLCALLBACKTYPE(void, FNDESTROYCALLBACK,(NodeType *pNode, void *pvUser));
/** Pointer to a callback for destroy. */
typedef FNDESTROYCALLBACK *PFNDESTROYCALLBACK;
/**
* Destroys the tree, starting with the root node.
*
* This will invoke the freeNode() method on the allocate for every node after
* first doing the callback to let the caller free additional resources
* referenced by the node.
*
* @returns IPRT status code.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_pfnCallBack Pointer to callback function. Optional.
* @param a_pvUser Callback user argument.
*
* @note This is mostly the same code as the doWithAllFromLeft().
*/
int destroy(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator,
PFNDESTROYCALLBACK a_pfnCallBack = NULL, void *a_pvUser = NULL) RT_NOEXCEPT
{
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
if (!pNode)
return VINF_SUCCESS;
/*
* We simulate recursive calling here. For safety reasons, we do not
* pop before going down the right tree like the original code did.
*/
uint32_t cNodesLeft = a_pAllocator->m_cNodes;
NodeType *apEntries[kMaxStack];
uint8_t abState[kMaxStack];
unsigned cEntries = 1;
abState[0] = 0;
apEntries[0] = pNode;
while (cEntries > 0)
{
pNode = apEntries[cEntries - 1];
switch (abState[cEntries - 1])
{
/* Go left. */
case 0:
{
abState[cEntries - 1] = 1;
NodeType * const pLeftNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxLeft));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode),
("idxLeft=%#x pLeftNode=%p\n", pNode->idxLeft, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
if (pLeftNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pLeftNode, pNode->idxLeft, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pLeftNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
/* right. */
case 1:
{
abState[cEntries - 1] = 2;
NodeType * const pRightNode = a_pAllocator->ptrFromInt(readIdx(&pNode->idxRight));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode),
("idxRight=%#x pRightNode=%p\n", pNode->idxRight, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
if (pRightNode)
{
#if RT_GNUC_PREREQ_EX(4,7,1) && defined(RTASSERT_HAVE_STATIC_ASSERT) /* 32-bit 4.4.7 has trouble, dunno when it started working */
AssertCompile(kMaxStack > 6); /* exactly. Seems having static_assert is required. */
#endif
AssertMsgReturnStmt(cEntries < RT_ELEMENTS(apEntries),
("%p[%#x] %p %p %p %p %p %p\n", pRightNode, pNode->idxRight, apEntries[kMaxStack - 1],
apEntries[kMaxStack - 2], apEntries[kMaxStack - 3], apEntries[kMaxStack - 4],
apEntries[kMaxStack - 5], apEntries[kMaxStack - 6]),
m_cErrors++, VERR_HARDAVL_STACK_OVERFLOW);
apEntries[cEntries] = pRightNode;
abState[cEntries] = 0;
cEntries++;
AssertReturn(cNodesLeft > 0, VERR_HARDAVL_TRAVERSED_TOO_MANY_NODES);
cNodesLeft--;
break;
}
RT_FALL_THROUGH();
}
default:
{
/* pop it and destroy it. */
if (a_pfnCallBack)
a_pfnCallBack(pNode, a_pvUser);
int rc = a_pAllocator->freeNode(pNode);
AssertRCReturnStmt(rc, m_cErrors++, rc);
cEntries -= 1;
break;
}
}
}
Assert(m_idxRoot == a_pAllocator->kNilIndex);
return VINF_SUCCESS;
}
/**
* Gets the tree height value (reads cHeigh from the root node).
*
* @retval UINT8_MAX if bogus tree.
*/
uint8_t getHeight(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator) RT_NOEXCEPT
{
NodeType *pNode = a_pAllocator->ptrFromInt(readIdx(&m_idxRoot));
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode), ("m_idxRoot=%#x pNode=%p\n", m_idxRoot, pNode),
m_cErrors++, UINT8_MAX);
if (pNode)
return pNode->cHeight;
return 0;
}
#ifdef RT_STRICT
static void dumpStack(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, HardAvlStack const *pStack) RT_NOEXCEPT
{
uint32_t const * const *paidx = pStack->apidxEntries;
RTAssertMsg2("stack: %u:\n", pStack->cEntries);
for (unsigned i = 0; i < pStack->cEntries; i++)
{
uint32_t idx = *paidx[i];
uint32_t idxNext = i + 1 < pStack->cEntries ? *paidx[i + 1] : UINT32_MAX;
NodeType const *pNode = a_pAllocator->ptrFromInt(idx);
RTAssertMsg2(" #%02u: %p[%#06x] pNode=%p h=%02d l=%#06x%c r=%#06x%c\n", i, paidx[i], idx, pNode, pNode->cHeight,
pNode->idxLeft, pNode->idxLeft == idxNext ? '*' : ' ',
pNode->idxRight, pNode->idxRight == idxNext ? '*' : ' ');
}
}
static void printTree(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, uint32_t a_idxRoot,
unsigned a_uLevel = 0, unsigned a_uMaxLevel = 8, const char *a_pszDir = "") RT_NOEXCEPT
{
if (a_idxRoot == a_pAllocator->kNilIndex)
RTAssertMsg2("%*snil\n", a_uLevel * 6, a_pszDir);
else if (a_uLevel < a_uMaxLevel)
{
NodeType *pNode = a_pAllocator->ptrFromInt(a_idxRoot);
printTree(a_pAllocator, readIdx(&pNode->idxRight), a_uLevel + 1, a_uMaxLevel, "/ ");
RTAssertMsg2("%*s%#x/%u\n", a_uLevel * 6, a_pszDir, a_idxRoot, pNode->cHeight);
printTree(a_pAllocator, readIdx(&pNode->idxLeft), a_uLevel + 1, a_uMaxLevel, "\\ ");
}
else
RTAssertMsg2("%*stoo deep\n", a_uLevel * 6, a_pszDir);
}
#endif
private:
/**
* Rewinds a stack of pointers to pointers to nodes, rebalancing the tree.
*
* @returns IPRT status code.
*
* @param a_pAllocator Pointer to the allocator.
* @param a_pStack Pointer to stack to rewind.
* @param a_fLog Log is done (DEBUG builds only).
*
* @code
* LOOP thru all stack entries
* BEGIN
* Get pointer to pointer to node (and pointer to node) from the stack.
* IF 2 higher left subtree than in right subtree THEN
* BEGIN
* IF higher (or equal) left-sub-subtree than right-sub-subtree THEN
* * n+2|n+3
* / \ / \
* n+2 n ==> n+1 n+1|n+2
* / \ / \
* n+1 n|n+1 n|n+1 n
*
* Or with keys:
*
* 4 2
* / \ / \
* 2 5 ==> 1 4
* / \ / \
* 1 3 3 5
*
* ELSE
* * n+2
* / \ / \
* n+2 n n+1 n+1
* / \ ==> / \ / \
* n n+1 n L R n
* / \
* L R
*
* Or with keys:
* 6 4
* / \ / \
* 2 7 ==> 2 6
* / \ / \ / \
* 1 4 1 3 5 7
* / \
* 3 5
* END
* ELSE IF 2 higher in right subtree than in left subtree THEN
* BEGIN
* Same as above but left <==> right. (invert the picture)
* ELSE
* IF correct height THEN break
* ELSE correct height.
* END
* @endcode
* @internal
*/
int i_rebalance(RTCHardAvlTreeSlabAllocator<NodeType> *a_pAllocator, HardAvlStack *a_pStack, bool a_fLog = false) RT_NOEXCEPT
{
RT_NOREF(a_fLog);
while (a_pStack->cEntries > 0)
{
/* pop */
uint32_t * const pidxNode = a_pStack->apidxEntries[--a_pStack->cEntries];
uint32_t const idxNode = readIdx(pidxNode);
NodeType * const pNode = a_pAllocator->ptrFromInt(idxNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pNode),
("pidxNode=%p[%#x] pNode=%p\n", pidxNode, *pidxNode, pNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pNode));
/* Read node properties: */
uint32_t const idxLeftNode = readIdx(&pNode->idxLeft);
NodeType * const pLeftNode = a_pAllocator->ptrFromInt(idxLeftNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftNode),
("idxLeftNode=%#x pLeftNode=%p\n", idxLeftNode, pLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftNode));
uint32_t const idxRightNode = readIdx(&pNode->idxRight);
NodeType * const pRightNode = a_pAllocator->ptrFromInt(idxRightNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightNode),
("idxRight=%#x pRightNode=%p\n", idxRightNode, pRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightNode));
uint8_t const cLeftHeight = pLeftNode ? pLeftNode->cHeight : 0;
AssertReturnStmt(cLeftHeight <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_LEFT_HEIGHT);
uint8_t const cRightHeight = pRightNode ? pRightNode->cHeight : 0;
AssertReturnStmt(cRightHeight <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_RIGHT_HEIGHT);
/* Decide what needs doing: */
if (cRightHeight + 1 < cLeftHeight)
{
Assert(cRightHeight + 2 == cLeftHeight);
AssertReturnStmt(pLeftNode, m_cErrors++, VERR_HARDAVL_UNEXPECTED_NULL_LEFT);
uint32_t const idxLeftLeftNode = readIdx(&pLeftNode->idxLeft);
NodeType * const pLeftLeftNode = a_pAllocator->ptrFromInt(idxLeftLeftNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftLeftNode),
("idxLeftLeftNode=%#x pLeftLeftNode=%p\n", idxLeftLeftNode, pLeftLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftLeftNode));
uint32_t const idxLeftRightNode = readIdx(&pLeftNode->idxRight);
NodeType * const pLeftRightNode = a_pAllocator->ptrFromInt(idxLeftRightNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pLeftRightNode),
("idxLeftRightNode=%#x pLeftRightNode=%p\n", idxLeftRightNode, pLeftRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pLeftRightNode));
uint8_t const cLeftRightHeight = pLeftRightNode ? pLeftRightNode->cHeight : 0;
if ((pLeftLeftNode ? pLeftLeftNode->cHeight : 0) >= cLeftRightHeight)
{
AssertReturnStmt(cLeftRightHeight + 2 <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_NEW_HEIGHT);
pNode->idxLeft = idxLeftRightNode;
pNode->cHeight = (uint8_t)(cLeftRightHeight + 1);
pLeftNode->cHeight = (uint8_t)(cLeftRightHeight + 2);
pLeftNode->idxRight = idxNode;
*pidxNode = idxLeftNode;
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #1\n", a_pStack->cEntries);
#endif
}
else
{
AssertReturnStmt(cLeftRightHeight <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_RIGHT_HEIGHT);
AssertReturnStmt(pLeftRightNode, m_cErrors++, VERR_HARDAVL_UNEXPECTED_NULL_RIGHT);
uint32_t const idxLeftRightLeftNode = readIdx(&pLeftRightNode->idxLeft);
AssertReturnStmt(a_pAllocator->isIntValid(idxLeftRightLeftNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
uint32_t const idxLeftRightRightNode = readIdx(&pLeftRightNode->idxRight);
AssertReturnStmt(a_pAllocator->isIntValid(idxLeftRightRightNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
pLeftNode->idxRight = idxLeftRightLeftNode;
pNode->idxLeft = idxLeftRightRightNode;
pLeftRightNode->idxLeft = idxLeftNode;
pLeftRightNode->idxRight = idxNode;
pLeftNode->cHeight = cLeftRightHeight;
pNode->cHeight = cLeftRightHeight;
pLeftRightNode->cHeight = cLeftHeight;
*pidxNode = idxLeftRightNode;
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #2\n", a_pStack->cEntries);
#endif
}
m_cRebalancingOperations++;
}
else if (cLeftHeight + 1 < cRightHeight)
{
Assert(cLeftHeight + 2 == cRightHeight);
AssertReturnStmt(pRightNode, m_cErrors++, VERR_HARDAVL_UNEXPECTED_NULL_RIGHT);
uint32_t const idxRightLeftNode = readIdx(&pRightNode->idxLeft);
NodeType * const pRightLeftNode = a_pAllocator->ptrFromInt(idxRightLeftNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightLeftNode),
("idxRightLeftNode=%#x pRightLeftNode=%p\n", idxRightLeftNode, pRightLeftNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightLeftNode));
uint32_t const idxRightRightNode = readIdx(&pRightNode->idxRight);
NodeType * const pRightRightNode = a_pAllocator->ptrFromInt(idxRightRightNode);
AssertMsgReturnStmt(a_pAllocator->isPtrRetOkay(pRightRightNode),
("idxRightRightNode=%#x pRightRightNode=%p\n", idxRightRightNode, pRightRightNode),
m_cErrors++, a_pAllocator->ptrErrToStatus(pRightRightNode));
uint8_t const cRightLeftHeight = pRightLeftNode ? pRightLeftNode->cHeight : 0;
if ((pRightRightNode ? pRightRightNode->cHeight : 0) >= cRightLeftHeight)
{
AssertReturnStmt(cRightLeftHeight + 2 <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_NEW_HEIGHT);
pNode->idxRight = idxRightLeftNode;
pRightNode->idxLeft = idxNode;
pNode->cHeight = (uint8_t)(cRightLeftHeight + 1);
pRightNode->cHeight = (uint8_t)(cRightLeftHeight + 2);
*pidxNode = idxRightNode;
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #3 h=%d, *pidxNode=%#x\n", a_pStack->cEntries, pRightNode->cHeight, *pidxNode);
#endif
RTHARDAVL_STRICT_CHECK_HEIGHTS(pRightNode, NULL, 0);
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, NULL, 0);
}
else
{
AssertReturnStmt(cRightLeftHeight <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_LEFT_HEIGHT);
AssertReturnStmt(pRightLeftNode, m_cErrors++, VERR_HARDAVL_UNEXPECTED_NULL_LEFT);
uint32_t const idxRightLeftRightNode = readIdx(&pRightLeftNode->idxRight);
AssertReturnStmt(a_pAllocator->isIntValid(idxRightLeftRightNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
uint32_t const idxRightLeftLeftNode = readIdx(&pRightLeftNode->idxLeft);
AssertReturnStmt(a_pAllocator->isIntValid(idxRightLeftLeftNode), m_cErrors++, VERR_HARDAVL_INDEX_OUT_OF_BOUNDS);
pRightNode->idxLeft = idxRightLeftRightNode;
pNode->idxRight = idxRightLeftLeftNode;
pRightLeftNode->idxRight = idxRightNode;
pRightLeftNode->idxLeft = idxNode;
pRightNode->cHeight = cRightLeftHeight;
pNode->cHeight = cRightLeftHeight;
pRightLeftNode->cHeight = cRightHeight;
*pidxNode = idxRightLeftNode;
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #4 h=%d, *pidxNode=%#x\n", a_pStack->cEntries, pRightLeftNode->cHeight, *pidxNode);
#endif
}
m_cRebalancingOperations++;
}
else
{
uint8_t const cHeight = (uint8_t)(RT_MAX(cLeftHeight, cRightHeight) + 1);
AssertReturnStmt(cHeight <= kMaxHeight, m_cErrors++, VERR_HARDAVL_BAD_NEW_HEIGHT);
if (cHeight == pNode->cHeight)
{
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #5, h=%d - done\n", a_pStack->cEntries, cHeight);
#endif
RTHARDAVL_STRICT_CHECK_HEIGHTS(pNode, NULL, 0);
if (pLeftNode)
RTHARDAVL_STRICT_CHECK_HEIGHTS(pLeftNode, NULL, 0);
if (pRightNode)
RTHARDAVL_STRICT_CHECK_HEIGHTS(pRightNode, NULL, 0);
break;
}
#ifdef DEBUG
if (a_fLog) RTAssertMsg2("rebalance: %#2u: op #5, h=%d - \n", a_pStack->cEntries, cHeight);
#endif
pNode->cHeight = cHeight;
}
}
return VINF_SUCCESS;
}
};
/** @} */
#endif /* !IPRT_INCLUDED_cpp_hardavlrange_h */
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