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//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: N-way tree container class
//
// $Revision: $
// $NoKeywords: $
//=============================================================================//
#ifndef UTLNTREE_H
#define UTLNTREE_H
#ifdef _WIN32
#pragma once
#endif
#include "basetypes.h"
#include "tier0/dbg.h"
#include "utlmemory.h"
#define INVALID_NTREE_IDX ((I)~0)
//-----------------------------------------------------------------------------
// class CUtlNTree:
// description:
// A lovely index-based linked list! T is the class type, I is the
//index type, which usually should be an unsigned short or smaller.
//-----------------------------------------------------------------------------
template <class T, class I = unsigned short>
class CUtlNTree {
public:
typedef T ElemType_t;
typedef I IndexType_t;
// constructor, destructor
CUtlNTree(int growSize = 0, int initSize = 0);
CUtlNTree(void* pMemory, int memsize);
~CUtlNTree();
// gets particular elements
T& Element(I i);
const T& Element(I i) const;
T& operator[](I i);
const T& operator[](I i) const;
// Make sure we have a particular amount of memory
void EnsureCapacity(int num);
// Clears the tree, doesn't deallocate memory
void RemoveAll();
// Memory deallocation
void Purge();
// Allocation/deallocation methods
I Alloc();
void Free(I elem);
void FreeSubTree(I elem);
// list modification
void SetRoot(I root);
void LinkChildBefore(I parent, I before, I elem);
void LinkChildAfter(I parent, I after, I elem);
void Unlink(I elem);
// Alloc + link combined
I InsertChildBefore(I parent, I before);
I InsertChildAfter(I parent, I after);
I InsertChildBefore(I parent, I before, const T& elem);
I InsertChildAfter(I parent, I after, const T& elem);
// Unlink + free combined
void Remove(I elem);
void RemoveSubTree(I elem);
// invalid index
inline static I InvalidIndex() { return INVALID_NTREE_IDX; }
inline static size_t ElementSize() { return sizeof(Node_t); }
// list statistics
int Count() const;
I MaxElementIndex() const;
// Traversing the list
I Root() const;
I FirstChild(I i) const;
I PrevSibling(I i) const;
I NextSibling(I i) const;
I Parent(I i) const;
// Are nodes in the list or valid?
bool IsValidIndex(I i) const;
bool IsInTree(I i) const;
protected:
// What the linked list element looks like
struct Node_t {
T m_Element;
I m_Parent;
I m_FirstChild;
I m_PrevSibling;
I m_NextSibling;
private:
// No copy constructor for these...
Node_t(const Node_t&);
};
// constructs the class
void ConstructList();
// Allocates the element, doesn't call the constructor
I AllocInternal();
// Gets at the node element....
Node_t& InternalNode(I i) { return m_Memory[i]; }
const Node_t& InternalNode(I i) const { return m_Memory[i]; }
void ResetDbgInfo() { m_pElements = m_Memory.Base(); }
// copy constructors not allowed
CUtlNTree(CUtlNTree<T, I> const& tree) { Assert(0); }
CUtlMemory<Node_t> m_Memory;
I m_Root;
I m_FirstFree;
I m_ElementCount; // The number actually in the tree
I m_MaxElementIndex; // The max index we've ever assigned
// For debugging purposes;
// it's in release builds so this can be used in libraries correctly
Node_t* m_pElements;
};
//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------
template <class T, class I>
CUtlNTree<T, I>::CUtlNTree(int growSize, int initSize)
: m_Memory(growSize, initSize) {
ConstructList();
ResetDbgInfo();
}
template <class T, class I>
CUtlNTree<T, I>::CUtlNTree(void* pMemory, int memsize)
: m_Memory(pMemory, memsize / sizeof(T)) {
ConstructList();
ResetDbgInfo();
}
template <class T, class I>
CUtlNTree<T, I>::~CUtlNTree() {
RemoveAll();
}
template <class T, class I>
void CUtlNTree<T, I>::ConstructList() {
m_Root = InvalidIndex();
m_FirstFree = InvalidIndex();
m_ElementCount = m_MaxElementIndex = 0;
}
//-----------------------------------------------------------------------------
// gets particular elements
//-----------------------------------------------------------------------------
template <class T, class I>
inline T& CUtlNTree<T, I>::Element(I i) {
return m_Memory[i].m_Element;
}
template <class T, class I>
inline const T& CUtlNTree<T, I>::Element(I i) const {
return m_Memory[i].m_Element;
}
template <class T, class I>
inline T& CUtlNTree<T, I>::operator[](I i) {
return m_Memory[i].m_Element;
}
template <class T, class I>
inline const T& CUtlNTree<T, I>::operator[](I i) const {
return m_Memory[i].m_Element;
}
//-----------------------------------------------------------------------------
// list statistics
//-----------------------------------------------------------------------------
template <class T, class I>
inline int CUtlNTree<T, I>::Count() const {
return m_ElementCount;
}
template <class T, class I>
inline I CUtlNTree<T, I>::MaxElementIndex() const {
return m_MaxElementIndex;
}
//-----------------------------------------------------------------------------
// Traversing the list
//-----------------------------------------------------------------------------
template <class T, class I>
inline I CUtlNTree<T, I>::Root() const {
return m_Root;
}
template <class T, class I>
inline I CUtlNTree<T, I>::FirstChild(I i) const {
Assert(IsInTree(i));
return InternalNode(i).m_FirstChild;
}
template <class T, class I>
inline I CUtlNTree<T, I>::PrevSibling(I i) const {
Assert(IsInTree(i));
return InternalNode(i).m_PrevSibling;
}
template <class T, class I>
inline I CUtlNTree<T, I>::NextSibling(I i) const {
Assert(IsInTree(i));
return InternalNode(i).m_NextSibling;
}
template <class T, class I>
inline I CUtlNTree<T, I>::Parent(I i) const {
Assert(IsInTree(i));
return InternalNode(i).m_Parent;
}
//-----------------------------------------------------------------------------
// Are nodes in the list or valid?
//-----------------------------------------------------------------------------
template <class T, class I>
inline bool CUtlNTree<T, I>::IsValidIndex(I i) const {
return (i < m_MaxElementIndex) && (i >= 0);
}
template <class T, class I>
inline bool CUtlNTree<T, I>::IsInTree(I i) const {
return (i < m_MaxElementIndex) && (i >= 0) &&
(InternalNode(i).m_PrevSibling != i);
}
//-----------------------------------------------------------------------------
// Makes sure we have enough memory allocated to store a requested # of elements
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::EnsureCapacity(int num) {
MEM_ALLOC_CREDIT_CLASS();
m_Memory.EnsureCapacity(num);
ResetDbgInfo();
}
//-----------------------------------------------------------------------------
// Deallocate memory
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::Purge() {
RemoveAll();
m_Memory.Purge();
m_FirstFree = InvalidIndex();
m_MaxElementIndex = 0;
ResetDbgInfo();
}
//-----------------------------------------------------------------------------
// Node allocation/deallocation
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlNTree<T, I>::AllocInternal() {
I elem;
if (m_FirstFree == INVALID_NTREE_IDX) {
// Nothing in the free list; add.
// Since nothing is in the free list, m_MaxElementIndex == total # of
// elements the list knows about.
if ((int)m_MaxElementIndex == m_Memory.NumAllocated()) {
MEM_ALLOC_CREDIT_CLASS();
m_Memory.Grow();
}
Assert(m_MaxElementIndex != INVALID_NTREE_IDX);
elem = (I)m_MaxElementIndex;
++m_MaxElementIndex;
if (elem == InvalidIndex()) {
Error("CUtlNTree overflow!\n");
}
} else {
elem = m_FirstFree;
m_FirstFree = InternalNode(m_FirstFree).m_NextSibling;
}
Node_t& node = InternalNode(elem);
node.m_NextSibling = node.m_PrevSibling = node.m_Parent =
node.m_FirstChild = INVALID_NTREE_IDX;
ResetDbgInfo();
// one more element baby
++m_ElementCount;
return elem;
}
template <class T, class I>
I CUtlNTree<T, I>::Alloc() {
I elem = AllocInternal();
Construct(&Element(elem));
return elem;
}
template <class T, class I>
void CUtlNTree<T, I>::Free(I elem) {
Assert(IsInTree(elem));
Unlink(elem);
// If there's children, this will result in leaks. Use FreeSubTree instead.
Assert(FirstChild(elem) == INVALID_NTREE_IDX);
Node_t& node = InternalNode(elem);
Destruct(&node.m_Element);
node.m_NextSibling = m_FirstFree;
node.m_PrevSibling = elem; // Marks it as being in the free list
node.m_Parent = node.m_FirstChild = INVALID_NTREE_IDX;
m_FirstFree = elem;
// one less element baby
--m_ElementCount;
}
template <class T, class I>
void CUtlNTree<T, I>::FreeSubTree(I elem) {
Assert(IsValidIndex(elem));
I child = FirstChild(elem);
while (child != INVALID_NTREE_IDX) {
I next = NextSibling(child);
FreeSubTree(child);
child = next;
}
Free(elem);
}
//-----------------------------------------------------------------------------
// Clears the tree
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::RemoveAll() {
if (m_MaxElementIndex == 0) return;
// Put everything into the free list (even unlinked things )
I prev = InvalidIndex();
for (int i = (int)m_MaxElementIndex; --i >= 0; prev = (I)i) {
Node_t& node = InternalNode(i);
if (IsInTree(i)) {
Destruct(&node.m_Element);
}
node.m_NextSibling = prev;
node.m_PrevSibling = (I)i; // Marks it as being in the free list
node.m_Parent = node.m_FirstChild = INVALID_NTREE_IDX;
}
// First free points to the first element
m_FirstFree = 0;
// Clear everything else out
m_Root = INVALID_NTREE_IDX;
m_ElementCount = 0;
}
//-----------------------------------------------------------------------------
// list modification
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::SetRoot(I root) {
// Resetting the root while it's got stuff in it is bad...
Assert(m_Root == InvalidIndex());
m_Root = root;
}
//-----------------------------------------------------------------------------
// Links a node after a particular node
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::LinkChildAfter(I parent, I after, I elem) {
Assert(IsInTree(elem));
// Unlink it if it's in the list at the moment
Unlink(elem);
Node_t& newElem = InternalNode(elem);
newElem.m_Parent = parent;
newElem.m_PrevSibling = after;
if (after != INVALID_NTREE_IDX) {
Node_t& prevSiblingNode = InternalNode(after);
newElem.m_NextSibling = prevSiblingNode.m_NextSibling;
prevSiblingNode.m_NextSibling = elem;
} else {
if (parent != INVALID_NTREE_IDX) {
Node_t& parentNode = InternalNode(parent);
newElem.m_NextSibling = parentNode.m_FirstChild;
parentNode.m_FirstChild = elem;
} else {
newElem.m_NextSibling = m_Root;
if (m_Root != INVALID_NTREE_IDX) {
Node_t& rootNode = InternalNode(m_Root);
rootNode.m_PrevSibling = elem;
}
m_Root = elem;
}
}
if (newElem.m_NextSibling != INVALID_NTREE_IDX) {
Node_t& nextSiblingNode = InternalNode(newElem.m_NextSibling);
nextSiblingNode.m_PrevSibling = elem;
}
}
//-----------------------------------------------------------------------------
// Links a node before a particular node
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::LinkChildBefore(I parent, I before, I elem) {
Assert(IsValidIndex(elem));
if (before != INVALID_NTREE_IDX) {
LinkChildAfter(parent, InternalNode(before).m_PrevSibling, elem);
return;
}
// NOTE: I made the choice to do an O(n) operation here
// instead of store more data per node (LastChild).
// This might not be the right choice. Revisit if we get perf problems.
I after;
if (parent != INVALID_NTREE_IDX) {
after = InternalNode(parent).m_FirstChild;
} else {
after = m_Root;
}
if (after == INVALID_NTREE_IDX) {
LinkChildAfter(parent, after, elem);
return;
}
I next = InternalNode(after).m_NextSibling;
while (next != InvalidIndex()) {
after = next;
next = InternalNode(next).m_NextSibling;
}
LinkChildAfter(parent, after, elem);
}
//-----------------------------------------------------------------------------
// Unlinks a node from the tree
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::Unlink(I elem) {
Assert(IsInTree(elem));
Node_t* pOldNode = &InternalNode(elem);
// If we're the first guy, reset the head
// otherwise, make our previous node's next pointer = our next
if (pOldNode->m_PrevSibling != INVALID_NTREE_IDX) {
InternalNode(pOldNode->m_PrevSibling).m_NextSibling =
pOldNode->m_NextSibling;
} else {
if (pOldNode->m_Parent != INVALID_NTREE_IDX) {
InternalNode(pOldNode->m_Parent).m_FirstChild =
pOldNode->m_NextSibling;
} else if (m_Root == elem) {
m_Root = pOldNode->m_NextSibling;
}
}
// If we're the last guy, reset the tail
// otherwise, make our next node's prev pointer = our prev
if (pOldNode->m_NextSibling != INVALID_NTREE_IDX) {
InternalNode(pOldNode->m_NextSibling).m_PrevSibling =
pOldNode->m_PrevSibling;
}
// Unlink everything except children
pOldNode->m_Parent = pOldNode->m_PrevSibling = pOldNode->m_NextSibling =
INVALID_NTREE_IDX;
}
//-----------------------------------------------------------------------------
// Alloc + link combined
//-----------------------------------------------------------------------------
template <class T, class I>
I CUtlNTree<T, I>::InsertChildBefore(I parent, I before) {
I elem = AllocInternal();
Construct(&Element(elem));
LinkChildBefore(parent, before, elem);
return elem;
}
template <class T, class I>
I CUtlNTree<T, I>::InsertChildAfter(I parent, I after) {
I elem = AllocInternal();
Construct(&Element(elem));
LinkChildAfter(parent, after, elem);
return elem;
}
template <class T, class I>
I CUtlNTree<T, I>::InsertChildBefore(I parent, I before, const T& data) {
I elem = AllocInternal();
CopyConstruct(&Element(elem), data);
LinkChildBefore(parent, before, elem);
return elem;
}
template <class T, class I>
I CUtlNTree<T, I>::InsertChildAfter(I parent, I after, const T& data) {
I elem = AllocInternal();
CopyConstruct(&Element(elem), data);
LinkChildAfter(parent, after, elem);
return elem;
}
//-----------------------------------------------------------------------------
// Unlink + free combined
//-----------------------------------------------------------------------------
template <class T, class I>
void CUtlNTree<T, I>::Remove(I elem) {
Unlink(elem);
Free(elem);
}
template <class T, class I>
void CUtlNTree<T, I>::RemoveSubTree(I elem) {
UnlinkSubTree(elem);
Free(elem);
}
#endif // UTLNTREE_H