//========= Copyright 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose: Linked list container class that doesn't move around
//
// $Revision: $
// $NoKeywords: $
//=============================================================================//
#ifndef UTLFIXEDLINKEDLIST_H
#define UTLFIXEDLINKEDLIST_H
#ifdef _WIN32
#pragma once
#endif
#include "basetypes.h"
#include "utlfixedmemory.h"
#include "tier0/dbg.h"
// This is a useful macro to iterate from head to tail in a linked list.
#undef FOR_EACH_LL
#define FOR_EACH_LL( listName, iteratorName ) \
for( int iteratorName=listName.Head(); iteratorName != listName.InvalidIndex(); iteratorName = listName.Next( iteratorName ) )
//-----------------------------------------------------------------------------
// class CUtlFixedLinkedList:
//-----------------------------------------------------------------------------
template <class T>
class CUtlFixedLinkedList
{
public:
typedef T ElemType_t;
typedef int I;
typedef int IndexType_t;
// constructor, destructor
CUtlFixedLinkedList( int growSize = 0, int initSize = 0 );
~CUtlFixedLinkedList( );
// gets particular elements
T& Element( I i );
T const& Element( I i ) const;
T& operator[]( I i );
T const& operator[]( I i ) const;
// Make sure we have a particular amount of memory
void EnsureCapacity( int num );
void SetGrowSize( int growSize );
// Memory deallocation
void Purge();
// Delete all the elements then call Purge.
void PurgeAndDeleteElements();
// Insertion methods....
I InsertBefore( I before );
I InsertAfter( I after );
I AddToHead( );
I AddToTail( );
I InsertBefore( I before, T const& src );
I InsertAfter( I after, T const& src );
I AddToHead( T const& src );
I AddToTail( T const& src );
// Find an element and return its index or InvalidIndex() if it couldn't be found.
I Find( const T &src ) const;
// Look for the element. If it exists, remove it and return true. Otherwise, return false.
bool FindAndRemove( const T &src );
// Removal methods
void Remove( I elem );
void RemoveAll();
// Allocation/deallocation methods
// If multilist == true, then list list may contain many
// non-connected lists, and IsInList and Head + Tail are meaningless...
I Alloc( bool multilist = false );
void Free( I elem );
// list modification
void LinkBefore( I before, I elem );
void LinkAfter( I after, I elem );
void Unlink( I elem );
void LinkToHead( I elem );
void LinkToTail( I elem );
// invalid index
inline static I InvalidIndex() { return 0; }
inline static size_t ElementSize() { return sizeof(ListElem_t); }
// list statistics
int Count() const;
// Traversing the list
I Head() const;
I Tail() const;
I Previous( I i ) const;
I Next( I i ) const;
// Are nodes in the list or valid?
bool IsValidIndex( I i ) const;
bool IsInList( I i ) const;
protected:
// What the linked list element looks like
struct ListElem_t
{
T m_Element;
I m_Previous;
I m_Next;
private:
// No copy constructor for these...
ListElem_t( const ListElem_t& );
};
// constructs the class
I AllocInternal( bool multilist = false );
void ConstructList();
// Gets at the list element....
ListElem_t& InternalElement( I i ) { return m_Memory[i]; }
ListElem_t const& InternalElement( I i ) const { return m_Memory[i]; }
// copy constructors not allowed
CUtlFixedLinkedList( const CUtlFixedLinkedList<T> &list ) { Assert(0); }
CUtlFixedMemory<ListElem_t> m_Memory;
I m_Head;
I m_Tail;
I m_FirstFree;
I m_ElementCount; // The number actually in the list
I m_TotalElements; // The total number of elements allocated
};
//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------
template <class T>
CUtlFixedLinkedList<T>::CUtlFixedLinkedList( int growSize, int initSize ) :
m_Memory(growSize, initSize)
{
ConstructList();
}
template <class T>
CUtlFixedLinkedList<T>::~CUtlFixedLinkedList( )
{
RemoveAll();
}
template <class T>
void CUtlFixedLinkedList<T>::ConstructList()
{
m_Head = InvalidIndex();
m_Tail = InvalidIndex();
m_FirstFree = InvalidIndex();
m_ElementCount = m_TotalElements = 0;
}
//-----------------------------------------------------------------------------
// gets particular elements
//-----------------------------------------------------------------------------
template <class T>
inline T& CUtlFixedLinkedList<T>::Element( I i )
{
return m_Memory[i].m_Element;
}
template <class T>
inline T const& CUtlFixedLinkedList<T>::Element( I i ) const
{
return m_Memory[i].m_Element;
}
template <class T>
inline T& CUtlFixedLinkedList<T>::operator[]( I i )
{
return m_Memory[i].m_Element;
}
template <class T>
inline T const& CUtlFixedLinkedList<T>::operator[]( I i ) const
{
return m_Memory[i].m_Element;
}
//-----------------------------------------------------------------------------
// list statistics
//-----------------------------------------------------------------------------
template <class T>
inline int CUtlFixedLinkedList<T>::Count() const
{
return m_ElementCount;
}
//-----------------------------------------------------------------------------
// Traversing the list
//-----------------------------------------------------------------------------
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Head() const
{
return m_Head;
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Tail() const
{
return m_Tail;
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Previous( I i ) const
{
Assert( IsValidIndex(i) );
return InternalElement(i).m_Previous;
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Next( I i ) const
{
Assert( IsValidIndex(i) );
return InternalElement(i).m_Next;
}
//-----------------------------------------------------------------------------
// Are nodes in the list or valid?
//-----------------------------------------------------------------------------
template <class T>
inline bool CUtlFixedLinkedList<T>::IsValidIndex( I i ) const
{
return (i != 0) && ((m_Memory[i].m_Previous != i) || (m_Memory[i].m_Next == i));
}
template <class T>
inline bool CUtlFixedLinkedList<T>::IsInList( I i ) const
{
return (i != 0) && (Previous(i) != i);
}
//-----------------------------------------------------------------------------
// Makes sure we have enough memory allocated to store a requested # of elements
//-----------------------------------------------------------------------------
template< class T >
void CUtlFixedLinkedList<T>::EnsureCapacity( int num )
{
m_Memory.EnsureCapacity(num);
}
template<class T>
void CUtlFixedLinkedList<T>::SetGrowSize( int growSize )
{
m_Memory.SetGrowSize( growSize );
}
//-----------------------------------------------------------------------------
// Deallocate memory
//-----------------------------------------------------------------------------
template <class T>
void CUtlFixedLinkedList<T>::Purge()
{
RemoveAll();
m_Memory.Purge( );
m_FirstFree = InvalidIndex();
m_TotalElements = 0;
}
template<class T>
void CUtlFixedLinkedList<T>::PurgeAndDeleteElements()
{
int iNext;
for( int i=Head(); i != InvalidIndex(); i=iNext )
{
iNext = Next(i);
delete Element(i);
}
Purge();
}
//-----------------------------------------------------------------------------
// Node allocation/deallocation
//-----------------------------------------------------------------------------
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::AllocInternal( bool multilist )
{
I elem;
if (m_FirstFree == InvalidIndex())
{
// Nothing in the free list; add.
// Since nothing is in the free list, m_TotalElements == total # of elements
// the list knows about.
elem = m_Memory.Alloc();
++m_TotalElements;
if ( elem == InvalidIndex() )
{
Error("CUtlFixedLinkedList overflow!\n");
}
}
else
{
elem = m_FirstFree;
m_FirstFree = InternalElement(m_FirstFree).m_Next;
}
if (!multilist)
{
InternalElement(elem).m_Next = InternalElement(elem).m_Previous = elem;
}
else
{
InternalElement(elem).m_Next = InternalElement(elem).m_Previous = InvalidIndex();
}
return elem;
}
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Alloc( bool multilist )
{
I elem = AllocInternal( multilist );
Construct( &Element(elem) );
return elem;
}
template <class T>
void CUtlFixedLinkedList<T>::Free( I elem )
{
Assert( IsValidIndex(elem) );
Unlink(elem);
ListElem_t &internalElem = InternalElement(elem);
Destruct( &internalElem.m_Element );
internalElem.m_Next = m_FirstFree;
m_FirstFree = elem;
}
//-----------------------------------------------------------------------------
// Insertion methods; allocates and links (uses default constructor)
//-----------------------------------------------------------------------------
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::InsertBefore( I before )
{
// Make a new node
I newNode = AllocInternal();
// Link it in
LinkBefore( before, newNode );
// Construct the data
Construct( &Element(newNode) );
return newNode;
}
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::InsertAfter( I after )
{
// Make a new node
I newNode = AllocInternal();
// Link it in
LinkAfter( after, newNode );
// Construct the data
Construct( &Element(newNode) );
return newNode;
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::AddToHead( )
{
return InsertAfter( InvalidIndex() );
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::AddToTail( )
{
return InsertBefore( InvalidIndex() );
}
//-----------------------------------------------------------------------------
// Insertion methods; allocates and links (uses copy constructor)
//-----------------------------------------------------------------------------
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::InsertBefore( I before, T const& src )
{
// Make a new node
I newNode = AllocInternal();
// Link it in
LinkBefore( before, newNode );
// Construct the data
CopyConstruct( &Element(newNode), src );
return newNode;
}
template <class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::InsertAfter( I after, T const& src )
{
// Make a new node
I newNode = AllocInternal();
// Link it in
LinkAfter( after, newNode );
// Construct the data
CopyConstruct( &Element(newNode), src );
return newNode;
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::AddToHead( T const& src )
{
return InsertAfter( InvalidIndex(), src );
}
template <class T>
inline typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::AddToTail( T const& src )
{
return InsertBefore( InvalidIndex(), src );
}
//-----------------------------------------------------------------------------
// Removal methods
//-----------------------------------------------------------------------------
template<class T>
typename CUtlFixedLinkedList<T>::I CUtlFixedLinkedList<T>::Find( const T &src ) const
{
for ( I i=Head(); i != InvalidIndex(); i = Next( i ) )
{
if ( Element( i ) == src )
return i;
}
return InvalidIndex();
}
template<class T>
bool CUtlFixedLinkedList<T>::FindAndRemove( const T &src )
{
I i = Find( src );
if ( i == InvalidIndex() )
{
return false;
}
else
{
Remove( i );
return true;
}
}
template <class T>
void CUtlFixedLinkedList<T>::Remove( I elem )
{
Free( elem );
}
template <class T>
void CUtlFixedLinkedList<T>::RemoveAll()
{
if (m_TotalElements == 0)
return;
// Have to do some convoluted stuff to invoke the destructor on all
// valid elements for the multilist case (since we don't have all elements
// connected to each other in a list).
// Put everything into the free list
I elem = m_Memory.FirstElement();
for (int i = 0; i < m_TotalElements; ++i )
{
// Invoke the destructor
if (IsValidIndex((I)elem))
{
Destruct( &Element((I)elem) );
}
elem = m_Memory.NextElement( elem );
}
// This doesn't actually deallocate the memory... purge does that
m_Memory.RemoveAll();
m_TotalElements = 0;
m_FirstFree = NULL;
// Clear everything else out
m_Head = InvalidIndex();
m_Tail = InvalidIndex();
m_ElementCount = 0;
}
//-----------------------------------------------------------------------------
// list modification
//-----------------------------------------------------------------------------
template <class T>
void CUtlFixedLinkedList<T>::LinkBefore( I before, I elem )
{
Assert( IsValidIndex(elem) );
// Unlink it if it's in the list at the moment
Unlink(elem);
ListElem_t& newElem = InternalElement(elem);
// The element *after* our newly linked one is the one we linked before.
newElem.m_Next = before;
if (before == InvalidIndex())
{
// In this case, we're linking to the end of the list, so reset the tail
newElem.m_Previous = m_Tail;
m_Tail = elem;
}
else
{
// Here, we're not linking to the end. Set the prev pointer to point to
// the element we're linking.
Assert( IsInList(before) );
ListElem_t& beforeElem = InternalElement(before);
newElem.m_Previous = beforeElem.m_Previous;
beforeElem.m_Previous = elem;
}
// Reset the head if we linked to the head of the list
if (newElem.m_Previous == InvalidIndex())
m_Head = elem;
else
InternalElement(newElem.m_Previous).m_Next = elem;
// one more element baby
++m_ElementCount;
}
template <class T>
void CUtlFixedLinkedList<T>::LinkAfter( I after, I elem )
{
Assert( IsValidIndex(elem) );
// Unlink it if it's in the list at the moment
if ( IsInList(elem) )
Unlink(elem);
ListElem_t& newElem = InternalElement(elem);
// The element *before* our newly linked one is the one we linked after
newElem.m_Previous = after;
if (after == InvalidIndex())
{
// In this case, we're linking to the head of the list, reset the head
newElem.m_Next = m_Head;
m_Head = elem;
}
else
{
// Here, we're not linking to the end. Set the next pointer to point to
// the element we're linking.
Assert( IsInList(after) );
ListElem_t& afterElem = InternalElement(after);
newElem.m_Next = afterElem.m_Next;
afterElem.m_Next = elem;
}
// Reset the tail if we linked to the tail of the list
if (newElem.m_Next == InvalidIndex())
m_Tail = elem;
else
InternalElement(newElem.m_Next).m_Previous = elem;
// one more element baby
++m_ElementCount;
}
template <class T>
void CUtlFixedLinkedList<T>::Unlink( I elem )
{
Assert( IsValidIndex(elem) );
if (IsInList(elem))
{
ListElem_t *pOldElem = &m_Memory[elem];
// If we're the first guy, reset the head
// otherwise, make our previous node's next pointer = our next
if ( pOldElem->m_Previous != 0 )
{
m_Memory[pOldElem->m_Previous].m_Next = pOldElem->m_Next;
}
else
{
m_Head = pOldElem->m_Next;
}
// If we're the last guy, reset the tail
// otherwise, make our next node's prev pointer = our prev
if ( pOldElem->m_Next != 0 )
{
m_Memory[pOldElem->m_Next].m_Previous = pOldElem->m_Previous;
}
else
{
m_Tail = pOldElem->m_Previous;
}
// This marks this node as not in the list,
// but not in the free list either
pOldElem->m_Previous = pOldElem->m_Next = elem;
// One less puppy
--m_ElementCount;
}
}
template <class T>
inline void CUtlFixedLinkedList<T>::LinkToHead( I elem )
{
LinkAfter( InvalidIndex(), elem );
}
template <class T>
inline void CUtlFixedLinkedList<T>::LinkToTail( I elem )
{
LinkBefore( InvalidIndex(), elem );
}
#endif // UTLFIXEDLINKEDLIST_H