source-engine/public/tier1/utlqueue.h

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2020-04-22 16:56:21 +00:00
//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//=============================================================================//
#ifndef UTLQUEUE_H
#define UTLQUEUE_H
#ifdef _WIN32
#pragma once
#endif
#include "utlmemory.h"
//#define TEST_UTLQUEUE
enum QueueIter_t { QUEUE_ITERATOR_INVALID = 0xffffffff };
// T is the type stored in the queue
template< class T, class M = CUtlMemory< T > >
class CUtlQueue
{
public:
CUtlQueue( int growSize = 0, int initSize = 0 );
CUtlQueue( T *pMemory, int numElements );
// return the item from the front of the queue and delete it
T RemoveAtHead();
bool RemoveAtHead( T &removedElement );
// return the item from the end of the queue and delete it
T RemoveAtTail();
bool RemoveAtTail( T &removedElement );
// return item at the front of the queue
T const& Head() const;
// return item at the end of the queue
T const& Tail() const;
// Add a new item to the end of the queue
void Insert( T const &element );
// checks if an element of this value already exists on the stack, returns true if it does
bool Check( T const element ) const;
// iterators may be invalidated by Insert()
QueueIter_t First() const;
QueueIter_t Next( QueueIter_t it ) const;
QueueIter_t Last() const;
QueueIter_t Previous( QueueIter_t it ) const;
bool IsValid( QueueIter_t it ) const;
T const& Element( QueueIter_t it ) const;
// Returns the count of elements in the queue
int Count() const;
// Return whether the queue is empty or not, faster than Count().
bool IsEmpty() const;
// doesn't deallocate memory
void RemoveAll();
// Memory deallocation
void Purge();
protected:
QueueIter_t Next_Unchecked( QueueIter_t it ) const;
QueueIter_t Previous_Unchecked( QueueIter_t it ) const;
M m_memory;
// if m_head == m_tail == QUEUE_ITERATOR_INVALID, then the queue is empty
QueueIter_t m_head;
QueueIter_t m_tail;
#ifdef TEST_UTLQUEUE
friend void CUtlQueue_Test();
#endif
};
//-----------------------------------------------------------------------------
// The CUtlQueueFixed class:
// A queue class with a fixed allocation scheme
//-----------------------------------------------------------------------------
template< class T, size_t MAX_SIZE >
class CUtlQueueFixed : public CUtlQueue< T, CUtlMemoryFixed<T, MAX_SIZE > >
{
typedef CUtlQueue< T, CUtlMemoryFixed<T, MAX_SIZE > > BaseClass;
public:
// constructor, destructor
CUtlQueueFixed( int growSize = 0, int initSize = 0 ) : BaseClass( growSize, initSize ) {}
CUtlQueueFixed( T* pMemory, int numElements ) : BaseClass( pMemory, numElements ) {}
};
template< class T, class M >
inline CUtlQueue<T, M>::CUtlQueue( int growSize, int initSize ) :
m_memory( growSize, initSize ), m_head( QUEUE_ITERATOR_INVALID ), m_tail( QUEUE_ITERATOR_INVALID )
{
}
template< class T, class M >
inline CUtlQueue<T, M>::CUtlQueue( T *pMemory, int numElements ) :
m_memory( pMemory, numElements ), m_head( QUEUE_ITERATOR_INVALID ), m_tail( QUEUE_ITERATOR_INVALID )
{
}
template <class T, class M>
inline T CUtlQueue<T, M>::RemoveAtHead()
{
T temp;
RemoveAtHead( temp );
return temp;
}
template <class T, class M>
inline bool CUtlQueue<T, M>::RemoveAtHead( T &removedElement )
{
Assert( m_head != QUEUE_ITERATOR_INVALID );
if ( m_head == QUEUE_ITERATOR_INVALID )
{
Construct( &removedElement );
return false;
}
QueueIter_t it = m_head;
removedElement = m_memory[ it ];
Destruct( &m_memory[ it ] );
if ( m_head == m_tail )
{
m_head = m_tail = QUEUE_ITERATOR_INVALID;
}
else
{
m_head = Next_Unchecked( m_head );
}
return true;
}
template <class T, class M>
inline T CUtlQueue<T, M>::RemoveAtTail()
{
T temp;
RemoveAtTail( temp );
return temp;
}
template <class T, class M>
inline bool CUtlQueue<T, M>::RemoveAtTail( T &removedElement )
{
Assert( m_tail != QUEUE_ITERATOR_INVALID );
if ( m_tail == QUEUE_ITERATOR_INVALID )
{
Construct( &removedElement );
return false;
}
removedElement = m_memory[ m_tail ];
Destruct( &m_memory[ m_tail ] );
if ( m_head == m_tail )
{
m_head = m_tail = QUEUE_ITERATOR_INVALID;
}
else
{
m_tail = Previous_Unchecked( m_tail );
}
return true;
}
template <class T, class M>
inline T const& CUtlQueue<T, M>::Head() const
{
Assert( m_head != QUEUE_ITERATOR_INVALID );
if ( m_head == QUEUE_ITERATOR_INVALID )
{
static T dummy;
return dummy;
}
return m_memory[ m_head ];
}
template <class T, class M>
inline T const& CUtlQueue<T, M>::Tail() const
{
Assert( m_tail != QUEUE_ITERATOR_INVALID );
if ( m_tail == QUEUE_ITERATOR_INVALID )
{
static T dummy;
return dummy;
}
return m_memory[ m_tail ];
}
template <class T, class M>
void CUtlQueue<T, M>::Insert( T const &element )
{
if ( m_tail == QUEUE_ITERATOR_INVALID )
{
// empty
m_memory.EnsureCapacity( 1 );
m_head = m_tail = QueueIter_t( 0 );
}
else
{
// non-empty
QueueIter_t nextTail = Next_Unchecked( m_tail );
if ( nextTail == m_head ) // if non-empty, and growing by 1 appears to make the queue of length 1, then we were already full before the Insert
{
int nOldAllocCount = m_memory.NumAllocated();
m_memory.Grow();
int nNewAllocCount = m_memory.NumAllocated();
int nGrowAmount = nNewAllocCount - nOldAllocCount;
nextTail = Next_Unchecked( m_tail ); // if nextTail was 0, then it now should be nOldAllocCount
if ( m_head != QueueIter_t( 0 ) )
{
// if the queue wraps around the end of m_memory, move the part at the end of memory to the new end of memory
Q_memmove( &m_memory[ m_head + nGrowAmount ], &m_memory[ m_head ], ( nOldAllocCount - m_head ) * sizeof( T ) );
#ifdef _DEBUG
Q_memset( &m_memory[ m_head ], 0xdd, nGrowAmount * sizeof( T ) );
#endif
m_head = QueueIter_t( m_head + nGrowAmount );
}
}
m_tail = nextTail;
}
CopyConstruct( &m_memory[ m_tail ], element );
}
template <class T, class M>
bool CUtlQueue<T, M>::Check( T const element ) const
{
for ( QueueIter_t it = First(); it != QUEUE_ITERATOR_INVALID; it = Next( it ) )
{
if ( m_memory[ it ] == element )
return true;
}
return false;
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::First() const
{
return m_head;
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::Next( QueueIter_t it ) const
{
if ( it == QUEUE_ITERATOR_INVALID )
return QUEUE_ITERATOR_INVALID;
if ( it == m_tail )
return QUEUE_ITERATOR_INVALID;
Assert( IsValid( it ) );
if ( !IsValid( it ) )
return QUEUE_ITERATOR_INVALID;
return Next_Unchecked( it );
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::Last() const
{
return m_tail;
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::Previous( QueueIter_t it ) const
{
if ( it == QUEUE_ITERATOR_INVALID )
return QUEUE_ITERATOR_INVALID;
if ( it == m_head )
return QUEUE_ITERATOR_INVALID;
Assert( IsValid( it ) );
if ( !IsValid( it ) )
return QUEUE_ITERATOR_INVALID;
return Previous_Unchecked( it );
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::Next_Unchecked( QueueIter_t it ) const
{
return it == m_memory.Count() - 1 ? QueueIter_t( 0 ) : QueueIter_t( it + 1 );
}
template <class T, class M>
QueueIter_t CUtlQueue<T, M>::Previous_Unchecked( QueueIter_t it ) const
{
return it == 0 ? QueueIter_t( m_memory.Count() - 1 ) : QueueIter_t( it - 1 );
}
template <class T, class M>
bool CUtlQueue<T, M>::IsValid( QueueIter_t it ) const
{
if ( it == QUEUE_ITERATOR_INVALID )
return false;
if ( m_head == QUEUE_ITERATOR_INVALID )
return false;
if ( m_head <= m_tail )
return it >= m_head && it <= m_tail;
return ( it >= m_head && it < m_memory.Count() ) || ( it >= 0 && it <= m_tail );
}
template <class T, class M>
T const& CUtlQueue<T, M>::Element( QueueIter_t it ) const
{
Assert( it != QUEUE_ITERATOR_INVALID );
if ( it == QUEUE_ITERATOR_INVALID )
{
static T dummy;
return dummy;
}
Assert( IsValid( it ) );
return m_memory[ it ];
}
template <class T, class M>
int CUtlQueue<T, M>::Count() const
{
if ( m_head == QUEUE_ITERATOR_INVALID )
{
Assert( m_tail == QUEUE_ITERATOR_INVALID );
return 0;
}
Assert( m_tail != QUEUE_ITERATOR_INVALID );
if ( m_head <= m_tail )
return m_tail + 1 - m_head;
return m_tail + 1 - m_head + m_memory.Count();
}
template <class T, class M>
bool CUtlQueue<T, M>::IsEmpty() const
{
Assert( ( m_head == QUEUE_ITERATOR_INVALID ) == ( m_tail == QUEUE_ITERATOR_INVALID ) );
return ( m_head == QUEUE_ITERATOR_INVALID );
}
template <class T, class M>
void CUtlQueue<T, M>::RemoveAll()
{
m_head = m_tail = QUEUE_ITERATOR_INVALID;
}
template <class T, class M>
void CUtlQueue<T, M>::Purge()
{
m_head = m_tail = QUEUE_ITERATOR_INVALID;
m_memory.Purge();
}
#ifdef TEST_UTLQUEUE
#include <stdlib.h>
struct Data_t
{
Data_t( int i = 0xffffffff ) : m_id( i ) {}
Data_t( const Data_t &that ) : m_id( that.m_id ) {}
~Data_t() { m_id = 0xdddddddd; }
Data_t &operator=( const Data_t &that ) { m_id = that.m_id; return *this; }
int m_id;
};
inline void CUtlQueue_Test()
{
CUtlQueue< Data_t > queue;
for ( int n = 1; n < 100; ++n )
{
Assert( queue.Count() == 0 );
Assert( queue.m_head == QUEUE_ITERATOR_INVALID );
Assert( queue.m_tail == QUEUE_ITERATOR_INVALID );
int w = rand() % n;
for ( int i = 0; i < w; ++i )
{
queue.Insert( Data_t( i ) );
}
if ( w > 0 )
{
Assert( queue.Head().m_id == queue.First() );
Assert( queue.Tail().m_id == queue.Last() );
Assert( queue.Head().m_id == 0 );
Assert( queue.Tail().m_id == w - 1 );
}
Assert( queue.Count() == w );
for ( int j = 0; j < n; ++j )
{
queue.Insert( Data_t( w + j ) );
if ( j == 0 )
{
Assert( queue.Count() == w + j + 1 );
for ( int i = 0; i < w; ++i )
{
queue.RemoveAtHead();
}
}
Assert( queue.Count() == j + 1 );
Assert( queue.m_head != QUEUE_ITERATOR_INVALID );
Assert( queue.m_tail != QUEUE_ITERATOR_INVALID );
int id = queue.Head().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.First(); it != QUEUE_ITERATOR_INVALID; it = queue.Next( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + 1 ) % queue.m_memory.Count();
}
id = queue.Tail().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.Last(); it != QUEUE_ITERATOR_INVALID; it = queue.Previous( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + queue.m_memory.Count() - 1 ) % queue.m_memory.Count();
}
for ( int i = 0; i < j; ++i )
{
int id = queue.m_memory[ i ].m_id;
if ( queue.IsValid( QueueIter_t( i ) ) )
{
Assert( ( id & 0xff000000 ) == 0 );
}
else
{
Assert( id == 0xdddddddd );
}
}
}
Assert( queue.Count() == n );
#if 0
for ( int j = 0; j < n; ++j )
{
Assert( queue.m_head != QUEUE_ITERATOR_INVALID );
Assert( queue.m_tail != QUEUE_ITERATOR_INVALID );
Assert( queue.Count() == n - j );
Data_t data = queue.RemoveAtHead();
Assert( queue.Count() == n - j - 1 );
if ( queue.Count() > 0 )
{
int id = queue.Head().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.First(); it != QUEUE_ITERATOR_INVALID; it = queue.Next( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + 1 ) % queue.m_memory.Count();
}
id = queue.Tail().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.Last(); it != QUEUE_ITERATOR_INVALID; it = queue.Previous( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + queue.m_memory.Count() - 1 ) % queue.m_memory.Count();
}
}
for ( int i = 0; i < j; ++i )
{
int id = queue.m_memory[ i ].m_id;
if ( queue.IsValid( QueueIter_t( i ) ) )
{
Assert( ( id & 0xff000000 ) == 0 );
}
else
{
Assert( id == 0xdddddddd );
}
}
}
#else
for ( int j = n - 1; j >= 0; --j )
{
Assert( queue.m_head != QUEUE_ITERATOR_INVALID );
Assert( queue.m_tail != QUEUE_ITERATOR_INVALID );
Assert( queue.Count() == j + 1 );
Data_t data = queue.RemoveAtTail();
Assert( queue.Count() == j );
if ( queue.Count() > 0 )
{
int id = queue.Head().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.First(); it != QUEUE_ITERATOR_INVALID; it = queue.Next( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + 1 ) % queue.m_memory.Count();
}
id = queue.Tail().m_id % queue.m_memory.Count();
for ( QueueIter_t it = queue.Last(); it != QUEUE_ITERATOR_INVALID; it = queue.Previous( it ) )
{
Assert( queue.Element( it ).m_id % queue.m_memory.Count() == id );
id = ( id + queue.m_memory.Count() - 1 ) % queue.m_memory.Count();
}
}
for ( int i = 0; i < j; ++i )
{
int id = queue.m_memory[ i ].m_id;
if ( queue.IsValid( QueueIter_t( i ) ) )
{
Assert( ( id & 0xff000000 ) == 0 );
}
else
{
Assert( id == 0xdddddddd );
}
}
}
#endif
Assert( queue.Count() == 0 );
Assert( queue.m_head == QUEUE_ITERATOR_INVALID );
Assert( queue.m_tail == QUEUE_ITERATOR_INVALID );
}
}
#endif // TEST_UTLQUEUE
#endif // UTLQUEUE_H