Paranoia2/game_shared/utlblockmemory.h

319 lines
8.5 KiB
C++

//===== Copyright © 1996-2005, Valve Corporation, All rights reserved. ======//
//
// Purpose:
//
// $NoKeywords: $
//
// A growable memory class.
//===========================================================================//
#ifndef UTLBLOCKMEMORY_H
#define UTLBLOCKMEMORY_H
#ifdef _WIN32
#pragma once
#endif
#pragma warning (disable:4100)
#pragma warning (disable:4514)
//-----------------------------------------------------------------------------
// The CUtlBlockMemory class:
// A growable memory class that allocates non-sequential blocks, but is indexed sequentially
//-----------------------------------------------------------------------------
template< class T, class I >
class CUtlBlockMemory
{
public:
// constructor, destructor
CUtlBlockMemory( int nGrowSize = 0, int nInitSize = 0 );
~CUtlBlockMemory();
// Set the size by which the memory grows - round up to the next power of 2
void Init( int nGrowSize = 0, int nInitSize = 0 );
// here to match CUtlMemory, but only used by ResetDbgInfo, so it can just return NULL
T* Base() { return NULL; }
const T* Base() const { return NULL; }
class Iterator_t
{
public:
Iterator_t( I i ) : index( i ) {}
I index;
bool operator==( const Iterator_t it ) const { return index == it.index; }
bool operator!=( const Iterator_t it ) const { return index != it.index; }
};
Iterator_t First() const { return Iterator_t( IsIdxValid( 0 ) ? 0 : InvalidIndex() ); }
Iterator_t Next( const Iterator_t &it ) const { return Iterator_t( IsIdxValid( it.index + 1 ) ? it.index + 1 : InvalidIndex() ); }
I GetIndex( const Iterator_t &it ) const { return it.index; }
bool IsIdxAfter( I i, const Iterator_t &it ) const { return i > it.index; }
bool IsValidIterator( const Iterator_t &it ) const { return IsIdxValid( it.index ); }
Iterator_t InvalidIterator() const { return Iterator_t( InvalidIndex() ); }
// element access
T& operator[]( I i );
const T& operator[]( I i ) const;
T& Element( I i );
const T& Element( I i ) const;
// Can we use this index?
bool IsIdxValid( I i ) const;
static I InvalidIndex() { return ( I )-1; }
void Swap( CUtlBlockMemory< T, I > &mem );
// Size
int NumAllocated() const;
int Count() const { return NumAllocated(); }
// Grows memory by max(num,growsize) rounded up to the next power of 2, and returns the allocation index/ptr
void Grow( int num = 1 );
// Makes sure we've got at least this much memory
void EnsureCapacity( int num );
// Memory deallocation
void Purge();
// Purge all but the given number of elements
void Purge( int numElements );
protected:
int Index( int major, int minor ) const { return ( major << m_nIndexShift ) | minor; }
int MajorIndex( int i ) const { return i >> m_nIndexShift; }
int MinorIndex( int i ) const { return i & m_nIndexMask; }
void ChangeSize( int nBlocks );
int NumElementsInBlock() const { return m_nIndexMask + 1; }
T** m_pMemory;
int m_nBlocks;
int m_nIndexMask : 27;
int m_nIndexShift : 5;
};
//-----------------------------------------------------------------------------
// constructor, destructor
//-----------------------------------------------------------------------------
template< class T, class I >
CUtlBlockMemory<T,I>::CUtlBlockMemory( int nGrowSize, int nInitAllocationCount )
: m_pMemory( 0 ), m_nBlocks( 0 ), m_nIndexMask( 0 ), m_nIndexShift( 0 )
{
Init( nGrowSize, nInitAllocationCount );
}
template< class T, class I >
CUtlBlockMemory<T,I>::~CUtlBlockMemory()
{
Purge();
}
//-----------------------------------------------------------------------------
// Fast swap
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlBlockMemory<T,I>::Swap( CUtlBlockMemory< T, I > &mem )
{
swap( m_pMemory, mem.m_pMemory );
swap( m_nBlocks, mem.m_nBlocks );
swap( m_nIndexMask, mem.m_nIndexMask );
swap( m_nIndexShift, mem.m_nIndexShift );
}
//-----------------------------------------------------------------------------
// Set the size by which the memory grows - round up to the next power of 2
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlBlockMemory<T,I>::Init( int nGrowSize /* = 0 */, int nInitSize /* = 0 */ )
{
Purge();
if ( nGrowSize == 0)
{
// default grow size is smallest size s.t. c++ allocation overhead is ~6% of block size
nGrowSize = ( 127 + sizeof( T ) ) / sizeof( T );
}
nGrowSize = SmallestPowerOfTwoGreaterOrEqual( nGrowSize );
m_nIndexMask = nGrowSize - 1;
m_nIndexShift = 0;
while ( nGrowSize > 1 )
{
nGrowSize >>= 1;
++m_nIndexShift;
}
assert( m_nIndexMask + 1 == ( 1 << m_nIndexShift ) );
Grow( nInitSize );
}
//-----------------------------------------------------------------------------
// element access
//-----------------------------------------------------------------------------
template< class T, class I >
inline T& CUtlBlockMemory<T,I>::operator[]( I i )
{
assert( IsIdxValid(i) );
T *pBlock = m_pMemory[ MajorIndex( i ) ];
return pBlock[ MinorIndex( i ) ];
}
template< class T, class I >
inline const T& CUtlBlockMemory<T,I>::operator[]( I i ) const
{
assert( IsIdxValid(i) );
const T *pBlock = m_pMemory[ MajorIndex( i ) ];
return pBlock[ MinorIndex( i ) ];
}
template< class T, class I >
inline T& CUtlBlockMemory<T,I>::Element( I i )
{
assert( IsIdxValid(i) );
T *pBlock = m_pMemory[ MajorIndex( i ) ];
return pBlock[ MinorIndex( i ) ];
}
template< class T, class I >
inline const T& CUtlBlockMemory<T,I>::Element( I i ) const
{
assert( IsIdxValid(i) );
const T *pBlock = m_pMemory[ MajorIndex( i ) ];
return pBlock[ MinorIndex( i ) ];
}
//-----------------------------------------------------------------------------
// Size
//-----------------------------------------------------------------------------
template< class T, class I >
inline int CUtlBlockMemory<T,I>::NumAllocated() const
{
return m_nBlocks * NumElementsInBlock();
}
//-----------------------------------------------------------------------------
// Is element index valid?
//-----------------------------------------------------------------------------
template< class T, class I >
inline bool CUtlBlockMemory<T,I>::IsIdxValid( I i ) const
{
return ( i >= 0 ) && ( MajorIndex( i ) < m_nBlocks );
}
template< class T, class I >
void CUtlBlockMemory<T,I>::Grow( int num )
{
if ( num <= 0 )
return;
int nBlockSize = NumElementsInBlock();
int nBlocks = ( num + nBlockSize - 1 ) / nBlockSize;
ChangeSize( m_nBlocks + nBlocks );
}
template< class T, class I >
void CUtlBlockMemory<T,I>::ChangeSize( int nBlocks )
{
int nBlocksOld = m_nBlocks;
m_nBlocks = nBlocks;
// free old blocks if shrinking
for ( int i = m_nBlocks; i < nBlocksOld; ++i )
{
free( (void*)m_pMemory[ i ] );
}
if ( m_pMemory )
{
m_pMemory = (T**)realloc( m_pMemory, m_nBlocks * sizeof(T*) );
assert( m_pMemory );
}
else
{
m_pMemory = (T**)malloc( m_nBlocks * sizeof(T*) );
assert( m_pMemory );
}
if ( !m_pMemory )
{
Error( "CUtlBlockMemory overflow!\n" );
}
// allocate new blocks if growing
int nBlockSize = NumElementsInBlock();
for ( int i = nBlocksOld; i < m_nBlocks; ++i )
{
m_pMemory[ i ] = (T*)malloc( nBlockSize * sizeof( T ) );
assert( m_pMemory[ i ] );
}
}
//-----------------------------------------------------------------------------
// Makes sure we've got at least this much memory
//-----------------------------------------------------------------------------
template< class T, class I >
inline void CUtlBlockMemory<T,I>::EnsureCapacity( int num )
{
Grow( num - NumAllocated() );
}
//-----------------------------------------------------------------------------
// Memory deallocation
//-----------------------------------------------------------------------------
template< class T, class I >
void CUtlBlockMemory<T,I>::Purge()
{
if ( !m_pMemory )
return;
for ( int i = 0; i < m_nBlocks; ++i )
{
free( (void*)m_pMemory[ i ] );
}
m_nBlocks = 0;
free( (void*)m_pMemory );
m_pMemory = 0;
}
template< class T, class I >
void CUtlBlockMemory<T,I>::Purge( int numElements )
{
assert( numElements >= 0 );
int nAllocated = NumAllocated();
if ( numElements > nAllocated )
{
// Ensure this isn't a grow request in disguise.
assert( numElements <= nAllocated );
return;
}
if ( numElements <= 0 )
{
Purge();
return;
}
int nBlockSize = NumElementsInBlock();
int nBlocksOld = m_nBlocks;
int nBlocks = ( numElements + nBlockSize - 1 ) / nBlockSize;
// If the number of blocks is the same as the allocated number of blocks, we are done.
if ( nBlocks == m_nBlocks )
return;
ChangeSize( nBlocks );
}
#endif // UTLBLOCKMEMORY_H