PoissonRecon/Src/BlockedVector.h

/*
Copyright (c) 2006, Michael Kazhdan and Matthew Bolitho
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer. Redistributions in binary form must reproduce
the above copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the distribution. 

Neither the name of the Johns Hopkins University nor the names of its contributors
may be used to endorse or promote products derived from this software without specific
prior written permission. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO THE IMPLIED WARRANTIES 
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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*/


#ifndef BLOCKED_VECTOR_INCLUDED
#define BLOCKED_VECTOR_INCLUDED

#include "MyMiscellany.h"

// This represents a vector that can only grow in size.
// It has the property that once a reference to an element is returned, that reference remains valid until the vector is destroyed.
template< typename T , unsigned int LogBlockSize=10 , unsigned int InitialBlocks=10 , unsigned int AllocationMultiplier=2 >
struct BlockedVector
{
	BlockedVector( T defaultValue=T() ) : _defaultValue( defaultValue )
	{
		_reservedBlocks = InitialBlocks;
		_blocks = NewPointer< Pointer( T ) >( _reservedBlocks );
		for( size_t i=0 ; i<_reservedBlocks ; i++ ) _blocks[i] = NullPointer( T );
		_allocatedBlocks = _size = 0;
	}
	~BlockedVector( void )
	{
		for( size_t i=0 ; i<_allocatedBlocks ; i++ ) DeletePointer( _blocks[i] );
		DeletePointer( _blocks );
	}
	BlockedVector( const BlockedVector& v )
	{
		_reservedBlocks = v._reservedBlocks , _allocatedBlocks = v._allocatedBlocks , _size = v._size , _defaultValue = v._defaultValue;
		_blocks = NewPointer< Pointer( T ) >( _reservedBlocks );
		for( size_t i=0 ; i<_allocatedBlocks ; i++ )
		{
			_blocks[i] = NewPointer< T >( _BlockSize );
			memcpy( _blocks[i] , v._blocks[i] , sizeof(T)*_BlockSize );
		}
		for( size_t i=_allocatedBlocks ; i<_reservedBlocks ; i++ ) _blocks[i] = NullPointer( Pointer ( T ) );
	}
	BlockedVector& operator = ( const BlockedVector&  v )
	{
		for( size_t i=0 ; i<_allocatedBlocks ; i++ ) DeletePointer( _blocks[i] );
		DeletePointer( _blocks );
		_reservedBlocks = v._reservedBlocks , _blocks = v._blocks , _allocatedBlocks = v._allocatedBlocks , _size = v._size , _defaultValue = v._defaultValue;
		_blocks = NewPointer< Pointer( T ) >( _reservedBlocks );
		for( size_t i=0 ; i<_allocatedBlocks ; i++ )
		{
			_blocks[i] = NewPointer< T >( _BlockSize );
			memcpy( _blocks[i] , v._blocks[i] , sizeof(T)*_BlockSize );
		}
		for( size_t i=_allocatedBlocks ; i<_reservedBlocks ; i++ ) _blocks[i] = NullPointer( T );
		return *this;
	}
	BlockedVector( BlockedVector&& v )
	{
		_reservedBlocks = v._reservedBlocks , _allocatedBlocks = v._allocatedBlocks , _size = v._size , _defaultValue = v._defaultValue , _blocks = v._blocks;
		v._reservedBlocks = v._allocatedBlocks = v._size = 0 , v._blocks = NullPointer( Pointer( T ) );
	}
	BlockedVector& operator = ( BlockedVector&& v )
	{
		for( size_t i=0 ; i<_allocatedBlocks ; i++ ) DeletePointer( _blocks[i] );
		DeletePointer( _blocks );
		_reservedBlocks = v._reservedBlocks , _allocatedBlocks = v._allocatedBlocks , _size = v._size , _defaultValue = v._defaultValue , _blocks = v._blocks;
		v._reservedBlocks = v._allocatedBlocks = v._size = 0 , v._blocks = NullPointer( Pointer( T ) );
		return *this;
	}

	size_t size( void ) const { return _size; }
	const T& operator[]( size_t idx ) const { return _blocks[idx>>LogBlockSize][idx&_Mask]; }
	T& operator[]( size_t idx ){ return _blocks[idx>>LogBlockSize][idx&_Mask]; }

	size_t resize( size_t size ){ return resize( size , _defaultValue ); }
	size_t resize( size_t size , const T& defaultValue )
	{
		if( size<=_size )
		{
#ifdef _MSC_VER
			WARN( "BlockedVector::resize: new size must be greater than old size: " , size , " > " , _size );
#else // !MSC_VER
			WARN( "BlockedVector::resize: new size must be greater than old size: " , size , " > ", _size );
#endif // _MSC_VER
			return _size;
		}
		size_t index = size-1;
		size_t block = index >> LogBlockSize;
		size_t blockIndex = index & _Mask;

		// If there are insufficiently many blocks
		if( block>=_reservedBlocks )
		{
			size_t newReservedSize = std::max< size_t >( _reservedBlocks * AllocationMultiplier , block+1 );
			Pointer( Pointer( T ) ) __blocks = NewPointer< Pointer( T ) >( newReservedSize );
			memcpy( __blocks , _blocks , sizeof( Pointer( T ) ) * _reservedBlocks );
			for( size_t i=_reservedBlocks ; i<newReservedSize ; i++ ) __blocks[i] = NullPointer( T );
			Pointer( Pointer( T ) ) _oldBlocks = _blocks;
			_blocks = __blocks;
			_reservedBlocks = newReservedSize;
			DeletePointer( _oldBlocks );
		}

		// If the block hasn't been allocated
		if( block>=_allocatedBlocks )
		{
			for( size_t b=_allocatedBlocks ; b<=block ; b++ )
			{
				_blocks[b] = NewPointer< T >( _BlockSize );
				for( size_t i=0 ; i<_BlockSize ; i++ ) _blocks[b][i] = defaultValue;
			}
			_allocatedBlocks = block+1;
		}
		_size = index+1;
		return index;
	}
	size_t push( void ){ return resize( _size+1 ); }

protected:
	static const size_t _BlockSize = 1<<LogBlockSize;
	static const size_t _Mask = (1<<LogBlockSize)-1;

	T _defaultValue;
	size_t _allocatedBlocks , _reservedBlocks;
	size_t _size;
	Pointer( Pointer( T ) ) _blocks;
};
#endif // BLOCKED_VECTOR_INCLUDED