84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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| * Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
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| *
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| * This software is provided 'as-is', without any express or implied
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| * warranty.  In no event will the authors be held liable for any damages
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| * arising from the use of this software.
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| * Permission is granted to anyone to use this software for any purpose,
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| * including commercial applications, and to alter it and redistribute it
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| * freely, subject to the following restrictions:
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| * 1. The origin of this software must not be misrepresented; you must not
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| * claim that you wrote the original software. If you use this software
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| * in a product, an acknowledgment in the product documentation would be
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| * appreciated but is not required.
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| * 2. Altered source versions must be plainly marked as such, and must not be
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| * misrepresented as being the original software.
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| * 3. This notice may not be removed or altered from any source distribution.
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| */
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| 
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| #include "Box2D/Common/b2StackAllocator.h"
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| #include "Box2D/Common/b2Math.h"
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| 
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| b2StackAllocator::b2StackAllocator()
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| {
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| 	m_index = 0;
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| 	m_allocation = 0;
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| 	m_maxAllocation = 0;
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| 	m_entryCount = 0;
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| }
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| 
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| b2StackAllocator::~b2StackAllocator()
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| {
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| 	b2Assert(m_index == 0);
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| 	b2Assert(m_entryCount == 0);
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| }
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| 
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| void* b2StackAllocator::Allocate(int32 size)
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| {
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| 	b2Assert(m_entryCount < b2_maxStackEntries);
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| 
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| 	b2StackEntry* entry = m_entries + m_entryCount;
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| 	entry->size = size;
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| 	if (m_index + size > b2_stackSize)
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| 	{
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| 		entry->data = (char*)b2Alloc(size);
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| 		entry->usedMalloc = true;
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| 	}
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| 	else
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| 	{
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| 		entry->data = m_data + m_index;
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| 		entry->usedMalloc = false;
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| 		m_index += size;
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| 	}
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| 
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| 	m_allocation += size;
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| 	m_maxAllocation = b2Max(m_maxAllocation, m_allocation);
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| 	++m_entryCount;
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| 
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| 	return entry->data;
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| }
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| 
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| void b2StackAllocator::Free(void* p)
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| {
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| 	b2Assert(m_entryCount > 0);
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| 	b2StackEntry* entry = m_entries + m_entryCount - 1;
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| 	b2Assert(p == entry->data);
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| 	if (entry->usedMalloc)
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| 	{
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| 		b2Free(p);
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| 	}
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| 	else
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| 	{
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| 		m_index -= entry->size;
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| 	}
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| 	m_allocation -= entry->size;
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| 	--m_entryCount;
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| 
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| 	p = nullptr;
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| }
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| 
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| int32 b2StackAllocator::GetMaxAllocation() const
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| {
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| 	return m_maxAllocation;
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| }
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