assimp/code/Common/StackAllocator.inl

/*
Open Asset Import Library (assimp)
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*/

#include "StackAllocator.h"
#include <assimp/ai_assert.h>
#include <algorithm>

using namespace Assimp;

inline StackAllocator::StackAllocator() : m_storageBlocks() {}

inline StackAllocator::~StackAllocator() {
    FreeAll();
}

inline void *StackAllocator::Allocate(size_t byteSize) {
    if (m_subIndex + byteSize > m_blockAllocationSize) // start a new block
    {
        // double block size every time, up to maximum of g_maxBytesPerBlock.
        // Block size must be at least as large as byteSize, but we want to use this for small allocations anyway.
        m_blockAllocationSize = std::max<std::size_t>(std::min<std::size_t>(m_blockAllocationSize * 2, g_maxBytesPerBlock), byteSize);
        uint8_t *data = new uint8_t[m_blockAllocationSize];
        m_storageBlocks.emplace_back(data);
        m_subIndex = byteSize;
        return data;
    }

    uint8_t *data = m_storageBlocks.back();
    data += m_subIndex;
    m_subIndex += byteSize;

    return data;
}

inline void StackAllocator::FreeAll() {
    for (size_t i = 0; i < m_storageBlocks.size(); i++) {
        delete [] m_storageBlocks[i];
    }
    std::vector<uint8_t *> empty;
    m_storageBlocks.swap(empty);
    // start over:
    m_blockAllocationSize = g_startBytesPerBlock;
    m_subIndex = g_maxBytesPerBlock;
}