kcontainerallocators.h

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#ifndef FBXFILESDK_COMPONENTS_KBASELIB_KLIB_KCONTAINERALLOCATORS_H
#define FBXFILESDK_COMPONENTS_KBASELIB_KLIB_KCONTAINERALLOCATORS_H

/**************************************************************************************

 Copyright (C) 2001 - 2009 Autodesk, Inc. and/or its licensors.
 All Rights Reserved.

 The coded instructions, statements, computer programs, and/or related material 
 (collectively the "Data") in these files contain unpublished information 
 proprietary to Autodesk, Inc. and/or its licensors, which is protected by 
 Canada and United States of America federal copyright law and by international 
 treaties. 
 
 The Data may not be disclosed or distributed to third parties, in whole or in
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 THE DATA IS PROVIDED "AS IS" AND WITHOUT WARRANTY.
 ALL WARRANTIES ARE EXPRESSLY EXCLUDED AND DISCLAIMED. AUTODESK MAKES NO
 WARRANTY OF ANY KIND WITH RESPECT TO THE DATA, EXPRESS, IMPLIED OR ARISING
 BY CUSTOM OR TRADE USAGE, AND DISCLAIMS ANY IMPLIED WARRANTIES OF TITLE, 
 NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE. 
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 OF THE DATA WILL BE UNINTERRUPTED OR ERROR FREE. 
 
 IN NO EVENT SHALL AUTODESK, ITS AFFILIATES, PARENT COMPANIES, LICENSORS
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**************************************************************************************/
#include <fbxfilesdk/fbxfilesdk_def.h>

#include <fbxfilesdk/components/kbaselib/klib/kdebug.h>

#include <fbxfilesdk/fbxfilesdk_nsbegin.h>

class KFBX_DLL KBaseAllocator
{
public:
    KBaseAllocator(size_t const pRecordSize)
        : mRecordSize(pRecordSize)
    {
    }

    void Reserve(size_t const pRecordCount)
    {
        // By default, ignore all preallocating requests.
    }

    void* AllocateRecords(size_t const pRecordCount = 1)
    {
        return FbxSdkMalloc(pRecordCount * mRecordSize);
    }

    void FreeMemory(void* pRecord)
    {
        FbxSdkFree(pRecord);
    }

    size_t GetRecordSize() const
    {
        return mRecordSize;
    }

    // Use default copy / assignment
    /*    operator=()
        *        The allocator must have appropriate copy semantics; does not need to
        *        copy its allocated blocks, but it should adjust its record size.
        */

private:
    size_t mRecordSize;
};

class KHungryAllocator
{
public:
    KHungryAllocator(size_t pRecordSize)
        : mRecordSize(pRecordSize)
        , mData(NULL)
        , mRecordPoolSize(0)
    {
    }

    KHungryAllocator(const KHungryAllocator& pOther)
        : mRecordSize(pOther.mRecordSize)
        , mData(0)
        , mRecordPoolSize(pOther.mRecordPoolSize)
    {
    }

    ~KHungryAllocator()
    {
        MemoryBlock* lCurrent = mData;
        MemoryBlock* lNext = lCurrent ? lCurrent->mNextBlock : 0;
        while (lCurrent)
        {
            FbxSdkDelete(lCurrent);
            lCurrent = lNext;
            lNext = lCurrent ? lCurrent->mNextBlock : 0;
        }
    }

    void Reserve(size_t const pRecordCount)
    {
        MemoryBlock* lMem = FbxSdkNew< MemoryBlock >(pRecordCount * mRecordSize);
        lMem->mNextBlock = mData;
        mData = lMem;
        mRecordPoolSize += pRecordCount;
    }

    void* AllocateRecords(size_t const pRecordCount = 1)
    {
        MemoryBlock* lBlock = mData;
        void* lRecord = NULL;

        while ((lBlock != NULL) &&
            ((lRecord = lBlock->GetChunk(pRecordCount * mRecordSize)) == NULL))
        {
            lBlock = lBlock->mNextBlock;
        }

        if (lRecord == NULL)
        {
            size_t lNumRecordToAllocate = mRecordPoolSize / 8 == 0 ? 2 : mRecordPoolSize / 8;
            if (lNumRecordToAllocate < pRecordCount)
            {
                lNumRecordToAllocate = pRecordCount;
            }
            Reserve(lNumRecordToAllocate);
            lRecord = AllocateRecords(pRecordCount);
        }

        return lRecord;
    }

    void FreeMemory(void* pRecord)
    {
        // "Hungry": release memory only when the allocator is destroyed.
    }

    size_t GetRecordSize() const
    {
        return mRecordSize;
    }

    KHungryAllocator& operator=(const KHungryAllocator& pOther)
    {
        if( this != &pOther )
        {
            // The next call to AllocateRecords() may skip over currently reserved
            // records if the size changes drastically, but otherwise GetChunk()
            // is size-oblivious.
            if( mRecordSize < pOther.mRecordSize )
            {
                mRecordPoolSize = 0;
            }

            mRecordSize = pOther.mRecordSize;
        }

        return(*this);
    }

private:
    class MemoryBlock
    {
    public:
        MemoryBlock(size_t pSize)
            : mNextBlock(NULL)
            , mData(NULL)
            , mFreeData(NULL)
            , mEnd(NULL)
        {
            mData = FbxSdkMalloc(pSize);
            mFreeData = mData;
            mEnd = reinterpret_cast<char*>(mData) + pSize;
        };

        ~MemoryBlock()
        {
            FbxSdkFree(mData);
        }

        void* GetChunk(size_t const pSize)
        {
            if (reinterpret_cast<char*>(mFreeData) + pSize < mEnd)
            {
                void* lChunk = mFreeData;
                mFreeData = reinterpret_cast<char*>(mFreeData) + pSize;
                return lChunk;
            }

            return NULL;
        }

        MemoryBlock* mNextBlock;
        void* mData;
        void* mFreeData;
        void* mEnd;
    };

    size_t mRecordSize;
    MemoryBlock* mData;
    size_t mRecordPoolSize;
};

#include <fbxfilesdk/fbxfilesdk_nsend.h>

#endif // FBXFILESDK_COMPONENTS_KBASELIB_KLIB_KCONTAINERALLOCATORS_H