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

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

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

#ifndef HBSHAREDMEMORYALLOCATORS_P_H

#define HBSHAREDMEMORYALLOCATORS_P_H

#include "hbthemecommon_p.h"

#include <QSharedMemory>

static const int ALIGN_SIZE = 4;

#define ALIGN(x) ((x + ALIGN_SIZE - 1) & ~(ALIGN_SIZE - 1))

// space for multisegment allocator bookkeeping - to be allocated from shared memory

static const int SPACE_NEEDED_FOR_MULTISEGMENT_ALLOCATOR = 512;

// threshold for allocs going to sub allocator and main allocator

static const int MAXIMUM_ALLOC_SIZE_FOR_SUBALLOCATOR = 224;

// used to identify memory allocated by main or sub allocator

// if metadata (integer just before allocated data) & MAIN_ALLOCATOR_IDENTIFIER

// == true, data was allocated using main allocator, otherwise suballocator

// was used

static const int MAIN_ALLOCATOR_IDENTIFIER = 0x80000000;

// max. amount of different chunk sizes in multisegment allocator

static const int AMOUNT_OF_DIFFERENT_CHUNK_SIZES = 8;

// wrapper for hiding Symbian specific protected chunk

class HbSharedMemoryWrapper

{

public:

    HbSharedMemoryWrapper(const QString &key, QObject *parent = 0);

    ~HbSharedMemoryWrapper();

    bool create(int size, QSharedMemory::AccessMode mode = QSharedMemory::ReadWrite);

    QSharedMemory::SharedMemoryError error() const;

    bool attach(QSharedMemory::AccessMode mode = QSharedMemory::ReadWrite);

    void *data();

    int size() const;

    void setErrorString(const QString &function, TInt errorCode);

#endif    

private:

    QSharedMemory::SharedMemoryError wrapperError;

    QString errorString;

    const QString key;

    RChunk chunk;

    int memorySize;

    void *memory;

#else

    QSharedMemory *chunk;

#endif

};

class HbSharedMemoryAllocator

{

public:

    virtual void initialize(HbSharedMemoryWrapper *sharedChunk,

        const quintptr offset = 0,

        HbSharedMemoryAllocator *mainAllocator = 0) = 0;

    virtual qptrdiff alloc(int size) = 0;

    virtual int allocatedSize(qptrdiff offset) = 0;

    virtual void free(qptrdiff offset) = 0;

    virtual ~HbSharedMemoryAllocator() { }

#ifdef HB_THEME_SERVER_MEMORY_REPORT

    virtual void writeReport(QTextStream &reportWriter) = 0;

#endif

};

class HbSplayTreeAllocator : public HbSharedMemoryAllocator

{

public:

    HbSplayTreeAllocator();

    ~HbSplayTreeAllocator();

    qptrdiff alloc(int size);

    int allocatedSize(qptrdiff offset);

    void free(qptrdiff offset);

    void initialize(HbSharedMemoryWrapper *sharedChunk,

        const quintptr offset = 0,

        HbSharedMemoryAllocator *mainAllocator = 0);

    int size();

#ifdef HB_THEME_SERVER_MEMORY_REPORT

    void writeReport(QTextStream &reportWriter);

#endif

    int freeBytes();

    int allocatedBytes();

private:

    struct TreeNode

    {

        quintptr key;

        quintptr rightNode;

        quintptr leftNode;

    };

    struct MemoryBlock

    {

        TreeNode lengthNode;

        TreeNode pointerNode;

        quintptr next;

        quintptr prev;

        int allocatorIdentifier;

    };

    struct HeapHeader

    {

        quintptr identifier;

        quintptr lengthNode;

        quintptr pointerNode;

        int freeBytes;

        int allocatedBytes;

    };

private:

    quintptr splay(quintptr *root, quintptr key);

    void insertNode(quintptr *root, TreeNode *node);

    void insertNode(quintptr *root, TreeNode *node, TreeNode *temp);

    void deleteNode(quintptr *root, TreeNode *node, bool splayed);

    void insertLengthNode(quintptr *root, TreeNode *node);

    void deleteLengthNode(quintptr *root, TreeNode *node, bool splayed);

    void *toPointer(quintptr offset) const;

    template<typename T>

    inline T *address(qptrdiff offset)

    {

        return reinterpret_cast<T *>(static_cast<char *>(chunk->data()) + offset);

    }

private:

    HbSharedMemoryWrapper *chunk;

    quintptr offset;

    HeapHeader *header;

};

class HbMultiSegmentAllocator : public HbSharedMemoryAllocator

{

public:

    HbMultiSegmentAllocator();

    ~HbMultiSegmentAllocator();

    qptrdiff alloc(int size);

    int allocatedSize(qptrdiff offset);

    void free(qptrdiff offset);

        const quintptr offset = 0,

        HbSharedMemoryAllocator *mainAllocator = 0);

#ifdef HB_THEME_SERVER_MEMORY_REPORT

    void writeReport(QTextStream &reportWriter);

#endif

private:

    struct MultiAllocatorHeader

    {

        quintptr identifier;

        // always points to the first list

        qptrdiff offsetsToChunkLists[AMOUNT_OF_DIFFERENT_CHUNK_SIZES];

        // always points to the list with free chunks

        qptrdiff offsetsToFreeChunkLists[AMOUNT_OF_DIFFERENT_CHUNK_SIZES];

    };

    struct ChunkListHeader

    {

        int chunkListIndex;

        qptrdiff freedChunkCursor;

        qptrdiff allocCursor;

        qptrdiff previousListOffset;

        qptrdiff nextListOffset;

        int allocatedChunks;

    };

private:

    // helper methods

    void addList(int index, qptrdiff offset);

    bool setFreeList(int index);

    template<typename T>

    inline T *address(qptrdiff offset)

    {

        return reinterpret_cast<T *>(static_cast<char *>(chunk->data()) + offset);

    }

private:

    HbSharedMemoryWrapper *chunk;

    quintptr offset;

    HbSharedMemoryAllocator *mainAllocator;

    MultiAllocatorHeader *header;

    int indexTable[MAXIMUM_ALLOC_SIZE_FOR_SUBALLOCATOR+1];

};

#endif //HBSHAREDMEMORYALLOCATORS_P_H