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

 *

 * Name:     gdal_rasterblock.h

 * Project:  GDAL Core

 * Purpose:  Declaration of GDALRasterBlock class

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

 ******************************************************************************

 * Copyright (c) 1998, Frank Warmerdam

 * Copyright (c) 2007-2014, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

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

#ifndef GDALRASTERBLOCK_H_INCLUDED

#define GDALRASTERBLOCK_H_INCLUDED

#include "cpl_port.h"

#include "cpl_atomic_ops.h"

#include "gdal.h"

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

/*                           GDALRasterBlock                            */

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

class GDALRasterBand;

/** A single raster block in the block cache.

 *

 * And the global block manager that manages a least-recently-used list of

 * blocks from various datasets/bands */

class CPL_DLL GDALRasterBlock final

{

    friend class GDALAbstractBandBlockCache;

    GDALDataType eType = GDT_Unknown;

    bool bDirty = false;

    volatile int nLockCount = 0;

    int nXOff = 0;

    int nYOff = 0;

    int nXSize = 0;

    int nYSize = 0;

    void *pData = nullptr;

    GDALRasterBand *poBand = nullptr;

    GDALRasterBlock *poNext = nullptr;

    GDALRasterBlock *poPrevious = nullptr;

    bool bMustDetach = false;

    CPL_INTERNAL void Detach_unlocked(void);

    CPL_INTERNAL void Touch_unlocked(void);

    CPL_INTERNAL void RecycleFor(int nXOffIn, int nYOffIn);

  public:

    GDALRasterBlock(GDALRasterBand *, int, int);

    GDALRasterBlock(int nXOffIn, int nYOffIn); /* only for lookup purpose */

    ~GDALRasterBlock();

    CPLErr Internalize(void);

    void Touch(void);

    void MarkDirty(void);

    void MarkClean(void);

    /** Increment the lock count */

    int AddLock(void)

    {

        return CPLAtomicInc(&nLockCount);

    }

    /** Decrement the lock count */

    int DropLock(void)

    {

        return CPLAtomicDec(&nLockCount);

    }

    void Detach();

    CPLErr Write();

    /** Return the data type

     * @return data type

     */

    GDALDataType GetDataType() const

    {

        return eType;

    }

    /** Return the x offset of the top-left corner of the block

     * @return x offset

     */

    int GetXOff() const

    {

        return nXOff;

    }

    /** Return the y offset of the top-left corner of the block

     * @return y offset

     */

    int GetYOff() const

    {

        return nYOff;

    }

    /** Return the width of the block

     * @return width

     */

    int GetXSize() const

    {

        return nXSize;

    }

    /** Return the height of the block

     * @return height

     */

    int GetYSize() const

    {

        return nYSize;

    }

    /** Return the dirty flag

     * @return dirty flag

     */

    int GetDirty() const

    {

        return bDirty;

    }

    /** Return the data buffer

     * @return data buffer

     */

    void *GetDataRef(void)

    {

        return pData;

    }

    /** Return the block size in bytes

     * @return block size.

     */

    GPtrDiff_t GetBlockSize() const

    {

        return static_cast<GPtrDiff_t>(nXSize) * nYSize *

               GDALGetDataTypeSizeBytes(eType);

    }

    int TakeLock();

    int DropLockForRemovalFromStorage();

    /// @brief Accessor to source GDALRasterBand object.

    /// @return source raster band of the raster block.

    GDALRasterBand *GetBand()

    {

        return poBand;

    }

    static void FlushDirtyBlocks();

    static int FlushCacheBlock(int bDirtyBlocksOnly = FALSE);

    static void Verify();

    static void EnterDisableDirtyBlockFlush();

    static void LeaveDisableDirtyBlockFlush();

#ifdef notdef

    static void CheckNonOrphanedBlocks(GDALRasterBand *poBand);

    void DumpBlock();

    static void DumpAll();

#endif

    /* Should only be called by GDALDestroyDriverManager() */

    //! @cond Doxygen_Suppress

    CPL_INTERNAL static void DestroyRBMutex();

    //! @endcond

  private:

    CPL_DISALLOW_COPY_ASSIGN(GDALRasterBlock)

};

#endif