gdal_rasterblock.h

/******************************************************************************
 *
 * 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;

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);

    int AddLock(void)
    {
        return CPLAtomicInc(&nLockCount);
    }

    int DropLock(void)
    {
        return CPLAtomicDec(&nLockCount);
    }
 
    void Detach();
 
    CPLErr Write();

    GDALDataType GetDataType() const
    {
        return eType;
    }

    int GetXOff() const
    {
        return nXOff;
    }

    int GetYOff() const
    {
        return nYOff;
    }

    int GetXSize() const
    {
        return nXSize;
    }

    int GetYSize() const
    {
        return nYSize;
    }

    int GetDirty() const
    {
        return bDirty;
    }

    void *GetDataRef(void)
    {
        return pData;
    }

    GPtrDiff_t GetBlockSize() const
    {
        return static_cast<GPtrDiff_t>(nXSize) * nYSize *
               GDALGetDataTypeSizeBytes(eType);
    }
 
    int TakeLock();
    int DropLockForRemovalFromStorage();

    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() */
    CPL_INTERNAL static void DestroyRBMutex();
 
  private:
    CPL_DISALLOW_COPY_ASSIGN(GDALRasterBlock)
};
 
#endif