vrtdataset.h

/******************************************************************************
 *
 * Project:  Virtual GDAL Datasets
 * Purpose:  Declaration of virtual gdal dataset classes.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2001, Frank Warmerdam <warmerdam@pobox.com>
 * Copyright (c) 2007-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/
 
#ifndef VIRTUALDATASET_H_INCLUDED
#define VIRTUALDATASET_H_INCLUDED
 
#ifndef DOXYGEN_SKIP
 
#include "cpl_hash_set.h"
#include "cpl_minixml.h"
#include "gdal_driver.h"
#include "gdal_multidim.h"
#include "gdal_pam.h"
#include "gdal_vrt.h"
#include "gdal_rat.h"
 
#include <atomic>
#include <deque>
#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <vector>
 
CPLErr GDALRegisterDefaultPixelFunc();
void GDALVRTRegisterDefaultProcessedDatasetFuncs();
CPLString CPL_DLL VRTSerializeNoData(double dfVal, GDALDataType eDataType,
                                     int nPrecision);
 
#if 0
int VRTWarpedOverviewTransform( void *pTransformArg, int bDstToSrc,
                                int nPointCount,
                                double *padfX, double *padfY, double *padfZ,
                                int *panSuccess );
void* VRTDeserializeWarpedOverviewTransformer( CPLXMLNode *psTree );
#endif
 
/************************************************************************/
/*                          VRTOverviewInfo()                           */
/************************************************************************/
class VRTOverviewInfo
{
    CPL_DISALLOW_COPY_ASSIGN(VRTOverviewInfo)
 
  public:
    CPLString osFilename{};
    int nBand = 0;
    GDALRasterBand *poBand = nullptr;
    int bTriedToOpen = FALSE;
 
    VRTOverviewInfo() = default;
 
    VRTOverviewInfo(VRTOverviewInfo &&oOther) noexcept
        : osFilename(std::move(oOther.osFilename)), nBand(oOther.nBand),
          poBand(oOther.poBand), bTriedToOpen(oOther.bTriedToOpen)
    {
        oOther.poBand = nullptr;
    }
 
    ~VRTOverviewInfo()
    {
        CloseDataset();
    }
 
    bool CloseDataset()
    {
        if (poBand == nullptr)
            return false;
 
        GDALDataset *poDS = poBand->GetDataset();
        // Nullify now, to prevent recursion in some cases !
        poBand = nullptr;
        if (poDS->GetShared())
            GDALClose(/* (GDALDatasetH) */ poDS);
        else
            poDS->Dereference();
 
        return true;
    }
};
 
/************************************************************************/
/*                        VRTMapSharedResources                         */
/************************************************************************/

class CPL_DLL VRTMapSharedResources
{
  public:
    VRTMapSharedResources() = default;

    GDALDataset *Get(const std::string &osKey) const;

    void Insert(const std::string &osKey, GDALDataset *poDS);

    void InitMutex();
 
  private:
    mutable std::mutex m_oMutex{};
    bool m_bUseMutex = false;
    std::map<std::string, GDALDataset *> m_oMap{};
 
    std::unique_ptr<std::lock_guard<std::mutex>> LockGuard() const;
 
    CPL_DISALLOW_COPY_ASSIGN(VRTMapSharedResources)
};
 
/************************************************************************/
/*                              VRTSource                               */
/************************************************************************/
 
class CPL_DLL VRTSource
{
  public:
    struct CPL_DLL WorkingState
    {
        // GByte whose initialization constructor does nothing
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Weffc++"
#endif
        struct NoInitByte
        {
#ifdef __COVERITY__
            GByte value = 0;
#else
            GByte value;
#endif
 
            // cppcheck-suppress uninitMemberVar
            NoInitByte()
            {
                // do nothing
            }
 
            inline operator GByte() const
            {
                return value;
            }
        };
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
 
        std::vector<NoInitByte> m_abyWrkBuffer{};
        std::vector<NoInitByte> m_abyWrkBufferMask{};
    };
 
    virtual ~VRTSource();
 
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArg,
                            WorkingState &oWorkingState) = 0;
 
    virtual double GetMinimum(int nXSize, int nYSize, int *pbSuccess) = 0;
    virtual double GetMaximum(int nXSize, int nYSize, int *pbSuccess) = 0;
    virtual CPLErr GetHistogram(int nXSize, int nYSize, double dfMin,
                                double dfMax, int nBuckets,
                                GUIntBig *panHistogram, int bIncludeOutOfRange,
                                int bApproxOK, GDALProgressFunc pfnProgress,
                                void *pProgressData) = 0;
 
    virtual CPLErr XMLInit(const CPLXMLNode *psTree, const char *,
                           VRTMapSharedResources &) = 0;
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath) = 0;
 
    virtual void GetFileList(char ***ppapszFileList, int *pnSize,
                             int *pnMaxSize, CPLHashSet *hSetFiles);

    virtual bool IsSimpleSource() const
    {
        return false;
    }
 
    const std::string &GetName() const
    {
        return m_osName;
    }
 
    void SetName(const std::string &s)
    {
        m_osName = s;
    }

    virtual const char *GetType() const = 0;
 
    virtual CPLErr FlushCache(bool /*bAtClosing*/)
    {
        return CE_None;
    }
 
  protected:
    VRTSource() = default;
    VRTSource(const VRTSource &) = default;
 
    std::string m_osName{};
};
 
typedef VRTSource *(*VRTSourceParser)(const CPLXMLNode *, const char *,
                                      VRTMapSharedResources &oMapSharedSources);
 
VRTSource *VRTParseCoreSources(const CPLXMLNode *psTree, const char *,
                               VRTMapSharedResources &oMapSharedSources);
VRTSource *VRTParseFilterSources(const CPLXMLNode *psTree, const char *,
                                 VRTMapSharedResources &oMapSharedSources);
VRTSource *VRTParseArraySource(const CPLXMLNode *psTree, const char *,
                               VRTMapSharedResources &oMapSharedSources);
 
/************************************************************************/
/*                              VRTDataset                              */
/************************************************************************/
 
class VRTRasterBand;
 
template <class T> struct VRTFlushCacheStruct
{
    static CPLErr FlushCache(T &obj, bool bAtClosing);
};
 
class VRTWarpedDataset;
class VRTPansharpenedDataset;
class VRTProcessedDataset;
class VRTGroup;
class VRTSimpleSource;
 
class CPL_DLL VRTDataset CPL_NON_FINAL : public GDALDataset
{
    friend class VRTRasterBand;
    friend struct VRTFlushCacheStruct<VRTDataset>;
    friend struct VRTFlushCacheStruct<VRTWarpedDataset>;
    friend struct VRTFlushCacheStruct<VRTPansharpenedDataset>;
    friend struct VRTFlushCacheStruct<VRTProcessedDataset>;
    friend class VRTSourcedRasterBand;
    friend class VRTDerivedRasterBand;
    friend class VRTSimpleSource;
    friend struct VRTSourcedRasterBandRasterIOJob;
    friend VRTDatasetH CPL_STDCALL VRTCreate(int nXSize, int nYSize);
 
    std::vector<gdal::GCP> m_asGCPs{};
    OGRSpatialReferenceRefCountedPtr m_poGCP_SRS{};
 
    bool m_bNeedsFlush = false;
    bool m_bWritable = true;
    bool m_bCanTakeRef = true;
 
    char *m_pszVRTPath = nullptr;
 
    std::unique_ptr<VRTRasterBand> m_poMaskBand{};
 
    mutable int m_nCompatibleForDatasetIO = -1;
    bool CheckCompatibleForDatasetIO() const;
 
    // Virtual (ie not materialized) overviews, created either implicitly
    // when it is cheap to do it, or explicitly.
    std::vector<GDALDataset *> m_apoOverviews{};
    std::vector<GDALDataset *> m_apoOverviewsBak{};
    CPLStringList m_aosOverviewList{};  // only temporarily set during Open()
    CPLString m_osOverviewResampling{};
    std::vector<int> m_anOverviewFactors{};
 
    char **m_papszXMLVRTMetadata = nullptr;
 
    VRTMapSharedResources m_oMapSharedSources{};
    std::shared_ptr<VRTGroup> m_poRootGroup{};
 
    // Used by VRTSourcedRasterBand::IRasterIO() in single-threaded situations
    VRTSource::WorkingState m_oWorkingState{};
 
    // Used by VRTSourcedRasterBand::IRasterIO() when using multi-threading
    struct QueueWorkingStates
    {
        std::mutex oMutex{};
        std::vector<std::unique_ptr<VRTSource::WorkingState>> oStates{};
    };
 
    QueueWorkingStates m_oQueueWorkingStates{};
 
    bool m_bMultiThreadedRasterIOLastUsed = false;
 
    std::unique_ptr<VRTRasterBand> InitBand(const char *pszSubclass, int nBand,
                                            bool bAllowPansharpenedOrProcessed);
    static GDALDataset *OpenVRTProtocol(const char *pszSpec);
    bool AddVirtualOverview(int nOvFactor, const char *pszResampling);
 
    bool GetShiftedDataset(int nXOff, int nYOff, int nXSize, int nYSize,
                           GDALDataset *&poSrcDataset, int &nSrcXOff,
                           int &nSrcYOff);
 
    static bool IsDefaultBlockSize(int nBlockSize, int nDimension);
 
    CPL_DISALLOW_COPY_ASSIGN(VRTDataset)
 
  protected:
    bool m_bBlockSizeSpecified = false;
    int m_nBlockXSize = 0;
    int m_nBlockYSize = 0;
 
    OGRSpatialReferenceRefCountedPtr m_poSRS{};
 
    int m_bGeoTransformSet = false;
    GDALGeoTransform m_gt{};
 
    int CloseDependentDatasets() override;
 
  public:
    VRTDataset(int nXSize, int nYSize, int nBlockXSize = 0,
               int nBlockYSize = 0);
    ~VRTDataset() override;
 
    void SetNeedsFlush()
    {
        m_bNeedsFlush = true;
    }
 
    CPLErr FlushCache(bool bAtClosing) override;
 
    void SetWritable(int bWritableIn)
    {
        m_bWritable = CPL_TO_BOOL(bWritableIn);
    }
 
    CPLErr CreateMaskBand(int nFlags) override;
    void SetMaskBand(std::unique_ptr<VRTRasterBand> poMaskBand);
 
    const OGRSpatialReference *GetSpatialRef() const override
    {
        return m_poSRS.get();
    }
 
    CPLErr SetSpatialRef(const OGRSpatialReference *poSRS) override;
 
    CPLErr GetGeoTransform(GDALGeoTransform &) const override;
    CPLErr SetGeoTransform(const GDALGeoTransform &) override;
 
    CPLErr SetMetadata(CSLConstList papszMetadata,
                       const char *pszDomain = "") override;
    CPLErr SetMetadataItem(const char *pszName, const char *pszValue,
                           const char *pszDomain = "") override;
 
    CSLConstList GetMetadata(const char *pszDomain = "") override;
    virtual const char *GetMetadataItem(const char *pszName,
                                        const char *pszDomain = "") override;
 
    int GetGCPCount() override;
 
    const OGRSpatialReference *GetGCPSpatialRef() const override
    {
        return m_poGCP_SRS.get();
    }
 
    const GDAL_GCP *GetGCPs() override;
    using GDALDataset::SetGCPs;
    CPLErr SetGCPs(int nGCPCount, const GDAL_GCP *pasGCPList,
                   const OGRSpatialReference *poSRS) override;
 
    virtual CPLErr AddBand(GDALDataType eType,
                           CSLConstList papszOptions = nullptr) override;
 
    char **GetFileList() override;
 
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, int nBandCount,
                     BANDMAP_TYPE panBandMap, GSpacing nPixelSpace,
                     GSpacing nLineSpace, GSpacing nBandSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    virtual CPLStringList
    GetCompressionFormats(int nXOff, int nYOff, int nXSize, int nYSize,
                          int nBandCount, const int *panBandList) override;
    virtual CPLErr ReadCompressedData(const char *pszFormat, int nXOff,
                                      int nYOff, int nXSize, int nYSize,
                                      int nBandCount, const int *panBandList,
                                      void **ppBuffer, size_t *pnBufferSize,
                                      char **ppszDetailedFormat) override;
 
    CPLErr AdviseRead(int nXOff, int nYOff, int nXSize, int nYSize,
                      int nBufXSize, int nBufYSize, GDALDataType eDT,
                      int nBandCount, int *panBandList,
                      CSLConstList papszOptions) override;
 
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath);
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *);
 
    CPLErr IBuildOverviews(const char *, int, const int *, int, const int *,
                           GDALProgressFunc, void *,
                           CSLConstList papszOptions) override;
 
    std::shared_ptr<GDALGroup> GetRootGroup() const override;
 
    std::shared_ptr<VRTGroup> GetRootVRTGroup() const
    {
        return m_poRootGroup;
    }
 
    void ClearStatistics() override;

    void SourceAdded()
    {
        m_nCompatibleForDatasetIO = -1;
    }
 
    /* Used by PDF driver for example */
    GDALDataset *GetSingleSimpleSource();
    void BuildVirtualOverviews();
 
    void UnsetPreservedRelativeFilenames();
 
    bool IsBlockSizeSpecified() const
    {
        return m_bBlockSizeSpecified;
    }
 
    int GetBlockXSize() const
    {
        return m_nBlockXSize;
    }
 
    int GetBlockYSize() const
    {
        return m_nBlockYSize;
    }
 
    static int Identify(GDALOpenInfo *);
    static GDALDataset *Open(GDALOpenInfo *);
    static std::unique_ptr<VRTDataset>
    OpenXML(const char *, const char * = nullptr,
            GDALAccess eAccess = GA_ReadOnly);
    static GDALDataset *Create(const char *pszName, int nXSize, int nYSize,
                               int nBands, GDALDataType eType,
                               CSLConstList papszOptions);
    static std::unique_ptr<VRTDataset>
    CreateVRTDataset(const char *pszName, int nXSize, int nYSize, int nBands,
                     GDALDataType eType, CSLConstList papszOptions);
    static GDALDataset *
    CreateMultiDimensional(const char *pszFilename,
                           CSLConstList papszRootGroupOptions,
                           CSLConstList papszOptions);
    static std::unique_ptr<VRTDataset>
    CreateVRTMultiDimensional(const char *pszFilename,
                              CSLConstList papszRootGroupOptions,
                              CSLConstList papszOptions);
    static CPLErr Delete(const char *pszFilename);
 
    static int GetNumThreads(GDALDataset *poDS);
 
    static bool IsRawRasterBandEnabled();
};
 
/************************************************************************/
/*                           VRTWarpedDataset                           */
/************************************************************************/
 
class GDALWarpOperation;
class VRTWarpedRasterBand;
 
class CPL_DLL VRTWarpedDataset final : public VRTDataset
{
    GDALWarpOperation *m_poWarper;
 
    bool m_bIsOverview = false;
    std::vector<VRTWarpedDataset *> m_apoOverviews{};
    int m_nSrcOvrLevel;
 
    bool GetOverviewSize(GDALDataset *poSrcDS, int iOvr, int iSrcOvr,
                         int &nOvrXSize, int &nOvrYSize, double &dfSrcRatioX,
                         double &dfSrcRatioY) const;
    int GetOverviewCount() const;
    int GetSrcOverviewLevel(int iOvr, bool &bThisLevelOnlyOut) const;
    VRTWarpedDataset *CreateImplicitOverview(int iOvr) const;
    void CreateImplicitOverviews();
 
    friend class VRTWarpedRasterBand;
 
    CPL_DISALLOW_COPY_ASSIGN(VRTWarpedDataset)
 
  protected:
    int CloseDependentDatasets() override;
 
  public:
    VRTWarpedDataset(int nXSize, int nYSize, int nBlockXSize = 0,
                     int nBlockYSize = 0);
    ~VRTWarpedDataset() override;
 
    CPLErr FlushCache(bool bAtClosing) override;
 
    CPLErr Initialize(/* GDALWarpOptions */ void *);
 
    CPLErr IBuildOverviews(const char *, int, const int *, int, const int *,
                           GDALProgressFunc, void *,
                           CSLConstList papszOptions) override;
 
    CPLErr SetMetadataItem(const char *pszName, const char *pszValue,
                           const char *pszDomain = "") override;
 
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
    CPLErr XMLInit(const CPLXMLNode *, const char *) override;
 
    virtual CPLErr AddBand(GDALDataType eType,
                           CSLConstList papszOptions = nullptr) override;
 
    char **GetFileList() override;
 
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, int nBandCount,
                     BANDMAP_TYPE panBandMap, GSpacing nPixelSpace,
                     GSpacing nLineSpace, GSpacing nBandSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    CPLErr ProcessBlock(int iBlockX, int iBlockY);
 
    void GetBlockSize(int *, int *) const;
};
 
/************************************************************************/
/*                        VRTPansharpenedDataset                        */
/************************************************************************/
 
class GDALPansharpenOperation;
 
typedef enum
{
    GTAdjust_Union,
    GTAdjust_Intersection,
    GTAdjust_None,
    GTAdjust_NoneWithoutWarning
} GTAdjustment;
 
class VRTPansharpenedDataset final : public VRTDataset
{
    friend class VRTPansharpenedRasterBand;
 
    std::unique_ptr<GDALPansharpenOperation> m_poPansharpener{};
    VRTPansharpenedDataset *m_poMainDataset;
    std::vector<std::unique_ptr<VRTPansharpenedDataset>>
        m_apoOverviewDatasets{};
    // Map from absolute to relative.
    std::map<CPLString, CPLString> m_oMapToRelativeFilenames{};
 
    int m_bLoadingOtherBands;
 
    GByte *m_pabyLastBufferBandRasterIO;
    int m_nLastBandRasterIOXOff;
    int m_nLastBandRasterIOYOff;
    int m_nLastBandRasterIOXSize;
    int m_nLastBandRasterIOYSize;
    GDALDataType m_eLastBandRasterIODataType;
 
    GTAdjustment m_eGTAdjustment;
    int m_bNoDataDisabled;
 
    std::vector<std::unique_ptr<GDALDataset, GDALDatasetUniquePtrReleaser>>
        m_apoDatasetsToReleaseRef{};
 
    CPL_DISALLOW_COPY_ASSIGN(VRTPansharpenedDataset)
 
  protected:
    int CloseDependentDatasets() override;
 
  public:
    VRTPansharpenedDataset(int nXSize, int nYSize, int nBlockXSize = 0,
                           int nBlockYSize = 0);
    ~VRTPansharpenedDataset() override;
 
    CPLErr FlushCache(bool bAtClosing) override;
 
    CPLErr XMLInit(const CPLXMLNode *, const char *) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
 
    CPLErr XMLInit(const CPLXMLNode *psTree, const char *pszVRTPath,
                   GDALRasterBandH hPanchroBandIn, int nInputSpectralBandsIn,
                   GDALRasterBandH *pahInputSpectralBandsIn);
 
    virtual CPLErr AddBand(GDALDataType eType,
                           CSLConstList papszOptions = nullptr) override;
 
    char **GetFileList() override;
 
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, int nBandCount,
                     BANDMAP_TYPE panBandMap, GSpacing nPixelSpace,
                     GSpacing nLineSpace, GSpacing nBandSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    void GetBlockSize(int *, int *) const;
 
    GDALPansharpenOperation *GetPansharpener()
    {
        return m_poPansharpener.get();
    }
};
 
/************************************************************************/
/*                        VRTPansharpenedDataset                        */
/************************************************************************/

class VRTProcessedDataset final : public VRTDataset
{
  public:
    VRTProcessedDataset(int nXSize, int nYSize);
    ~VRTProcessedDataset() override;
 
    CPLErr FlushCache(bool bAtClosing) override;
 
    CPLErr XMLInit(const CPLXMLNode *, const char *) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
 
    void GetBlockSize(int *, int *) const;
 
    // GByte whose initialization constructor does nothing
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Weffc++"
#endif
    struct NoInitByte
    {
#ifdef __COVERITY__
        GByte value = 0;
#else
        GByte value;
#endif
 
        // cppcheck-suppress uninitMemberVar
        NoInitByte()
        {
            // do nothing
        }
 
        inline operator GByte() const
        {
            return value;
        }
    };
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
 
  protected:
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, int nBandCount,
                     BANDMAP_TYPE panBandMap, GSpacing nPixelSpace,
                     GSpacing nLineSpace, GSpacing nBandSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
  private:
    friend class VRTProcessedRasterBand;

    struct Step
    {
        std::string osAlgorithm{};

        CPLStringList aosArguments{};

        GDALDataType eInDT = GDT_Unknown;

        GDALDataType eOutDT = GDT_Unknown;

        int nInBands = 0;

        int nOutBands = 0;

        std::vector<double> adfInNoData{};

        std::vector<double> adfOutNoData{};

        VRTPDWorkingDataPtr pWorkingData = nullptr;
 
        // NOTE: if adding a new member, edit the move constructor and
        // assignment operators!
 
        Step() = default;
        ~Step();
        Step(Step &&);
        Step &operator=(Step &&);
 
      private:
        Step(const Step &) = delete;
        Step &operator=(const Step &) = delete;
        void deinit();
    };

    std::string m_osVRTPath{};

    std::unique_ptr<GDALDataset> m_poVRTSrcDS{};

    std::unique_ptr<GDALDataset> m_poSrcDS{};

    std::vector<Step> m_aoSteps{};

    CPLXMLTreeCloser m_oXMLTree{nullptr};

    std::vector<std::unique_ptr<GDALDataset>> m_apoOverviewDatasets{};

    std::vector<NoInitByte> m_abyInput{};

    std::vector<NoInitByte> m_abyOutput{};

    enum class ValueProvenance
    {
        FROM_VRTRASTERBAND,
        FROM_SOURCE,
        FROM_LAST_STEP,
        USER_PROVIDED,
    };

    ValueProvenance m_outputBandCountProvenance = ValueProvenance::FROM_SOURCE;

    int m_outputBandCountValue = 0;

    ValueProvenance m_outputBandDataTypeProvenance =
        ValueProvenance::FROM_SOURCE;

    GDALDataType m_outputBandDataTypeValue = GDT_Unknown;

    int m_nWorkingBytesPerPixel = 1;

    GIntBig m_nAllowedRAMUsage = 0;
 
    CPLErr Init(const CPLXMLNode *, const char *,
                const VRTProcessedDataset *poParentDS,
                GDALDataset *poParentSrcDS, int iOvrLevel);
 
    bool ParseStep(const CPLXMLNode *psStep, bool bIsFinalStep,
                   GDALDataType &eCurrentDT, int &nCurrentBandCount,
                   std::vector<double> &adfInNoData,
                   std::vector<double> &adfOutNoData);
    bool ProcessRegion(int nXOff, int nYOff, int nBufXSize, int nBufYSize,
                       GDALProgressFunc pfnProgress, void *pProgressData);
};
 
/************************************************************************/
/*                            VRTRasterBand                             */
/*                                                                      */
/*      Provides support for all the various kinds of metadata but      */
/*      no raster access.  That is handled by derived classes.          */
/************************************************************************/
 
constexpr double VRT_DEFAULT_NODATA_VALUE = -10000.0;
 
class CPL_DLL VRTRasterBand CPL_NON_FINAL : public GDALRasterBand
{
  private:
    void ResetNoDataValues();
 
  protected:
    friend class VRTDataset;
 
    bool m_bIsMaskBand = false;
 
    bool m_bNoDataValueSet = false;
    // If set to true, will not report the existence of nodata.
    int m_bHideNoDataValue = false;
    double m_dfNoDataValue = VRT_DEFAULT_NODATA_VALUE;
 
    bool m_bNoDataSetAsInt64 = false;
    int64_t m_nNoDataValueInt64 = GDAL_PAM_DEFAULT_NODATA_VALUE_INT64;
 
    bool m_bNoDataSetAsUInt64 = false;
    uint64_t m_nNoDataValueUInt64 = GDAL_PAM_DEFAULT_NODATA_VALUE_UINT64;
 
    std::unique_ptr<GDALColorTable> m_poColorTable{};
 
    GDALColorInterp m_eColorInterp = GCI_Undefined;
 
    std::string m_osUnitType{};
    CPLStringList m_aosCategoryNames{};
 
    double m_dfOffset = 0.0;
    double m_dfScale = 1.0;
 
    CPLXMLTreeCloser m_psSavedHistograms{nullptr};
 
    void Initialize(int nXSize, int nYSize);
 
    std::vector<VRTOverviewInfo> m_aoOverviewInfos{};
 
    std::unique_ptr<VRTRasterBand> m_poMaskBand{};
 
    std::unique_ptr<GDALRasterAttributeTable> m_poRAT{};
 
    CPL_DISALLOW_COPY_ASSIGN(VRTRasterBand)
 
    bool IsNoDataValueInDataTypeRange() const;
 
  public:
    VRTRasterBand();
    ~VRTRasterBand() override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &);
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage);
 
    CPLErr SetNoDataValue(double) override;
    CPLErr SetNoDataValueAsInt64(int64_t nNoData) override;
    CPLErr SetNoDataValueAsUInt64(uint64_t nNoData) override;
    double GetNoDataValue(int *pbSuccess = nullptr) override;
    int64_t GetNoDataValueAsInt64(int *pbSuccess = nullptr) override;
    uint64_t GetNoDataValueAsUInt64(int *pbSuccess = nullptr) override;
    CPLErr DeleteNoDataValue() override;
 
    CPLErr SetColorTable(GDALColorTable *) override;
    GDALColorTable *GetColorTable() override;
 
    GDALRasterAttributeTable *GetDefaultRAT() override;
    virtual CPLErr
    SetDefaultRAT(const GDALRasterAttributeTable *poRAT) override;
 
    CPLErr SetColorInterpretation(GDALColorInterp) override;
    GDALColorInterp GetColorInterpretation() override;
 
    const char *GetUnitType() override;
    CPLErr SetUnitType(const char *) override;
 
    char **GetCategoryNames() override;
    CPLErr SetCategoryNames(char **) override;
 
    CPLErr SetMetadata(CSLConstList papszMD,
                       const char *pszDomain = "") override;
    CPLErr SetMetadataItem(const char *pszName, const char *pszValue,
                           const char *pszDomain = "") override;
 
    double GetOffset(int *pbSuccess = nullptr) override;
    CPLErr SetOffset(double) override;
    double GetScale(int *pbSuccess = nullptr) override;
    CPLErr SetScale(double) override;
 
    int GetOverviewCount() override;
    GDALRasterBand *GetOverview(int) override;
 
    CPLErr GetHistogram(double dfMin, double dfMax, int nBuckets,
                        GUIntBig *panHistogram, int bIncludeOutOfRange,
                        int bApproxOK, GDALProgressFunc,
                        void *pProgressData) override;
 
    CPLErr GetDefaultHistogram(double *pdfMin, double *pdfMax, int *pnBuckets,
                               GUIntBig **ppanHistogram, int bForce,
                               GDALProgressFunc, void *pProgressData) override;
 
    virtual CPLErr SetDefaultHistogram(double dfMin, double dfMax, int nBuckets,
                                       GUIntBig *panHistogram) override;
 
    CPLErr CopyCommonInfoFrom(const GDALRasterBand *);
 
    virtual void GetFileList(char ***ppapszFileList, int *pnSize,
                             int *pnMaxSize, CPLHashSet *hSetFiles);
 
    void SetDescription(const char *) override;
 
    GDALRasterBand *GetMaskBand() override;
    int GetMaskFlags() override;
 
    CPLErr CreateMaskBand(int nFlagsIn) override;
 
    void SetMaskBand(std::unique_ptr<VRTRasterBand> poMaskBand);
 
    void SetIsMaskBand();
 
    bool IsMaskBand() const override;
 
    CPLErr UnsetNoDataValue();
 
    virtual int CloseDependentDatasets();
 
    virtual bool IsSourcedRasterBand()
    {
        return false;
    }
 
    virtual bool IsPansharpenRasterBand()
    {
        return false;
    }
};
 
/************************************************************************/
/*                         VRTSourcedRasterBand                         */
/************************************************************************/
 
class VRTSimpleSource;
 
class CPL_DLL VRTSourcedRasterBand CPL_NON_FINAL : public VRTRasterBand
{
  private:
    CPLString m_osLastLocationInfo{};
    CPLStringList m_aosSourceList{};
    int m_nSkipBufferInitialization = -1;
 
    bool CanUseSourcesMinMaxImplementations();
 
    bool IsMosaicOfNonOverlappingSimpleSourcesOfFullRasterNoResAndTypeChange(
        bool bAllowMaxValAdjustment) const;
 
    CPL_DISALLOW_COPY_ASSIGN(VRTSourcedRasterBand)
 
  protected:
    bool SkipBufferInitialization();
 
    void InitializeOutputBuffer(void *pData, int nBufXSize, int nBufYSize,
                                GDALDataType eBufType, GSpacing nPixelSpace,
                                GSpacing nLineSpace) const;
 
  public:
    std::vector<std::unique_ptr<VRTSource>> m_papoSources{};
 
    VRTSourcedRasterBand(GDALDataset *poDS, int nBand);
    VRTSourcedRasterBand(GDALDataType eType, int nXSize, int nYSize);
    VRTSourcedRasterBand(GDALDataset *poDS, int nBand, GDALDataType eType,
                         int nXSize, int nYSize);
    VRTSourcedRasterBand(GDALDataset *poDS, int nBand, GDALDataType eType,
                         int nXSize, int nYSize, int nBlockXSizeIn,
                         int nBlockYSizeIn);
    ~VRTSourcedRasterBand() override;
 
    void CopyForCloneWithoutSources(const VRTSourcedRasterBand *poSrcBand);
 
    virtual std::unique_ptr<VRTSourcedRasterBand>
    CloneWithoutSources(GDALDataset *poNewDS, int nNewXSize,
                        int nNewYSize) const;
 
    CPLErr IRasterIO(GDALRWFlag, int, int, int, int, void *, int, int,
                     GDALDataType, GSpacing nPixelSpace, GSpacing nLineSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    bool MayMultiBlockReadingBeMultiThreaded() const override;
 
    virtual int IGetDataCoverageStatus(int nXOff, int nYOff, int nXSize,
                                       int nYSize, int nMaskFlagStop,
                                       double *pdfDataPct) override;
 
    char **GetMetadataDomainList() override;
    virtual const char *GetMetadataItem(const char *pszName,
                                        const char *pszDomain = "") override;
    CSLConstList GetMetadata(const char *pszDomain = "") override;
    CPLErr SetMetadata(CSLConstList papszMetadata,
                       const char *pszDomain = "") override;
    CPLErr SetMetadataItem(const char *pszName, const char *pszValue,
                           const char *pszDomain = "") override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &) override;
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
 
    double GetMinimum(int *pbSuccess = nullptr) override;
    double GetMaximum(int *pbSuccess = nullptr) override;
    virtual CPLErr ComputeRasterMinMax(int bApproxOK,
                                       double *adfMinMax) override;
    virtual CPLErr ComputeStatistics(int bApproxOK, double *pdfMin,
                                     double *pdfMax, double *pdfMean,
                                     double *pdfStdDev,
                                     GDALProgressFunc pfnProgress,
                                     void *pProgressData) override;
    CPLErr GetHistogram(double dfMin, double dfMax, int nBuckets,
                        GUIntBig *panHistogram, int bIncludeOutOfRange,
                        int bApproxOK, GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    CPLErr AddSource(std::unique_ptr<VRTSource>);
 
    CPLErr AddSource(VRTSource *);
 
    CPLErr AddSimpleSource(const char *pszFilename, int nBand,
                           double dfSrcXOff = -1, double dfSrcYOff = -1,
                           double dfSrcXSize = -1, double dfSrcYSize = -1,
                           double dfDstXOff = -1, double dfDstYOff = -1,
                           double dfDstXSize = -1, double dfDstYSize = -1,
                           const char *pszResampling = "near",
                           double dfNoDataValue = VRT_NODATA_UNSET);
 
    CPLErr AddSimpleSource(GDALRasterBand *poSrcBand, double dfSrcXOff = -1,
                           double dfSrcYOff = -1, double dfSrcXSize = -1,
                           double dfSrcYSize = -1, double dfDstXOff = -1,
                           double dfDstYOff = -1, double dfDstXSize = -1,
                           double dfDstYSize = -1,
                           const char *pszResampling = "near",
                           double dfNoDataValue = VRT_NODATA_UNSET);
 
    CPLErr AddComplexSource(const char *pszFilename, int nBand,
                            double dfSrcXOff = -1, double dfSrcYOff = -1,
                            double dfSrcXSize = -1, double dfSrcYSize = -1,
                            double dfDstXOff = -1, double dfDstYOff = -1,
                            double dfDstXSize = -1, double dfDstYSize = -1,
                            double dfScaleOff = 0.0, double dfScaleRatio = 1.0,
                            double dfNoDataValue = VRT_NODATA_UNSET,
                            int nColorTableComponent = 0);
 
    CPLErr AddComplexSource(GDALRasterBand *poSrcBand, double dfSrcXOff = -1,
                            double dfSrcYOff = -1, double dfSrcXSize = -1,
                            double dfSrcYSize = -1, double dfDstXOff = -1,
                            double dfDstYOff = -1, double dfDstXSize = -1,
                            double dfDstYSize = -1, double dfScaleOff = 0.0,
                            double dfScaleRatio = 1.0,
                            double dfNoDataValue = VRT_NODATA_UNSET,
                            int nColorTableComponent = 0);
 
    CPLErr AddMaskBandSource(GDALRasterBand *poSrcBand, double dfSrcXOff = -1,
                             double dfSrcYOff = -1, double dfSrcXSize = -1,
                             double dfSrcYSize = -1, double dfDstXOff = -1,
                             double dfDstYOff = -1, double dfDstXSize = -1,
                             double dfDstYSize = -1);
 
    CPLErr AddFuncSource(VRTImageReadFunc pfnReadFunc, void *hCBData,
                         double dfNoDataValue = VRT_NODATA_UNSET);
 
    void ConfigureSource(VRTSimpleSource *poSimpleSource,
                         GDALRasterBand *poSrcBand, int bAddAsMaskBand,
                         double dfSrcXOff, double dfSrcYOff, double dfSrcXSize,
                         double dfSrcYSize, double dfDstXOff, double dfDstYOff,
                         double dfDstXSize, double dfDstYSize);
 
    void RemoveCoveredSources(CSLConstList papszOptions = nullptr);
 
    bool CanIRasterIOBeForwardedToEachSource(
        GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize,
        int nBufXSize, int nBufYSize,
        const GDALRasterIOExtraArg *psExtraArg) const;
 
    bool CanMultiThreadRasterIO(double dfXOff, double dfYOff, double dfXSize,
                                double dfYSize,
                                int &nContributingSources) const;
 
    CPLErr IReadBlock(int, int, void *) override;
 
    virtual void GetFileList(char ***ppapszFileList, int *pnSize,
                             int *pnMaxSize, CPLHashSet *hSetFiles) override;
 
    int CloseDependentDatasets() override;
 
    bool IsSourcedRasterBand() override
    {
        return true;
    }
 
    CPLErr FlushCache(bool bAtClosing) override;
};
 
/************************************************************************/
/*                         VRTWarpedRasterBand                          */
/************************************************************************/
 
class CPL_DLL VRTWarpedRasterBand final : public VRTRasterBand
{
  public:
    VRTWarpedRasterBand(GDALDataset *poDS, int nBand,
                        GDALDataType eType = GDT_Unknown);
    ~VRTWarpedRasterBand() override;
 
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
 
    CPLErr IReadBlock(int, int, void *) override;
    CPLErr IWriteBlock(int, int, void *) override;
 
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, GSpacing nPixelSpace,
                     GSpacing nLineSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    int GetOverviewCount() override;
    GDALRasterBand *GetOverview(int) override;
 
    bool
    EmitErrorMessageIfWriteNotSupported(const char *pszCaller) const override;
 
  private:
    int m_nIRasterIOCounter =
        0;  
 
    int GetBestOverviewLevel(int &nXOff, int &nYOff, int &nXSize, int &nYSize,
                             int nBufXSize, int nBufYSize,
                             GDALRasterIOExtraArg *psExtraArg) const;
};
 
/************************************************************************/
/*                      VRTPansharpenedRasterBand                       */
/************************************************************************/
 
class VRTPansharpenedRasterBand final : public VRTRasterBand
{
    int m_nIndexAsPansharpenedBand;
 
  public:
    VRTPansharpenedRasterBand(GDALDataset *poDS, int nBand,
                              GDALDataType eDataType = GDT_Unknown);
    ~VRTPansharpenedRasterBand() override;
 
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
 
    CPLErr IReadBlock(int, int, void *) override;
 
    CPLErr IRasterIO(GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize,
                     int nYSize, void *pData, int nBufXSize, int nBufYSize,
                     GDALDataType eBufType, GSpacing nPixelSpace,
                     GSpacing nLineSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    int GetOverviewCount() override;
    GDALRasterBand *GetOverview(int) override;
 
    bool IsPansharpenRasterBand() override
    {
        return true;
    }
 
    void SetIndexAsPansharpenedBand(int nIdx)
    {
        m_nIndexAsPansharpenedBand = nIdx;
    }
 
    int GetIndexAsPansharpenedBand() const
    {
        return m_nIndexAsPansharpenedBand;
    }
};
 
/************************************************************************/
/*                        VRTProcessedRasterBand                        */
/************************************************************************/
 
class VRTProcessedRasterBand final : public VRTRasterBand
{
  public:
    VRTProcessedRasterBand(VRTProcessedDataset *poDS, int nBand,
                           GDALDataType eDataType = GDT_Unknown);
 
    CPLErr IReadBlock(int, int, void *) override;
 
    int GetOverviewCount() override;
    GDALRasterBand *GetOverview(int) override;
 
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
};
 
/************************************************************************/
/*                         VRTDerivedRasterBand                         */
/************************************************************************/
 
class VRTDerivedRasterBandPrivateData;
 
class CPL_DLL VRTDerivedRasterBand CPL_NON_FINAL : public VRTSourcedRasterBand
{
    VRTDerivedRasterBandPrivateData *m_poPrivate;
    bool InitializePython();
    CPLErr GetPixelFunctionArguments(
        const CPLString &, const std::vector<int> &anMapBufferIdxToSourceIdx,
        int nXOff, int nYOff, std::vector<std::pair<CPLString, CPLString>> &);
 
    CPL_DISALLOW_COPY_ASSIGN(VRTDerivedRasterBand)
 
  public:
    CPLString osFuncName{};
    GDALDataType eSourceTransferType;
 
    using PixelFunc =
        std::function<CPLErr(void **, int, void *, int, int, GDALDataType,
                             GDALDataType, int, int, CSLConstList)>;
 
    VRTDerivedRasterBand(GDALDataset *poDS, int nBand);
    VRTDerivedRasterBand(GDALDataset *poDS, int nBand, GDALDataType eType,
                         int nXSize, int nYSize, int nBlockXSizeIn = 0,
                         int nBlockYSizeIn = 0);
    ~VRTDerivedRasterBand() override;
 
    void CopyForCloneWithoutSources(const VRTDerivedRasterBand *poSrcBand);
 
    std::unique_ptr<VRTSourcedRasterBand>
    CloneWithoutSources(GDALDataset *poNewDS, int nNewXSize,
                        int nNewYSize) const override;
 
    CPLErr IRasterIO(GDALRWFlag, int, int, int, int, void *, int, int,
                     GDALDataType, GSpacing nPixelSpace, GSpacing nLineSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    virtual int IGetDataCoverageStatus(int nXOff, int nYOff, int nXSize,
                                       int nYSize, int nMaskFlagStop,
                                       double *pdfDataPct) override;
 
    static CPLErr AddPixelFunction(const char *pszFuncNameIn,
                                   GDALDerivedPixelFunc pfnPixelFunc);
    static CPLErr AddPixelFunction(const char *pszFuncNameIn,
                                   GDALDerivedPixelFuncWithArgs pfnPixelFunc,
                                   const char *pszMetadata);
 
    static const std::pair<PixelFunc, std::string> *
    GetPixelFunction(const char *pszFuncNameIn);
 
    static std::vector<std::string> GetPixelFunctionNames();
 
    void SetPixelFunctionName(const char *pszFuncNameIn);
    void AddPixelFunctionArgument(const char *pszArg, const char *pszValue);
    void SetSkipNonContributingSources(bool bSkip);
    void SetSourceTransferType(GDALDataType eDataType);
    void SetPixelFunctionLanguage(const char *pszLanguage);
 
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &) override;
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
 
    double GetMinimum(int *pbSuccess = nullptr) override;
    double GetMaximum(int *pbSuccess = nullptr) override;
    virtual CPLErr ComputeRasterMinMax(int bApproxOK,
                                       double *adfMinMax) override;
    virtual CPLErr ComputeStatistics(int bApproxOK, double *pdfMin,
                                     double *pdfMax, double *pdfMean,
                                     double *pdfStdDev,
                                     GDALProgressFunc pfnProgress,
                                     void *pProgressData) override;
    CPLErr GetHistogram(double dfMin, double dfMax, int nBuckets,
                        GUIntBig *panHistogram, int bIncludeOutOfRange,
                        int bApproxOK, GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    static void Cleanup();
};
 
#ifndef GDAL_VRT_DISABLE_RAWRASTERBAND
/************************************************************************/
/*                           VRTRawRasterBand                           */
/************************************************************************/
 
class RawRasterBand;
 
class CPL_DLL VRTRawRasterBand CPL_NON_FINAL : public VRTRasterBand
{
    RawRasterBand *m_poRawRaster;
 
    char *m_pszSourceFilename;
    int m_bRelativeToVRT;
 
    CPL_DISALLOW_COPY_ASSIGN(VRTRawRasterBand)
 
  public:
    VRTRawRasterBand(GDALDataset *poDS, int nBand,
                     GDALDataType eType = GDT_Unknown);
    ~VRTRawRasterBand() override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &) override;
    virtual CPLXMLNode *SerializeToXML(const char *pszVRTPath,
                                       bool &bHasWarnedAboutRAMUsage,
                                       size_t &nAccRAMUsage) override;
 
    CPLErr IRasterIO(GDALRWFlag, int, int, int, int, void *, int, int,
                     GDALDataType, GSpacing nPixelSpace, GSpacing nLineSpace,
                     GDALRasterIOExtraArg *psExtraArg) override;
 
    CPLErr IReadBlock(int, int, void *) override;
    CPLErr IWriteBlock(int, int, void *) override;
 
    CPLErr SetRawLink(const char *pszFilename, const char *pszVRTPath,
                      int bRelativeToVRT, vsi_l_offset nImageOffset,
                      int nPixelOffset, int nLineOffset,
                      const char *pszByteOrder);
 
    void ClearRawLink();
 
    CPLVirtualMem *GetVirtualMemAuto(GDALRWFlag eRWFlag, int *pnPixelSpace,
                                     GIntBig *pnLineSpace,
                                     CSLConstList papszOptions) override;
 
    virtual void GetFileList(char ***ppapszFileList, int *pnSize,
                             int *pnMaxSize, CPLHashSet *hSetFiles) override;
};
#endif
 
/************************************************************************/
/*                              VRTDriver                               */
/************************************************************************/
 
class VRTDriver final : public GDALDriver
{
    CPL_DISALLOW_COPY_ASSIGN(VRTDriver)
 
    std::mutex m_oMutex{};
    std::map<std::string, VRTSourceParser> m_oMapSourceParser{};
 
  public:
    VRTDriver();
    ~VRTDriver() override;
 
    char **papszSourceParsers;
 
    char **GetMetadataDomainList() override;
    CSLConstList GetMetadata(const char *pszDomain = "") override;
    CPLErr SetMetadata(CSLConstList papszMetadata,
                       const char *pszDomain = "") override;
 
    VRTSource *ParseSource(const CPLXMLNode *psSrc, const char *pszVRTPath,
                           VRTMapSharedResources &oMapSharedSources);
    void AddSourceParser(const char *pszElementName, VRTSourceParser pfnParser);
};
 
/************************************************************************/
/*                           VRTSimpleSource                            */
/************************************************************************/
 
class CPL_DLL VRTSimpleSource CPL_NON_FINAL : public VRTSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTSimpleSource)
 
  private:
    // Owned by the VRTDataset
    VRTMapSharedResources *m_poMapSharedSources = nullptr;
 
    mutable GDALRasterBand *m_poRasterBand = nullptr;
 
    // When poRasterBand is a mask band, poMaskBandMainBand is the band
    // from which the mask band is taken.
    mutable GDALRasterBand *m_poMaskBandMainBand = nullptr;
 
    CPLStringList m_aosOpenOptionsOri{};  // as read in the original source XML
    CPLStringList
        m_aosOpenOptions{};  // same as above, but potentially augmented with ROOT_PATH
    bool m_bSrcDSNameFromVRT =
        false;  // whereas content in m_osSrcDSName is a <VRTDataset> XML node
 
    void OpenSource() const;
 
    GDALDataset *GetSourceDataset() const;
 
  protected:
    friend class VRTSourcedRasterBand;
    friend class VRTDerivedRasterBand;
    friend class VRTDataset;
    friend class GDALTileIndexDataset;
    friend class GDALTileIndexBand;
 
    int m_nBand = 0;
    bool m_bGetMaskBand = false;
 
    /* Value for uninitialized source or destination window. It is chosen such
     * that SrcToDst() and DstToSrc() are no-ops if both source and destination
     * windows are unset.
     */
    static constexpr double UNINIT_WINDOW = -1.0;
 
    double m_dfSrcXOff = UNINIT_WINDOW;
    double m_dfSrcYOff = UNINIT_WINDOW;
    double m_dfSrcXSize = UNINIT_WINDOW;
    double m_dfSrcYSize = UNINIT_WINDOW;
 
    double m_dfDstXOff = UNINIT_WINDOW;
    double m_dfDstYOff = UNINIT_WINDOW;
    double m_dfDstXSize = UNINIT_WINDOW;
    double m_dfDstYSize = UNINIT_WINDOW;
 
    CPLString m_osResampling{};
 
    int m_nMaxValue = 0;
 
    int m_bRelativeToVRTOri = -1;
    CPLString m_osSourceFileNameOri{};
    int m_nExplicitSharedStatus = -1;  // -1 unknown, 0 = unshared, 1 = shared
    CPLString m_osSrcDSName{};
 
    bool m_bDropRefOnSrcBand = true;
 
    int NeedMaxValAdjustment() const;
 
    GDALRasterBand *GetRasterBandNoOpen() const
    {
        return m_poRasterBand;
    }
 
    void SetRasterBand(GDALRasterBand *poBand, bool bDropRef)
    {
        m_poRasterBand = poBand;
        m_bDropRefOnSrcBand = bDropRef;
    }
 
    virtual bool ValidateOpenedBand(GDALRasterBand * /*poBand*/) const
    {
        return true;
    }

    bool IsSrcWinSet() const
    {
        return m_dfSrcXOff != UNINIT_WINDOW || m_dfSrcYOff != UNINIT_WINDOW ||
               m_dfSrcXSize != UNINIT_WINDOW || m_dfSrcYSize != UNINIT_WINDOW;
    }

    bool IsDstWinSet() const
    {
        return m_dfDstXOff != UNINIT_WINDOW || m_dfDstYOff != UNINIT_WINDOW ||
               m_dfDstXSize != UNINIT_WINDOW || m_dfDstYSize != UNINIT_WINDOW;
    }
 
    void AddSourceFilenameNode(const char *pszVRTPath, CPLXMLNode *psSrc);
 
  public:
    VRTSimpleSource();
    VRTSimpleSource(const VRTSimpleSource *poSrcSource, double dfXDstRatio,
                    double dfYDstRatio);
    ~VRTSimpleSource() override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *psTree, const char *,
                           VRTMapSharedResources &) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
 
    CPLErr ParseSrcRectAndDstRect(const CPLXMLNode *psSrc);
 
    void SetSrcBand(const char *pszFilename, int nBand);
    void SetSrcBand(GDALRasterBand *);
    void SetSrcMaskBand(GDALRasterBand *);
    void SetSrcWindow(double, double, double, double);
    void SetDstWindow(double, double, double, double);
    void GetDstWindow(double &, double &, double &, double &) const;
    bool DstWindowIntersects(double dfXOff, double dfYOff, double dfXSize,
                             double dfYSize) const;
 
    const std::string &GetSourceDatasetName() const
    {
        return m_osSrcDSName;
    }
 
    // Must be called after SetSrcBand()
    void SetSourceDatasetName(const char *pszFilename, bool bRelativeToVRT);
 
    const CPLString &GetResampling() const
    {
        return m_osResampling;
    }
 
    void SetResampling(const char *pszResampling);
 
    int GetSrcDstWindow(double, double, double, double, int, int,
                        double *pdfReqXOff, double *pdfReqYOff,
                        double *pdfReqXSize, double *pdfReqYSize, int *, int *,
                        int *, int *, int *, int *, int *, int *,
                        bool &bErrorOut);
 
    int GetSrcDstWindow(double, double, double, double, int, int,
                        GDALRIOResampleAlg eResampleAlg, double *pdfReqXOff,
                        double *pdfReqYOff, double *pdfReqXSize,
                        double *pdfReqYSize, int *, int *, int *, int *, int *,
                        int *, int *, int *, bool &bErrorOut);
 
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArgIn,
                            WorkingState &oWorkingState) override;
 
    double GetMinimum(int nXSize, int nYSize, int *pbSuccess) override;
    double GetMaximum(int nXSize, int nYSize, int *pbSuccess) override;
    CPLErr GetHistogram(int nXSize, int nYSize, double dfMin, double dfMax,
                        int nBuckets, GUIntBig *panHistogram,
                        int bIncludeOutOfRange, int bApproxOK,
                        GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    void DstToSrc(double dfX, double dfY, double &dfXOut, double &dfYOut) const;
    void SrcToDst(double dfX, double dfY, double &dfXOut, double &dfYOut) const;
 
    virtual void GetFileList(char ***ppapszFileList, int *pnSize,
                             int *pnMaxSize, CPLHashSet *hSetFiles) override;
 
    bool IsSimpleSource() const override
    {
        return true;
    }

    static const char *GetTypeStatic();
 
    const char *GetType() const override;
 
    CPLErr FlushCache(bool bAtClosing) override;
 
    GDALRasterBand *GetRasterBand() const;
    GDALRasterBand *GetMaskBandMainBand();
    bool IsSameExceptBandNumber(const VRTSimpleSource *poOtherSource) const;
    CPLErr DatasetRasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                           int nXSize, int nYSize, void *pData, int nBufXSize,
                           int nBufYSize, GDALDataType eBufType, int nBandCount,
                           const int *panBandMap, GSpacing nPixelSpace,
                           GSpacing nLineSpace, GSpacing nBandSpace,
                           GDALRasterIOExtraArg *psExtraArg);
 
    void UnsetPreservedRelativeFilenames();
 
    void SetMaxValue(int nVal)
    {
        m_nMaxValue = nVal;
    }
 
    static std::pair<std::string, bool>
    ComputeSourceNameAndRelativeFlag(const char *pszVRTPath,
                                     const std::string &osSourceNameIn);
};
 
/************************************************************************/
/*                          VRTAveragedSource                           */
/************************************************************************/
 
class VRTAveragedSource final : public VRTSimpleSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTAveragedSource)
 
    int m_bNoDataSet = false;
    double m_dfNoDataValue = VRT_NODATA_UNSET;
 
  public:
    VRTAveragedSource();
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArgIn,
                            WorkingState &oWorkingState) override;
 
    double GetMinimum(int nXSize, int nYSize, int *pbSuccess) override;
    double GetMaximum(int nXSize, int nYSize, int *pbSuccess) override;
    CPLErr GetHistogram(int nXSize, int nYSize, double dfMin, double dfMax,
                        int nBuckets, GUIntBig *panHistogram,
                        int bIncludeOutOfRange, int bApproxOK,
                        GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    void SetNoDataValue(double dfNoDataValue);
 
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;

    static const char *GetTypeStatic();
 
    const char *GetType() const override;
};
 
/************************************************************************/
/*                       VRTNoDataFromMaskSource                        */
/************************************************************************/
 
class VRTNoDataFromMaskSource final : public VRTSimpleSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTNoDataFromMaskSource)
 
    bool m_bNoDataSet = false;
    double m_dfNoDataValue = 0;
    double m_dfMaskValueThreshold = 0;
    bool m_bHasRemappedValue = false;
    double m_dfRemappedValue = 0;
 
  public:
    VRTNoDataFromMaskSource();
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArgIn,
                            WorkingState &oWorkingState) override;
 
    double GetMinimum(int nXSize, int nYSize, int *pbSuccess) override;
    double GetMaximum(int nXSize, int nYSize, int *pbSuccess) override;
    CPLErr GetHistogram(int nXSize, int nYSize, double dfMin, double dfMax,
                        int nBuckets, GUIntBig *panHistogram,
                        int bIncludeOutOfRange, int bApproxOK,
                        GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    void SetParameters(double dfNoDataValue, double dfMaskValueThreshold);
    void SetParameters(double dfNoDataValue, double dfMaskValueThreshold,
                       double dfRemappedValue);
 
    virtual CPLErr XMLInit(const CPLXMLNode *psTree, const char *,
                           VRTMapSharedResources &) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;

    static const char *GetTypeStatic();
 
    const char *GetType() const override;
};
 
/************************************************************************/
/*                           VRTComplexSource                           */
/************************************************************************/
 
class CPL_DLL VRTComplexSource CPL_NON_FINAL : public VRTSimpleSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTComplexSource)
 
  protected:
    static constexpr int PROCESSING_FLAG_NODATA = 1 << 0;
    static constexpr int PROCESSING_FLAG_USE_MASK_BAND =
        1 << 1;  // Mutually exclusive with NODATA
    static constexpr int PROCESSING_FLAG_SCALING_LINEAR = 1 << 2;
    static constexpr int PROCESSING_FLAG_SCALING_EXPONENTIAL =
        1 << 3;  // Mutually exclusive with SCALING_LINEAR
    static constexpr int PROCESSING_FLAG_COLOR_TABLE_EXPANSION = 1 << 4;
    static constexpr int PROCESSING_FLAG_LUT = 1 << 5;
 
    int m_nProcessingFlags = 0;
 
    // adjusted value should be read with GetAdjustedNoDataValue()
    double m_dfNoDataValue = VRT_NODATA_UNSET;
    std::string
        m_osNoDataValueOri{};  // string value read in XML deserialization
 
    double m_dfScaleOff = 0;    // For linear scaling.
    double m_dfScaleRatio = 1;  // For linear scaling.
 
    // For non-linear scaling with a power function.
    bool m_bSrcMinMaxDefined = false;
    double m_dfSrcMin = 0;
    double m_dfSrcMax = 0;
    double m_dfDstMin = 0;
    double m_dfDstMax = 0;
    double m_dfExponent = 1;
    bool m_bClip = true;  // Only taken into account for non-linear scaling
 
    int m_nColorTableComponent = 0;
 
    std::vector<double> m_adfLUTInputs{};
    std::vector<double> m_adfLUTOutputs{};
 
    double GetAdjustedNoDataValue() const;
 
    template <class WorkingDT>
    CPLErr
    RasterIOInternal(GDALRasterBand *poSourceBand,
                     GDALDataType eVRTBandDataType, int nReqXOff, int nReqYOff,
                     int nReqXSize, int nReqYSize, void *pData, int nOutXSize,
                     int nOutYSize, GDALDataType eBufType, GSpacing nPixelSpace,
                     GSpacing nLineSpace, GDALRasterIOExtraArg *psExtraArg,
                     GDALDataType eWrkDataType, WorkingState &oWorkingState);
 
    template <class WorkingDT, GDALDataType eWorkDT>
    CPLErr RasterIOProcessNoData(GDALRasterBand *poSourceBand,
                                 GDALDataType eVRTBandDataType, int nReqXOff,
                                 int nReqYOff, int nReqXSize, int nReqYSize,
                                 void *pData, int nOutXSize, int nOutYSize,
                                 GDALDataType eBufType, GSpacing nPixelSpace,
                                 GSpacing nLineSpace,
                                 GDALRasterIOExtraArg *psExtraArg,
                                 WorkingState &oWorkingState);
 
  public:
    VRTComplexSource() = default;
    VRTComplexSource(const VRTComplexSource *poSrcSource, double dfXDstRatio,
                     double dfYDstRatio);
 
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArgIn,
                            WorkingState &oWorkingState) override;
 
    double GetMinimum(int nXSize, int nYSize, int *pbSuccess) override;
    double GetMaximum(int nXSize, int nYSize, int *pbSuccess) override;
    CPLErr GetHistogram(int nXSize, int nYSize, double dfMin, double dfMax,
                        int nBuckets, GUIntBig *panHistogram,
                        int bIncludeOutOfRange, int bApproxOK,
                        GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &) override;

    static const char *GetTypeStatic();
 
    const char *GetType() const override;
 
    bool AreValuesUnchanged() const;
 
    double LookupValue(double dfInput);
 
    void SetNoDataValue(double dfNoDataValue);
 
    void SetUseMaskBand(bool bUseMaskBand)
    {
        if (bUseMaskBand)
            m_nProcessingFlags |= PROCESSING_FLAG_USE_MASK_BAND;
        else
            m_nProcessingFlags &= ~PROCESSING_FLAG_USE_MASK_BAND;
    }
 
    void SetLinearScaling(double dfOffset, double dfScale);
    void SetPowerScaling(double dfExponent, double dfSrcMin, double dfSrcMax,
                         double dfDstMin, double dfDstMax, bool bClip = true);
    void SetColorTableComponent(int nComponent);
 
    void SetLUT(const std::vector<double> &adfLUTInputs,
                const std::vector<double> &adfLUTOutputs);
};
 
/************************************************************************/
/*                          VRTFilteredSource                           */
/************************************************************************/
 
class VRTFilteredSource CPL_NON_FINAL : public VRTComplexSource
{
  private:
    int IsTypeSupported(GDALDataType eTestType) const;
 
    CPL_DISALLOW_COPY_ASSIGN(VRTFilteredSource)
 
  protected:
    int m_nSupportedTypesCount;
    GDALDataType m_aeSupportedTypes[20];
 
    int m_nExtraEdgePixels;
 
  public:
    VRTFilteredSource();
    ~VRTFilteredSource() override;
 
    const char *GetType() const override = 0;
 
    void SetExtraEdgePixels(int);
    void SetFilteringDataTypesSupported(int, GDALDataType *);
 
    virtual CPLErr FilterData(int nXSize, int nYSize, GDALDataType eType,
                              GByte *pabySrcData, GByte *pabyDstData) = 0;
 
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArg,
                            WorkingState &oWorkingState) override;
};
 
/************************************************************************/
/*                       VRTKernelFilteredSource                        */
/************************************************************************/
 
class VRTKernelFilteredSource CPL_NON_FINAL : public VRTFilteredSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTKernelFilteredSource)
 
  protected:
    int m_nKernelSize = 0;
    bool m_bSeparable = false;
    // m_nKernelSize elements if m_bSeparable, m_nKernelSize * m_nKernelSize otherwise
    std::vector<double> m_adfKernelCoefs{};
    bool m_bNormalized = false;
    std::string m_function{};
 
  public:
    VRTKernelFilteredSource();
 
    const char *GetType() const override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *psTree, const char *,
                           VRTMapSharedResources &) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
 
    virtual CPLErr FilterData(int nXSize, int nYSize, GDALDataType eType,
                              GByte *pabySrcData, GByte *pabyDstData) override;
 
    CPLErr SetKernel(int nKernelSize, bool bSeparable,
                     const std::vector<double> &adfNewCoefs);
    void SetNormalized(bool);
 
    void SetFunction(const std::string &s)
    {
        m_function = s;
    }
};
 
/************************************************************************/
/*                       VRTAverageFilteredSource                       */
/************************************************************************/
 
class VRTAverageFilteredSource final : public VRTKernelFilteredSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTAverageFilteredSource)
 
  public:
    explicit VRTAverageFilteredSource(int nKernelSize);
    ~VRTAverageFilteredSource() override;
 
    const char *GetType() const override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *psTree, const char *,
                           VRTMapSharedResources &) override;
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
};
 
/************************************************************************/
/*                            VRTFuncSource                             */
/************************************************************************/
class VRTFuncSource final : public VRTSource
{
    CPL_DISALLOW_COPY_ASSIGN(VRTFuncSource)
 
  public:
    VRTFuncSource();
    ~VRTFuncSource() override;
 
    virtual CPLErr XMLInit(const CPLXMLNode *, const char *,
                           VRTMapSharedResources &) override
    {
        return CE_Failure;
    }
 
    CPLXMLNode *SerializeToXML(const char *pszVRTPath) override;
 
    virtual CPLErr RasterIO(GDALDataType eVRTBandDataType, int nXOff, int nYOff,
                            int nXSize, int nYSize, void *pData, int nBufXSize,
                            int nBufYSize, GDALDataType eBufType,
                            GSpacing nPixelSpace, GSpacing nLineSpace,
                            GDALRasterIOExtraArg *psExtraArg,
                            WorkingState &oWorkingState) override;
 
    double GetMinimum(int nXSize, int nYSize, int *pbSuccess) override;
    double GetMaximum(int nXSize, int nYSize, int *pbSuccess) override;
    CPLErr GetHistogram(int nXSize, int nYSize, double dfMin, double dfMax,
                        int nBuckets, GUIntBig *panHistogram,
                        int bIncludeOutOfRange, int bApproxOK,
                        GDALProgressFunc pfnProgress,
                        void *pProgressData) override;
 
    const char *GetType() const override;
 
    VRTImageReadFunc pfnReadFunc;
    void *pCBData;
    GDALDataType eType;
 
    float fNoDataValue;
};
 
/************************************************************************/
/*                               VRTGroup                               */
/************************************************************************/
 
#ifdef TMPEXPORT
#define TMP_CPL_DLL CPL_DLL
#else
#define TMP_CPL_DLL
#endif
 
class VRTMDArray;
class VRTAttribute;
class VRTDimension;
 
class VRTGroup final : public GDALGroup
{
  public:
    struct Ref
    {
        VRTGroup *m_ptr;
 
        explicit Ref(VRTGroup *ptr) : m_ptr(ptr)
        {
        }
 
        Ref(const Ref &) = delete;
        Ref &operator=(const Ref &) = delete;
    };
 
  private:
    std::shared_ptr<Ref> m_poSharedRefRootGroup{};
    std::weak_ptr<Ref> m_poWeakRefRootGroup{};
    std::shared_ptr<Ref> m_poRefSelf{};
 
    std::string m_osFilename{};
    mutable bool m_bDirty = false;
    std::string m_osVRTPath{};
    std::vector<std::string> m_aosGroupNames{};
    std::map<std::string, std::shared_ptr<VRTGroup>> m_oMapGroups{};
    std::vector<std::string> m_aosMDArrayNames{};
    std::map<std::string, std::shared_ptr<VRTMDArray>> m_oMapMDArrays{};
    std::map<std::string, std::shared_ptr<VRTAttribute>> m_oMapAttributes{};
    std::map<std::string, std::shared_ptr<VRTDimension>> m_oMapDimensions{};
 
    std::shared_ptr<VRTGroup>
    OpenGroupInternal(const std::string &osName) const;
    void SetRootGroupRef(const std::weak_ptr<Ref> &rgRef);
    std::weak_ptr<Ref> GetRootGroupRef() const;
 
  protected:
    friend class VRTMDArray;
    friend std::shared_ptr<GDALMDArray>
    VRTDerivedArrayCreate(const char *pszVRTPath, const CPLXMLNode *psTree);
 
    explicit VRTGroup(const char *pszVRTPath);
    VRTGroup(const std::string &osParentName, const std::string &osName);
 
  public:
    static std::shared_ptr<VRTGroup> Create(const std::string &osParentName,
                                            const std::string &osName)
    {
        auto poGroup =
            std::shared_ptr<VRTGroup>(new VRTGroup(osParentName, osName));
        poGroup->SetSelf(poGroup);
        return poGroup;
    }
 
    ~VRTGroup() override;
 
    bool XMLInit(const std::shared_ptr<VRTGroup> &poRoot,
                 const std::shared_ptr<VRTGroup> &poThisGroup,
                 const CPLXMLNode *psNode, const char *pszVRTPath);
 
    std::vector<std::string>
    GetMDArrayNames(CSLConstList papszOptions) const override;
    std::shared_ptr<GDALMDArray>
    OpenMDArray(const std::string &osName,
                CSLConstList papszOptions = nullptr) const override;
 
    std::vector<std::string>
    GetGroupNames(CSLConstList papszOptions) const override;
 
    std::shared_ptr<GDALGroup> OpenGroup(const std::string &osName,
                                         CSLConstList) const override
    {
        return OpenGroupInternal(osName);
    }
 
    std::vector<std::shared_ptr<GDALDimension>>
        GetDimensions(CSLConstList) const override;
 
    std::vector<std::shared_ptr<GDALAttribute>>
        GetAttributes(CSLConstList) const override;
 
    std::shared_ptr<VRTDimension> GetDimension(const std::string &name) const
    {
        auto oIter = m_oMapDimensions.find(name);
        return oIter == m_oMapDimensions.end() ? nullptr : oIter->second;
    }
 
    std::shared_ptr<VRTDimension>
    GetDimensionFromFullName(const std::string &name, bool bEmitError) const;
 
    std::shared_ptr<GDALGroup>
    CreateGroup(const std::string &osName,
                CSLConstList papszOptions = nullptr) override;
 
    std::shared_ptr<VRTGroup>
    CreateVRTGroup(const std::string &osName,
                   CSLConstList papszOptions = nullptr);
 
    std::shared_ptr<GDALDimension>
    CreateDimension(const std::string &osName, const std::string &osType,
                    const std::string &osDirection, GUInt64 nSize,
                    CSLConstList papszOptions = nullptr) override;
 
    std::shared_ptr<GDALAttribute>
    CreateAttribute(const std::string &osName,
                    const std::vector<GUInt64> &anDimensions,
                    const GDALExtendedDataType &oDataType,
                    CSLConstList papszOptions = nullptr) override;
 
    std::shared_ptr<GDALMDArray> CreateMDArray(
        const std::string &osName,
        const std::vector<std::shared_ptr<GDALDimension>> &aoDimensions,
        const GDALExtendedDataType &oDataType,
        CSLConstList papszOptions = nullptr) override;
 
    std::shared_ptr<VRTMDArray> CreateVRTMDArray(
        const std::string &osName,
        const std::vector<std::shared_ptr<GDALDimension>> &aoDimensions,
        const GDALExtendedDataType &oDataType,
        CSLConstList papszOptions = nullptr);
 
    void SetIsRootGroup();
 
    const std::shared_ptr<Ref> &GetRef() const
    {
        return m_poRefSelf;
    }
 
    VRTGroup *GetRootGroup() const;
    std::shared_ptr<VRTGroup> GetRootGroupSharedPtr() const;
 
    const std::string &GetVRTPath() const
    {
        return m_osVRTPath;
    }
 
    void SetVRTPath(const std::string &osVRTPath)
    {
        m_osVRTPath = osVRTPath;
    }
 
    void SetDirty();
 
    void SetFilename(const std::string &osFilename)
    {
        m_osFilename = osFilename;
    }
 
    const std::string &GetFilename() const
    {
        return m_osFilename;
    }
 
    bool Serialize() const;
    CPLXMLNode *SerializeToXML(const char *pszVRTPathIn) const;
    void Serialize(CPLXMLNode *psParent, const char *pszVRTPathIn) const;
};
 
/************************************************************************/
/*                             VRTDimension                             */
/************************************************************************/
 
class VRTDimension final : public GDALDimension
{
    std::weak_ptr<VRTGroup::Ref> m_poGroupRef;
    std::string m_osIndexingVariableName;
 
  public:
    VRTDimension(const std::shared_ptr<VRTGroup::Ref> &poGroupRef,
                 const std::string &osParentName, const std::string &osName,
                 const std::string &osType, const std::string &osDirection,
                 GUInt64 nSize, const std::string &osIndexingVariableName)
        : GDALDimension(osParentName, osName, osType, osDirection, nSize),
          m_poGroupRef(poGroupRef),
          m_osIndexingVariableName(osIndexingVariableName)
    {
    }
 
    VRTGroup *GetGroup() const;
 
    static std::shared_ptr<VRTDimension>
    Create(const std::shared_ptr<VRTGroup> &poThisGroup,
           const std::string &osParentName, const CPLXMLNode *psNode);
 
    std::shared_ptr<GDALMDArray> GetIndexingVariable() const override;
 
    bool SetIndexingVariable(
        std::shared_ptr<GDALMDArray> poIndexingVariable) override;
 
    void Serialize(CPLXMLNode *psParent) const;
};
 
/************************************************************************/
/*                             VRTAttribute                             */
/************************************************************************/
 
class VRTAttribute final : public GDALAttribute
{
    GDALExtendedDataType m_dt;
    std::vector<std::string> m_aosList{};
    std::vector<std::shared_ptr<GDALDimension>> m_dims{};
 
  protected:
    bool IRead(const GUInt64 *arrayStartIdx, const size_t *count,
               const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
               const GDALExtendedDataType &bufferDataType,
               void *pDstBuffer) const override;
 
    bool IWrite(const GUInt64 *arrayStartIdx, const size_t *count,
                const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
                const GDALExtendedDataType &bufferDataType,
                const void *pSrcBuffer) override;
 
  public:
    VRTAttribute(const std::string &osParentName, const std::string &osName,
                 const GDALExtendedDataType &dt,
                 std::vector<std::string> &&aosList)
        : GDALAbstractMDArray(osParentName, osName),
          GDALAttribute(osParentName, osName), m_dt(dt),
          m_aosList(std::move(aosList))
    {
        if (m_aosList.size() > 1)
        {
            m_dims.emplace_back(std::make_shared<GDALDimension>(
                std::string(), "dim", std::string(), std::string(),
                m_aosList.size()));
        }
    }
 
    VRTAttribute(const std::string &osParentName, const std::string &osName,
                 GUInt64 nDim, const GDALExtendedDataType &dt)
        : GDALAbstractMDArray(osParentName, osName),
          GDALAttribute(osParentName, osName), m_dt(dt)
    {
        if (nDim != 0)
        {
            m_dims.emplace_back(std::make_shared<GDALDimension>(
                std::string(), "dim", std::string(), std::string(), nDim));
        }
    }
 
    static bool CreationCommonChecks(
        const std::string &osName, const std::vector<GUInt64> &anDimensions,
        const std::map<std::string, std::shared_ptr<VRTAttribute>>
            &oMapAttributes);
 
    static std::shared_ptr<VRTAttribute> Create(const std::string &osParentName,
                                                const CPLXMLNode *psNode);
 
    const std::vector<std::shared_ptr<GDALDimension>> &
    GetDimensions() const override
    {
        return m_dims;
    }
 
    const GDALExtendedDataType &GetDataType() const override
    {
        return m_dt;
    }
 
    void Serialize(CPLXMLNode *psParent) const;
};
 
/************************************************************************/
/*                           VRTMDArraySource                           */
/************************************************************************/
 
class VRTMDArraySource
{
  public:
    virtual ~VRTMDArraySource();
 
    enum class RelationShip
    {
        NO_INTERSECTION,
        PARTIAL_INTERSECTION,
        SOURCE_BLOCK_MATCH,
    };
 
    virtual RelationShip GetRelationship(const uint64_t *arrayStartIdx,
                                         const size_t *count) const = 0;
 
    virtual bool GetRawBlockInfo(const uint64_t *arrayStartIdx,
                                 const size_t *count,
                                 GDALMDArrayRawBlockInfo &info) const = 0;
 
    virtual bool Read(const GUInt64 *arrayStartIdx, const size_t *count,
                      const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
                      const GDALExtendedDataType &bufferDataType,
                      void *pDstBuffer) const = 0;
 
    virtual void Serialize(CPLXMLNode *psParent,
                           const char *pszVRTPath) const = 0;
};
 
/************************************************************************/
/*                              VRTMDArray                              */
/************************************************************************/
 
class VRTMDArray final : public GDALMDArray
{
  protected:
    friend class VRTGroup;  // for access to SetSelf()
 
    std::weak_ptr<VRTGroup::Ref> m_poGroupRef;
    std::string m_osVRTPath{};
    std::shared_ptr<VRTGroup> m_poDummyOwningGroup{};
 
    GDALExtendedDataType m_dt;
    std::vector<std::shared_ptr<GDALDimension>> m_dims;
    std::map<std::string, std::shared_ptr<VRTAttribute>> m_oMapAttributes{};
    std::vector<std::unique_ptr<VRTMDArraySource>> m_sources{};
    std::shared_ptr<OGRSpatialReference> m_poSRS{};
    std::vector<GByte> m_abyNoData{};
    std::string m_osUnit{};
    double m_dfScale = 1.0;
    double m_dfOffset = 0.0;
    bool m_bHasScale = false;
    bool m_bHasOffset = false;
    std::string m_osFilename{};
    std::vector<GUInt64> m_anBlockSize{};
    std::vector<std::string> m_aosOverviewFullname{};
    mutable std::vector<std::shared_ptr<GDALMDArray>> m_apoOverviews{};
 
    bool IRead(const GUInt64 *arrayStartIdx, const size_t *count,
               const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
               const GDALExtendedDataType &bufferDataType,
               void *pDstBuffer) const override;
 
    void SetDirty();
 
  public:
    VRTMDArray(
        const std::shared_ptr<VRTGroup::Ref> &poGroupRef,
        const std::string &osParentName, const std::string &osName,
        const GDALExtendedDataType &dt,
        std::vector<std::shared_ptr<GDALDimension>> &&dims,
        std::map<std::string, std::shared_ptr<VRTAttribute>> &&oMapAttributes,
        std::vector<GUInt64> &&anBlockSize)
        : GDALAbstractMDArray(osParentName, osName),
          GDALMDArray(osParentName, osName), m_poGroupRef(poGroupRef),
          m_osVRTPath(poGroupRef->m_ptr->GetVRTPath()), m_dt(dt),
          m_dims(std::move(dims)), m_oMapAttributes(std::move(oMapAttributes)),
          m_osFilename(poGroupRef->m_ptr->GetFilename()),
          m_anBlockSize(std::move(anBlockSize))
    {
    }
 
    VRTMDArray(const std::shared_ptr<VRTGroup::Ref> &poGroupRef,
               const std::string &osParentName, const std::string &osName,
               const std::vector<std::shared_ptr<GDALDimension>> &dims,
               const GDALExtendedDataType &dt,
               const std::vector<GUInt64> &anBlockSize)
        : GDALAbstractMDArray(osParentName, osName),
          GDALMDArray(osParentName, osName), m_poGroupRef(poGroupRef),
          m_osVRTPath(poGroupRef->m_ptr->GetVRTPath()), m_dt(dt), m_dims(dims),
          m_osFilename(poGroupRef->m_ptr->GetFilename()),
          m_anBlockSize(anBlockSize)
    {
    }
 
    bool IsWritable() const override
    {
        return false;
    }
 
    const std::string &GetFilename() const override
    {
        return m_osFilename;
    }
 
    static std::shared_ptr<VRTMDArray> Create(const char *pszVRTPath,
                                              const CPLXMLNode *psNode);
 
    static std::shared_ptr<VRTMDArray>
    Create(const std::shared_ptr<VRTGroup> &poThisGroup,
           const std::string &osParentName, const CPLXMLNode *psNode);
 
    const std::vector<std::shared_ptr<GDALDimension>> &
    GetDimensions() const override
    {
        return m_dims;
    }
 
    std::vector<std::shared_ptr<GDALAttribute>>
        GetAttributes(CSLConstList) const override;
 
    const GDALExtendedDataType &GetDataType() const override
    {
        return m_dt;
    }
 
    bool SetSpatialRef(const OGRSpatialReference *poSRS) override;
 
    std::shared_ptr<OGRSpatialReference> GetSpatialRef() const override
    {
        return m_poSRS;
    }
 
    const void *GetRawNoDataValue() const override;
 
    bool SetRawNoDataValue(const void *pRawNoData) override;
 
    const std::string &GetUnit() const override
    {
        return m_osUnit;
    }
 
    bool SetUnit(const std::string &osUnit) override
    {
        m_osUnit = osUnit;
        return true;
    }
 
    double GetOffset(bool *pbHasOffset,
                     GDALDataType *peStorageType) const override
    {
        if (pbHasOffset)
            *pbHasOffset = m_bHasOffset;
        if (peStorageType)
            *peStorageType = GDT_Unknown;
        return m_dfOffset;
    }
 
    double GetScale(bool *pbHasScale,
                    GDALDataType *peStorageType) const override
    {
        if (pbHasScale)
            *pbHasScale = m_bHasScale;
        if (peStorageType)
            *peStorageType = GDT_Unknown;
        return m_dfScale;
    }
 
    bool SetOffset(double dfOffset,
                   GDALDataType /* eStorageType */ = GDT_Unknown) override
    {
        SetDirty();
        m_bHasOffset = true;
        m_dfOffset = dfOffset;
        return true;
    }
 
    bool SetScale(double dfScale,
                  GDALDataType /* eStorageType */ = GDT_Unknown) override
    {
        SetDirty();
        m_bHasScale = true;
        m_dfScale = dfScale;
        return true;
    }
 
    void AddSource(std::unique_ptr<VRTMDArraySource> &&poSource);
 
    std::shared_ptr<GDALAttribute>
    CreateAttribute(const std::string &osName,
                    const std::vector<GUInt64> &anDimensions,
                    const GDALExtendedDataType &oDataType,
                    CSLConstList papszOptions = nullptr) override;
 
    bool CopyFrom(GDALDataset *poSrcDS, const GDALMDArray *poSrcArray,
                  bool bStrict, GUInt64 &nCurCost, const GUInt64 nTotalCost,
                  GDALProgressFunc pfnProgress, void *pProgressData) override;
 
    void Serialize(CPLXMLNode *psParent, const char *pszVRTPathIn) const;
 
    VRTGroup *GetGroup() const;
 
    const std::string &GetVRTPath() const
    {
        return m_osVRTPath;
    }
 
    std::shared_ptr<VRTGroup> GetRootVRTGroup() const
    {
        auto poGroup = m_poGroupRef.lock();
        if (poGroup)
            return poGroup->m_ptr->GetRootGroupSharedPtr();
        return nullptr;
    }
 
    std::shared_ptr<GDALGroup> GetRootGroup() const override
    {
        return GetRootVRTGroup();
    }
 
    std::vector<GUInt64> GetBlockSize() const override
    {
        return m_anBlockSize;
    }
 
    bool GetRawBlockInfo(const uint64_t *panBlockCoordinates,
                         GDALMDArrayRawBlockInfo &info) const override;
 
    int GetOverviewCount() const override;
 
    std::shared_ptr<GDALMDArray> GetOverview(int idx) const override;
};
 
/************************************************************************/
/*                    VRTMDArraySourceInlinedValues                     */
/************************************************************************/
 
class VRTMDArraySourceInlinedValues final : public VRTMDArraySource
{
    const VRTMDArray *m_poDstArray = nullptr;
    bool m_bIsConstantValue;
    std::vector<GUInt64> m_anOffset{};
    std::vector<size_t> m_anCount{};
    std::vector<GByte> m_abyValues{};
    std::vector<size_t> m_anInlinedArrayStrideInBytes{};
    GDALExtendedDataType m_dt;
 
    VRTMDArraySourceInlinedValues(const VRTMDArraySourceInlinedValues &) =
        delete;
    VRTMDArraySourceInlinedValues &
    operator=(const VRTMDArraySourceInlinedValues &) = delete;
 
  public:
    VRTMDArraySourceInlinedValues(const VRTMDArray *poDstArray,
                                  bool bIsConstantValue,
                                  std::vector<GUInt64> &&anOffset,
                                  std::vector<size_t> &&anCount,
                                  std::vector<GByte> &&abyValues)
        : m_poDstArray(poDstArray), m_bIsConstantValue(bIsConstantValue),
          m_anOffset(std::move(anOffset)), m_anCount(std::move(anCount)),
          m_abyValues(std::move(abyValues)), m_dt(poDstArray->GetDataType())
    {
        const auto nDims(poDstArray->GetDimensionCount());
        m_anInlinedArrayStrideInBytes.resize(nDims);
        if (!bIsConstantValue && nDims > 0)
        {
            m_anInlinedArrayStrideInBytes.back() =
                poDstArray->GetDataType().GetSize();
            for (size_t i = nDims - 1; i > 0;)
            {
                --i;
                m_anInlinedArrayStrideInBytes[i] =
                    m_anInlinedArrayStrideInBytes[i + 1] * m_anCount[i + 1];
            }
        }
    }
 
    ~VRTMDArraySourceInlinedValues() override;
 
    static std::unique_ptr<VRTMDArraySourceInlinedValues>
    Create(const VRTMDArray *poDstArray, const CPLXMLNode *psNode);
 
    RelationShip GetRelationship(const uint64_t * /*arrayStartIdx*/,
                                 const size_t * /*count*/) const override
    {
        return RelationShip::PARTIAL_INTERSECTION;
    }
 
    bool GetRawBlockInfo(const uint64_t * /*arrayStartIdx*/,
                         const size_t * /*count*/,
                         GDALMDArrayRawBlockInfo & /*info*/) const override
    {
        return false;
    }
 
    bool Read(const GUInt64 *arrayStartIdx, const size_t *count,
              const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
              const GDALExtendedDataType &bufferDataType,
              void *pDstBuffer) const override;
 
    void Serialize(CPLXMLNode *psParent, const char *pszVRTPath) const override;
};
 
/************************************************************************/
/*                   VRTMDArraySourceRegularlySpaced                    */
/************************************************************************/
 
class VRTMDArraySourceRegularlySpaced final : public VRTMDArraySource
{
    double m_dfStart;
    double m_dfIncrement;
 
  public:
    VRTMDArraySourceRegularlySpaced(double dfStart, double dfIncrement)
        : m_dfStart(dfStart), m_dfIncrement(dfIncrement)
    {
    }
 
    RelationShip GetRelationship(const uint64_t * /*arrayStartIdx*/,
                                 const size_t * /*count*/) const override
    {
        return RelationShip::PARTIAL_INTERSECTION;
    }
 
    bool GetRawBlockInfo(const uint64_t * /*arrayStartIdx*/,
                         const size_t * /*count*/,
                         GDALMDArrayRawBlockInfo & /*info*/) const override
    {
        return false;
    }
 
    bool Read(const GUInt64 *arrayStartIdx, const size_t *count,
              const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
              const GDALExtendedDataType &bufferDataType,
              void *pDstBuffer) const override;
 
    void Serialize(CPLXMLNode *psParent, const char *pszVRTPath) const override;
};
 
/************************************************************************/
/*                      VRTMDArraySourceFromArray                       */
/************************************************************************/
 
struct VRTArrayDatasetWrapper;
 
class VRTMDArraySourceFromArray final : public VRTMDArraySource
{
    const VRTMDArray *m_poDstArray = nullptr;
    bool m_bRelativeToVRTSet = false;
    bool m_bRelativeToVRT = false;
    std::string m_osFilename{};
    std::string m_osArray{};
    std::string m_osBand{};
    std::vector<int> m_anTransposedAxis{};
    std::string m_osViewExpr{};
    std::vector<GUInt64> m_anSrcOffset{};
    mutable std::vector<GUInt64> m_anCount{};
    std::vector<GUInt64> m_anStep{};
    std::vector<GUInt64> m_anDstOffset{};
 
    std::pair<std::shared_ptr<VRTArrayDatasetWrapper>,
              std::shared_ptr<GDALMDArray>>
    GetSourceArray() const;
 
    VRTMDArraySourceFromArray(const VRTMDArraySourceFromArray &) = delete;
    VRTMDArraySourceFromArray &
    operator=(const VRTMDArraySourceFromArray &) = delete;
 
  public:
    VRTMDArraySourceFromArray(
        const VRTMDArray *poDstArray, bool bRelativeToVRTSet,
        bool bRelativeToVRT, const std::string &osFilename,
        const std::string &osArray, const std::string &osBand,
        std::vector<int> &&anTransposedAxis, const std::string &osViewExpr,
        std::vector<GUInt64> &&anSrcOffset, std::vector<GUInt64> &&anCount,
        std::vector<GUInt64> &&anStep, std::vector<GUInt64> &&anDstOffset)
        : m_poDstArray(poDstArray), m_bRelativeToVRTSet(bRelativeToVRTSet),
          m_bRelativeToVRT(bRelativeToVRT), m_osFilename(osFilename),
          m_osArray(osArray), m_osBand(osBand),
          m_anTransposedAxis(std::move(anTransposedAxis)),
          m_osViewExpr(osViewExpr), m_anSrcOffset(std::move(anSrcOffset)),
          m_anCount(std::move(anCount)), m_anStep(std::move(anStep)),
          m_anDstOffset(std::move(anDstOffset))
    {
    }
 
    ~VRTMDArraySourceFromArray() override;
 
    static std::unique_ptr<VRTMDArraySourceFromArray>
    Create(const VRTMDArray *poDstArray, const CPLXMLNode *psNode);
 
    RelationShip GetRelationship(const uint64_t *arrayStartIdx,
                                 const size_t *count) const override;
 
    bool GetRawBlockInfo(const uint64_t *arrayStartIdx, const size_t *count,
                         GDALMDArrayRawBlockInfo &info) const override;
 
    bool Read(const GUInt64 *arrayStartIdx, const size_t *count,
              const GInt64 *arrayStep, const GPtrDiff_t *bufferStride,
              const GDALExtendedDataType &bufferDataType,
              void *pDstBuffer) const override;
 
    void Serialize(CPLXMLNode *psParent, const char *pszVRTPath) const override;
};
 
#endif /* #ifndef DOXYGEN_SKIP */
 
#endif /* ndef VIRTUALDATASET_H_INCLUDED */