MemoryMap.h

#pragma once
 
#include <cpl_virtualmem.h>
#include <gdal_priv.h>
#include <memory>
 
#include "../forward.h"
 
namespace isce3 { namespace io { namespace gdal { namespace detail {
 
class MemoryMap {
public:
 
    MemoryMap() : _mmap(nullptr, [](CPLVirtualMem *) {}) {}
 
    explicit operator bool() const { return _mmap.get(); }
 
    // Get pointer to start of virtual memory mapping
    void * data() { return CPLVirtualMemGetAddr(_mmap.get()); }
 
    // Get pointer to start of virtual memory mapping
    const void * data() const { return CPLVirtualMemGetAddr(_mmap.get()); }
 
    // Size in bytes of mapped region
    std::size_t size() const { return CPLVirtualMemGetSize(_mmap.get()); }
 
    // Access mode
    CPLVirtualMemAccessMode access() const { return CPLVirtualMemGetAccessMode(_mmap.get()); }
 
    // Stride in bytes between the start of adjacent columns
    std::size_t colstride() const { return _colstride; }
 
    // Stride in bytes between the start of adjacent rows
    std::size_t rowstride() const { return _rowstride; }
 
    friend class isce3::io::gdal::Raster;
 
private:
 
    MemoryMap(const GDALRasterBand * raster);
 
    MemoryMap(GDALRasterBand * raster, GDALAccess access);
 
    std::shared_ptr<CPLVirtualMem> _mmap;
    std::size_t _colstride = 0;
    std::size_t _rowstride = 0;
};
 
}}}}