libtiff fork test

libtiff-fork-test.cpp

#include <tiffio.h>
#include <unistd.h>

#include <iostream>
#include <memory>

int main()
{
    const char * dem = "/home/tlj/sandbox/world_robin_611m_ocean_hss20.tif";

    TIFF *tiff = TIFFOpen(dem, "rcm");
    unsigned width, height;
    TIFFGetField(tiff, TIFFTAG_IMAGEWIDTH, &width);
    TIFFGetField(tiff, TIFFTAG_IMAGELENGTH, &height);
    std::clog << "width: " << width << std::endl;
    std::clog << "height: " << height << std::endl;

    tsize_t tile_size = TIFFTileSize(tiff);
    std::clog << "tile size: " << tile_size << std::endl;
    std::unique_ptr<char[]> tile_buffer(new char[tile_size]);

    fork();

    unsigned div = 10000;

    for (unsigned i = 0; i < div; i += 100)
    {
        for (unsigned j = 0; j < div; j += 100)
        {
            unsigned x = (width / div) * j;
            unsigned y = (height / div) * i;

            ttile_t tile = TIFFComputeTile(tiff, x, y, 0, 0);
            if (TIFFReadEncodedTile(tiff,tile , tile_buffer.get(), tile_size) == -1)
            {
                std::clog << "TIFFReadEncodedTile error!" << std::endl;
            }
        }
    }
}