exiv2/samples/mmap-test.cpp

// SPDX-License-Identifier: GPL-2.0-or-later
// Simple mmap tests

#include <exiv2/exiv2.hpp>

#include <iostream>

using namespace Exiv2;

int main(int argc, char* const argv[]) try {
  Exiv2::XmpParser::initialize();
  ::atexit(Exiv2::XmpParser::terminate);
#ifdef EXV_ENABLE_BMFF
  Exiv2::enableBMFF();
#endif

  if (argc != 2) {
    std::cout << "Usage: " << argv[0] << " file\n";
    return 1;
  }
  const char* path = argv[1];

  FileIo file(path);
  // Open the file in read mode
  if (file.open("rb") != 0) {
    throw Error(ErrorCode::kerFileOpenFailed, path, "rb", strError());
  }
  // Map it to memory
  const Exiv2::byte* pData = file.mmap();
  DataBuf buf(file.size());
  // Read from the memory mapped region
  buf.copyBytes(0, pData, buf.size());
  // Reopen file in write mode and write to it
  file.write(buf.c_data(), buf.size());
  // Read from the mapped region again
  buf.copyBytes(0, pData, buf.size());
  file.close();

  return 0;
} catch (const Error& e) {
  std::cout << e << "\n";
}