crc.cc

//  Boost CRC example program file  ------------------------------------------//

//  Copyright 2003 Daryle Walker.  Use, modification, and distribution are
//  subject to the Boost Software License, Version 1.0.  (See accompanying file
//  LICENSE_1_0.txt or a copy at <http://www.boost.org/LICENSE_1_0.txt>.)

//  See <http://www.boost.org/libs/crc/> for the library's home page.

//  Revision History
//  17 Jun 2003  Initial version (Daryle Walker)

#include <boost/crc.hpp>  // for boost::crc_32_type

#include <cstdlib>    // for EXIT_SUCCESS, EXIT_FAILURE
#include <exception>  // for std::exception
#include <fstream>    // for std::ifstream
#include <ios>        // for std::ios_base, etc.
#include <iostream>   // for std::cerr, std::cout
#include <ostream>    // for std::endl

// Redefine this to change to processing buffer size
std::streamsize const buffer_size = 1024;

// constexpr boost::crc_32_type::value_type convert_polynomial() {
//   return boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
//          boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
//          boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
//          boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal;
// }
// constexpr boost::crc_32_type::value_type poly = noexcept(convert_polynomial());
// Main program
int main(int argc, char const *argv[]) {
  try {
    boost::crc_32_type reference;

    boost::crc_optimal<32,
                       boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
                           boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
                           boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal *
                           boost::crc_32_type::truncated_polynominal * boost::crc_32_type::truncated_polynominal,
                       0xFFFFFFFF, 0xFFFFFFFF, true, true>
        padded_crc;
    for (int i = 1; i < argc; ++i) {
      std::ifstream ifs(argv[i], std::ios_base::binary);

      if (ifs) {
        do {
          char buffer[buffer_size];
          char buffer_unpacked[buffer_size * 8];
          ifs.read(buffer, buffer_size);
          size_t count = ifs.gcount();
          for (size_t byte_in = 0; byte_in < buffer_size; ++byte_in) {
            for (size_t bit = 0; bit < 8; ++bit) buffer_unpacked[byte_in * 8 + bit] = buffer[byte_in] & (1 << bit);
          }

          reference.process_bytes(buffer, count);
          padded_crc.process_bytes(buffer_unpacked, count * 8);
        } while (ifs);
      } else {
        std::cerr << "Failed to open file '" << argv[i] << "'." << std::endl;
      }
    }

    std::cout << "ref: " << std::hex << std::uppercase << reference.checksum() << std::endl;
    std::cout << "padded_crc: " << std::hex << std::uppercase << reference.checksum() << std::endl;
    return EXIT_SUCCESS;
  } catch (std::exception &e) {
    std::cerr << "Found an exception with '" << e.what() << "'." << std::endl;
    return EXIT_FAILURE;
  } catch (...) {
    std::cerr << "Found an unknown exception." << std::endl;
    return EXIT_FAILURE;
  }
}