Files
mfem/general/binaryio.cpp
T
2020-03-09 15:36:41 -07:00

56 lines
1.5 KiB
C++

// Copyright (c) 2010-2020, Lawrence Livermore National Security, LLC. Produced
// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
// LICENSE and NOTICE for details. LLNL-CODE-806117.
//
// This file is part of the MFEM library. For more information and source code
// availability visit https://mfem.org.
//
// MFEM is free software; you can redistribute it and/or modify it under the
// terms of the BSD-3 license. We welcome feedback and contributions, see file
// CONTRIBUTING.md for details.
#include "binaryio.hpp"
#include "error.hpp"
namespace mfem
{
namespace bin_io
{
static const char *b64str
= "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
void WriteBase64(std::ostream &out, const void *bytes, size_t nbytes)
{
const unsigned char *in = static_cast<const unsigned char *>(bytes);
const unsigned char *end = in + nbytes;
while (end - in >= 3)
{
out << b64str[in[0] >> 2];
out << b64str[((in[0] & 0x03) << 4) | (in[1] >> 4)];
out << b64str[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
out << b64str[in[2] & 0x3f];
in += 3;
}
if (end - in > 0) // Padding
{
out << b64str[in[0] >> 2];
if (end - in == 1)
{
out << b64str[(in[0] & 0x03) << 4];
out << '=';
}
else // end - in == 2
{
out << b64str[((in[0] & 0x03) << 4) | (in[1] >> 4)];
out << b64str[(in[1] & 0x0f) << 2];
}
out << '=';
}
}
} // namespace mfem::bin_io
} // namespace mfem