CompressData.cpp

Go to the documentation of this file.

////////////////////////////////////////////////////////////////////////////////
//
//  File: CompressData.cpp
//
//  For more information, please see: http://www.nektar.info/
//
//  The MIT License
//
//  Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
//  Department of Aeronautics, Imperial College London (UK), and Scientific
//  Computing and Imaging Institute, University of Utah (USA).
//
//  Permission is hereby granted, free of charge, to any person obtaining a
//  copy of this software and associated documentation files (the "Software"),
//  to deal in the Software without restriction, including without limitation
//  the rights to use, copy, modify, merge, publish, distribute, sublicense,
//  and/or sell copies of the Software, and to permit persons to whom the
//  Software is furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included
//  in all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
//  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//  DEALINGS IN THE SOFTWARE.
//
//  Description: Routines for compressing and inflating data
//
////////////////////////////////////////////////////////////////////////////////
#define NOMINMAX
 
#include <LibUtilities/BasicConst/GitRevision.h>
#include <LibUtilities/BasicUtils/CompressData.h>
 
#include <boost/archive/iterators/base64_from_binary.hpp>
#include <boost/archive/iterators/binary_from_base64.hpp>
#include <boost/archive/iterators/transform_width.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filter/zlib.hpp>
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/lexical_cast.hpp>
 
#include <cstdint>
#include <set>
 
#ifdef NEKTAR_USE_MPI
#include <mpi.h>
#endif
 
#ifndef NEKTAR_VERSION
#define NEKTAR_VERSION "Unknown"
#endif
 
namespace Nektar::LibUtilities
{
 
/**
 * run time determination of endianness, returning an EndianType
 */
EndianType Endianness(void)
{
    union
    {
        std::uint32_t value;
        std::uint8_t data[sizeof(std::uint32_t)];
    } number;
 
    number.data[0] = 0x00;
    number.data[1] = 0x01;
    number.data[2] = 0x02;
    number.data[3] = 0x03;
 
    switch (number.value)
    {
        case UINT32_C(0x00010203):
            return eEndianBig;
        case UINT32_C(0x03020100):
            return eEndianLittle;
        case UINT32_C(0x02030001):
            return eEndianBigWord;
        case UINT32_C(0x01000302):
            return eEndianLittleWord;
        default:
            return eEndianUnknown;
    }
}
 
namespace CompressData
{
 
/**
 * Return a string describing this compression and endianness
 */
std::string GetCompressString(void)
{
    return "B64Z-" + EndianTypeMap[Endianness()];
}
 
std::string GetBitSizeStr(void)
{
    return std::to_string(sizeof(void *) * 8);
}
 
/**
 * Convert a binary string to Base 64 string
 */
void BinaryStrToBase64Str(std::string &compressedDataString,
                          std::string &base64string)
{
    // If the string length is not divisible by 3,
    // pad it. There is a bug in transform_width
    // that will make it reference past the end
    // and crash.
    switch (compressedDataString.length() % 3)
    {
        case 1:
            compressedDataString += '\0';
            /* Falls through. */
        case 2:
            compressedDataString += '\0';
            break;
    }
 
    // Convert from binary to base64.
    typedef boost::archive::iterators::base64_from_binary<
        boost::archive::iterators::transform_width<std::string::const_iterator,
                                                   6, 8>>
        base64_t;
    base64string = std::string(base64_t(compressedDataString.begin()),
                               base64_t(compressedDataString.end()));
}
 
/**
 * Convert a Base 64 string into a binary string
 */
void Base64StrToBinaryStr(std::string &base64string,
                          std::string &compressedDataString)
{
    // Convert from base64 to binary.
    typedef boost::archive::iterators::transform_width<
        boost::archive::iterators::binary_from_base64<
            std::string::const_iterator>,
        8, 6>
        binary_t;
    compressedDataString = std::string(binary_t(base64string.begin()),
                                       binary_t(base64string.end()));
}
} // namespace CompressData
} // namespace Nektar::LibUtilities