binary.h

// Copyright 2012-2023:
//   GobySoft, LLC (2013-)
//   Massachusetts Institute of Technology (2007-2014)
//   Community contributors (see AUTHORS file)
// File authors:
//   Toby Schneider <toby@gobysoft.org>
//   Nathan Knotts <nknotts@gmail.com>
//
//
// This file is part of the Dynamic Compact Control Language Library
// ("DCCL").
//
// DCCL is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// DCCL is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DCCL.  If not, see <http://www.gnu.org/licenses/>.
#ifndef DCCLBINARY20100713H
#define DCCLBINARY20100713H
 
#include <cmath>
#include <iomanip>
#include <sstream>
 
#include "common.h"
#include "dccl/def.h"
 
#if DCCL_HAS_B64
#include <cstdio>
#define BUFFERSIZE BUFSIZ
#include "b64/decode.h"
#include "b64/encode.h"
#endif
 
namespace dccl
{
 
 
inline void hex_decode(const std::string& in, std::string* out)
{
    static constexpr short char0_9_to_number = 48;
    static constexpr short charA_F_to_number = 55;
    static constexpr short chara_f_to_number = 87;
 
    int in_size = in.size();
    int out_size = in_size >> 1;
    if (in_size & 1)
        ++out_size;
 
    out->assign(out_size, '\0');
    for (int i = (in_size & 1) ? -1 : 0, n = in_size; i < n; i += 2)
    {
        int out_i = (in_size & 1) ? (i + 1) / 2 : i / 2;
 
        if (i >= 0)
        {
            if (in[i] >= '0' && in[i] <= '9')
                (*out)[out_i] |= ((in[i] - char0_9_to_number) & 0x0f) << 4;
            else if (in[i] >= 'A' && in[i] <= 'F')
                (*out)[out_i] |= ((in[i] - charA_F_to_number) & 0x0f) << 4;
            else if (in[i] >= 'a' && in[i] <= 'f')
                (*out)[out_i] |= ((in[i] - chara_f_to_number) & 0x0f) << 4;
        }
 
        if (in[i + 1] >= '0' && in[i + 1] <= '9')
            (*out)[out_i] |= (in[i + 1] - char0_9_to_number) & 0x0f;
        else if (in[i + 1] >= 'A' && in[i + 1] <= 'F')
            (*out)[out_i] |= (in[i + 1] - charA_F_to_number) & 0x0f;
        else if (in[i + 1] >= 'a' && in[i + 1] <= 'f')
            (*out)[out_i] |= (in[i + 1] - chara_f_to_number) & 0x0f;
    }
}
 
inline std::string hex_decode(const std::string& in)
{
    std::string out;
    hex_decode(in, &out);
    return out;
}
 
template <typename CharIterator>
inline void hex_encode(CharIterator begin, CharIterator end, std::string* out,
                       bool upper_case = false)
{
    static constexpr short char0_9_to_number = 48;
    static constexpr short charA_F_to_number = 55;
    static constexpr short chara_f_to_number = 87;
 
    size_t in_size = std::distance(begin, end);
    size_t out_size = in_size << 1;
 
    out->clear();
    out->resize(out_size);
 
    size_t i = 0;
    for (CharIterator it = begin; it != end; ++it)
    {
        short msn = (*it >> 4) & 0x0f;
        short lsn = *it & 0x0f;
 
        if (msn >= 0 && msn <= 9)
            (*out)[2 * i] = msn + char0_9_to_number;
        else if (msn >= 10 && msn <= 15)
            (*out)[2 * i] = msn + (upper_case ? charA_F_to_number : chara_f_to_number);
 
        if (lsn >= 0 && lsn <= 9)
            (*out)[2 * i + 1] = lsn + char0_9_to_number;
        else if (lsn >= 10 && lsn <= 15)
            (*out)[2 * i + 1] = lsn + (upper_case ? charA_F_to_number : chara_f_to_number);
 
        i++;
    }
}
 
template <typename CharIterator> inline std::string hex_encode(CharIterator begin, CharIterator end)
{
    std::string out;
    hex_encode(begin, end, &out);
    return out;
}
 
inline void hex_encode(const std::string& in, std::string* out, bool upper_case = false)
{
    hex_encode(in.begin(), in.end(), out, upper_case);
}
 
inline std::string hex_encode(const std::string& in)
{
    std::string out;
    hex_encode(in, &out);
    return out;
}
 
#if DCCL_HAS_B64
inline std::string b64_encode(const std::string& in)
{
    std::stringstream instream(in);
    std::stringstream outstream;
    base64::encoder D;
    D.encode(instream, outstream);
    return outstream.str();
}
 
inline std::string b64_decode(const std::string& in)
{
    std::stringstream instream(in);
    std::stringstream outstream;
    base64::decoder D;
    D.decode(instream, outstream);
    return outstream.str();
}
#endif
 
inline unsigned ceil_log2(dccl::uint64 v)
{
    // r will be one greater (ceil) if v is not a power of 2
    unsigned r = ((v & (v - 1)) == 0) ? 0 : 1;
    while (v >>= 1) r++;
    return r;
}
 
inline unsigned long ceil_log2(double d)
{
    return ceil_log2(static_cast<dccl::uint64>(std::ceil(d)));
}
 
inline unsigned long ceil_log2(int i) { return ceil_log2(static_cast<dccl::uint64>(i)); }
 
inline unsigned long ceil_log2(long i) { return ceil_log2(static_cast<dccl::uint64>(i)); }
 
inline unsigned long ceil_log2(unsigned i) { return ceil_log2(static_cast<dccl::uint64>(i)); }
 
inline double log2(double d) { return std::log2(d); }
 
} // namespace dccl
 
#endif