mirror of
https://git.wownero.com/wownero/wownero.git
synced 2024-08-15 01:03:23 +00:00
62 lines
2 KiB
C++
62 lines
2 KiB
C++
// Copyright (c) 2012-2013 The Cryptonote developers
|
|
// Distributed under the MIT/X11 software license, see the accompanying
|
|
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
|
|
|
|
#pragma once
|
|
|
|
#include <limits>
|
|
#include <type_traits>
|
|
#include <utility>
|
|
#include <sstream>
|
|
#include <string>
|
|
|
|
namespace tools {
|
|
|
|
template<typename OutputIt, typename T>
|
|
typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value, void>::type
|
|
write_varint(OutputIt &&dest, T i) {
|
|
while (i >= 0x80) {
|
|
*dest++ = (static_cast<char>(i) & 0x7f) | 0x80;
|
|
i >>= 7;
|
|
}
|
|
*dest++ = static_cast<char>(i);
|
|
}
|
|
|
|
template<typename t_type>
|
|
std::string get_varint_data(const t_type& v)
|
|
{
|
|
std::stringstream ss;
|
|
write_varint(std::ostreambuf_iterator<char>(ss), v);
|
|
return ss.str();
|
|
}
|
|
|
|
template<int bits, typename InputIt, typename T>
|
|
typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value && 0 <= bits && bits <= std::numeric_limits<T>::digits, int>::type
|
|
read_varint(InputIt &&first, InputIt &&last, T &i) {
|
|
int read = 0;
|
|
i = 0;
|
|
for (int shift = 0;; shift += 7) {
|
|
if (first == last) {
|
|
return read; // End of input.
|
|
}
|
|
unsigned char byte = *first++;
|
|
++read;
|
|
if (shift + 7 >= bits && byte >= 1 << (bits - shift)) {
|
|
return -1; // Overflow.
|
|
}
|
|
if (byte == 0 && shift != 0) {
|
|
return -2; // Non-canonical representation.
|
|
}
|
|
i |= static_cast<T>(byte & 0x7f) << shift;
|
|
if ((byte & 0x80) == 0) {
|
|
break;
|
|
}
|
|
}
|
|
return read;
|
|
}
|
|
|
|
template<typename InputIt, typename T>
|
|
int read_varint(InputIt &&first, InputIt &&last, T &i) {
|
|
return read_varint<std::numeric_limits<T>::digits, InputIt, T>(std::move(first), std::move(last), i);
|
|
}
|
|
}
|