Files
lms/src/libs/utils/impl/UUID.cpp
T
2023-11-01 23:56:13 +01:00

90 lines
2.2 KiB
C++

/*
* Copyright (C) 2020 Emeric Poupon
*
* This file is part of LMS.
*
* LMS is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* LMS 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with LMS. If not, see <http://www.gnu.org/licenses/>.
*/
#include "utils/UUID.hpp"
#include <cassert>
#include <iomanip>
#include <regex>
#include <sstream>
#include "utils/Random.hpp"
#include "utils/String.hpp"
namespace StringUtils
{
template <>
std::optional<UUID>
readAs(std::string_view str)
{
return UUID::fromString(str);
}
}
namespace
{
bool stringIsUUID(std::string_view str)
{
static const std::regex re{ R"([0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12})" };
return std::regex_match(std::cbegin(str), std::cend(str), re);
}
}
UUID::UUID(std::string_view str)
: _value{ StringUtils::stringToLower(str) }
{
}
std::optional<UUID> UUID::fromString(std::string_view str)
{
if (!stringIsUUID(str))
return std::nullopt;
return UUID{ str };
}
UUID UUID::generate()
{
// Form is "123e4567-e89b-12d3-a456-426614174000"
// TODO: store 128 bits and only convert to string when necessary
std::ostringstream oss;
auto concatRandomBytes{ [](std::ostream& os, std::size_t byteCount)
{
for (std::size_t i {}; i < byteCount; ++i)
os << std::hex << std::setfill('0') << std::setw(2) << static_cast<int>(Random::getRandom<std::uint8_t>(0, 255));
} };
concatRandomBytes(oss, 4);
oss << "-";
concatRandomBytes(oss, 2);
oss << "-";
concatRandomBytes(oss, 2);
oss << "-";
concatRandomBytes(oss, 2);
oss << "-";
concatRandomBytes(oss, 6);
const auto uuid{fromString(oss.str())};
assert(uuid);
return uuid.value();
}