suyu/src/common/uuid.cpp
Morph 99ceb03a1c general: Convert source file copyright comments over to SPDX
This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
2022-04-23 05:55:32 -04:00

212 lines
5.7 KiB
C++

// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include <bit>
#include <optional>
#include <random>
#include <fmt/format.h>
#include "common/assert.h"
#include "common/tiny_mt.h"
#include "common/uuid.h"
namespace Common {
namespace {
constexpr size_t RawStringSize = sizeof(UUID) * 2;
constexpr size_t FormattedStringSize = RawStringSize + 4;
std::optional<u8> HexCharToByte(char c) {
if (c >= '0' && c <= '9') {
return static_cast<u8>(c - '0');
}
if (c >= 'a' && c <= 'f') {
return static_cast<u8>(c - 'a' + 10);
}
if (c >= 'A' && c <= 'F') {
return static_cast<u8>(c - 'A' + 10);
}
ASSERT_MSG(false, "{} is not a hexadecimal digit!", c);
return std::nullopt;
}
std::array<u8, 0x10> ConstructFromRawString(std::string_view raw_string) {
std::array<u8, 0x10> uuid;
for (size_t i = 0; i < RawStringSize; i += 2) {
const auto upper = HexCharToByte(raw_string[i]);
const auto lower = HexCharToByte(raw_string[i + 1]);
if (!upper || !lower) {
return {};
}
uuid[i / 2] = static_cast<u8>((*upper << 4) | *lower);
}
return uuid;
}
std::array<u8, 0x10> ConstructFromFormattedString(std::string_view formatted_string) {
std::array<u8, 0x10> uuid;
size_t i = 0;
// Process the first 8 characters.
const auto* str = formatted_string.data();
for (; i < 4; ++i) {
const auto upper = HexCharToByte(*(str++));
const auto lower = HexCharToByte(*(str++));
if (!upper || !lower) {
return {};
}
uuid[i] = static_cast<u8>((*upper << 4) | *lower);
}
// Process the next 4 characters.
++str;
for (; i < 6; ++i) {
const auto upper = HexCharToByte(*(str++));
const auto lower = HexCharToByte(*(str++));
if (!upper || !lower) {
return {};
}
uuid[i] = static_cast<u8>((*upper << 4) | *lower);
}
// Process the next 4 characters.
++str;
for (; i < 8; ++i) {
const auto upper = HexCharToByte(*(str++));
const auto lower = HexCharToByte(*(str++));
if (!upper || !lower) {
return {};
}
uuid[i] = static_cast<u8>((*upper << 4) | *lower);
}
// Process the next 4 characters.
++str;
for (; i < 10; ++i) {
const auto upper = HexCharToByte(*(str++));
const auto lower = HexCharToByte(*(str++));
if (!upper || !lower) {
return {};
}
uuid[i] = static_cast<u8>((*upper << 4) | *lower);
}
// Process the last 12 characters.
++str;
for (; i < 16; ++i) {
const auto upper = HexCharToByte(*(str++));
const auto lower = HexCharToByte(*(str++));
if (!upper || !lower) {
return {};
}
uuid[i] = static_cast<u8>((*upper << 4) | *lower);
}
return uuid;
}
std::array<u8, 0x10> ConstructUUID(std::string_view uuid_string) {
const auto length = uuid_string.length();
if (length == 0) {
return {};
}
// Check if the input string contains 32 hexadecimal characters.
if (length == RawStringSize) {
return ConstructFromRawString(uuid_string);
}
// Check if the input string has the length of a RFC 4122 formatted UUID string.
if (length == FormattedStringSize) {
return ConstructFromFormattedString(uuid_string);
}
ASSERT_MSG(false, "UUID string has an invalid length of {} characters!", length);
return {};
}
} // Anonymous namespace
UUID::UUID(std::string_view uuid_string) : uuid{ConstructUUID(uuid_string)} {}
std::string UUID::RawString() const {
return fmt::format("{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}"
"{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}",
uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5], uuid[6], uuid[7],
uuid[8], uuid[9], uuid[10], uuid[11], uuid[12], uuid[13], uuid[14],
uuid[15]);
}
std::string UUID::FormattedString() const {
return fmt::format("{:02x}{:02x}{:02x}{:02x}"
"-{:02x}{:02x}-{:02x}{:02x}-{:02x}{:02x}-"
"{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}",
uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5], uuid[6], uuid[7],
uuid[8], uuid[9], uuid[10], uuid[11], uuid[12], uuid[13], uuid[14],
uuid[15]);
}
size_t UUID::Hash() const noexcept {
u64 upper_hash;
u64 lower_hash;
std::memcpy(&upper_hash, uuid.data(), sizeof(u64));
std::memcpy(&lower_hash, uuid.data() + sizeof(u64), sizeof(u64));
return upper_hash ^ std::rotl(lower_hash, 1);
}
u128 UUID::AsU128() const {
u128 uuid_old;
std::memcpy(&uuid_old, uuid.data(), sizeof(UUID));
return uuid_old;
}
UUID UUID::MakeRandom() {
std::random_device device;
return MakeRandomWithSeed(device());
}
UUID UUID::MakeRandomWithSeed(u32 seed) {
// Create and initialize our RNG.
TinyMT rng;
rng.Initialize(seed);
UUID uuid;
// Populate the UUID with random bytes.
rng.GenerateRandomBytes(uuid.uuid.data(), sizeof(UUID));
return uuid;
}
UUID UUID::MakeRandomRFC4122V4() {
auto uuid = MakeRandom();
// According to Proposed Standard RFC 4122 Section 4.4, we must:
// 1. Set the two most significant bits (bits 6 and 7) of the
// clock_seq_hi_and_reserved to zero and one, respectively.
uuid.uuid[8] = 0x80 | (uuid.uuid[8] & 0x3F);
// 2. Set the four most significant bits (bits 12 through 15) of the
// time_hi_and_version field to the 4-bit version number from Section 4.1.3.
uuid.uuid[6] = 0x40 | (uuid.uuid[6] & 0xF);
return uuid;
}
} // namespace Common