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Diffstat (limited to 'nihil.uuid/uuid.ccm')
| -rw-r--r-- | nihil.uuid/uuid.ccm | 842 |
1 files changed, 842 insertions, 0 deletions
diff --git a/nihil.uuid/uuid.ccm b/nihil.uuid/uuid.ccm new file mode 100644 index 0000000..4aa424e --- /dev/null +++ b/nihil.uuid/uuid.ccm @@ -0,0 +1,842 @@ +/* + * From https://github.com/mariusbancila/stduuid + * + * Copyright (c) 2017 + * + * 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. + */ + +module; + +#include <algorithm> +#include <array> +#include <atomic> +#include <chrono> +#include <cstring> +#include <functional> +#include <iomanip> +#include <iterator> +#include <memory> +#include <numeric> +#include <optional> +#include <random> +#include <ranges> +#include <span> +#include <string> +#include <sstream> +#include <string_view> +#include <type_traits> + +export module nihil.uuid; + +namespace nihil { + +template <typename TChar> +[[nodiscard]] constexpr auto hex2char(TChar const ch) noexcept -> unsigned char +{ + if (ch >= static_cast<TChar>('0') && ch <= static_cast<TChar>('9')) + return static_cast<unsigned char>( + ch - static_cast<TChar>('0')); + + if (ch >= static_cast<TChar>('a') && ch <= static_cast<TChar>('f')) + return static_cast<unsigned char>( + 10 + ch - static_cast<TChar>('a')); + + if (ch >= static_cast<TChar>('A') && ch <= static_cast<TChar>('F')) + return static_cast<unsigned char>( + 10 + ch - static_cast<TChar>('A')); + + return 0; +} + +template <typename TChar> +[[nodiscard]] constexpr auto is_hex(TChar const ch) noexcept -> bool +{ + return (ch >= static_cast<TChar>('0') && + ch <= static_cast<TChar>('9')) || + (ch >= static_cast<TChar>('a') && + ch <= static_cast<TChar>('f')) || + (ch >= static_cast<TChar>('A') && + ch <= static_cast<TChar>('F')); +} + +template <typename TChar> +[[nodiscard]] constexpr auto to_string_view(TChar const *str) noexcept + -> std::basic_string_view<TChar> +{ + if (str) + return str; + return {}; +} + +template <typename StringType> +[[nodiscard]] constexpr auto to_string_view(StringType const &str) noexcept + -> std::basic_string_view< + typename StringType::value_type, + typename StringType::traits_type> +{ + return str; +} + +struct sha1 +{ + using digest32_t = std::array<std::uint32_t, 5>; + using digest8_t = std::array<std::uint8_t, 20>; + + static constexpr unsigned int block_bytes = 64; + + sha1() + { + reset(); + } + + [[nodiscard]] inline static auto + left_rotate(std::uint32_t value, std::size_t const count) noexcept + -> std::uint32_t + { + return (value << count) ^ (value >> (32 - count)); + } + + auto reset(this sha1 &self) noexcept -> void + { + self.m_digest[0] = 0x67452301; + self.m_digest[1] = 0xEFCDAB89; + self.m_digest[2] = 0x98BADCFE; + self.m_digest[3] = 0x10325476; + self.m_digest[4] = 0xC3D2E1F0; + self.m_blockByteIndex = 0; + self.m_byteCount = 0; + } + + auto process_byte(this sha1 &self, std::uint8_t octet) -> void + { + self.m_block[self.m_blockByteIndex++] = octet; + ++self.m_byteCount; + + if (self.m_blockByteIndex == block_bytes) { + self.m_blockByteIndex = 0; + self.process_block(); + } + } + + auto process_block(this sha1 &self, + void const *const start, + void const *const end) + -> void + { + auto *first = static_cast<uint8_t const *>(start); + auto *last = static_cast<uint8_t const *>(end); + + while (first != last) { + self.process_byte(*first); + first++; + } + } + + auto process_bytes(this sha1 &self, + void const *const data, + size_t const len) + -> void + { + auto *block = static_cast<uint8_t const *>(data); + self.process_block(block, block + len); + } + + auto get_digest(this sha1 &self) -> digest32_t + { + auto const bit_count = self.m_byteCount * 8; + + self.process_byte(0x80); + if (self.m_blockByteIndex > 56) { + while (self.m_blockByteIndex != 0) + self.process_byte(0); + + while (self.m_blockByteIndex < 56) + self.process_byte(0); + } else { + while (self.m_blockByteIndex < 56) + self.process_byte(0); + } + + self.process_byte(0); + self.process_byte(0); + self.process_byte(0); + self.process_byte(0); + self.process_byte(static_cast<unsigned char>( + (bit_count >> 24) & 0xFF)); + self.process_byte(static_cast<unsigned char>( + (bit_count >> 16) & 0xFF)); + self.process_byte(static_cast<unsigned char>( + (bit_count >> 8) & 0xFF)); + self.process_byte(static_cast<unsigned char>( + (bit_count) & 0xFF)); + + return self.m_digest; + } + + auto get_digest_bytes(this sha1 &self) -> digest8_t + { + auto d32 = self.get_digest(); + auto digest = digest8_t{}; + + auto di = std::size_t{0}; + + digest[di++] = static_cast<uint8_t>(d32[0] >> 24); + digest[di++] = static_cast<uint8_t>(d32[0] >> 16); + digest[di++] = static_cast<uint8_t>(d32[0] >> 8); + digest[di++] = static_cast<uint8_t>(d32[0] >> 0); + + digest[di++] = static_cast<uint8_t>(d32[1] >> 24); + digest[di++] = static_cast<uint8_t>(d32[1] >> 16); + digest[di++] = static_cast<uint8_t>(d32[1] >> 8); + digest[di++] = static_cast<uint8_t>(d32[1] >> 0); + + digest[di++] = static_cast<uint8_t>(d32[2] >> 24); + digest[di++] = static_cast<uint8_t>(d32[2] >> 16); + digest[di++] = static_cast<uint8_t>(d32[2] >> 8); + digest[di++] = static_cast<uint8_t>(d32[2] >> 0); + + digest[di++] = static_cast<uint8_t>(d32[3] >> 24); + digest[di++] = static_cast<uint8_t>(d32[3] >> 16); + digest[di++] = static_cast<uint8_t>(d32[3] >> 8); + digest[di++] = static_cast<uint8_t>(d32[3] >> 0); + + digest[di++] = static_cast<uint8_t>(d32[4] >> 24); + digest[di++] = static_cast<uint8_t>(d32[4] >> 16); + digest[di++] = static_cast<uint8_t>(d32[4] >> 8); + digest[di++] = static_cast<uint8_t>(d32[4] >> 0); + + return digest; + } + +private: + auto process_block(this sha1 &self) -> void + { + auto w = std::array<std::uint32_t, 80>(); + + for (std::size_t i = 0; i < 16; i++) { + w[i] = static_cast<std::uint32_t>( + self.m_block[i * 4 + 0]) << 24; + w[i] |= static_cast<std::uint32_t>( + self.m_block[i * 4 + 1]) << 16; + w[i] |= static_cast<std::uint32_t>( + self.m_block[i * 4 + 2]) << 8; + w[i] |= static_cast<std::uint32_t>( + self.m_block[i * 4 + 3]); + } + + for (std::size_t i = 16; i < 80; i++) { + w[i] = left_rotate((w[i - 3] ^ w[i - 8] ^ + w[i - 14] ^ w[i - 16]), 1); + } + + auto a = self.m_digest[0]; + auto b = self.m_digest[1]; + auto c = self.m_digest[2]; + auto d = self.m_digest[3]; + auto e = self.m_digest[4]; + + for (std::size_t i = 0; i < 80; ++i) { + auto f = std::uint32_t{0}; + auto k = std::uint32_t{0}; + + if (i < 20) { + f = (b & c) | (~b & d); + k = 0x5A827999; + } else if (i < 40) { + f = b ^ c ^ d; + k = 0x6ED9EBA1; + } else if (i < 60) { + f = (b & c) | (b & d) | (c & d); + k = 0x8F1BBCDC; + } else { + f = b ^ c ^ d; + k = 0xCA62C1D6; + } + + auto temp = std::uint32_t{left_rotate(a, 5) + + f + e + k + w[i]}; + e = d; + d = c; + c = left_rotate(b, 30); + b = a; + a = temp; + } + + self.m_digest[0] += a; + self.m_digest[1] += b; + self.m_digest[2] += c; + self.m_digest[3] += d; + self.m_digest[4] += e; + } + + digest32_t m_digest; + std::array<std::uint8_t, 64> m_block; + std::size_t m_blockByteIndex; + std::size_t m_byteCount; +}; + +template <typename CharT> +inline constexpr std::string_view empty_guid = + "00000000-0000-0000-0000-000000000000"; + +template <> +inline constexpr std::wstring_view empty_guid<wchar_t> + = L"00000000-0000-0000-0000-000000000000"; + +template <typename CharT> +inline constexpr std::string_view guid_encoder = "0123456789abcdef"; + +template <> +inline constexpr std::wstring_view guid_encoder<wchar_t> = L"0123456789abcdef"; + +// --------------------------------------------------------------------- +// UUID format https://tools.ietf.org/html/rfc4122 +// --------------------------------------------------------------------- + +// --------------------------------------------------------------------- +// Field NDR Data Type Octet # Note +// Note +// --------------------------------------------------------------------- +// time_low unsigned long 0 - 3 +// The low field of the timestamp. +// time_mid unsigned short 4 - 5 +// The middle field of the timestamp. +// time_hi_and_version unsigned short 6 - 7 +// The high field of the timestamp multiplexed with the version number. +// clock_seq_hi_and_reserved unsigned small 8 +// The high field of the clock sequence multiplexed with the variant. +// clock_seq_low unsigned small 9 +// The low field of the clock sequence. +// node character 10 - 15 +// The spatially unique node identifier. +// --------------------------------------------------------------------- +// 0 1 2 3 +// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | time_low | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | time_mid | time_hi_and_version | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// |clk_seq_hi_res | clk_seq_low | node (0-1) | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +// | node (2-5) | +// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +// --------------------------------------------------------------------- +// enumerations +// --------------------------------------------------------------------- + +// indicated by a bit pattern in octet 8, marked with N in +// xxxxxxxx-xxxx-xxxx-Nxxx-xxxxxxxxxxxx +export enum struct uuid_variant { + // NCS backward compatibility (with the obsolete Apollo Network + // Computing System 1.5 UUID format). + // N bit pattern: 0xxx + // > the first 6 octets of the UUID are a 48-bit timestamp (the number + // of 4 microsecond units of time since 1 Jan 1980 UTC); + // > the next 2 octets are reserved; + // > the next octet is the "address family"; + // > the final 7 octets are a 56-bit host ID in the form specified by + // the address family + ncs, + + // RFC 4122/DCE 1.1 + // N bit pattern: 10xx + // > big-endian byte order + rfc, + + // Microsoft Corporation backward compatibility + // N bit pattern: 110x + // > little endian byte order + // > formely used in the Component Object Model (COM) library + microsoft, + + // reserved for possible future definition + // N bit pattern: 111x + reserved +}; + +// indicated by a bit pattern in octet 6, marked with M in +// xxxxxxxx-xxxx-Mxxx-xxxx-xxxxxxxxxxxx +export enum struct uuid_version { + // only possible for nil or invalid uuids + none = 0, + // The time-based version specified in RFC 4122 + time_based = 1, + // DCE Security version, with embedded POSIX UIDs. + dce_security = 2, + // The name-based version specified in RFS 4122 with MD5 hashing + name_based_md5 = 3, + // The randomly or pseudo-randomly generated version specified in RFS 4122 + random_number_based = 4, + // The name-based version specified in RFS 4122 with SHA1 hashing + name_based_sha1 = 5 +}; + +// Forward declare uuid and to_string so that we can declare to_string as a +// friend later. +export struct uuid; +export template <typename CharT = char, + typename Traits = std::char_traits<CharT>, + typename Allocator = std::allocator<CharT>> +auto to_string(uuid const &id) -> std::basic_string<CharT, Traits, Allocator>; + +// -------------------------------------------------------------------------------------------------------------------------- +// uuid class +// -------------------------------------------------------------------------------------------------------------------------- +export struct uuid { + using value_type = std::uint8_t; + + constexpr uuid() noexcept = default; + + uuid(value_type(&arr)[16]) noexcept // NOLINT + { + std::ranges::copy(arr, std::ranges::begin(data)); + } + + constexpr uuid(std::array<value_type, 16> const &arr) noexcept + : data{arr} + { + } + + explicit uuid(std::span<value_type, 16> bytes) + { + std::ranges::copy(bytes, std::ranges::begin(data)); + } + + explicit uuid(std::span<value_type> bytes) + { + if (bytes.size() != 16) + throw std::logic_error("wrong size for uuid"); + std::ranges::copy(bytes, std::ranges::begin(data)); + } + + template<typename ForwardIterator> + explicit uuid(ForwardIterator first, ForwardIterator last) + { + if (std::distance(first, last) != 16) + throw std::logic_error("wrong size for uuid"); + + std::copy(first, last, std::begin(data)); + } + + [[nodiscard]] constexpr auto variant() const noexcept -> uuid_variant + { + if ((data[8] & 0x80) == 0x00) + return uuid_variant::ncs; + else if ((data[8] & 0xC0) == 0x80) + return uuid_variant::rfc; + else if ((data[8] & 0xE0) == 0xC0) + return uuid_variant::microsoft; + else + return uuid_variant::reserved; + } + + [[nodiscard]] constexpr auto version() const noexcept -> uuid_version + { + if ((data[6] & 0xF0) == 0x10) + return uuid_version::time_based; + else if ((data[6] & 0xF0) == 0x20) + return uuid_version::dce_security; + else if ((data[6] & 0xF0) == 0x30) + return uuid_version::name_based_md5; + else if ((data[6] & 0xF0) == 0x40) + return uuid_version::random_number_based; + else if ((data[6] & 0xF0) == 0x50) + return uuid_version::name_based_sha1; + else + return uuid_version::none; + } + + [[nodiscard]] constexpr auto is_nil() const noexcept -> bool + { + for (auto i : data) + if (i != 0) + return false; + return true; + } + + auto swap(uuid &other) noexcept -> void + { + data.swap(other.data); + } + + [[nodiscard]] inline auto as_bytes() const + -> std::span<std::byte const, 16> + { + return std::span<std::byte const, 16>( + reinterpret_cast<std::byte const*>(data.data()), + 16); + } + + template <typename StringType> + [[nodiscard]] constexpr static auto + is_valid_uuid(StringType const &in_str) noexcept + -> bool + { + auto str = to_string_view(in_str); + auto firstDigit = true; + auto hasBraces = std::size_t{0}; + auto index = std::size_t{0}; + + if (str.empty()) + return false; + + if (str.front() == '{') + hasBraces = 1; + + if (hasBraces && str.back() != '}') + return false; + + for (size_t i = hasBraces; i < str.size() - hasBraces; ++i) { + if (str[i] == '-') + continue; + + if (index >= 16 || !is_hex(str[i])) + return false; + + if (firstDigit) { + firstDigit = false; + } else { + index++; + firstDigit = true; + } + } + + if (index < 16) + return false; + + return true; + } + + template <typename StringType> + [[nodiscard]] constexpr static auto + from_string(StringType const & in_str) noexcept + -> std::optional<uuid> + { + auto str = to_string_view(in_str); + bool firstDigit = true; + size_t hasBraces = 0; + size_t index = 0; + + std::array<uint8_t, 16> data{ { 0 } }; + + if (str.empty()) + return {}; + + if (str.front() == '{') + hasBraces = 1; + if (hasBraces && str.back() != '}') + return {}; + + for (size_t i = hasBraces; i < str.size() - hasBraces; ++i) { + if (str[i] == '-') + continue; + + if (index >= 16 || !is_hex(str[i])) { + return {}; + } + + if (firstDigit) { + data[index] = static_cast<uint8_t>(hex2char(str[i]) << 4); + firstDigit = false; + } else { + data[index] = static_cast<uint8_t>(data[index] | hex2char(str[i])); + index++; + firstDigit = true; + } + } + + if (index < 16) { + return {}; + } + + return uuid{data}; + } + +private: + std::array<value_type, 16> data{ { 0 } }; + + friend auto operator==(uuid const &, uuid const &) noexcept -> bool; + friend auto operator<(uuid const &, uuid const &) noexcept -> bool; + + template <class Elem, class Traits> + friend auto operator<<(std::basic_ostream<Elem, Traits> &s, + uuid const &id) + -> std::basic_ostream<Elem, Traits> &; + + template<class CharT, class Traits, class Allocator> + friend auto to_string(uuid const &id) + -> std::basic_string<CharT, Traits, Allocator>; + + friend std::hash<uuid>; +}; + +// -------------------------------------------------------------------------------------------------------------------------- +// operators and non-member functions +// -------------------------------------------------------------------------------------------------------------------------- + +export [[nodiscard]] +auto operator== (uuid const &lhs, uuid const &rhs) noexcept -> bool +{ + return lhs.data == rhs.data; +} + +export [[nodiscard]] +auto operator!= (uuid const &lhs, uuid const &rhs) noexcept -> bool +{ + return !(lhs == rhs); +} + +export [[nodiscard]] +auto operator< (uuid const &lhs, uuid const &rhs) noexcept -> bool +{ + return lhs.data < rhs.data; +} + +export template <typename CharT, typename Traits, typename Allocator> +[[nodiscard]] auto to_string(uuid const &id) + -> std::basic_string<CharT, Traits, Allocator> +{ + auto uustr = std::basic_string<CharT, Traits, Allocator>( + std::from_range, empty_guid<CharT>); + + for (std::size_t i = 0, index = 0; i < 36; ++i) { + if (i == 8 || i == 13 || i == 18 || i == 23) + continue; + + uustr[i] = guid_encoder<CharT>[id.data[index] >> 4 & 0x0f]; + uustr[++i] = guid_encoder<CharT>[id.data[index] & 0x0f]; + index++; + } + + return uustr; +} + +export template <class Elem, class Traits> +auto operator<<(std::basic_ostream<Elem, Traits> &s, uuid const &id) + -> std::basic_ostream<Elem, Traits> & +{ + s << to_string(id); + return s; +} + +export auto swap(uuid &lhs, uuid &rhs) noexcept -> void +{ + lhs.swap(rhs); +} + +/*********************************************************************** + * namespace IDs that could be used for generating name-based uuids + */ + +// Name string is a fully-qualified domain name +export uuid uuid_namespace_dns{{ + 0x6b, 0xa7, 0xb8, 0x10, 0x9d, 0xad, 0x11, 0xd1, + 0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8 +}}; + +// Name string is a URL +export uuid uuid_namespace_url{{ + 0x6b, 0xa7, 0xb8, 0x11, 0x9d, 0xad, 0x11, 0xd1, + 0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8 +}}; + +// Name string is an ISO OID (See https://oidref.com/, +// https://en.wikipedia.org/wiki/Object_identifier) +export uuid uuid_namespace_oid{{ + 0x6b, 0xa7, 0xb8, 0x12, 0x9d, 0xad, 0x11, 0xd1, + 0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8 +}}; + +// Name string is an X.500 DN, in DER or a text output format (See +// https://en.wikipedia.org/wiki/X.500, +// https://en.wikipedia.org/wiki/Abstract_Syntax_Notation_One) +export uuid uuid_namespace_x500{{ + 0x6b, 0xa7, 0xb8, 0x14, 0x9d, 0xad, 0x11, 0xd1, + 0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8 +}}; + +/*********************************************************************** + * uuid generators + */ + +export template <typename UniformRandomNumberGenerator> +struct basic_uuid_random_generator +{ + using engine_type = UniformRandomNumberGenerator; + + explicit basic_uuid_random_generator(engine_type &gen) + : generator(&gen, [](auto) {}) + { + } + + explicit basic_uuid_random_generator(engine_type *gen) + : generator(gen, [](auto) {}) + { + } + + [[nodiscard]] auto operator()() -> uuid + { + alignas(std::uint32_t) + auto bytes = std::array<std::uint8_t, 16>{}; + + for (int i = 0; i < 16; i += 4) + *reinterpret_cast<std::uint32_t *>(bytes.data() + i) = + distribution(*generator); + + // variant must be 10xxxxxx + bytes[8] &= 0xBF; + bytes[8] |= 0x80; + + // version must be 0100xxxx + bytes[6] &= 0x4F; + bytes[6] |= 0x40; + + return uuid{std::begin(bytes), std::end(bytes)}; + } + +private: + std::uniform_int_distribution<std::uint32_t> distribution; + std::shared_ptr<UniformRandomNumberGenerator> generator; +}; + +export using uuid_random_generator = basic_uuid_random_generator<std::mt19937>; + +export struct uuid_name_generator +{ + explicit uuid_name_generator(uuid const &namespace_uuid) noexcept + : nsuuid(namespace_uuid) + { + } + + template <typename StringType> + [[nodiscard]] auto operator()(StringType const &name) -> uuid + { + reset(); + process_characters(to_string_view(name)); + return make_uuid(); + } + +private: + auto reset() -> void + { + hasher.reset(); + + auto nsbytes = nsuuid.as_bytes(); + + auto bytes = std::array<std::byte, 16>(); + std::ranges::copy(nsbytes, std::ranges::begin(bytes)); + + hasher.process_bytes(bytes.data(), bytes.size()); + } + + template <typename CharT, typename Traits> + auto process_characters( + std::basic_string_view<CharT, Traits> const str) -> void + { + for (std::uint32_t c : str) { + hasher.process_byte(static_cast<std::uint8_t>(c & 0xFF)); + if constexpr (!std::is_same_v<CharT, char>) { + hasher.process_byte( + static_cast<uint8_t>((c >> 8) & 0xFF)); + hasher.process_byte( + static_cast<uint8_t>((c >> 16) & 0xFF)); + hasher.process_byte( + static_cast<uint8_t>((c >> 24) & 0xFF)); + } + } + } + + [[nodiscard]] auto make_uuid() -> uuid + { + auto digest = hasher.get_digest_bytes(); + + // variant must be 0b10xxxxxx + digest[8] &= 0xBF; + digest[8] |= 0x80; + + // version must be 0b0101xxxx + digest[6] &= 0x5F; + digest[6] |= 0x50; + + return uuid(std::span(digest).subspan(0, 16)); + } + +private: + uuid nsuuid; + sha1 hasher; +}; + +/* + * Create a random UUID. + */ +export auto random_uuid() -> uuid +{ + auto rd = std::random_device(); + auto seed_data = std::array<int, std::mt19937::state_size> {}; + std::ranges::generate(seed_data, std::ref(rd)); + + auto seq = std::seed_seq(std::ranges::begin(seed_data), + std::ranges::end(seed_data)); + auto generator = std::mt19937(seq); + auto gen = uuid_random_generator{generator}; + + return gen(); +} + +} // namespace nihil + +namespace std { + +export template <> +struct hash<nihil::uuid> +{ + using argument_type = nihil::uuid; + using result_type = std::size_t; + + [[nodiscard]] auto operator()(argument_type const &uuid) const + -> result_type + { + std::uint64_t l = + static_cast<uint64_t>(uuid.data[0]) << 56 | + static_cast<uint64_t>(uuid.data[1]) << 48 | + static_cast<uint64_t>(uuid.data[2]) << 40 | + static_cast<uint64_t>(uuid.data[3]) << 32 | + static_cast<uint64_t>(uuid.data[4]) << 24 | + static_cast<uint64_t>(uuid.data[5]) << 16 | + static_cast<uint64_t>(uuid.data[6]) << 8 | + static_cast<uint64_t>(uuid.data[7]); + + std::uint64_t h = + static_cast<uint64_t>(uuid.data[8]) << 56 | + static_cast<uint64_t>(uuid.data[9]) << 48 | + static_cast<uint64_t>(uuid.data[10]) << 40 | + static_cast<uint64_t>(uuid.data[11]) << 32 | + static_cast<uint64_t>(uuid.data[12]) << 24 | + static_cast<uint64_t>(uuid.data[13]) << 16 | + static_cast<uint64_t>(uuid.data[14]) << 8 | + static_cast<uint64_t>(uuid.data[15]); + + return std::hash<std::uint64_t>{}(l ^ h); + } +}; + +} // namespace std |