pixwerx/src/deps/stduuid/include/uuid.h

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#pragma once
#include <cstring>
#include <string>
#include <sstream>
#include <iomanip>
#include <array>
#include <string_view>
#include <iterator>
#include <random>
#include <memory>
#include <functional>
#include <type_traits>
#include <optional>
#include <chrono>
#include <numeric>
#include <atomic>
#include <span>
#ifdef _WIN32
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#ifndef NOMINMAX
#define NOMINMAX
#endif
#ifdef UUID_SYSTEM_GENERATOR
#include <objbase.h>
#endif
#include <windows.h>
#include <intrin.h>
#include <iphlpapi.h>
#pragma comment(lib, "IPHLPAPI.lib")
#elif defined(__linux__) || defined(__unix__)
#ifdef UUID_SYSTEM_GENERATOR
#include <uuid/uuid.h>
#endif
#elif defined(__APPLE__)
#ifdef UUID_SYSTEM_GENERATOR
#include <CoreFoundation/CFUUID.h>
#endif
#endif
namespace uuids
{
#ifdef __cpp_lib_span
template <class ElementType, std::size_t Extent>
using span = std::span<ElementType, Extent>;
#else
template <class ElementType, std::ptrdiff_t Extent>
using span = gsl::span<ElementType, Extent>;
#endif
namespace detail
{
template <typename TChar>
constexpr inline unsigned char hex2char(TChar const ch)
{
if (ch >= static_cast<TChar>('0') && ch <= static_cast<TChar>('9'))
return ch - static_cast<TChar>('0');
if (ch >= static_cast<TChar>('a') && ch <= static_cast<TChar>('f'))
return 10 + ch - static_cast<TChar>('a');
if (ch >= static_cast<TChar>('A') && ch <= static_cast<TChar>('F'))
return 10 + ch - static_cast<TChar>('A');
return 0;
}
template <typename TChar>
constexpr inline bool is_hex(TChar const ch)
{
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>
constexpr inline unsigned char hexpair2char(TChar const a, TChar const b)
{
return (hex2char(a) << 4) | hex2char(b);
}
class sha1
{
public:
using digest32_t = uint32_t[5];
using digest8_t = uint8_t[20];
static constexpr unsigned int block_bytes = 64;
inline static uint32_t left_rotate(uint32_t value, size_t const count)
{
return (value << count) ^ (value >> (32 - count));
}
sha1() { reset(); }
void reset()
{
m_digest[0] = 0x67452301;
m_digest[1] = 0xEFCDAB89;
m_digest[2] = 0x98BADCFE;
m_digest[3] = 0x10325476;
m_digest[4] = 0xC3D2E1F0;
m_blockByteIndex = 0;
m_byteCount = 0;
}
void process_byte(uint8_t octet)
{
this->m_block[this->m_blockByteIndex++] = octet;
++this->m_byteCount;
if (m_blockByteIndex == block_bytes)
{
this->m_blockByteIndex = 0;
process_block();
}
}
void process_block(void const * const start, void const * const end)
{
const uint8_t* begin = static_cast<const uint8_t*>(start);
const uint8_t* finish = static_cast<const uint8_t*>(end);
while (begin != finish)
{
process_byte(*begin);
begin++;
}
}
void process_bytes(void const * const data, size_t const len)
{
const uint8_t* block = static_cast<const uint8_t*>(data);
process_block(block, block + len);
}
uint32_t const * get_digest(digest32_t digest)
{
size_t const bitCount = this->m_byteCount * 8;
process_byte(0x80);
if (this->m_blockByteIndex > 56) {
while (m_blockByteIndex != 0) {
process_byte(0);
}
while (m_blockByteIndex < 56) {
process_byte(0);
}
}
else {
while (m_blockByteIndex < 56) {
process_byte(0);
}
}
process_byte(0);
process_byte(0);
process_byte(0);
process_byte(0);
process_byte(static_cast<unsigned char>((bitCount >> 24) & 0xFF));
process_byte(static_cast<unsigned char>((bitCount >> 16) & 0xFF));
process_byte(static_cast<unsigned char>((bitCount >> 8) & 0xFF));
process_byte(static_cast<unsigned char>((bitCount) & 0xFF));
memcpy(digest, m_digest, 5 * sizeof(uint32_t));
return digest;
}
uint8_t const * get_digest_bytes(digest8_t digest)
{
digest32_t d32;
get_digest(d32);
size_t di = 0;
digest[di++] = (uint8_t)(d32[0] >> 24);
digest[di++] = (uint8_t)(d32[0] >> 16);
digest[di++] = (uint8_t)(d32[0] >> 8);
digest[di++] = (uint8_t)(d32[0] >> 0);
digest[di++] = (uint8_t)(d32[1] >> 24);
digest[di++] = (uint8_t)(d32[1] >> 16);
digest[di++] = (uint8_t)(d32[1] >> 8);
digest[di++] = (uint8_t)(d32[1] >> 0);
digest[di++] = (uint8_t)(d32[2] >> 24);
digest[di++] = (uint8_t)(d32[2] >> 16);
digest[di++] = (uint8_t)(d32[2] >> 8);
digest[di++] = (uint8_t)(d32[2] >> 0);
digest[di++] = (uint8_t)(d32[3] >> 24);
digest[di++] = (uint8_t)(d32[3] >> 16);
digest[di++] = (uint8_t)(d32[3] >> 8);
digest[di++] = (uint8_t)(d32[3] >> 0);
digest[di++] = (uint8_t)(d32[4] >> 24);
digest[di++] = (uint8_t)(d32[4] >> 16);
digest[di++] = (uint8_t)(d32[4] >> 8);
digest[di++] = (uint8_t)(d32[4] >> 0);
return digest;
}
private:
void process_block()
{
uint32_t w[80];
for (size_t i = 0; i < 16; i++) {
w[i] = (m_block[i * 4 + 0] << 24);
w[i] |= (m_block[i * 4 + 1] << 16);
w[i] |= (m_block[i * 4 + 2] << 8);
w[i] |= (m_block[i * 4 + 3]);
}
for (size_t i = 16; i < 80; i++) {
w[i] = left_rotate((w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16]), 1);
}
uint32_t a = m_digest[0];
uint32_t b = m_digest[1];
uint32_t c = m_digest[2];
uint32_t d = m_digest[3];
uint32_t e = m_digest[4];
for (std::size_t i = 0; i < 80; ++i)
{
uint32_t f = 0;
uint32_t k = 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;
}
uint32_t temp = left_rotate(a, 5) + f + e + k + w[i];
e = d;
d = c;
c = left_rotate(b, 30);
b = a;
a = temp;
}
m_digest[0] += a;
m_digest[1] += b;
m_digest[2] += c;
m_digest[3] += d;
m_digest[4] += e;
}
private:
digest32_t m_digest;
uint8_t m_block[64];
size_t m_blockByteIndex;
size_t m_byteCount;
};
static std::mt19937 clock_gen(std::random_device{}());
static std::uniform_int_distribution<short> clock_dis{ -32768, 32767 };
static std::atomic_short clock_sequence = clock_dis(clock_gen);
}
// --------------------------------------------------------------------------------------------------------------------------
// UUID format https://tools.ietf.org/html/rfc4122
// --------------------------------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------------------------------
// Field NDR Data Type Octet # 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
enum class 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
enum class uuid_version
{
none = 0, // only possible for nil or invalid uuids
time_based = 1, // The time-based version specified in RFC 4122
dce_security = 2, // DCE Security version, with embedded POSIX UIDs.
name_based_md5 = 3, // The name-based version specified in RFS 4122 with MD5 hashing
random_number_based = 4, // The randomly or pseudo-randomly generated version specified in RFS 4122
name_based_sha1 = 5 // The name-based version specified in RFS 4122 with SHA1 hashing
};
// --------------------------------------------------------------------------------------------------------------------------
// uuid class
// --------------------------------------------------------------------------------------------------------------------------
class uuid
{
public:
using value_type = uint8_t;
constexpr uuid() noexcept : data({}) {};
uuid(value_type(&arr)[16]) noexcept
{
std::copy(std::cbegin(arr), std::cend(arr), std::begin(data));
}
uuid(std::array<value_type, 16> const & arr) noexcept
{
std::copy(std::cbegin(arr), std::cend(arr), std::begin(data));
}
explicit uuid(span<value_type, 16> bytes)
{
std::copy(std::cbegin(bytes), std::cend(bytes), std::begin(data));
}
template<typename ForwardIterator>
explicit uuid(ForwardIterator first, ForwardIterator last)
{
if (std::distance(first, last) == 16)
std::copy(first, last, std::begin(data));
}
constexpr uuid_variant variant() const noexcept
{
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;
}
constexpr uuid_version version() const noexcept
{
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;
}
constexpr bool is_nil() const noexcept
{
for (size_t i = 0; i < data.size(); ++i) if (data[i] != 0) return false;
return true;
}
void swap(uuid & other) noexcept
{
data.swap(other.data);
}
inline span<std::byte const, 16> as_bytes() const
{
return span<std::byte const, 16>(reinterpret_cast<std::byte const*>(data.data()), 16);
}
template<class CharT = char>
static bool is_valid_uuid(CharT const * str) noexcept
{
bool firstDigit = true;
int hasBraces = 0;
size_t index = 0;
size_t size = 0;
if constexpr(std::is_same_v<CharT, char>)
size = strlen(str);
else
size = wcslen(str);
if (str == nullptr || size == 0)
return false;
if (str[0] == static_cast<CharT>('{'))
hasBraces = 1;
if (hasBraces && str[size - 1] != static_cast<CharT>('}'))
return false;
for (size_t i = hasBraces; i < size - hasBraces; ++i)
{
if (str[i] == static_cast<CharT>('-')) continue;
if (index >= 16 || !detail::is_hex(str[i]))
{
return false;
}
if (firstDigit)
{
firstDigit = false;
}
else
{
index++;
firstDigit = true;
}
}
if (index < 16)
{
return false;
}
return true;
}
template<class CharT = char,
class Traits = std::char_traits<CharT>,
class Allocator = std::allocator<CharT>>
static bool is_valid_uuid(std::basic_string<CharT, Traits, Allocator> const & str) noexcept
{
return is_valid_uuid(str.c_str());
}
template<class CharT = char>
static std::optional<uuid> from_string(CharT const * str) noexcept
{
CharT digit = 0;
bool firstDigit = true;
int hasBraces = 0;
size_t index = 0;
size_t size = 0;
if constexpr(std::is_same_v<CharT, char>)
size = strlen(str);
else
size = wcslen(str);
std::array<uint8_t, 16> data{ { 0 } };
if (str == nullptr || size == 0) return {};
if (str[0] == static_cast<CharT>('{'))
hasBraces = 1;
if (hasBraces && str[size - 1] != static_cast<CharT>('}'))
return {};
for (size_t i = hasBraces; i < size - hasBraces; ++i)
{
if (str[i] == static_cast<CharT>('-')) continue;
if (index >= 16 || !detail::is_hex(str[i]))
{
return {};
}
if (firstDigit)
{
digit = str[i];
firstDigit = false;
}
else
{
data[index++] = detail::hexpair2char(digit, str[i]);
firstDigit = true;
}
}
if (index < 16)
{
return {};
}
return uuid{ std::cbegin(data), std::cend(data) };
}
template<class CharT = char,
class Traits = std::char_traits<CharT>,
class Allocator = std::allocator<CharT>>
static std::optional<uuid> from_string(std::basic_string<CharT, Traits, Allocator> const & str) noexcept
{
return from_string(str.c_str());
}
private:
std::array<value_type, 16> data{ { 0 } };
friend bool operator==(uuid const & lhs, uuid const & rhs) noexcept;
friend bool operator<(uuid const & lhs, uuid const & rhs) noexcept;
template <class Elem, class Traits>
friend std::basic_ostream<Elem, Traits> & operator<<(std::basic_ostream<Elem, Traits> &s, uuid const & id);
};
// --------------------------------------------------------------------------------------------------------------------------
// operators and non-member functions
// --------------------------------------------------------------------------------------------------------------------------
inline bool operator== (uuid const& lhs, uuid const& rhs) noexcept
{
return lhs.data == rhs.data;
}
inline bool operator!= (uuid const& lhs, uuid const& rhs) noexcept
{
return !(lhs == rhs);
}
inline bool operator< (uuid const& lhs, uuid const& rhs) noexcept
{
return lhs.data < rhs.data;
}
template <class Elem, class Traits>
std::basic_ostream<Elem, Traits> & operator<<(std::basic_ostream<Elem, Traits> &s, uuid const & id)
{
// save current flags
std::ios_base::fmtflags f(s.flags());
// manipulate stream as needed
s << std::hex << std::setfill(static_cast<Elem>('0'))
<< std::setw(2) << (int)id.data[0]
<< std::setw(2) << (int)id.data[1]
<< std::setw(2) << (int)id.data[2]
<< std::setw(2) << (int)id.data[3]
<< '-'
<< std::setw(2) << (int)id.data[4]
<< std::setw(2) << (int)id.data[5]
<< '-'
<< std::setw(2) << (int)id.data[6]
<< std::setw(2) << (int)id.data[7]
<< '-'
<< std::setw(2) << (int)id.data[8]
<< std::setw(2) << (int)id.data[9]
<< '-'
<< std::setw(2) << (int)id.data[10]
<< std::setw(2) << (int)id.data[11]
<< std::setw(2) << (int)id.data[12]
<< std::setw(2) << (int)id.data[13]
<< std::setw(2) << (int)id.data[14]
<< std::setw(2) << (int)id.data[15];
// restore original flags
s.flags(f);
return s;
}
template<class CharT = char,
class Traits = std::char_traits<CharT>,
class Allocator = std::allocator<CharT>>
inline std::basic_string<CharT, Traits, Allocator> to_string(uuid const & id)
{
std::basic_stringstream<CharT, Traits, Allocator> sstr;
sstr << id;
return sstr.str();
}
inline void swap(uuids::uuid & lhs, uuids::uuid & rhs) noexcept
{
lhs.swap(rhs);
}
// --------------------------------------------------------------------------------------------------------------------------
// namespace IDs that could be used for generating name-based uuids
// --------------------------------------------------------------------------------------------------------------------------
// Name string is a fully-qualified domain name
static 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
static 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)
static 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)
static uuid uuid_namespace_x500{ {0x6b, 0xa7, 0xb8, 0x14, 0x9d, 0xad, 0x11, 0xd1, 0x80, 0xb4, 0x00, 0xc0, 0x4f, 0xd4, 0x30, 0xc8} };
// --------------------------------------------------------------------------------------------------------------------------
// uuid generators
// --------------------------------------------------------------------------------------------------------------------------
#ifdef UUID_SYSTEM_GENERATOR
class uuid_system_generator
{
public:
using result_type = uuid;
uuid operator()()
{
#ifdef _WIN32
GUID newId;
::CoCreateGuid(&newId);
std::array<uint8_t, 16> bytes =
{ {
(unsigned char)((newId.Data1 >> 24) & 0xFF),
(unsigned char)((newId.Data1 >> 16) & 0xFF),
(unsigned char)((newId.Data1 >> 8) & 0xFF),
(unsigned char)((newId.Data1) & 0xFF),
(unsigned char)((newId.Data2 >> 8) & 0xFF),
(unsigned char)((newId.Data2) & 0xFF),
(unsigned char)((newId.Data3 >> 8) & 0xFF),
(unsigned char)((newId.Data3) & 0xFF),
newId.Data4[0],
newId.Data4[1],
newId.Data4[2],
newId.Data4[3],
newId.Data4[4],
newId.Data4[5],
newId.Data4[6],
newId.Data4[7]
} };
return uuid{ std::begin(bytes), std::end(bytes) };
#elif defined(__linux__) || defined(__unix__)
uuid_t id;
uuid_generate(id);
std::array<uint8_t, 16> bytes =
{ {
id[0],
id[1],
id[2],
id[3],
id[4],
id[5],
id[6],
id[7],
id[8],
id[9],
id[10],
id[11],
id[12],
id[13],
id[14],
id[15]
} };
return uuid{ std::begin(bytes), std::end(bytes) };
#elif defined(__APPLE__)
auto newId = CFUUIDCreate(NULL);
auto bytes = CFUUIDGetUUIDBytes(newId);
CFRelease(newId);
std::array<uint8_t, 16> arrbytes =
{ {
bytes.byte0,
bytes.byte1,
bytes.byte2,
bytes.byte3,
bytes.byte4,
bytes.byte5,
bytes.byte6,
bytes.byte7,
bytes.byte8,
bytes.byte9,
bytes.byte10,
bytes.byte11,
bytes.byte12,
bytes.byte13,
bytes.byte14,
bytes.byte15
} };
return uuid{ std::begin(arrbytes), std::end(arrbytes) };
#else
return uuid{};
#endif
}
};
#endif
template <typename UniformRandomNumberGenerator>
class basic_uuid_random_generator
{
public:
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) {}) {}
uuid operator()()
{
uint8_t bytes[16];
for (int i = 0; i < 16; i += 4)
*reinterpret_cast<uint32_t*>(bytes + 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<uint32_t> distribution;
std::shared_ptr<UniformRandomNumberGenerator> generator;
};
using uuid_random_generator = basic_uuid_random_generator<std::mt19937>;
class uuid_name_generator
{
public:
explicit uuid_name_generator(uuid const& namespace_uuid) noexcept
: nsuuid(namespace_uuid)
{}
template<class CharT = char>
uuid operator()(CharT const * name)
{
size_t size = 0;
if constexpr (std::is_same_v<CharT, char>)
size = strlen(name);
else
size = wcslen(name);
reset();
process_characters(name, size);
return make_uuid();
}
template<class CharT = char,
class Traits = std::char_traits<CharT>,
class Allocator = std::allocator<CharT>>
uuid operator()(std::basic_string<CharT, Traits, Allocator> const & name)
{
reset();
process_characters(name.data(), name.size());
return make_uuid();
}
private:
void reset()
{
hasher.reset();
std::byte bytes[16];
auto nsbytes = nsuuid.as_bytes();
std::copy(std::cbegin(nsbytes), std::cend(nsbytes), bytes);
hasher.process_bytes(bytes, 16);
}
template <typename char_type,
typename = std::enable_if_t<std::is_integral<char_type>::value>>
void process_characters(char_type const * const characters, size_t const count)
{
for (size_t i = 0; i < count; i++)
{
uint32_t c = characters[i];
hasher.process_byte(static_cast<unsigned char>((c >> 0) & 0xFF));
hasher.process_byte(static_cast<unsigned char>((c >> 8) & 0xFF));
hasher.process_byte(static_cast<unsigned char>((c >> 16) & 0xFF));
hasher.process_byte(static_cast<unsigned char>((c >> 24) & 0xFF));
}
}
void process_characters(const char * const characters, size_t const count)
{
hasher.process_bytes(characters, count);
}
uuid make_uuid()
{
detail::sha1::digest8_t digest;
hasher.get_digest_bytes(digest);
// variant must be 0b10xxxxxx
digest[8] &= 0xBF;
digest[8] |= 0x80;
// version must be 0b0101xxxx
digest[6] &= 0x5F;
digest[6] |= 0x50;
return uuid{ digest, digest + 16 };
}
private:
uuid nsuuid;
detail::sha1 hasher;
};
// !!! DO NOT USE THIS IN PRODUCTION
// this implementation is unreliable for good uuids
class uuid_time_generator
{
using mac_address = std::array<unsigned char, 6>;
std::optional<mac_address> device_address;
bool get_mac_address()
{
if (device_address.has_value())
{
return true;
}
#ifdef _WIN32
DWORD len = 0;
auto ret = GetAdaptersInfo(nullptr, &len);
if (ret != ERROR_BUFFER_OVERFLOW) return false;
std::vector<unsigned char> buf(len);
auto pips = reinterpret_cast<PIP_ADAPTER_INFO>(&buf.front());
ret = GetAdaptersInfo(pips, &len);
if (ret != ERROR_SUCCESS) return false;
mac_address addr;
std::copy(pips->Address, pips->Address + 6, std::begin(addr));
device_address = addr;
#endif
return device_address.has_value();
}
long long get_time_intervals()
{
auto start = std::chrono::system_clock::from_time_t(time_t(-12219292800));
auto diff = std::chrono::system_clock::now() - start;
auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(diff).count();
return ns / 100;
}
public:
uuid_time_generator()
{
}
uuid operator()()
{
if (get_mac_address())
{
std::array<uuids::uuid::value_type, 16> data;
auto tm = get_time_intervals();
short clock_seq = detail::clock_sequence++;
clock_seq &= 0x3FFF;
auto ptm = reinterpret_cast<uuids::uuid::value_type*>(&tm);
ptm[0] &= 0x0F;
memcpy(&data[0], ptm + 4, 4);
memcpy(&data[4], ptm + 2, 2);
memcpy(&data[6], ptm, 2);
memcpy(&data[8], reinterpret_cast<uuids::uuid::value_type*>(&clock_seq), 2);
// variant must be 0b10xxxxxx
data[8] &= 0xBF;
data[8] |= 0x80;
// version must be 0b0001xxxx
data[6] &= 0x5F;
data[6] |= 0x10;
memcpy(&data[10], &device_address.value()[0], 6);
return uuids::uuid{std::cbegin(data), std::cend(data)};
}
return {};
}
};
}
namespace std
{
template <>
struct hash<uuids::uuid>
{
using argument_type = uuids::uuid;
using result_type = std::size_t;
result_type operator()(argument_type const &uuid) const
{
std::hash<std::string> hasher;
return static_cast<result_type>(hasher(uuids::to_string(uuid)));
}
};
}