boost/uuid/uuid_generators.hpp
// Boost uuid_generators.hpp header file ----------------------------------------------//
// Copyright 2006 Andy Tompkins.
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Revision History
// 06 Feb 2006 - Initial Revision
#ifndef BOOST_UUID_GENERATORS_HPP
#define BOOST_UUID_GENERATORS_HPP
#include <boost/uuid/uuid.hpp>
#include <boost/uuid/sha1.hpp>
#include <boost/uuid/seed_rng.hpp>
#include <algorithm>
#include <string>
#include <limits>
#include <cstring>
#include <cwchar>
#include <iterator> // for distance
#include <boost/cstdint.hpp>
#include <boost/assert.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/random/variate_generator.hpp>
#include <boost/random/mersenne_twister.hpp>
#ifdef BOOST_NO_STDC_NAMESPACE
namespace std {
using ::strlen;
using ::wcslen;
} //namespace std
#endif //BOOST_NO_STDC_NAMESPACE
namespace boost {
namespace uuids {
// generate a nil uuid
struct nil_generator {
typedef uuid result_type;
uuid operator()() const {
// initialize to all zeros
uuid u = {{0}};
return u;
}
};
inline uuid nil_uuid() {
return nil_generator()();
}
// generate a uuid from a string
// lexical_cast works fine using uuid_io.hpp
// but this generator should accept more forms
// and be more efficient
// would like to accept the following forms:
// 0123456789abcdef0123456789abcdef
// 01234567-89ab-cdef-0123456789abcdef
// {01234567-89ab-cdef-0123456789abcdef}
// {0123456789abcdef0123456789abcdef}
// others?
struct string_generator {
typedef uuid result_type;
template <typename ch, typename char_traits, typename alloc>
uuid operator()(std::basic_string<ch, char_traits, alloc> const& s) const {
return operator()(s.begin(), s.end());
};
uuid operator()(char const*const s) const {
return operator()(s, s+std::strlen(s));
}
uuid operator()(wchar_t const*const s) const {
return operator()(s, s+std::wcslen(s));
}
template <typename CharIterator>
uuid operator()(CharIterator begin, CharIterator end) const
{
typedef typename std::iterator_traits<CharIterator>::value_type char_type;
// check open brace
char_type c = get_next_char(begin, end);
bool has_open_brace = is_open_brace(c);
char_type open_brace_char = c;
if (has_open_brace) {
c = get_next_char(begin, end);
}
bool has_dashes = false;
uuid u;
int i=0;
for (uuid::iterator it_byte=u.begin(); it_byte!=u.end(); ++it_byte, ++i) {
if (it_byte != u.begin()) {
c = get_next_char(begin, end);
}
if (i == 4) {
has_dashes = is_dash(c);
if (has_dashes) {
c = get_next_char(begin, end);
}
}
if (has_dashes) {
if (i == 6 || i == 8 || i == 10) {
if (is_dash(c)) {
c = get_next_char(begin, end);
} else {
throw_invalid();
}
}
}
*it_byte = get_value(c);
c = get_next_char(begin, end);
*it_byte <<= 4;
*it_byte |= get_value(c);
}
// check close brace
if (has_open_brace) {
c = get_next_char(begin, end);
check_close_brace(c, open_brace_char);
}
return u;
}
private:
template <typename CharIterator>
typename std::iterator_traits<CharIterator>::value_type
get_next_char(CharIterator& begin, CharIterator end) const {
if (begin == end) {
throw_invalid();
}
return *begin++;
}
unsigned char get_value(char c) const {
static char const*const digits_begin = "0123456789abcdefABCDEF";
static char const*const digits_end = digits_begin + 22;
static unsigned char const values[] =
{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,10,11,12,13,14,15
, static_cast<unsigned char>(-1) };
char const* d = std::find(digits_begin, digits_end, c);
return values[std::distance(digits_begin, d)];
}
unsigned char get_value(wchar_t c) const {
static wchar_t const*const digits_begin = L"0123456789abcdefABCDEF";
static wchar_t const*const digits_end = digits_begin + 22;
static unsigned char const values[] =
{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,10,11,12,13,14,15
, static_cast<unsigned char>(-1) };
wchar_t const* d = std::find(digits_begin, digits_end, c);
return values[std::distance(digits_begin, d)];
}
bool is_dash(char c) const {
return c == '-';
}
bool is_dash(wchar_t c) const {
return c == L'-';
}
// return closing brace
bool is_open_brace(char c) const {
return (c == '{');
}
bool is_open_brace(wchar_t c) const {
return (c == L'{');
}
void check_close_brace(char c, char open_brace) const {
if (open_brace == '{' && c == '}') {
//great
} else {
throw_invalid();
}
}
void check_close_brace(wchar_t c, wchar_t open_brace) const {
if (open_brace == L'{' && c == L'}') {
// great
} else {
throw_invalid();
}
}
void throw_invalid() const {
throw std::runtime_error("invalid uuid string");
}
};
// generate a name-based uuid
// TODO: add in common namesspace uuids
class name_generator {
public:
typedef uuid result_type;
explicit name_generator(uuid const& namespace_uuid)
: namespace_uuid(namespace_uuid)
{}
uuid operator()(const char* name) {
reset();
process_characters(name, std::strlen(name));
return sha_to_uuid();
}
uuid operator()(const wchar_t* name) {
reset();
process_characters(name, std::wcslen(name));
return sha_to_uuid();
}
template <typename ch, typename char_traits, typename alloc>
uuid operator()(std::basic_string<ch, char_traits, alloc> const& name) {
reset();
process_characters(name.c_str(), name.length());
return sha_to_uuid();
}
uuid operator()(void const* buffer, std::size_t byte_count) {
reset();
sha.process_bytes(buffer, byte_count);
return sha_to_uuid();
};
private:
// we convert all characters to uint32_t so that each
// character is 4 bytes reguardless of sizeof(char) or
// sizeof(wchar_t). We want the name string on any
// platform / compiler to generate the same uuid
// except for char
template <typename char_type>
void process_characters(char_type const*const characters, size_t count) {
BOOST_ASSERT(sizeof(uint32_t) >= sizeof(char_type));
for (size_t i=0; i<count; i++) {
uint32_t c = characters[i];
sha.process_byte( (c >> 0) && 0xFF );
sha.process_byte( (c >> 8) && 0xFF );
sha.process_byte( (c >> 16) && 0xFF );
sha.process_byte( (c >> 24) && 0xFF );
}
}
void process_characters(char const*const characters, size_t count) {
sha.process_bytes(characters, count);
}
void reset()
{
sha.reset();
sha.process_bytes(namespace_uuid.begin(), namespace_uuid.size());
}
uuid sha_to_uuid()
{
unsigned int digest[5];
sha.get_digest(digest);
uuid u;
for (int i=0; i<4; ++i) {
*(u.begin() + i*4+0) = ((digest[i] >> 24) & 0xFF);
*(u.begin() + i*4+1) = ((digest[i] >> 16) & 0xFF);
*(u.begin() + i*4+2) = ((digest[i] >> 8) & 0xFF);
*(u.begin() + i*4+3) = ((digest[i] >> 0) & 0xFF);
}
// set variant
// must be 0b10xxxxxx
*(u.begin()+8) &= 0xBF;
*(u.begin()+8) |= 0x80;
// set version
// must be 0b0101xxxx
*(u.begin()+6) &= 0x5F; //0b01011111
*(u.begin()+6) |= 0x50; //0b01010000
return u;
}
private:
uuid namespace_uuid;
detail::sha1 sha;
};
// generate a random-based uuid
template <typename UniformRandomNumberGenerator>
class basic_random_generator {
private:
typedef uniform_int<unsigned long> distribution_type;
typedef variate_generator<UniformRandomNumberGenerator*, distribution_type> generator_type;
struct null_deleter
{
void operator()(void const *) const {}
};
public:
typedef uuid result_type;
// default constructor creates the random number generator
basic_random_generator()
: pURNG(new UniformRandomNumberGenerator)
, generator
( pURNG.get()
, distribution_type
( (std::numeric_limits<unsigned long>::min)()
, (std::numeric_limits<unsigned long>::max)()
)
)
{
// seed the random number generator
detail::seed(*pURNG);
}
// keep a reference to a random number generator
// don't seed a given random number generator
explicit basic_random_generator(UniformRandomNumberGenerator& gen)
: pURNG(&gen, null_deleter())
, generator
( pURNG.get()
, distribution_type
( (std::numeric_limits<unsigned long>::min)()
, (std::numeric_limits<unsigned long>::max)()
)
)
{}
// keep a pointer to a random number generator
// don't seed a given random number generator
explicit basic_random_generator(UniformRandomNumberGenerator* pGen)
: pURNG(pGen, null_deleter())
, generator
( pURNG.get()
, distribution_type
( (std::numeric_limits<unsigned long>::min)()
, (std::numeric_limits<unsigned long>::max)()
)
)
{
BOOST_ASSERT(pURNG);
}
uuid operator()()
{
uuid u;
int i=0;
unsigned long random_value = generator();
for (uuid::iterator it=u.begin(); it!=u.end(); ++it, ++i) {
if (i==sizeof(unsigned long)) {
random_value = generator();
}
*it = ((random_value >> (i*8)) & 0xFF);
}
// set variant
// must be 0b10xxxxxx
*(u.begin()+8) &= 0xBF;
*(u.begin()+8) |= 0x80;
// set version
// must be 0b0100xxxx
*(u.begin()+6) &= 0x4F; //0b01001111
*(u.begin()+6) |= 0x40; //0b01000000
return u;
}
private:
shared_ptr<UniformRandomNumberGenerator> pURNG;
generator_type generator;
};
typedef basic_random_generator<mt19937> random_generator;
//TODO add native_generator
}} //namespace boost::uuids
#endif //BOOST_UUID_GENERATORS_HPP