Chris@16: // Boost string_generator.hpp header file  ----------------------------------------------//
Chris@16: 
Chris@16: // Copyright 2010 Andy Tompkins.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_UUID_STRING_GENERATOR_HPP
Chris@16: #define BOOST_UUID_STRING_GENERATOR_HPP
Chris@16: 
Chris@16: #include <boost/uuid/uuid.hpp>
Chris@16: #include <string>
Chris@16: #include <cstring> // for strlen, wcslen
Chris@16: #include <iterator>
Chris@16: #include <algorithm> // for find
Chris@16: #include <stdexcept>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_NO_STDC_NAMESPACE
Chris@16: namespace std {
Chris@16:     using ::strlen;
Chris@16:     using ::wcslen;
Chris@16: } //namespace std
Chris@16: #endif //BOOST_NO_STDC_NAMESPACE
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace uuids {
Chris@16: 
Chris@16: // generate a uuid from a string
Chris@16: // lexical_cast works fine using uuid_io.hpp
Chris@16: // but this generator should accept more forms
Chris@16: // and be more efficient
Chris@16: // would like to accept the following forms:
Chris@16: // 0123456789abcdef0123456789abcdef
Chris@16: // 01234567-89ab-cdef-0123456789abcdef
Chris@16: // {01234567-89ab-cdef-0123456789abcdef}
Chris@16: // {0123456789abcdef0123456789abcdef}
Chris@16: // others?
Chris@16: struct string_generator {
Chris@16:     typedef uuid result_type;
Chris@16:     
Chris@16:     template <typename ch, typename char_traits, typename alloc>
Chris@16:     uuid operator()(std::basic_string<ch, char_traits, alloc> const& s) const {
Chris@16:         return operator()(s.begin(), s.end());
Chris@16:     }
Chris@16: 
Chris@16:     uuid operator()(char const*const s) const {
Chris@16:         return operator()(s, s+std::strlen(s));
Chris@16:     }
Chris@16: 
Chris@16:     uuid operator()(wchar_t const*const s) const {
Chris@16:         return operator()(s, s+std::wcslen(s));
Chris@16:     }
Chris@16: 
Chris@16:     template <typename CharIterator>
Chris@16:     uuid operator()(CharIterator begin, CharIterator end) const
Chris@16:     {
Chris@16:         typedef typename std::iterator_traits<CharIterator>::value_type char_type;
Chris@16: 
Chris@16:         // check open brace
Chris@16:         char_type c = get_next_char(begin, end);
Chris@16:         bool has_open_brace = is_open_brace(c);
Chris@16:         char_type open_brace_char = c;
Chris@16:         if (has_open_brace) {
Chris@16:             c = get_next_char(begin, end);
Chris@16:         }
Chris@16: 
Chris@16:         bool has_dashes = false;
Chris@16: 
Chris@16:         uuid u;
Chris@16:         int i=0;
Chris@16:         for (uuid::iterator it_byte=u.begin(); it_byte!=u.end(); ++it_byte, ++i) {
Chris@16:             if (it_byte != u.begin()) {
Chris@16:                 c = get_next_char(begin, end);
Chris@16:             }
Chris@16:             
Chris@16:             if (i == 4) {
Chris@16:                 has_dashes = is_dash(c);
Chris@16:                 if (has_dashes) {
Chris@16:                     c = get_next_char(begin, end);
Chris@16:                 }
Chris@16:             }
Chris@16:             
Chris@16:             if (has_dashes) {
Chris@16:                 if (i == 6 || i == 8 || i == 10) {
Chris@16:                     if (is_dash(c)) {
Chris@16:                         c = get_next_char(begin, end);
Chris@16:                     } else {
Chris@16:                         throw_invalid();
Chris@16:                     }
Chris@16:                 }
Chris@16:             }
Chris@16: 
Chris@16:             *it_byte = get_value(c);
Chris@16: 
Chris@16:             c = get_next_char(begin, end);
Chris@16:             *it_byte <<= 4;
Chris@16:             *it_byte |= get_value(c);
Chris@16:         }
Chris@16: 
Chris@16:         // check close brace
Chris@16:         if (has_open_brace) {
Chris@16:             c = get_next_char(begin, end);
Chris@16:             check_close_brace(c, open_brace_char);
Chris@16:         }
Chris@16:         
Chris@16:         return u;
Chris@16:     }
Chris@16:     
Chris@16: private:
Chris@16:     template <typename CharIterator>
Chris@16:     typename std::iterator_traits<CharIterator>::value_type
Chris@16:     get_next_char(CharIterator& begin, CharIterator end) const {
Chris@16:         if (begin == end) {
Chris@16:             throw_invalid();
Chris@16:         }
Chris@16:         return *begin++;
Chris@16:     }
Chris@16: 
Chris@16:     unsigned char get_value(char c) const {
Chris@16:         static char const*const digits_begin = "0123456789abcdefABCDEF";
Chris@16:         static char const*const digits_end = digits_begin + 22;
Chris@16: 
Chris@16:         static unsigned char const values[] =
Chris@16:             { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,10,11,12,13,14,15
Chris@16:             , static_cast<unsigned char>(-1) };
Chris@16: 
Chris@16:         char const* d = std::find(digits_begin, digits_end, c);
Chris@16:         return values[d - digits_begin];
Chris@16:     }
Chris@16: 
Chris@16:     unsigned char get_value(wchar_t c) const {
Chris@16:         static wchar_t const*const digits_begin = L"0123456789abcdefABCDEF";
Chris@16:         static wchar_t const*const digits_end = digits_begin + 22;
Chris@16:         
Chris@16:         static unsigned char const values[] =
Chris@16:             { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,10,11,12,13,14,15
Chris@16:             , static_cast<unsigned char>(-1) };
Chris@16: 
Chris@16:         wchar_t const* d = std::find(digits_begin, digits_end, c);
Chris@16:         return values[d - digits_begin];
Chris@16:     }
Chris@16: 
Chris@16:     bool is_dash(char c) const {
Chris@16:         return c == '-';
Chris@16:     }
Chris@16:     
Chris@16:     bool is_dash(wchar_t c) const {
Chris@16:         return c == L'-';
Chris@16:     }
Chris@16:     
Chris@16:     // return closing brace
Chris@16:     bool is_open_brace(char c) const {
Chris@16:         return (c == '{');
Chris@16:     }
Chris@16:     
Chris@16:     bool is_open_brace(wchar_t c) const {
Chris@16:         return (c == L'{');
Chris@16:     }
Chris@16:     
Chris@16:     void check_close_brace(char c, char open_brace) const {
Chris@16:         if (open_brace == '{' && c == '}') {
Chris@16:             //great
Chris@16:         } else {
Chris@16:             throw_invalid();
Chris@16:         }
Chris@16:     }
Chris@16:     
Chris@16:     void check_close_brace(wchar_t c, wchar_t open_brace) const {
Chris@16:         if (open_brace == L'{' && c == L'}') {
Chris@16:             // great
Chris@16:         } else {
Chris@16:             throw_invalid();
Chris@16:         }
Chris@16:     }
Chris@16:     
Chris@16:     void throw_invalid() const {
Chris@16:         BOOST_THROW_EXCEPTION(std::runtime_error("invalid uuid string"));
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }} // namespace boost::uuids
Chris@16: 
Chris@16: #endif //BOOST_UUID_STRING_GENERATOR_HPP
Chris@16: