Chris@16: #ifndef BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP
Chris@16: #define BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
Chris@16: // binary_from_base64.hpp
Chris@16: 
Chris@16: // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 
Chris@16: // Use, modification and distribution is subject to the Boost Software
Chris@16: // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: //  See http://www.boost.org for updates, documentation, and revision history.
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: 
Chris@16: #include <boost/serialization/throw_exception.hpp>
Chris@16: #include <boost/serialization/pfto.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: 
Chris@16: #include <boost/iterator/transform_iterator.hpp>
Chris@16: #include <boost/archive/iterators/dataflow_exception.hpp>
Chris@16: 
Chris@16: namespace boost { 
Chris@16: namespace archive {
Chris@16: namespace iterators {
Chris@16: 
Chris@16: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
Chris@16: // convert base64 characters to binary data
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<class CharType>
Chris@16: struct to_6_bit {
Chris@16:     typedef CharType result_type;
Chris@16:     CharType operator()(CharType t) const{
Chris@16:         const signed char lookup_table[] = {
Chris@16:             -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
Chris@16:             -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
Chris@16:             -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63,
Chris@16:             52,53,54,55,56,57,58,59,60,61,-1,-1,-1, 0,-1,-1, // render '=' as 0
Chris@16:             -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,
Chris@16:             15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,
Chris@16:             -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
Chris@16:             41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1
Chris@16:         };
Chris@16:         // metrowerks trips this assertion - how come?
Chris@16:         #if ! defined(__MWERKS__)
Chris@16:         BOOST_STATIC_ASSERT(128 == sizeof(lookup_table));
Chris@16:         #endif
Chris@16:         signed char value = -1;
Chris@16:         if((unsigned)t <= 127)
Chris@16:             value = lookup_table[(unsigned)t];
Chris@16:         if(-1 == value)
Chris@16:             boost::serialization::throw_exception(
Chris@16:                 dataflow_exception(dataflow_exception::invalid_base64_character)
Chris@16:             );
Chris@16:         return value;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: // note: what we would like to do is
Chris@101: // template<class Base, class CharType = typename Base::value_type>
Chris@16: //  typedef transform_iterator<
Chris@16: //      from_6_bit<CharType>,
Chris@16: //      transform_width<Base, 6, sizeof(Base::value_type) * 8, CharType>
Chris@16: //  > base64_from_binary;
Chris@16: // but C++ won't accept this.  Rather than using a "type generator" and
Chris@16: // using a different syntax, make a derivation which should be equivalent.
Chris@16: //
Chris@16: // Another issue addressed here is that the transform_iterator doesn't have
Chris@16: // a templated constructor.  This makes it incompatible with the dataflow
Chris@16: // ideal.  This is also addressed here.
Chris@16: 
Chris@16: template<
Chris@16:     class Base, 
Chris@101:     class CharType = typename boost::iterator_value<Base>::type
Chris@16: >
Chris@16: class binary_from_base64 : public
Chris@16:     transform_iterator<
Chris@16:         detail::to_6_bit<CharType>,
Chris@16:         Base
Chris@16:     >
Chris@16: {
Chris@16:     friend class boost::iterator_core_access;
Chris@16:     typedef transform_iterator<
Chris@16:         detail::to_6_bit<CharType>,
Chris@16:         Base
Chris@16:     > super_t;
Chris@16: public:
Chris@16:     // make composible buy using templated constructor
Chris@16:     template<class T>
Chris@16:     binary_from_base64(BOOST_PFTO_WRAPPER(T)  start) :
Chris@16:         super_t(
Chris@16:             Base(BOOST_MAKE_PFTO_WRAPPER(static_cast< T >(start))), 
Chris@16:             detail::to_6_bit<CharType>()
Chris@16:         )
Chris@16:     {}
Chris@16:     // intel 7.1 doesn't like default copy constructor
Chris@16:     binary_from_base64(const binary_from_base64 & rhs) : 
Chris@16:         super_t(
Chris@16:             Base(rhs.base_reference()),
Chris@16:             detail::to_6_bit<CharType>()
Chris@16:         )
Chris@16:     {}
Chris@16: //    binary_from_base64(){};
Chris@16: };
Chris@16: 
Chris@16: } // namespace iterators
Chris@16: } // namespace archive
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP