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// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// 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.)
// See http://www.boost.org/libs/iostreams for documentation.
#ifndef BOOST_IOSTREAMS_INVERT_HPP_INCLUDED
#define BOOST_IOSTREAMS_INVERT_HPP_INCLUDED
#if defined(_MSC_VER)
# pragma once
#endif
#include <algorithm> // copy, min.
#include <boost/assert.hpp>
#include <boost/config.hpp> // BOOST_DEDUCED_TYPENAME.
#include <boost/detail/workaround.hpp> // default_filter_buffer_size.
#include <boost/iostreams/char_traits.hpp>
#include <boost/iostreams/compose.hpp>
#include <boost/iostreams/constants.hpp>
#include <boost/iostreams/device/array.hpp>
#include <boost/iostreams/detail/buffer.hpp>
#include <boost/iostreams/detail/counted_array.hpp>
#include <boost/iostreams/detail/execute.hpp>
#include <boost/iostreams/detail/functional.hpp> // clear_flags, call_reset
#include <boost/mpl/if.hpp>
#include <boost/ref.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/type_traits/is_convertible.hpp>
// Must come last.
#include <boost/iostreams/detail/config/disable_warnings.hpp> // MSVC.
namespace boost { namespace iostreams {
//
// Template name: inverse.
// Template parameters:
// Filter - A model of InputFilter or OutputFilter.
// Description: Generates an InputFilter from an OutputFilter or
// vice versa.
//
template<typename Filter>
class inverse {
private:
BOOST_STATIC_ASSERT(is_filter<Filter>::value);
typedef typename category_of<Filter>::type base_category;
typedef reference_wrapper<Filter> filter_ref;
public:
typedef typename char_type_of<Filter>::type char_type;
typedef typename int_type_of<Filter>::type int_type;
typedef char_traits<char_type> traits_type;
typedef typename
mpl::if_<
is_convertible<
base_category,
input
>,
output,
input
>::type mode;
struct category
: mode,
filter_tag,
multichar_tag,
closable_tag
{ };
explicit inverse( const Filter& filter,
std::streamsize buffer_size =
default_filter_buffer_size)
: pimpl_(new impl(filter, buffer_size))
{ }
template<typename Source>
std::streamsize read(Source& src, char* s, std::streamsize n)
{
typedef detail::counted_array_sink<char_type> array_sink;
typedef composite<filter_ref, array_sink> filtered_array_sink;
BOOST_ASSERT((flags() & f_write) == 0);
if (flags() == 0) {
flags() = f_read;
buf().set(0, 0);
}
filtered_array_sink snk(filter(), array_sink(s, n));
int_type status;
for ( status = traits_type::good();
snk.second().count() < n && status == traits_type::good(); )
{
status = buf().fill(src);
buf().flush(snk);
}
return snk.second().count() == 0 &&
status == traits_type::eof()
?
-1
:
snk.second().count();
}
template<typename Sink>
std::streamsize write(Sink& dest, const char* s, std::streamsize n)
{
typedef detail::counted_array_source<char_type> array_source;
typedef composite<filter_ref, array_source> filtered_array_source;
BOOST_ASSERT((flags() & f_read) == 0);
if (flags() == 0) {
flags() = f_write;
buf().set(0, 0);
}
filtered_array_source src(filter(), array_source(s, n));
for (bool good = true; src.second().count() < n && good; ) {
buf().fill(src);
good = buf().flush(dest);
}
return src.second().count();
}
template<typename Device>
void close(Device& dev)
{
detail::execute_all(
detail::flush_buffer(buf(), dev, (flags() & f_write) != 0),
detail::call_close_all(pimpl_->filter_, dev),
detail::clear_flags(flags())
);
}
private:
filter_ref filter() { return boost::ref(pimpl_->filter_); }
detail::buffer<char_type>& buf() { return pimpl_->buf_; }
int& flags() { return pimpl_->flags_; }
enum flags_ {
f_read = 1, f_write = 2
};
struct impl {
impl(const Filter& filter, std::streamsize n)
: filter_(filter), buf_(n), flags_(0)
{ buf_.set(0, 0); }
Filter filter_;
detail::buffer<char_type> buf_;
int flags_;
};
shared_ptr<impl> pimpl_;
};
//
// Template name: invert.
// Template parameters:
// Filter - A model of InputFilter or OutputFilter.
// Description: Returns an instance of an appropriate specialization of inverse.
//
template<typename Filter>
inverse<Filter> invert(const Filter& f) { return inverse<Filter>(f); }
//----------------------------------------------------------------------------//
} } // End namespaces iostreams, boost.
#include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC.
#endif // #ifndef BOOST_IOSTREAMS_INVERT_HPP_INCLUDED
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