Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   attachable_sstream_buf.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   29.07.2007
Chris@16:  *
Chris@16:  * \brief  This header is the Boost.Log library implementation, see the library documentation
Chris@16:  *         at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_ATTACHABLE_SSTREAM_BUF_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_ATTACHABLE_SSTREAM_BUF_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <memory>
Chris@16: #include <string>
Chris@16: #include <streambuf>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/utility/addressof.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: //! A streambuf that puts the formatted data to an external string
Chris@16: template<
Chris@16:     typename CharT,
Chris@16:     typename TraitsT = std::char_traits< CharT >,
Chris@16:     typename AllocatorT = std::allocator< CharT >
Chris@16: >
Chris@16: class basic_ostringstreambuf :
Chris@16:     public std::basic_streambuf< CharT, TraitsT >
Chris@16: {
Chris@16:     //! Self type
Chris@16:     typedef basic_ostringstreambuf< CharT, TraitsT, AllocatorT > this_type;
Chris@16:     //! Base type
Chris@16:     typedef std::basic_streambuf< CharT, TraitsT > base_type;
Chris@16: 
Chris@16:     //! Buffer size
Chris@16:     enum { buffer_size = 16 };
Chris@16: 
Chris@16: public:
Chris@16:     //! Character type
Chris@16:     typedef typename base_type::char_type char_type;
Chris@16:     //! Traits type
Chris@16:     typedef typename base_type::traits_type traits_type;
Chris@16:     //! String type
Chris@16:     typedef std::basic_string< char_type, traits_type, AllocatorT > string_type;
Chris@16:     //! Int type
Chris@16:     typedef typename base_type::int_type int_type;
Chris@16: 
Chris@16: private:
Chris@16:     //! A reference to the string that will be filled
Chris@16:     string_type* m_Storage;
Chris@16:     //! A buffer used to temporarily store output
Chris@16:     char_type m_Buffer[buffer_size];
Chris@16: 
Chris@16: public:
Chris@16:     //! Constructor
Chris@16:     explicit basic_ostringstreambuf() : m_Storage(0)
Chris@16:     {
Chris@16:         base_type::setp(m_Buffer, m_Buffer + (sizeof(m_Buffer) / sizeof(*m_Buffer)));
Chris@16:     }
Chris@16:     //! Constructor
Chris@16:     explicit basic_ostringstreambuf(string_type& storage) : m_Storage(boost::addressof(storage))
Chris@16:     {
Chris@16:         base_type::setp(m_Buffer, m_Buffer + (sizeof(m_Buffer) / sizeof(*m_Buffer)));
Chris@16:     }
Chris@16: 
Chris@16:     //! Clears the buffer to the initial state
Chris@16:     void clear()
Chris@16:     {
Chris@101:         char_type* pBase = this->pbase();
Chris@101:         char_type* pPtr = this->pptr();
Chris@16:         if (pBase != pPtr)
Chris@16:             this->pbump(static_cast< int >(pBase - pPtr));
Chris@16:     }
Chris@16: 
Chris@16:     //! Detaches the buffer from the string
Chris@16:     void detach()
Chris@16:     {
Chris@16:         if (m_Storage)
Chris@16:         {
Chris@16:             this_type::sync();
Chris@16:             m_Storage = 0;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     //! Attaches the buffer to another string
Chris@16:     void attach(string_type& storage)
Chris@16:     {
Chris@16:         detach();
Chris@16:         m_Storage = boost::addressof(storage);
Chris@16:     }
Chris@16: 
Chris@16:     //! Returns a pointer to the attached string
Chris@16:     string_type* storage() const { return m_Storage; }
Chris@16: 
Chris@16: protected:
Chris@16:     //! Puts all buffered data to the string
Chris@16:     int sync()
Chris@16:     {
Chris@16:         BOOST_ASSERT(m_Storage != 0);
Chris@101:         char_type* pBase = this->pbase();
Chris@101:         char_type* pPtr = this->pptr();
Chris@16:         if (pBase != pPtr)
Chris@16:         {
Chris@16:             m_Storage->append(pBase, pPtr);
Chris@16:             this->pbump(static_cast< int >(pBase - pPtr));
Chris@16:         }
Chris@16:         return 0;
Chris@16:     }
Chris@16:     //! Puts an unbuffered character to the string
Chris@16:     int_type overflow(int_type c)
Chris@16:     {
Chris@16:         BOOST_ASSERT(m_Storage != 0);
Chris@16:         basic_ostringstreambuf::sync();
Chris@16:         if (!traits_type::eq_int_type(c, traits_type::eof()))
Chris@16:         {
Chris@16:             m_Storage->push_back(traits_type::to_char_type(c));
Chris@16:             return c;
Chris@16:         }
Chris@16:         else
Chris@16:             return traits_type::not_eof(c);
Chris@16:     }
Chris@16:     //! Puts a character sequence to the string
Chris@16:     std::streamsize xsputn(const char_type* s, std::streamsize n)
Chris@16:     {
Chris@16:         BOOST_ASSERT(m_Storage != 0);
Chris@16:         basic_ostringstreambuf::sync();
Chris@16:         typedef typename string_type::size_type string_size_type;
Chris@101:         const string_size_type max_storage_left =
Chris@16:             m_Storage->max_size() - m_Storage->size();
Chris@16:         if (static_cast< string_size_type >(n) < max_storage_left)
Chris@16:         {
Chris@16:             m_Storage->append(s, static_cast< string_size_type >(n));
Chris@16:             return n;
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             m_Storage->append(s, max_storage_left);
Chris@16:             return static_cast< std::streamsize >(max_storage_left);
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     //! Copy constructor (closed)
Chris@16:     BOOST_DELETED_FUNCTION(basic_ostringstreambuf(basic_ostringstreambuf const& that))
Chris@16:     //! Assignment (closed)
Chris@16:     BOOST_DELETED_FUNCTION(basic_ostringstreambuf& operator= (basic_ostringstreambuf const& that))
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // BOOST_LOG_ATTACHABLE_SSTREAM_BUF_HPP_INCLUDED_