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   format.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   15.11.2012
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_DETAIL_FORMAT_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_DETAIL_FORMAT_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <string>
Chris@16: #include <vector>
Chris@16: #include <iosfwd>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/move/core.hpp>
Chris@16: #include <boost/move/utility.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/unhandled_exception_count.hpp>
Chris@16: #include <boost/log/detail/cleanup_scope_guard.hpp>
Chris@16: #include <boost/log/utility/formatting_ostream.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: //! An element (either literal or placeholder) of the format string
Chris@16: struct format_element
Chris@16: {
Chris@16:     //! Argument placeholder number or -1 if it's not a placeholder (i.e. a literal)
Chris@16:     int arg_number;
Chris@16:     //! If the element describes a constant literal, the starting character and length of the literal
Chris@16:     unsigned int literal_start_pos, literal_len;
Chris@16: 
Chris@16:     format_element() : arg_number(0), literal_start_pos(0), literal_len(0)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     static format_element literal(unsigned int start_pos, unsigned int len)
Chris@16:     {
Chris@16:         format_element el;
Chris@16:         el.arg_number = -1;
Chris@16:         el.literal_start_pos = start_pos;
Chris@16:         el.literal_len = len;
Chris@16:         return el;
Chris@16:     }
Chris@16: 
Chris@16:     static format_element positional_argument(unsigned int arg_n)
Chris@16:     {
Chris@16:         format_element el;
Chris@16:         el.arg_number = arg_n;
Chris@16:         return el;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Parsed format string description
Chris@16: template< typename CharT >
Chris@16: struct format_description
Chris@16: {
Chris@16:     BOOST_COPYABLE_AND_MOVABLE_ALT(format_description)
Chris@16: 
Chris@16: public:
Chris@16:     //! Character type
Chris@16:     typedef CharT char_type;
Chris@16:     //! String type
Chris@16:     typedef std::basic_string< char_type > string_type;
Chris@16: 
Chris@16:     //! Array of format element descriptors
Chris@16:     typedef std::vector< format_element > format_element_list;
Chris@16: 
Chris@16:     //! Characters of all literal parts of the format string
Chris@16:     string_type literal_chars;
Chris@16:     //! Format element descriptors
Chris@16:     format_element_list format_elements;
Chris@16: 
Chris@16:     BOOST_DEFAULTED_FUNCTION(format_description(), {})
Chris@16: 
Chris@16:     format_description(format_description const& that) : literal_chars(that.literal_chars), format_elements(that.format_elements)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     format_description(BOOST_RV_REF(format_description) that)
Chris@16:     {
Chris@16:         literal_chars.swap(that.literal_chars);
Chris@16:         format_elements.swap(that.format_elements);
Chris@16:     }
Chris@16: 
Chris@16:     format_description& operator= (format_description that)
Chris@16:     {
Chris@16:         literal_chars.swap(that.literal_chars);
Chris@16:         format_elements.swap(that.format_elements);
Chris@16:         return *this;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Parses format string
Chris@16: template< typename CharT >
Chris@16: BOOST_LOG_API format_description< CharT > parse_format(const CharT* begin, const CharT* end);
Chris@16: 
Chris@16: //! Parses format string
Chris@16: template< typename CharT >
Chris@16: BOOST_FORCEINLINE format_description< CharT > parse_format(const CharT* begin)
Chris@16: {
Chris@16:     return parse_format(begin, begin + std::char_traits< CharT >::length(begin));
Chris@16: }
Chris@16: 
Chris@16: //! Parses format string
Chris@16: template< typename CharT, typename TraitsT, typename AllocatorT >
Chris@16: BOOST_FORCEINLINE format_description< CharT > parse_format(std::basic_string< CharT, TraitsT, AllocatorT > const& fmt)
Chris@16: {
Chris@16:     const CharT* begin = fmt.c_str();
Chris@16:     return parse_format(begin, begin + fmt.size());
Chris@16: }
Chris@16: 
Chris@16: //! Formatter object
Chris@16: template< typename CharT >
Chris@16: class basic_format
Chris@16: {
Chris@16: public:
Chris@16:     //! Character type
Chris@16:     typedef CharT char_type;
Chris@16:     //! String type
Chris@16:     typedef std::basic_string< char_type > string_type;
Chris@16:     //! Stream type
Chris@16:     typedef basic_formatting_ostream< char_type > stream_type;
Chris@16:     //! Format description type
Chris@16:     typedef format_description< char_type > format_description_type;
Chris@16: 
Chris@16:     //! The pump receives arguments and formats them into strings. At destruction the pump composes the final string in the attached stream.
Chris@16:     class pump;
Chris@16:     friend class pump;
Chris@16: 
Chris@16: private:
Chris@16:     //! Formatting params for a single placeholder in the format string
Chris@16:     struct formatting_params
Chris@16:     {
Chris@16:         //! Formatting element index in the format description
Chris@16:         unsigned int element_idx;
Chris@16:         //! Formatting result
Chris@16:         string_type target;
Chris@16: 
Chris@16:         formatting_params() : element_idx(~0u) {}
Chris@16:     };
Chris@16:     typedef std::vector< formatting_params > formatting_params_list;
Chris@16: 
Chris@16: private:
Chris@16:     //! Format string description
Chris@16:     format_description_type m_format;
Chris@16:     //! Formatting parameters for all placeholders
Chris@16:     formatting_params_list m_formatting_params;
Chris@16:     //! Current formatting position
Chris@16:     unsigned int m_current_idx;
Chris@16: 
Chris@16: public:
Chris@16:     //! Initializing constructor
Chris@16:     explicit basic_format(string_type const& fmt) : m_format(aux::parse_format(fmt)), m_current_idx(0)
Chris@16:     {
Chris@16:         init_params();
Chris@16:     }
Chris@16:     //! Initializing constructor
Chris@16:     explicit basic_format(const char_type* fmt) : m_format(aux::parse_format(fmt)), m_current_idx(0)
Chris@16:     {
Chris@16:         init_params();
Chris@16:     }
Chris@16: 
Chris@16:     //! Clears all formatted strings and resets the current formatting position
Chris@16:     void clear() BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         for (typename formatting_params_list::iterator it = m_formatting_params.begin(), end = m_formatting_params.end(); it != end; ++it)
Chris@16:         {
Chris@16:             it->target.clear();
Chris@16:         }
Chris@16:         m_current_idx = 0;
Chris@16:     }
Chris@16: 
Chris@16:     //! Creates a pump that will receive all format arguments and put the formatted string into the stream
Chris@16:     pump make_pump(stream_type& strm) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return pump(*this, strm);
Chris@16:     }
Chris@16: 
Chris@16:     //! Composes the final string from the formatted pieces
Chris@16:     void compose(string_type& str) const
Chris@16:     {
Chris@16:         typename format_description_type::format_element_list::const_iterator it = m_format.format_elements.begin(), end = m_format.format_elements.end();
Chris@16:         for (; it != end; ++it)
Chris@16:         {
Chris@16:             if (it->arg_number >= 0)
Chris@16:             {
Chris@16:                 // This is a placeholder
Chris@16:                 str.append(m_formatting_params[it->arg_number].target);
Chris@16:             }
Chris@16:             else
Chris@16:             {
Chris@16:                 // This is a literal
Chris@16:                 const char_type* p = m_format.literal_chars.c_str() + it->literal_start_pos;
Chris@16:                 str.append(p, it->literal_len);
Chris@16:             }
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     //! Composes the final string from the formatted pieces
Chris@16:     string_type str() const
Chris@16:     {
Chris@16:         string_type result;
Chris@16:         compose(result);
Chris@16:         return boost::move(result);
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     //! Initializes the formatting params
Chris@16:     void init_params()
Chris@16:     {
Chris@16:         typename format_description_type::format_element_list::const_iterator it = m_format.format_elements.begin(), end = m_format.format_elements.end();
Chris@16:         for (; it != end; ++it)
Chris@16:         {
Chris@16:             if (it->arg_number >= 0)
Chris@16:             {
Chris@16:                 if (static_cast< unsigned int >(it->arg_number) >= m_formatting_params.size())
Chris@16:                     m_formatting_params.resize(it->arg_number + 1);
Chris@16:                 m_formatting_params[it->arg_number].element_idx = static_cast< unsigned int >(it - m_format.format_elements.begin());
Chris@16:             }
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! The pump receives arguments and formats them into strings. At destruction the pump composes the final string in the attached stream.
Chris@16: template< typename CharT >
Chris@16: class basic_format< CharT >::pump
Chris@16: {
Chris@16:     BOOST_MOVABLE_BUT_NOT_COPYABLE(pump)
Chris@16: 
Chris@16: private:
Chris@16:     //! The guard temporarily replaces storage string in the specified stream
Chris@16:     struct scoped_storage
Chris@16:     {
Chris@16:         scoped_storage(stream_type& strm, string_type& storage) : m_stream(strm), m_storage_backup(*strm.rdbuf()->storage())
Chris@16:         {
Chris@16:             strm.attach(storage);
Chris@16:         }
Chris@16:         ~scoped_storage()
Chris@16:         {
Chris@16:             m_stream.attach(m_storage_backup);
Chris@16:         }
Chris@16: 
Chris@16:     private:
Chris@16:         stream_type& m_stream;
Chris@16:         string_type& m_storage_backup;
Chris@16:     };
Chris@16: 
Chris@16: private:
Chris@16:     //! Reference to the owner
Chris@16:     basic_format* m_owner;
Chris@16:     //! Reference to the stream
Chris@16:     stream_type* m_stream;
Chris@16:     //! Unhandled exception count
Chris@16:     const unsigned int m_exception_count;
Chris@16: 
Chris@16: public:
Chris@16:     //! Initializing constructor
Chris@16:     pump(basic_format& owner, stream_type& strm) BOOST_NOEXCEPT : m_owner(&owner), m_stream(&strm), m_exception_count(unhandled_exception_count())
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     //! Move constructor
Chris@16:     pump(BOOST_RV_REF(pump) that) BOOST_NOEXCEPT : m_owner(that.m_owner), m_stream(that.m_stream), m_exception_count(that.m_exception_count)
Chris@16:     {
Chris@16:         that.m_owner = NULL;
Chris@16:         that.m_stream = NULL;
Chris@16:     }
Chris@16: 
Chris@16:     //! Destructor
Chris@16:     ~pump() BOOST_NOEXCEPT_IF(false)
Chris@16:     {
Chris@16:         if (m_owner)
Chris@16:         {
Chris@16:             // Whether or not the destructor is called because of an exception, the format object has to be cleared
Chris@16:             boost::log::aux::cleanup_guard< basic_format< char_type > > cleanup1(*m_owner);
Chris@16: 
Chris@16:             BOOST_ASSERT(m_stream != NULL);
Chris@16:             if (m_exception_count >= unhandled_exception_count())
Chris@16:             {
Chris@16:                 // Compose the final string in the stream buffer
Chris@16:                 m_stream->flush();
Chris@16:                 m_owner->compose(*m_stream->rdbuf()->storage());
Chris@16:             }
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * Puts an argument to the formatter. Note the pump has to be returned by value and not by reference in order this to
Chris@16:      * work with Boost.Phoenix expressions. Otherwise the pump that is returned from \c basic_format::make_pump is
Chris@16:      * destroyed after the first call to \c operator%, and the returned reference becomes dangling.
Chris@16:      */
Chris@16:     template< typename T >
Chris@16:     pump operator% (T const& val)
Chris@16:     {
Chris@16:         BOOST_ASSERT_MSG(m_owner != NULL && m_stream != NULL, "Boost.Log: This basic_format::pump has already been moved from");
Chris@16: 
Chris@16:         if (m_owner->m_current_idx < m_owner->m_formatting_params.size())
Chris@16:         {
Chris@16:             scoped_storage storage_guard(*m_stream, m_owner->m_formatting_params[m_owner->m_current_idx].target);
Chris@16: 
Chris@16:             *m_stream << val;
Chris@16:             m_stream->flush();
Chris@16: 
Chris@16:             ++m_owner->m_current_idx;
Chris@16:         }
Chris@16: 
Chris@16:         return boost::move(*this);
Chris@16:     }
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@101: #endif // BOOST_LOG_DETAIL_FORMAT_HPP_INCLUDED_