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   basic_sink_frontend.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   14.07.2009
Chris@16:  *
Chris@16:  * The header contains implementation of a base class for sink frontends.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_SINKS_BASIC_SINK_FRONTEND_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_SINKS_BASIC_SINK_FRONTEND_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/cleanup_scope_guard.hpp>
Chris@16: #include <boost/log/detail/code_conversion.hpp>
Chris@16: #include <boost/log/detail/attachable_sstream_buf.hpp>
Chris@16: #include <boost/log/detail/fake_mutex.hpp>
Chris@16: #include <boost/log/core/record_view.hpp>
Chris@16: #include <boost/log/sinks/sink.hpp>
Chris@16: #include <boost/log/sinks/frontend_requirements.hpp>
Chris@16: #include <boost/log/expressions/filter.hpp>
Chris@16: #include <boost/log/expressions/formatter.hpp>
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: #include <boost/thread/exceptions.hpp>
Chris@16: #include <boost/thread/tss.hpp>
Chris@16: #include <boost/thread/locks.hpp>
Chris@16: #include <boost/log/detail/locks.hpp>
Chris@16: #include <boost/log/detail/light_rw_mutex.hpp>
Chris@16: #endif // !defined(BOOST_LOG_NO_THREADS)
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 sinks {
Chris@16: 
Chris@16: //! A base class for a logging sink frontend
Chris@16: class BOOST_LOG_NO_VTABLE basic_sink_frontend :
Chris@16:     public sink
Chris@16: {
Chris@16:     //! Base type
Chris@16:     typedef sink base_type;
Chris@16: 
Chris@16: public:
Chris@16:     //! An exception handler type
Chris@16:     typedef base_type::exception_handler_type exception_handler_type;
Chris@16: 
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: protected:
Chris@16:     //! Mutex type
Chris@16:     typedef boost::log::aux::light_rw_mutex mutex_type;
Chris@16: 
Chris@16: private:
Chris@16:     //! Synchronization mutex
Chris@16:     mutable mutex_type m_Mutex;
Chris@16: #endif
Chris@16: 
Chris@16: private:
Chris@16:     //! Filter
Chris@16:     filter m_Filter;
Chris@16:     //! Exception handler
Chris@16:     exception_handler_type m_ExceptionHandler;
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * \brief Initializing constructor
Chris@16:      *
Chris@16:      * \param cross_thread The flag indicates whether the sink passes log records between different threads
Chris@16:      */
Chris@16:     explicit basic_sink_frontend(bool cross_thread) : sink(cross_thread)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets sink-specific filter functional object
Chris@16:      */
Chris@16:     template< typename FunT >
Chris@16:     void set_filter(FunT const& filter)
Chris@16:     {
Chris@16:         BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:         m_Filter = filter;
Chris@16:     }
Chris@16:     /*!
Chris@16:      * The method resets the filter
Chris@16:      */
Chris@16:     void reset_filter()
Chris@16:     {
Chris@16:         BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:         m_Filter.reset();
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets an exception handler function
Chris@16:      */
Chris@16:     template< typename FunT >
Chris@16:     void set_exception_handler(FunT const& handler)
Chris@16:     {
Chris@16:         BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:         m_ExceptionHandler = handler;
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method resets the exception handler function
Chris@16:      */
Chris@16:     void reset_exception_handler()
Chris@16:     {
Chris@16:         BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:         m_ExceptionHandler.clear();
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method returns \c true if no filter is set or the attribute values pass the filter
Chris@16:      *
Chris@16:      * \param attrs A set of attribute values of a logging record
Chris@16:      */
Chris@16:     bool will_consume(attribute_value_set const& attrs)
Chris@16:     {
Chris@16:         BOOST_LOG_EXPR_IF_MT(boost::log::aux::shared_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:         try
Chris@16:         {
Chris@16:             return m_Filter(attrs);
Chris@16:         }
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             if (m_ExceptionHandler.empty())
Chris@16:                 throw;
Chris@16:             m_ExceptionHandler();
Chris@16:             return false;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16: protected:
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:     //! Returns reference to the frontend mutex
Chris@16:     mutex_type& frontend_mutex() const { return m_Mutex; }
Chris@16: #endif
Chris@16: 
Chris@16:     //! Returns reference to the exception handler
Chris@16:     exception_handler_type& exception_handler() { return m_ExceptionHandler; }
Chris@16:     //! Returns reference to the exception handler
Chris@16:     exception_handler_type const& exception_handler() const { return m_ExceptionHandler; }
Chris@16: 
Chris@16:     //! Feeds log record to the backend
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     void feed_record(record_view const& rec, BackendMutexT& backend_mutex, BackendT& backend)
Chris@16:     {
Chris@16:         try
Chris@16:         {
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< BackendMutexT > lock(backend_mutex);)
Chris@16:             backend.consume(rec);
Chris@16:         }
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::shared_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:             if (m_ExceptionHandler.empty())
Chris@16:                 throw;
Chris@16:             m_ExceptionHandler();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     //! Attempts to feeds log record to the backend, does not block if \a backend_mutex is locked
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     bool try_feed_record(record_view const& rec, BackendMutexT& backend_mutex, BackendT& backend)
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         unique_lock< BackendMutexT > lock;
Chris@16:         try
Chris@16:         {
Chris@16:             unique_lock< BackendMutexT > tmp_lock(backend_mutex, try_to_lock);
Chris@16:             if (!tmp_lock.owns_lock())
Chris@16:                 return false;
Chris@16:             lock.swap(tmp_lock);
Chris@16:         }
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             boost::log::aux::shared_lock_guard< mutex_type > frontend_lock(this->frontend_mutex());
Chris@16:             if (this->exception_handler().empty())
Chris@16:                 throw;
Chris@16:             this->exception_handler()();
Chris@101:             return false;
Chris@16:         }
Chris@16: #endif
Chris@16:         // No need to lock anything in the feed_record method
Chris@16:         boost::log::aux::fake_mutex m;
Chris@16:         feed_record(rec, m, backend);
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     //! Flushes record buffers in the backend, if one supports it
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     void flush_backend(BackendMutexT& backend_mutex, BackendT& backend)
Chris@16:     {
Chris@16:         typedef typename BackendT::frontend_requirements frontend_requirements;
Chris@16:         flush_backend_impl(backend_mutex, backend,
Chris@16:             typename has_requirement< frontend_requirements, flushing >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     //! Flushes record buffers in the backend (the actual implementation)
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     void flush_backend_impl(BackendMutexT& backend_mutex, BackendT& backend, mpl::true_)
Chris@16:     {
Chris@16:         try
Chris@16:         {
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< BackendMutexT > lock(backend_mutex);)
Chris@16:             backend.flush();
Chris@16:         }
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::shared_lock_guard< mutex_type > lock(m_Mutex);)
Chris@16:             if (m_ExceptionHandler.empty())
Chris@16:                 throw;
Chris@16:             m_ExceptionHandler();
Chris@16:         }
Chris@16:     }
Chris@16:     //! Flushes record buffers in the backend (stub for backends that don't support flushing)
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     void flush_backend_impl(BackendMutexT&, BackendT&, mpl::false_)
Chris@16:     {
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! A base class for a logging sink frontend with formatting support
Chris@16: template< typename CharT >
Chris@16: class BOOST_LOG_NO_VTABLE basic_formatting_sink_frontend :
Chris@16:     public basic_sink_frontend
Chris@16: {
Chris@16:     typedef basic_sink_frontend base_type;
Chris@16: 
Chris@16: public:
Chris@16:     //! Character type
Chris@16:     typedef CharT char_type;
Chris@16:     //! Formatted string type
Chris@16:     typedef std::basic_string< char_type > string_type;
Chris@16: 
Chris@16:     //! Formatter function object type
Chris@16:     typedef basic_formatter< char_type > formatter_type;
Chris@16:     //! Output stream type
Chris@16:     typedef typename formatter_type::stream_type stream_type;
Chris@16: 
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: protected:
Chris@16:     //! Mutex type
Chris@16:     typedef typename base_type::mutex_type mutex_type;
Chris@16: #endif
Chris@16: 
Chris@16: private:
Chris@16:     struct formatting_context
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         //! Object version
Chris@16:         const unsigned int m_Version;
Chris@16: #endif
Chris@16:         //! Formatted log record storage
Chris@16:         string_type m_FormattedRecord;
Chris@16:         //! Formatting stream
Chris@16:         stream_type m_FormattingStream;
Chris@16:         //! Formatter functor
Chris@16:         formatter_type m_Formatter;
Chris@16: 
Chris@16:         formatting_context() :
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:             m_Version(0),
Chris@16: #endif
Chris@16:             m_FormattingStream(m_FormattedRecord)
Chris@16:         {
Chris@16:             m_FormattingStream.exceptions(std::ios_base::badbit | std::ios_base::failbit);
Chris@16:         }
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         formatting_context(unsigned int version, std::locale const& loc, formatter_type const& formatter) :
Chris@16:             m_Version(version),
Chris@16:             m_FormattingStream(m_FormattedRecord),
Chris@16:             m_Formatter(formatter)
Chris@16:         {
Chris@16:             m_FormattingStream.exceptions(std::ios_base::badbit | std::ios_base::failbit);
Chris@16:             m_FormattingStream.imbue(loc);
Chris@16:         }
Chris@16: #endif
Chris@16:     };
Chris@16: 
Chris@16: private:
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: 
Chris@16:     //! State version
Chris@16:     volatile unsigned int m_Version;
Chris@16: 
Chris@16:     //! Formatter functor
Chris@16:     formatter_type m_Formatter;
Chris@16:     //! Locale to perform formatting
Chris@16:     std::locale m_Locale;
Chris@16: 
Chris@16:     //! Formatting state
Chris@16:     thread_specific_ptr< formatting_context > m_pContext;
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16:     //! Formatting state
Chris@16:     formatting_context m_Context;
Chris@16: 
Chris@16: #endif // !defined(BOOST_LOG_NO_THREADS)
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * \brief Initializing constructor
Chris@16:      *
Chris@16:      * \param cross_thread The flag indicates whether the sink passes log records between different threads
Chris@16:      */
Chris@16:     explicit basic_formatting_sink_frontend(bool cross_thread) :
Chris@16:         basic_sink_frontend(cross_thread)
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         , m_Version(0)
Chris@16: #endif
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets sink-specific formatter function object
Chris@16:      */
Chris@16:     template< typename FunT >
Chris@16:     void set_formatter(FunT const& formatter)
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         boost::log::aux::exclusive_lock_guard< mutex_type > lock(this->frontend_mutex());
Chris@16:         m_Formatter = formatter;
Chris@16:         ++m_Version;
Chris@16: #else
Chris@16:         m_Context.m_Formatter = formatter;
Chris@16: #endif
Chris@16:     }
Chris@16:     /*!
Chris@16:      * The method resets the formatter
Chris@16:      */
Chris@16:     void reset_formatter()
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         boost::log::aux::exclusive_lock_guard< mutex_type > lock(this->frontend_mutex());
Chris@16:         m_Formatter.reset();
Chris@16:         ++m_Version;
Chris@16: #else
Chris@16:         m_Context.m_Formatter.reset();
Chris@16: #endif
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method returns the current locale used for formatting
Chris@16:      */
Chris@16:     std::locale getloc() const
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         boost::log::aux::exclusive_lock_guard< mutex_type > lock(this->frontend_mutex());
Chris@16:         return m_Locale;
Chris@16: #else
Chris@16:         return m_Context.m_FormattingStream.getloc();
Chris@16: #endif
Chris@16:     }
Chris@16:     /*!
Chris@16:      * The method sets the locale used for formatting
Chris@16:      */
Chris@16:     void imbue(std::locale const& loc)
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         boost::log::aux::exclusive_lock_guard< mutex_type > lock(this->frontend_mutex());
Chris@16:         m_Locale = loc;
Chris@16:         ++m_Version;
Chris@16: #else
Chris@16:         m_Context.m_FormattingStream.imbue(loc);
Chris@16: #endif
Chris@16:     }
Chris@16: 
Chris@16: protected:
Chris@16:     //! Returns reference to the formatter
Chris@16:     formatter_type& formatter()
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         return m_Formatter;
Chris@16: #else
Chris@16:         return m_Context.m_Formatter;
Chris@16: #endif
Chris@16:     }
Chris@16: 
Chris@16:     //! Feeds log record to the backend
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     void feed_record(record_view const& rec, BackendMutexT& backend_mutex, BackendT& backend)
Chris@16:     {
Chris@16:         formatting_context* context;
Chris@16: 
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         context = m_pContext.get();
Chris@16:         if (!context || context->m_Version != m_Version)
Chris@16:         {
Chris@16:             {
Chris@16:                 boost::log::aux::shared_lock_guard< mutex_type > lock(this->frontend_mutex());
Chris@16:                 context = new formatting_context(m_Version, m_Locale, m_Formatter);
Chris@16:             }
Chris@16:             m_pContext.reset(context);
Chris@16:         }
Chris@16: #else
Chris@16:         context = &m_Context;
Chris@16: #endif
Chris@16: 
Chris@16:         boost::log::aux::cleanup_guard< stream_type > cleanup1(context->m_FormattingStream);
Chris@16:         boost::log::aux::cleanup_guard< string_type > cleanup2(context->m_FormattedRecord);
Chris@16: 
Chris@16:         try
Chris@16:         {
Chris@16:             // Perform the formatting
Chris@16:             context->m_Formatter(rec, context->m_FormattingStream);
Chris@16:             context->m_FormattingStream.flush();
Chris@16: 
Chris@16:             // Feed the record
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::exclusive_lock_guard< BackendMutexT > lock(backend_mutex);)
Chris@16:             backend.consume(rec, context->m_FormattedRecord);
Chris@16:         }
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             BOOST_LOG_EXPR_IF_MT(boost::log::aux::shared_lock_guard< mutex_type > lock(this->frontend_mutex());)
Chris@16:             if (this->exception_handler().empty())
Chris@16:                 throw;
Chris@16:             this->exception_handler()();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     //! Attempts to feeds log record to the backend, does not block if \a backend_mutex is locked
Chris@16:     template< typename BackendMutexT, typename BackendT >
Chris@16:     bool try_feed_record(record_view const& rec, BackendMutexT& backend_mutex, BackendT& backend)
Chris@16:     {
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16:         unique_lock< BackendMutexT > lock;
Chris@16:         try
Chris@16:         {
Chris@16:             unique_lock< BackendMutexT > tmp_lock(backend_mutex, try_to_lock);
Chris@16:             if (!tmp_lock.owns_lock())
Chris@16:                 return false;
Chris@16:             lock.swap(tmp_lock);
Chris@16:         }
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             boost::log::aux::shared_lock_guard< mutex_type > frontend_lock(this->frontend_mutex());
Chris@16:             if (this->exception_handler().empty())
Chris@16:                 throw;
Chris@16:             this->exception_handler()();
Chris@101:             return false;
Chris@16:         }
Chris@16: #endif
Chris@16:         // No need to lock anything in the feed_record method
Chris@16:         boost::log::aux::fake_mutex m;
Chris@16:         feed_record(rec, m, backend);
Chris@16:         return true;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16:     template<
Chris@16:         typename BackendT,
Chris@16:         bool RequiresFormattingV = has_requirement<
Chris@16:             typename BackendT::frontend_requirements,
Chris@16:             formatted_records
Chris@16:         >::value
Chris@16:     >
Chris@16:     struct make_sink_frontend_base
Chris@16:     {
Chris@16:         typedef basic_sink_frontend type;
Chris@16:     };
Chris@16:     template< typename BackendT >
Chris@16:     struct make_sink_frontend_base< BackendT, true >
Chris@16:     {
Chris@16:         typedef basic_formatting_sink_frontend< typename BackendT::char_type > type;
Chris@16:     };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: } // namespace sinks
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_SINKS_BASIC_SINK_FRONTEND_HPP_INCLUDED_