1 /* 2 * Copyright Andrey Semashev 2007 - 2015. 3 * Distributed under the Boost Software License, Version 1.0. 4 * (See accompanying file LICENSE_1_0.txt or copy at 5 * http://www.boost.org/LICENSE_1_0.txt) 6 */ 7 /*! 8 * \file drop_on_overflow.hpp 9 * \author Andrey Semashev 10 * \date 04.01.2012 11 * 12 * The header contains implementation of \c drop_on_overflow strategy for handling 13 * queue overflows in bounded queues for the asynchronous sink frontend. 14 */ 15 16 #ifndef BOOST_LOG_SINKS_DROP_ON_OVERFLOW_HPP_INCLUDED_ 17 #define BOOST_LOG_SINKS_DROP_ON_OVERFLOW_HPP_INCLUDED_ 18 19 #include <boost/log/detail/config.hpp> 20 #include <boost/log/core/record_view.hpp> 21 #include <boost/log/detail/header.hpp> 22 23 #ifdef BOOST_HAS_PRAGMA_ONCE 24 #pragma once 25 #endif 26 27 namespace boost { 28 29 BOOST_LOG_OPEN_NAMESPACE 30 31 namespace sinks { 32 33 /*! 34 * \brief Log record dropping strategy 35 * 36 * This strategy will cause log records to be discarded in case of 37 * queue overflow in bounded asynchronous sinks. It should not be used 38 * if losing log records is not acceptable. 39 */ 40 class drop_on_overflow 41 { 42 #ifndef BOOST_LOG_DOXYGEN_PASS 43 public: 44 /*! 45 * This method is called by the queue when overflow is detected. 46 * 47 * \retval true Attempt to enqueue the record again. 48 * \retval false Discard the record. 49 */ 50 template< typename LockT > on_overflow(record_view const &,LockT &)51 static bool on_overflow(record_view const&, LockT&) 52 { 53 return false; 54 } 55 56 /*! 57 * This method is called by the queue when there appears a free space. 58 */ on_queue_space_available()59 static void on_queue_space_available() 60 { 61 } 62 63 /*! 64 * This method is called by the queue to interrupt any possible waits in \c on_overflow. 65 */ interrupt()66 static void interrupt() 67 { 68 } 69 #endif // BOOST_LOG_DOXYGEN_PASS 70 }; 71 72 } // namespace sinks 73 74 BOOST_LOG_CLOSE_NAMESPACE // namespace log 75 76 } // namespace boost 77 78 #include <boost/log/detail/footer.hpp> 79 80 #endif // BOOST_LOG_SINKS_DROP_ON_OVERFLOW_HPP_INCLUDED_ 81