ceph/src/boost/libs/log/include/boost/log/sinks/drop_on_overflow.hpp

   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 >
  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      */
  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      */
  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_