Line data    Source code

       1              : /*
       2              :  * Copyright (c) 2012-2015:  G-CSC, Goethe University Frankfurt
       3              :  * Author: Sebastian Reiter
       4              :  * 
       5              :  * This file is part of UG4.
       6              :  * 
       7              :  * UG4 is free software: you can redistribute it and/or modify it under the
       8              :  * terms of the GNU Lesser General Public License version 3 (as published by the
       9              :  * Free Software Foundation) with the following additional attribution
      10              :  * requirements (according to LGPL/GPL v3 §7):
      11              :  * 
      12              :  * (1) The following notice must be displayed in the Appropriate Legal Notices
      13              :  * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
      14              :  * 
      15              :  * (2) The following notice must be displayed at a prominent place in the
      16              :  * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
      17              :  * 
      18              :  * (3) The following bibliography is recommended for citation and must be
      19              :  * preserved in all covered files:
      20              :  * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
      21              :  *   parallel geometric multigrid solver on hierarchically distributed grids.
      22              :  *   Computing and visualization in science 16, 4 (2013), 151-164"
      23              :  * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
      24              :  *   flexible software system for simulating pde based models on high performance
      25              :  *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
      26              :  * 
      27              :  * This program is distributed in the hope that it will be useful,
      28              :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      29              :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      30              :  * GNU Lesser General Public License for more details.
      31              :  */
      32              : 
      33              : #ifndef __H__UG__empty_stream__
      34              : #define __H__UG__empty_stream__
      35              : 
      36              : #include <iostream>
      37              : 
      38              : namespace ug
      39              : {
      40              : 
      41              : /// \addtogroup ugbase_common_io
      42              : /// \{
      43              : 
      44              : ///     Used by EmptyStream, to send tokens into nirvana!
      45              : /**     Note that the implementation is not really the fastest, since a virtual
      46              :  * function is called for each token. However, not much is done in that
      47              :  * virtual function...
      48              :  */
      49            0 : class EmptyStreamBuffer : public std::streambuf
      50              : {
      51              :         public:
      52              :                 EmptyStreamBuffer()
      53            1 :                         {setp(m_buf, m_buf + BUF_SIZE);}
      54              : 
      55              :         //      implementation of virtual std::streambuf methods.
      56            0 :                 inline virtual int_type overflow(int_type c = traits_type::eof())
      57              :                 {
      58            0 :                         setp(m_buf, m_buf + BUF_SIZE);
      59            0 :                         return c;
      60              :                 }
      61              : 
      62              :         protected:
      63              :                 static const int        BUF_SIZE = 128;
      64              :                 char_type       m_buf[BUF_SIZE];
      65              : };
      66              : 
      67              : 
      68              : ///     a specialization of std::ostream, which doesn't write anything
      69              : /**     The intention of the empty-buffer is, that methods and functions in
      70              :  * a stream are executed, even if nothing shall be printed or be written to
      71              :  * a file. This is important since it allows us to to call communicating
      72              :  * methods during parallel output without risking a stall.
      73              :  */
      74              : class EmptyOStream : public std::ostream
      75              : {
      76              :         public:
      77              :                 EmptyOStream() : std::ostream(&m_streamBuf) {}
      78              : 
      79              :         protected:
      80              :                 EmptyStreamBuffer       m_streamBuf;
      81              : };
      82              : 
      83              : // end group ugbase_common_io
      84              : /// \}
      85              : 
      86              : }//     end of namespace
      87              : 
      88              : #endif