src/IO/LineSplitter.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_IO_LINE_SOURCE_HPP
  25 #define XCSOAR_IO_LINE_SOURCE_HPP
  26
  27 #include "LineReader.hpp"
  28 #include "Source.hpp"
  29 #include "Util/ReusableArray.hpp"
  30
  31 #include <utility>
  32
  33 /**
  34  * An adapter for a Source object which reads line-by-line.  It is
  35  * limited to narrow characters, but may work with multi-byte
  36  * characters.  It assumes that lines are delimited by a linefeed
  37  * character, and deletes carriage returns.
  38  *
  39  * The maximum length of a line is limited by the buffer size of the
  40  * Source object.
  41  */
  42 class LineSplitter : public NLineReader {
  43 protected:
  44   Source<char> &source;
  45
  46   /**
  47    * The remaining range of the buffer returned by the Source.
  48    */
  49   Source<char>::Range remaining;
  50
  51   /** a buffer for guaranteeing that the last line is
  52       null-terminated */
  53   ReusableArray<char> last;
  54
  55 public:
  56   LineSplitter(Source<char> &_source)
  57     :source(_source), remaining((char *)NULL, 0) {}
  58
  59   /**
  60    * Discards the buffer that holds the data after the last line.
  61    * This can be used to implement Source::Rewind(): after rewinding
  62    * the Source object, the LineSplitter must forget the buffer.
  63    */
  64   void ResetBuffer() {
  65     remaining.length = 0;
  66   }
  67
  68   /* virtual methods from class NLineReader */
  69   virtual char *ReadLine() override;
  70   virtual long GetSize() const override;
  71   virtual long Tell() const override;
  72 };
  73
  74 #endif