common/buffer.h

   1 /*
   2  *  Copyright 2003 Adrian Thurston <thurston@cs.queensu.ca>
   3  */
   4
   5 /*  This file is part of Ragel.
   6  *
   7  *  Ragel is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  Ragel is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with Ragel; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #ifndef _BUFFER_H
  23 #define _BUFFER_H
  24
  25 #define BUFFER_INITIAL_SIZE 4096
  26
  27 /* An automatically grown buffer for collecting tokens. Always reuses space;
  28  * never down resizes. */
  29 struct Buffer
  30 {
  31         Buffer()
  32         {
  33                 data = (char*) malloc( BUFFER_INITIAL_SIZE );
  34                 allocated = BUFFER_INITIAL_SIZE;
  35                 length = 0;
  36         }
  37         ~Buffer() { free(data); }
  38
  39         void append( char p )
  40         {
  41                 if ( length == allocated ) {
  42                         allocated *= 2;
  43                         data = (char*) realloc( data, allocated );
  44                 }
  45                 data[length++] = p;
  46         }
  47
  48         void clear() { length = 0; }
  49
  50         char *data;
  51         int allocated;
  52         int length;
  53 };
  54
  55 #endif /* _BUFFER_H */