libjava/classpath/gnu/xml/stream/CRLFReader.java

   1 /* CRLFReader.java --
   2    Copyright (C) 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.xml.stream;
  39
  40 import java.io.BufferedReader;
  41 import java.io.IOException;
  42 import java.io.Reader;
  43
  44 /**
  45  * Filtered reader that normalizes CRLF pairs into LFs.
  46  *
  47  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  48  */
  49 class CRLFReader
  50   extends Reader
  51 {
  52
  53   /**
  54    * The CR octet.
  55    */
  56   public static final int CR = 13;
  57
  58   /**
  59    * The LF octet.
  60    */
  61   public static final int LF = 10;
  62
  63   private boolean doReset;
  64
  65   protected Reader in;
  66
  67   /**
  68    * Constructor.
  69    */
  70   protected CRLFReader(Reader in)
  71   {
  72     if (!in.markSupported())
  73       in = new BufferedReader(in);
  74     this.in = in;
  75   }
  76
  77   public int read()
  78     throws IOException
  79   {
  80     int c = in.read();
  81     if (c == 13) // CR
  82       {
  83         in.mark(1);
  84         int d = in.read();
  85         if (d == 10) // LF
  86           c = d;
  87         else
  88           in.reset();
  89       }
  90     return c;
  91   }
  92
  93   public int read(char[] b)
  94     throws IOException
  95   {
  96     return read(b, 0, b.length);
  97   }
  98
  99   public int read(char[] b, int off, int len)
 100     throws IOException
 101   {
 102     in.mark(len + 1);
 103     int l = in.read(b, off, len);
 104     if (l > 0)
 105       {
 106         int i = indexOfCRLF(b, off, l);
 107         if (doReset)
 108           {
 109             in.reset();
 110             if (i != -1)
 111               {
 112                 l = in.read(b, off, (i + 1) - off); // read to CR
 113                 in.read(); // skip LF
 114                 b[i] = '\n'; // fix CR as LF
 115               }
 116             else
 117               l = in.read(b, off, len); // CR(s) but no LF
 118           }
 119       }
 120     return l;
 121   }
 122
 123   public boolean markSupported()
 124   {
 125     return in.markSupported();
 126   }
 127
 128   public void mark(int limit)
 129     throws IOException
 130   {
 131     in.mark(limit);
 132   }
 133
 134   public void reset()
 135     throws IOException
 136   {
 137     in.reset();
 138   }
 139
 140   public long skip(long n)
 141     throws IOException
 142   {
 143     return in.skip(n);
 144   }
 145
 146   public void close()
 147     throws IOException
 148   {
 149     in.close();
 150   }
 151
 152   private int indexOfCRLF(char[] b, int off, int len)
 153     throws IOException
 154   {
 155     doReset = false;
 156     int lm1 = len - 1;
 157     for (int i = off; i < len; i++)
 158       {
 159         if (b[i] == '\r') // CR
 160           {
 161             int d;
 162             if (i == lm1)
 163               {
 164                 d = in.read();
 165                 doReset = true;
 166               }
 167             else
 168               d = b[i + 1];
 169             if (d == '\n') // LF
 170               {
 171                 doReset = true;
 172                 return i;
 173               }
 174           }
 175       }
 176     return -1;
 177   }
 178
 179 }
 180