libjava/gnu/java/nio/charset/US_ASCII.java

   1 /* US_ASCII.java --
   2    Copyright (C) 2002 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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.java.nio.charset;
  39
  40 import java.nio.ByteBuffer;
  41 import java.nio.CharBuffer;
  42 import java.nio.charset.Charset;
  43 import java.nio.charset.CharsetDecoder;
  44 import java.nio.charset.CharsetEncoder;
  45 import java.nio.charset.CoderResult;
  46
  47 /**
  48  * US-ASCII charset.
  49  *
  50  * @author Jesse Rosenstock
  51  */
  52 final class US_ASCII extends Charset
  53 {
  54   US_ASCII ()
  55   {
  56     super ("US-ASCII", new String[]{"ISO646-US"});
  57   }
  58
  59   public boolean contains (Charset cs)
  60   {
  61     return cs instanceof US_ASCII;
  62   }
  63
  64   public CharsetDecoder newDecoder ()
  65   {
  66     return new Decoder (this);
  67   }
  68
  69   public CharsetEncoder newEncoder ()
  70   {
  71     return new Encoder (this);
  72   }
  73
  74   private static final class Decoder extends CharsetDecoder
  75   {
  76     private Decoder (Charset cs)
  77     {
  78       super (cs, 1.0f, 1.0f);
  79     }
  80
  81     protected CoderResult decodeLoop (ByteBuffer in, CharBuffer out)
  82     {
  83       // TODO: Optimize this in the case in.hasArray() / out.hasArray()
  84       while (in.hasRemaining ())
  85         {
  86           byte b = in.get ();
  87
  88           if (b < 0)
  89             {
  90               in.position (in.position () - 1);
  91               return CoderResult.malformedForLength (1);
  92             }
  93           if (!out.hasRemaining ())
  94             {
  95               in.position (in.position () - 1);
  96               return CoderResult.OVERFLOW;
  97             }
  98
  99           out.put ((char) b);
 100         }
 101
 102       return CoderResult.UNDERFLOW;
 103     }
 104   }
 105
 106   private static final class Encoder extends CharsetEncoder
 107   {
 108     private Encoder (Charset cs)
 109     {
 110       super (cs, 1.0f, 1.0f);
 111     }
 112
 113     protected CoderResult encodeLoop (CharBuffer in, ByteBuffer out)
 114     {
 115       // TODO: Optimize this in the case in.hasArray() / out.hasArray()
 116       while (in.hasRemaining ())
 117       {
 118         char c = in.get ();
 119
 120         if (c > Byte.MAX_VALUE)
 121           {
 122             in.position (in.position () - 1);
 123             return CoderResult.unmappableForLength (1);
 124           }
 125         if (!out.hasRemaining ())
 126           {
 127             in.position (in.position () - 1);
 128             return CoderResult.OVERFLOW;
 129           }
 130
 131         out.put ((byte) c);
 132       }
 133
 134       return CoderResult.UNDERFLOW;
 135     }
 136   }
 137 }