1 /*
   2  * Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  */
  28 
  29 
  30 import java.nio.ByteBuffer;
  31 import java.nio.CharBuffer;
  32 import java.nio.charset.Charset;
  33 import java.nio.charset.CharsetDecoder;
  34 import java.nio.charset.CoderResult;
  35 import java.nio.charset.CharacterCodingException;
  36 import java.nio.charset.MalformedInputException;
  37 import java.nio.charset.UnmappableCharacterException;
  38 
  39 
  40 public abstract class SingleByteDecoder
  41     extends CharsetDecoder
  42 {
  43 
  44     private final String byteToCharTable;
  45 
  46     protected SingleByteDecoder(Charset cs, String byteToCharTable) {
  47         super(cs, 1.0f, 1.0f);
  48         this.byteToCharTable = byteToCharTable;
  49     }
  50 
  51     private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {
  52         byte[] sa = src.array();
  53         int sp = src.arrayOffset() + src.position();
  54         int sl = src.arrayOffset() + src.limit();
  55         assert (sp <= sl);
  56         sp = (sp <= sl ? sp : sl);
  57         char[] da = dst.array();
  58         int dp = dst.arrayOffset() + dst.position();
  59         int dl = dst.arrayOffset() + dst.limit();
  60         assert (dp <= dl);
  61         dp = (dp <= dl ? dp : dl);
  62 
  63         try {
  64             while (sp < sl) {
  65                 int b = sa[sp];
  66 
  67                 char c = decode(b);
  68                 if (c == '\uFFFD')
  69                     return CoderResult.unmappableForLength(1);
  70                 if (dl - dp < 1)
  71                     return CoderResult.OVERFLOW;
  72                 da[dp++] = c;
  73                 sp++;
  74             }
  75             return CoderResult.UNDERFLOW;
  76         } finally {
  77             src.position(sp - src.arrayOffset());
  78             dst.position(dp - dst.arrayOffset());
  79         }
  80     }
  81 
  82     private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {
  83         int mark = src.position();
  84         try {
  85             while (src.hasRemaining()) {
  86                 int b = src.get();
  87 
  88                 char c = decode(b);
  89                 if (c == '\uFFFD')
  90                     return CoderResult.unmappableForLength(1);
  91                 if (!dst.hasRemaining())
  92                     return CoderResult.OVERFLOW;
  93                 mark++;
  94                 dst.put(c);
  95             }
  96             return CoderResult.UNDERFLOW;
  97         } finally {
  98             src.position(mark);
  99         }
 100     }
 101 
 102     protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
 103         if (true && src.hasArray() && dst.hasArray())
 104             return decodeArrayLoop(src, dst);
 105         else
 106             return decodeBufferLoop(src, dst);
 107     }
 108 
 109     public char decode(int byteIndex) {
 110         int n = byteIndex + 128;
 111         if (n >= byteToCharTable.length() || n < 0)
 112             return '\uFFFD';
 113         return byteToCharTable.charAt(n);
 114     }
 115 }