libjava/gnu/java/nio/CharBufferImpl.java

   1 /* CharBufferImpl.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;
  39
  40 import java.nio.ByteBuffer;
  41 import java.nio.ByteOrder;
  42 import java.nio.CharBuffer;
  43 import java.nio.ReadOnlyBufferException;
  44
  45 /**
  46  * This is a Heap memory implementation
  47  */
  48 public final class CharBufferImpl extends CharBuffer
  49 {
  50   private boolean readOnly;
  51
  52   public CharBufferImpl(int cap, int off, int lim)
  53   {
  54     super (cap, lim, off, 0);
  55     this.backing_buffer = new char [cap];
  56     readOnly = false;
  57   }
  58
  59   public CharBufferImpl(char[] array, int offset, int length)
  60   {
  61     super (array.length, length, offset, 0);
  62     this.backing_buffer = array;
  63     readOnly = false;
  64   }
  65
  66   public CharBufferImpl (CharBufferImpl copy)
  67   {
  68     super (copy.capacity (), copy.limit (), copy.position (), 0);
  69     backing_buffer = copy.backing_buffer;
  70     readOnly = copy.isReadOnly ();
  71   }
  72
  73   private static native char[] nio_cast (byte[] copy);
  74
  75   CharBufferImpl (byte[] copy)
  76   {
  77     super (copy.length / 2, copy.length / 2, 0, 0);
  78     this.backing_buffer = (copy != null ? nio_cast (copy) : null);
  79     readOnly = false;
  80   }
  81
  82   private static native byte nio_get_Byte (CharBufferImpl b, int index, int limit);
  83
  84   private static native void nio_put_Byte (CharBufferImpl b, int index, int limit, byte value);
  85
  86   public ByteBuffer asByteBuffer ()
  87   {
  88     ByteBufferImpl res = new ByteBufferImpl (backing_buffer);
  89     res.limit ((limit () * 1) / 2);
  90     return res;
  91   }
  92
  93
  94   public boolean isReadOnly()
  95   {
  96     return readOnly;
  97   }
  98
  99   public CharBuffer slice()
 100   {
 101     return new CharBufferImpl (this);
 102   }
 103
 104   public CharBuffer duplicate()
 105   {
 106     return new CharBufferImpl(this);
 107   }
 108
 109   public CharBuffer asReadOnlyBuffer()
 110   {
 111     CharBufferImpl result = new CharBufferImpl (this);
 112     result.readOnly = true;
 113     return result;
 114   }
 115
 116   public CharBuffer compact()
 117   {
 118     return this;
 119   }
 120
 121   public boolean isDirect()
 122   {
 123     return false;
 124   }
 125
 126   final public CharSequence subSequence (int start, int end)
 127   {
 128     if (start < 0 ||
 129         end > length () ||
 130         start > end)
 131       throw new IndexOutOfBoundsException ();
 132
 133     // No support for direct buffers yet.
 134     // assert array () != null;
 135     return new CharBufferImpl (array (), position () + start,
 136                                position () + end);
 137   }
 138
 139   /**
 140    * Relative get method. Reads the next character from the buffer.
 141    */
 142   final public char get()
 143   {
 144     char e = backing_buffer[position()];
 145     position(position()+1);
 146     return e;
 147   }
 148
 149   /**
 150    * Relative put method. Writes <code>value</code> to the next position
 151    * in the buffer.
 152    *
 153    * @exception ReadOnlyBufferException If this buffer is read-only.
 154    */
 155   final public CharBuffer put(char b)
 156   {
 157     if (readOnly)
 158       throw new ReadOnlyBufferException ();
 159
 160     backing_buffer[position()] = b;
 161     position(position()+1);
 162     return this;
 163   }
 164
 165   /**
 166    * Absolute get method. Reads the character at position <code>index</code>.
 167    *
 168    * @exception IndexOutOfBoundsException If index is negative or not smaller
 169    * than the buffer's limit.
 170    */
 171   final public char get(int index)
 172   {
 173     if (index < 0
 174         || index >= limit ())
 175       throw new IndexOutOfBoundsException ();
 176
 177     return backing_buffer[index];
 178   }
 179
 180   /**
 181    * Absolute put method. Writes <code>value</value> to position
 182    * <code>index</code> in the buffer.
 183    *
 184    * @exception IndexOutOfBoundsException If index is negative or not smaller
 185    * than the buffer's limit.
 186    * @exception ReadOnlyBufferException If this buffer is read-only.
 187    */
 188   final public CharBuffer put(int index, char b)
 189   {
 190     if (index < 0
 191         || index >= limit ())
 192       throw new IndexOutOfBoundsException ();
 193
 194     if (readOnly)
 195       throw new ReadOnlyBufferException ();
 196
 197     backing_buffer[index] = b;
 198     return this;
 199   }
 200
 201
 202   public final ByteOrder order()
 203   {
 204     return ByteOrder.BIG_ENDIAN;
 205   }
 206 }