libjava/classpath/java/nio/CharBufferImpl.java

   1 /* CharBufferImpl.java --
   2    Copyright (C) 2002, 2003, 2004 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
  39 package java.nio;
  40
  41 /**
  42  * This is a Heap memory implementation
  43  */
  44 final class CharBufferImpl extends CharBuffer
  45 {
  46   private boolean readOnly;
  47
  48   CharBufferImpl (int capacity)
  49   {
  50     this (new char [capacity], 0, capacity, capacity, 0, -1, false);
  51   }
  52
  53   CharBufferImpl (char[] buffer, int offset, int capacity, int limit, int position, int mark, boolean readOnly)
  54   {
  55     super (capacity, limit, position, mark);
  56     this.backing_buffer = buffer;
  57     this.array_offset = offset;
  58     this.readOnly = readOnly;
  59   }
  60
  61   public CharBufferImpl (CharBufferImpl copy)
  62   {
  63     super (copy.capacity (), copy.limit (), copy.position (), 0);
  64     backing_buffer = copy.backing_buffer;
  65     array_offset = copy.array_offset;
  66     readOnly = copy.isReadOnly ();
  67   }
  68
  69   public boolean isReadOnly ()
  70   {
  71     return readOnly;
  72   }
  73
  74   public CharBuffer slice ()
  75   {
  76     return new CharBufferImpl (backing_buffer, array_offset + position (), remaining (), remaining (), 0, -1, isReadOnly ());
  77   }
  78
  79   public CharBuffer duplicate ()
  80   {
  81     return new CharBufferImpl (backing_buffer, array_offset, capacity (), limit (), position (), mark, isReadOnly ());
  82   }
  83
  84   public CharBuffer asReadOnlyBuffer ()
  85   {
  86     return new CharBufferImpl (backing_buffer, array_offset, capacity (), limit (), position (), mark, true);
  87   }
  88
  89   public CharBuffer compact ()
  90   {
  91     checkIfReadOnly();
  92     mark = -1;
  93     int p = position();
  94     int n = limit() - p;
  95     if (n > 0)
  96       {
  97         System.arraycopy(backing_buffer, array_offset + p,
  98                          backing_buffer, array_offset, n);
  99       }
 100     position(n);
 101     limit(capacity());
 102     return this;
 103   }
 104
 105   public boolean isDirect ()
 106   {
 107     return false;
 108   }
 109
 110   public CharSequence subSequence (int start, int end)
 111   {
 112     if (start < 0
 113         || start > length ()
 114         || end < start
 115         || end > length ())
 116       throw new IndexOutOfBoundsException ();
 117
 118     return new CharBufferImpl (backing_buffer, array_offset, capacity (), position () + end, position () + start, -1, isReadOnly ());
 119   }
 120
 121   /**
 122    * Reads the <code>char</code> at this buffer's current position,
 123    * and then increments the position.
 124    *
 125    * @exception BufferUnderflowException If there are no remaining
 126    * <code>char</code>s in this buffer.
 127    */
 128   public char get ()
 129   {
 130     if (pos >= limit)
 131         throw new BufferUnderflowException();
 132
 133     return backing_buffer [(pos++) + array_offset];
 134   }
 135
 136   /**
 137    * Relative put method. Writes <code>value</code> to the next position
 138    * in the buffer.
 139    *
 140    * @exception ReadOnlyBufferException If this buffer is read-only.
 141    */
 142   public CharBuffer put (char value)
 143   {
 144     if (readOnly)
 145         throw new ReadOnlyBufferException();
 146     if (pos >= limit)
 147         throw new BufferOverflowException();
 148
 149     backing_buffer [(pos++) + array_offset] = value;
 150     return this;
 151   }
 152
 153   /**
 154    * Absolute get method. Reads the <code>char</code> at position
 155    * <code>index</code>.
 156    *
 157    * @param index Position to read the <code>char</code> from.
 158    *
 159    * @exception IndexOutOfBoundsException If index is negative or not smaller
 160    * than the buffer's limit.
 161    */
 162   public char get (int index)
 163   {
 164     checkIndex(index);
 165
 166     return backing_buffer [index + array_offset];
 167   }
 168
 169   /**
 170    * Bulk get, overloaded for speed.
 171    */
 172   public CharBuffer get (char[] dst, int offset, int length)
 173   {
 174     checkArraySize(dst.length, offset, length);
 175     checkForUnderflow(length);
 176
 177     System.arraycopy(backing_buffer, pos + array_offset,
 178                      dst, offset, length);
 179     pos += length;
 180     return this;
 181   }
 182
 183   /**
 184    * Bulk put, overloaded for speed.
 185    */
 186   public CharBuffer put (char[] src, int offset, int length)
 187   {
 188     checkArraySize(src.length, offset, length);
 189     checkForOverflow(length);
 190
 191     System.arraycopy(src, offset,
 192                      backing_buffer, pos + array_offset, length);
 193     pos += length;
 194     return this;
 195   }
 196
 197   /**
 198    * Absolute put method. Writes <code>value</code> to position
 199    * <code>index</code> in the buffer.
 200    *
 201    * @exception IndexOutOfBoundsException If index is negative or not smaller
 202    * than the buffer's limit.
 203    * @exception ReadOnlyBufferException If this buffer is read-only.
 204    */
 205   public CharBuffer put (int index, char value)
 206   {
 207     checkIndex(index);
 208     checkIfReadOnly();
 209
 210     backing_buffer [index + array_offset] = value;
 211     return this;
 212   }
 213
 214   public ByteOrder order ()
 215   {
 216     return ByteOrder.nativeOrder ();
 217   }
 218 }