libjava/classpath/java/nio/DoubleBufferImpl.java

   1 /* DoubleBufferImpl.java --
   2    Copyright (C) 2002, 2003, 2004, 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
  39 package java.nio;
  40
  41 /**
  42  * This is a Heap memory implementation
  43  */
  44 final class DoubleBufferImpl extends DoubleBuffer
  45 {
  46   private final boolean readOnly;
  47
  48   DoubleBufferImpl (int capacity)
  49   {
  50     this (new double [capacity], 0, capacity, capacity, 0, -1, false);
  51   }
  52
  53   DoubleBufferImpl (double[] buffer, int offset, int capacity, int limit,
  54                     int position, int mark, boolean readOnly)
  55   {
  56     super (capacity, limit, position, mark, null, buffer, offset);
  57     this.readOnly = readOnly;
  58   }
  59
  60   public boolean isReadOnly ()
  61   {
  62     return readOnly;
  63   }
  64
  65   public DoubleBuffer slice ()
  66   {
  67     return new DoubleBufferImpl (backing_buffer, array_offset + position (),
  68                                  remaining (), remaining (), 0, -1, isReadOnly ());
  69   }
  70
  71   public DoubleBuffer duplicate ()
  72   {
  73     return new DoubleBufferImpl (backing_buffer, array_offset, capacity (),
  74                                  limit (), position (), mark, isReadOnly ());
  75   }
  76
  77   public DoubleBuffer asReadOnlyBuffer ()
  78   {
  79     return new DoubleBufferImpl (backing_buffer, array_offset, capacity (),
  80                                  limit (), position (), mark, true);
  81   }
  82
  83   public DoubleBuffer compact ()
  84   {
  85     checkIfReadOnly();
  86     mark = -1;
  87     int p = position();
  88     int n = limit() - p;
  89     if (n > 0)
  90       {
  91         System.arraycopy(backing_buffer, array_offset + p,
  92                          backing_buffer, array_offset, n);
  93       }
  94     position(n);
  95     limit(capacity());
  96     return this;
  97   }
  98
  99   public boolean isDirect ()
 100   {
 101     return false;
 102   }
 103
 104   /**
 105    * Reads the <code>double</code> at this buffer's current position,
 106    * and then increments the position.
 107    *
 108    * @exception BufferUnderflowException If there are no remaining
 109    * <code>double</code>s in this buffer.
 110    */
 111   public double get ()
 112   {
 113     checkForUnderflow();
 114
 115     double result = backing_buffer [position ()];
 116     position (position () + 1);
 117     return result;
 118   }
 119
 120   /**
 121    * Relative put method. Writes <code>value</code> to the next position
 122    * in the buffer.
 123    *
 124    * @exception BufferOverflowException If there no remaining
 125    * space in this buffer.
 126    * @exception ReadOnlyBufferException If this buffer is read-only.
 127    */
 128   public DoubleBuffer put (double value)
 129   {
 130     checkIfReadOnly();
 131     checkForOverflow();
 132
 133     backing_buffer [position ()] = value;
 134     position (position () + 1);
 135     return this;
 136   }
 137
 138   /**
 139    * Absolute get method. Reads the <code>double</code> at position
 140    * <code>index</code>.
 141    *
 142    * @exception IndexOutOfBoundsException If index is negative or not smaller
 143    * than the buffer's limit.
 144    */
 145   public double get (int index)
 146   {
 147     checkIndex(index);
 148
 149     return backing_buffer [index];
 150   }
 151
 152   /**
 153    * Absolute put method. Writes <code>value</code> to position
 154    * <code>index</code> in the buffer.
 155    *
 156    * @exception IndexOutOfBoundsException If index is negative or not smaller
 157    * than the buffer's limit.
 158    * @exception ReadOnlyBufferException If this buffer is read-only.
 159    */
 160   public DoubleBuffer put (int index, double value)
 161   {
 162     checkIfReadOnly();
 163     checkIndex(index);
 164
 165     backing_buffer [index] = value;
 166     return this;
 167   }
 168
 169   public ByteOrder order ()
 170   {
 171     return ByteOrder.nativeOrder ();
 172   }
 173 }