libjava/java/nio/DoubleViewBufferImpl.java

   1 /* DoubleViewBufferImpl.java --
   2    Copyright (C) 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., 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
  39 package java.nio;
  40
  41 final class DoubleViewBufferImpl extends DoubleBuffer
  42 {
  43   /** Position in bb (i.e. a byte offset) where this buffer starts. */
  44   private int offset;
  45   private ByteBuffer bb;
  46   private boolean readOnly;
  47   private ByteOrder endian;
  48
  49   DoubleViewBufferImpl (ByteBuffer bb, int capacity)
  50   {
  51     super (capacity, capacity, 0, -1);
  52     this.bb = bb;
  53     this.offset = bb.position();
  54     this.readOnly = bb.isReadOnly();
  55     this.endian = bb.order();
  56   }
  57
  58   public DoubleViewBufferImpl (ByteBuffer bb, int offset, int capacity,
  59                                int limit, int position, int mark,
  60                                boolean readOnly, ByteOrder endian)
  61   {
  62     super (capacity, limit, position, mark);
  63     this.bb = bb;
  64     this.offset = offset;
  65     this.readOnly = readOnly;
  66     this.endian = endian;
  67   }
  68
  69   /**
  70    * Reads the <code>double</code> at this buffer's current position,
  71    * and then increments the position.
  72    *
  73    * @exception BufferUnderflowException If there are no remaining
  74    * <code>double</code>s in this buffer.
  75    */
  76   public double get ()
  77   {
  78     int p = position();
  79     double result = ByteBufferHelper.getDouble(bb, (p << 3) + offset, endian);
  80     position(p + 1);
  81     return result;
  82   }
  83
  84   /**
  85    * Absolute get method. Reads the <code>double</code> at position
  86    * <code>index</code>.
  87    *
  88    * @exception IndexOutOfBoundsException If index is negative or not smaller
  89    * than the buffer's limit.
  90    */
  91   public double get (int index)
  92   {
  93     return ByteBufferHelper.getDouble(bb, (index << 3) + offset, endian);
  94   }
  95
  96   public DoubleBuffer put (double value)
  97   {
  98     int p = position();
  99     ByteBufferHelper.putDouble(bb, (p << 3) + offset, value, endian);
 100     position(p + 1);
 101     return this;
 102   }
 103
 104   public DoubleBuffer put (int index, double value)
 105   {
 106     ByteBufferHelper.putDouble(bb, (index << 3) + offset, value, endian);
 107     return this;
 108   }
 109
 110   public DoubleBuffer compact ()
 111   {
 112     if (position () > 0)
 113       {
 114         int count = limit () - position ();
 115         bb.shiftDown(offset, offset + 8 * position(), 8 * count);
 116         position (count);
 117         limit (capacity ());
 118       }
 119     return this;
 120   }
 121
 122   public DoubleBuffer slice ()
 123   {
 124     return new DoubleViewBufferImpl (bb, (position () >> 3) + offset,
 125                                      remaining(), remaining(), 0, -1,
 126                                      readOnly, endian);
 127   }
 128
 129   DoubleBuffer duplicate (boolean readOnly)
 130   {
 131     int pos = position();
 132     reset();
 133     int mark = position();
 134     position(pos);
 135     return new DoubleViewBufferImpl (bb, offset, capacity(), limit(),
 136                                      pos, mark, readOnly, endian);
 137   }
 138
 139   public DoubleBuffer duplicate ()
 140   {
 141     return duplicate(readOnly);
 142   }
 143
 144   public DoubleBuffer asReadOnlyBuffer ()
 145   {
 146     return duplicate(true);
 147   }
 148
 149   public boolean isReadOnly ()
 150   {
 151     return readOnly;
 152   }
 153
 154   public boolean isDirect ()
 155   {
 156     return bb.isDirect ();
 157   }
 158
 159   public ByteOrder order ()
 160   {
 161     return endian;
 162   }
 163 }