libjava/java/nio/ShortViewBufferImpl.java

   1 /* ShortViewBufferImpl.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 ShortViewBufferImpl extends ShortBuffer
  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   ShortViewBufferImpl (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     if (bb.isDirect())
  57       this.address = VMDirectByteBuffer.adjustAddress(bb.address, offset);
  58   }
  59
  60   public ShortViewBufferImpl (ByteBuffer bb, int offset, int capacity,
  61                               int limit, int position, int mark,
  62                               boolean readOnly, ByteOrder endian)
  63   {
  64     super (capacity, limit, position, mark);
  65     this.bb = bb;
  66     this.offset = offset;
  67     this.readOnly = readOnly;
  68     this.endian = endian;
  69     if (bb.isDirect())
  70       this.address = VMDirectByteBuffer.adjustAddress(bb.address, offset);
  71   }
  72
  73   /**
  74    * Reads the <code>short</code> at this buffer's current position,
  75    * and then increments the position.
  76    *
  77    * @exception BufferUnderflowException If there are no remaining
  78    * <code>short</code>s in this buffer.
  79    */
  80   public short get ()
  81   {
  82     int p = position();
  83     short result = ByteBufferHelper.getShort(bb, (p << 1) + offset, endian);
  84     position(p + 1);
  85     return result;
  86   }
  87
  88   /**
  89    * Absolute get method. Reads the <code>short</code> at position
  90    * <code>index</code>.
  91    *
  92    * @exception IndexOutOfBoundsException If index is negative or not smaller
  93    * than the buffer's limit.
  94    */
  95   public short get (int index)
  96   {
  97     return ByteBufferHelper.getShort(bb, (index << 1) + offset, endian);
  98   }
  99
 100   public ShortBuffer put (short value)
 101   {
 102     int p = position();
 103     ByteBufferHelper.putShort(bb, (p << 1) + offset, value, endian);
 104     position(p + 1);
 105     return this;
 106   }
 107
 108   public ShortBuffer put (int index, short value)
 109   {
 110     ByteBufferHelper.putShort(bb, (index << 1) + offset, value, endian);
 111     return this;
 112   }
 113
 114   public ShortBuffer compact ()
 115   {
 116     if (position () > 0)
 117       {
 118         int count = limit () - position ();
 119         bb.shiftDown(offset, offset + 2 * position(), 2 * count);
 120         position (count);
 121         limit (capacity ());
 122       }
 123     else
 124       {
 125         position(limit());
 126         limit(capacity());
 127       }
 128     return this;
 129   }
 130
 131   public ShortBuffer slice ()
 132   {
 133     // Create a sliced copy of this object that shares its content.
 134     return new ShortViewBufferImpl (bb, (position () >> 1) + offset,
 135                                     remaining(), remaining(), 0, -1,
 136                                     readOnly, endian);
 137   }
 138
 139   ShortBuffer duplicate (boolean readOnly)
 140   {
 141     int pos = position();
 142     reset();
 143     int mark = position();
 144     position(pos);
 145     return new ShortViewBufferImpl (bb, offset, capacity(), limit(),
 146                                     pos, mark, readOnly, endian);
 147   }
 148
 149   public ShortBuffer duplicate ()
 150   {
 151     return duplicate(readOnly);
 152   }
 153
 154   public ShortBuffer asReadOnlyBuffer ()
 155   {
 156     return duplicate(true);
 157   }
 158
 159   public boolean isReadOnly ()
 160   {
 161     return readOnly;
 162   }
 163
 164   public boolean isDirect ()
 165   {
 166     return bb.isDirect ();
 167   }
 168
 169   public ByteOrder order ()
 170   {
 171     return endian;
 172   }
 173 }