libjava/java/nio/ShortViewBufferImpl.java

   1 /* ShortViewBufferImpl.java --
   2    Copyright (C) 2003 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 class ShortViewBufferImpl extends ShortBuffer
  42 {
  43   private boolean readOnly;
  44   private int offset;
  45   private ByteBuffer bb;
  46   private ByteOrder endian;
  47
  48   public ShortViewBufferImpl (ByteBuffer bb, boolean readOnly)
  49   {
  50     super (bb.remaining () >> 1, bb.remaining () >> 1, bb.position (), 0);
  51     this.bb = bb;
  52     this.readOnly = readOnly;
  53     // FIXME: What if this is called from ShortByteBufferImpl and ByteBuffer has changed its endianess ?
  54     this.endian = bb.order ();
  55   }
  56
  57   public ShortViewBufferImpl (ByteBuffer bb, int offset, int capacity,
  58                                int limit, int position, int mark,
  59                                boolean readOnly)
  60   {
  61     super (limit >> 1, limit >> 1, position >> 1, mark >> 1);
  62     this.bb = bb;
  63     this.offset = offset;
  64     this.readOnly = readOnly;
  65     // FIXME: What if this is called from ShortViewBufferImpl and ByteBuffer has changed its endianess ?
  66     this.endian = bb.order ();
  67   }
  68
  69   public short get ()
  70   {
  71     short result = bb.getShort ((position () << 1) + offset);
  72     position (position () + 1);
  73     return result;
  74   }
  75
  76   public short get (int index)
  77   {
  78     return bb.getShort ((index << 1) + offset);
  79   }
  80
  81   public ShortBuffer put (short value)
  82   {
  83     bb.putShort ((position () << 1) + offset, value);
  84     position (position () + 1);
  85     return this;
  86   }
  87
  88   public ShortBuffer put (int index, short value)
  89   {
  90     bb.putShort ((index << 1) + offset, value);
  91     return this;
  92   }
  93
  94   public ShortBuffer compact ()
  95   {
  96     if (position () > 0)
  97       {
  98         // Copy all data from position() to limit() to the beginning of the
  99         // buffer, set position to end of data and limit to capacity
 100         // XXX: This can surely be optimized, for direct and non-direct buffers
 101
 102         int count = limit () - position ();
 103
 104         for (int i = 0; i < count; i++)
 105           {
 106             bb.putShort ((i >> 1) + offset,
 107                           bb.getShort (((i + position ()) >> 1) + offset));
 108           }
 109
 110         position (count);
 111         limit (capacity ());
 112       }
 113
 114     return this;
 115   }
 116
 117   public ShortBuffer duplicate ()
 118   {
 119     // Create a copy of this object that shares its content
 120     // FIXME: mark is not correct
 121     return new ShortViewBufferImpl (bb, offset, capacity (), limit (),
 122                                      position (), -1, isReadOnly ());
 123   }
 124
 125   public ShortBuffer slice ()
 126   {
 127     // Create a sliced copy of this object that shares its content.
 128     return new ShortViewBufferImpl (bb, (position () >> 1) + offset,
 129                                       remaining (), remaining (), 0, -1,
 130                                      isReadOnly ());
 131   }
 132
 133   public ShortBuffer asReadOnlyBuffer ()
 134   {
 135     // Create a copy of this object that shares its content and is read-only
 136     return new ShortViewBufferImpl (bb, (position () >> 1) + offset,
 137                                      remaining (), remaining (), 0, -1, true);
 138   }
 139
 140   public boolean isReadOnly ()
 141   {
 142     return readOnly;
 143   }
 144
 145   public boolean isDirect ()
 146   {
 147     return bb.isDirect ();
 148   }
 149
 150   public ByteOrder order ()
 151   {
 152     return ByteOrder.LITTLE_ENDIAN;
 153   }
 154 }