libjava/classpath/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., 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 final class ShortViewBufferImpl extends ShortBuffer
  42 {
  43   /** Position in bb (i.e. a byte offset) where this buffer starts. */
  44   private final int offset;
  45   private final ByteBuffer bb;
  46   private final boolean readOnly;
  47   private final ByteOrder endian;
  48
  49   ShortViewBufferImpl (ByteBuffer bb, int capacity)
  50   {
  51     super (capacity, capacity, 0, -1, bb.isDirect() ?
  52            VMDirectByteBuffer.adjustAddress(bb.address, bb.position()):null, null, 0);
  53     this.bb = bb;
  54     this.offset = bb.position();
  55     this.readOnly = bb.isReadOnly();
  56     this.endian = bb.order();
  57   }
  58
  59   public ShortViewBufferImpl (ByteBuffer bb, int offset, int capacity,
  60                               int limit, int position, int mark,
  61                               boolean readOnly, ByteOrder endian)
  62   {
  63     super (capacity, limit, position, mark, bb.isDirect() ?
  64            VMDirectByteBuffer.adjustAddress(bb.address, offset):null, null, 0);
  65     this.bb = bb;
  66     this.offset = offset;
  67     this.readOnly = readOnly;
  68     this.endian = endian;
  69   }
  70
  71   /**
  72    * Reads the <code>short</code> at this buffer's current position,
  73    * and then increments the position.
  74    *
  75    * @exception BufferUnderflowException If there are no remaining
  76    * <code>short</code>s in this buffer.
  77    */
  78   public short get ()
  79   {
  80     int p = position();
  81     short result = ByteBufferHelper.getShort(bb, (p << 1) + offset, endian);
  82     position(p + 1);
  83     return result;
  84   }
  85
  86   /**
  87    * Absolute get method. Reads the <code>short</code> at position
  88    * <code>index</code>.
  89    *
  90    * @exception IndexOutOfBoundsException If index is negative or not smaller
  91    * than the buffer's limit.
  92    */
  93   public short get (int index)
  94   {
  95     return ByteBufferHelper.getShort(bb, (index << 1) + offset, endian);
  96   }
  97
  98   public ShortBuffer put (short value)
  99   {
 100     int p = position();
 101     ByteBufferHelper.putShort(bb, (p << 1) + offset, value, endian);
 102     position(p + 1);
 103     return this;
 104   }
 105
 106   public ShortBuffer put (int index, short value)
 107   {
 108     ByteBufferHelper.putShort(bb, (index << 1) + offset, value, endian);
 109     return this;
 110   }
 111
 112   public ShortBuffer compact ()
 113   {
 114     if (position () > 0)
 115       {
 116         int count = limit () - position ();
 117         bb.shiftDown(offset, offset + 2 * position(), 2 * count);
 118         position (count);
 119         limit (capacity ());
 120       }
 121     else
 122       {
 123         position(limit());
 124         limit(capacity());
 125       }
 126     return this;
 127   }
 128
 129   public ShortBuffer slice ()
 130   {
 131     // Create a sliced copy of this object that shares its content.
 132     return new ShortViewBufferImpl (bb, (position () << 1) + offset,
 133                                     remaining(), remaining(), 0, -1,
 134                                     readOnly, endian);
 135   }
 136
 137   ShortBuffer duplicate (boolean readOnly)
 138   {
 139     int pos = position();
 140     reset();
 141     int mark = position();
 142     position(pos);
 143     return new ShortViewBufferImpl (bb, offset, capacity(), limit(),
 144                                     pos, mark, readOnly, endian);
 145   }
 146
 147   public ShortBuffer duplicate ()
 148   {
 149     return duplicate(readOnly);
 150   }
 151
 152   public ShortBuffer asReadOnlyBuffer ()
 153   {
 154     return duplicate(true);
 155   }
 156
 157   public boolean isReadOnly ()
 158   {
 159     return readOnly;
 160   }
 161
 162   public boolean isDirect ()
 163   {
 164     return bb.isDirect ();
 165   }
 166
 167   public ByteOrder order ()
 168   {
 169     return endian;
 170   }
 171 }