libjava/java/nio/LongBuffer.java

   1 /* LongBuffer.java --
   2    Copyright (C) 2002, 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 /**
  42  * @since 1.4
  43  */
  44 public abstract class LongBuffer extends Buffer
  45   implements Comparable
  46 {
  47   int array_offset;
  48   long[] backing_buffer;
  49
  50   LongBuffer (int capacity, int limit, int position, int mark)
  51   {
  52     super (capacity, limit, position, mark);
  53     array_offset = 0;
  54   }
  55
  56   LongBuffer (long[] buffer, int offset, int capacity, int limit, int position, int mark)
  57   {
  58     super (capacity, limit, position, mark);
  59     this.backing_buffer = buffer;
  60     this.array_offset = offset;
  61   }
  62
  63   /**
  64    * Allocates a new <code>LongBuffer</code> object with a given capacity.
  65    */
  66   public static LongBuffer allocate (int capacity)
  67   {
  68     return new LongBufferImpl (capacity);
  69   }
  70
  71   /**
  72    * Wraps a <code>long</code> array into a <code>LongBuffer</code>
  73    * object.
  74    *
  75    * @exception IndexOutOfBoundsException If the preconditions on the offset
  76    * and length parameters do not hold
  77    */
  78   final public static LongBuffer wrap (long[] array, int offset, int length)
  79   {
  80     return new LongBufferImpl (array, 0, array.length, offset + length, offset, -1, false);
  81   }
  82
  83   /**
  84    * Wraps a <code>long</code> array into a <code>LongBuffer</code>
  85    * object.
  86    */
  87   final public static LongBuffer wrap (long[] array)
  88   {
  89     return wrap (array, 0, array.length);
  90   }
  91
  92   /**
  93    * This method transfers <code>longs<code> from this buffer into the given
  94    * destination array.
  95    *
  96    * @param dst The destination array
  97    * @param offset The offset within the array of the first <code>long</code>
  98    * to be written; must be non-negative and no larger than dst.length.
  99    * @param length The maximum number of bytes to be written to the given array;
 100    * must be non-negative and no larger than dst.length - offset.
 101    *
 102    * @exception BufferUnderflowException If there are fewer than length
 103    * <code>longs</code> remaining in this buffer.
 104    * @exception IndexOutOfBoundsException If the preconditions on the offset
 105    * and length parameters do not hold.
 106    */
 107   public LongBuffer get (long[] dst, int offset, int length)
 108   {
 109     for (int i = offset; i < offset + length; i++)
 110       {
 111         dst [i] = get ();
 112       }
 113
 114     return this;
 115   }
 116
 117   /**
 118    * This method transfers <code>longs<code> from this buffer into the given
 119    * destination array.
 120    *
 121    * @param dst The byte array to write into.
 122    *
 123    * @exception BufferUnderflowException If there are fewer than dst.length
 124    * <code>longs</code> remaining in this buffer.
 125    */
 126   public LongBuffer get (long[] dst)
 127   {
 128     return get (dst, 0, dst.length);
 129   }
 130
 131   /**
 132    * Writes the content of the the <code>LongBUFFER</code> src
 133    * into the buffer.
 134    *
 135    * @param src The source data.
 136    *
 137    * @exception BufferOverflowException If there is insufficient space in this
 138    * buffer for the remaining <code>longs<code> in the source buffer.
 139    * @exception IllegalArgumentException If the source buffer is this buffer.
 140    * @exception ReadOnlyBufferException If this buffer is read-only.
 141    */
 142   public LongBuffer put (LongBuffer src)
 143   {
 144     if (src == this)
 145       throw new IllegalArgumentException ();
 146
 147     if (src.remaining () > remaining ())
 148       throw new BufferOverflowException ();
 149
 150     if (src.remaining () > 0)
 151       {
 152         long[] toPut = new long [src.remaining ()];
 153         src.get (toPut);
 154         src.put (toPut);
 155       }
 156
 157     return this;
 158   }
 159
 160   /**
 161    * Writes the content of the the <code>long array</code> src
 162    * into the buffer.
 163    *
 164    * @param src The array to copy into the buffer.
 165    * @param offset The offset within the array of the first byte to be read;
 166    * must be non-negative and no larger than src.length.
 167    * @param length The number of bytes to be read from the given array;
 168    * must be non-negative and no larger than src.length - offset.
 169    *
 170    * @exception BufferOverflowException If there is insufficient space in this
 171    * buffer for the remaining <code>longs<code> in the source array.
 172    * @exception IndexOutOfBoundsException If the preconditions on the offset
 173    * and length parameters do not hold
 174    * @exception ReadOnlyBufferException If this buffer is read-only.
 175    */
 176   public LongBuffer put (long[] src, int offset, int length)
 177   {
 178     for (int i = offset; i < offset + length; i++)
 179       put (src [i]);
 180
 181     return this;
 182   }
 183
 184   /**
 185    * Writes the content of the the <code>long array</code> src
 186    * into the buffer.
 187    *
 188    * @param src The array to copy into the buffer.
 189    *
 190    * @exception BufferOverflowException If there is insufficient space in this
 191    * buffer for the remaining <code>longs<code> in the source array.
 192    * @exception ReadOnlyBufferException If this buffer is read-only.
 193    */
 194   public final LongBuffer put (long[] src)
 195   {
 196     return put (src, 0, src.length);
 197   }
 198
 199   /**
 200    * Tells whether ot not this buffer is backed by an accessible
 201    * <code>long</code> array.
 202    */
 203   public final boolean hasArray ()
 204   {
 205     return (backing_buffer != null
 206             && !isReadOnly ());
 207   }
 208
 209   /**
 210    * Returns the <code>long</code> array that backs this buffer.
 211    *
 212    * @exception ReadOnlyBufferException If this buffer is read-only.
 213    * @exception UnsupportedOperationException If this buffer is not backed
 214    * by an accessible array.
 215    */
 216   public final long[] array ()
 217   {
 218     if (backing_buffer == null)
 219       throw new UnsupportedOperationException ();
 220
 221     if (isReadOnly ())
 222       throw new ReadOnlyBufferException ();
 223
 224     return backing_buffer;
 225   }
 226
 227   /**
 228    * Returns the offset within this buffer's backing array of the first element.
 229    *
 230    * @exception ReadOnlyBufferException If this buffer is read-only.
 231    * @exception UnsupportedOperationException If this buffer is not backed
 232    * by an accessible array.
 233    */
 234   public final int arrayOffset ()
 235   {
 236     if (backing_buffer == null)
 237       throw new UnsupportedOperationException ();
 238
 239     if (isReadOnly ())
 240       throw new ReadOnlyBufferException ();
 241
 242     return array_offset;
 243   }
 244
 245   /**
 246    * Calculates a hash code for this buffer.
 247    */
 248   public int hashCode ()
 249   {
 250     // FIXME: Check what SUN calculates here.
 251     return super.hashCode ();
 252   }
 253
 254   /**
 255    * Checks if this buffer is equal to obj.
 256    */
 257   public boolean equals (Object obj)
 258   {
 259     if (obj instanceof LongBuffer)
 260       {
 261         return compareTo (obj) == 0;
 262       }
 263
 264     return false;
 265   }
 266
 267   /**
 268    * Compares two <code>LongBuffer</code> objects.
 269    *
 270    * @exception ClassCastException If obj is not an object derived from
 271    * <code>LongBuffer</code>.
 272    */
 273   public int compareTo (Object obj)
 274   {
 275     LongBuffer a = (LongBuffer) obj;
 276
 277     if (a.remaining () != remaining ())
 278       return 1;
 279
 280     if (! hasArray () ||
 281         ! a.hasArray ())
 282       {
 283         return 1;
 284       }
 285
 286     int r = remaining ();
 287     int i1 = position ();
 288     int i2 = a.position ();
 289
 290     for (int i = 0; i < r; i++)
 291       {
 292         int t = (int) (get (i1) - a.get (i2));
 293
 294         if (t != 0)
 295           {
 296             return (int) t;
 297           }
 298       }
 299
 300     return 0;
 301   }
 302
 303   /**
 304    * Returns the byte order of this buffer.
 305    */
 306   public abstract ByteOrder order ();
 307
 308   /**
 309    * Reads the <code>long</code> at this buffer's current position,
 310    * and then increments the position.
 311    *
 312    * @exception BufferUnderflowException If there are no remaining
 313    * <code>longs</code> in this buffer.
 314    */
 315   public abstract long get ();
 316
 317   /**
 318    * Writes the <code>long</code> at this buffer's current position,
 319    * and then increments the position.
 320    *
 321    * @exception BufferOverflowException If there no remaining
 322    * <code>longs</code> in this buffer.
 323    * @exception ReadOnlyBufferException If this buffer is read-only.
 324    */
 325   public abstract LongBuffer put (long b);
 326
 327   /**
 328    * Absolute get method.
 329    *
 330    * @exception IndexOutOfBoundsException If index is negative or not smaller
 331    * than the buffer's limit.
 332    */
 333   public abstract long get (int index);
 334
 335   /**
 336    * Absolute put method.
 337    *
 338    * @exception IndexOutOfBoundsException If index is negative or not smaller
 339    * than the buffer's limit.
 340    * @exception ReadOnlyBufferException If this buffer is read-only.
 341    */
 342   public abstract LongBuffer put (int index, long b);
 343
 344   /**
 345    * Compacts this buffer.
 346    *
 347    * @exception ReadOnlyBufferException If this buffer is read-only.
 348    */
 349   public abstract LongBuffer compact ();
 350
 351   /**
 352    * Tells wether or not this buffer is direct.
 353    */
 354   public abstract boolean isDirect ();
 355
 356   /**
 357    * Creates a new <code>LongBuffer</code> whose content is a shared
 358    * subsequence of this buffer's content.
 359    */
 360   public abstract LongBuffer slice ();
 361
 362   /**
 363    * Creates a new <code>LongBuffer</code> that shares this buffer's
 364    * content.
 365    */
 366   public abstract LongBuffer duplicate ();
 367
 368   /**
 369    * Creates a new read-only <code>LongBuffer</code> that shares this
 370    * buffer's content.
 371    */
 372   public abstract LongBuffer asReadOnlyBuffer ();
 373 }