libjava/java/nio/LongBuffer.java

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