001/* IntBuffer.java --
002   Copyright (C) 2002, 2003, 2004, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.nio;
040
041// GCJ LOCAL: Change gnu.classpath.Pointer to RawData
042import gnu.gcj.RawData;
043
044/**
045 * @since 1.4
046 */
047public abstract class IntBuffer extends Buffer
048  implements Comparable<IntBuffer>
049{
050  final int array_offset;
051  final int[] backing_buffer;
052
053  IntBuffer (int capacity, int limit, int position, int mark,
054              RawData address, int[] backing_buffer, int array_offset)
055  {
056    super (capacity, limit, position, mark, address);
057    this.backing_buffer = backing_buffer;
058    this.array_offset = array_offset;
059  }
060
061  /**
062   * Allocates a new <code>IntBuffer</code> object with a given capacity.
063   */
064  public static IntBuffer allocate (int capacity)
065  {
066    return new IntBufferImpl (capacity);
067  }
068
069  /**
070   * Wraps a <code>int</code> array into a <code>IntBuffer</code>
071   * object.
072   *
073   * @exception IndexOutOfBoundsException If the preconditions on the offset
074   * and length parameters do not hold
075   */
076  public static final IntBuffer wrap (int[] array, int offset, int length)
077  {
078    return new IntBufferImpl (array, 0, array.length, offset + length, offset,
079                              -1, false);
080  }
081
082  /**
083   * Wraps a <code>int</code> array into a <code>IntBuffer</code>
084   * object.
085   */
086  public static final IntBuffer wrap (int[] array)
087  {
088    return wrap (array, 0, array.length);
089  }
090
091  /**
092   * This method transfers <code>int</code>s from this buffer into the given
093   * destination array. Before the transfer, it checks if there are fewer than
094   * length <code>int</code>s remaining in this buffer.
095   *
096   * @param dst The destination array
097   * @param offset The offset within the array of the first <code>int</code>
098   * to be written; must be non-negative and no larger than dst.length.
099   * @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>int</code>s remaining in this buffer.
104   * @exception IndexOutOfBoundsException If the preconditions on the offset
105   * and length parameters do not hold.
106   */
107  public IntBuffer get (int[] dst, int offset, int length)
108  {
109    checkArraySize(dst.length, offset, length);
110    checkForUnderflow(length);
111
112    for (int i = offset; i < offset + length; i++)
113      {
114        dst [i] = get ();
115      }
116
117    return this;
118  }
119
120  /**
121   * This method transfers <code>int</code>s from this buffer into the given
122   * destination array.
123   *
124   * @param dst The byte array to write into.
125   *
126   * @exception BufferUnderflowException If there are fewer than dst.length
127   * <code>int</code>s remaining in this buffer.
128   */
129  public IntBuffer get (int[] dst)
130  {
131    return get (dst, 0, dst.length);
132  }
133
134  /**
135   * Writes the content of the the <code>IntBUFFER</code> src
136   * into the buffer. Before the transfer, it checks if there is fewer than
137   * <code>src.remaining()</code> space remaining in this buffer.
138   *
139   * @param src The source data.
140   *
141   * @exception BufferOverflowException If there is insufficient space in this
142   * buffer for the remaining <code>int</code>s in the source buffer.
143   * @exception IllegalArgumentException If the source buffer is this buffer.
144   * @exception ReadOnlyBufferException If this buffer is read-only.
145   */
146  public IntBuffer put (IntBuffer src)
147  {
148    if (src == this)
149      throw new IllegalArgumentException ();
150
151    checkForOverflow(src.remaining ());
152
153    if (src.remaining () > 0)
154      {
155        int[] toPut = new int [src.remaining ()];
156        src.get (toPut);
157        put (toPut);
158      }
159
160    return this;
161  }
162
163  /**
164   * Writes the content of the the <code>int array</code> src
165   * into the buffer. Before the transfer, it checks if there is fewer than
166   * length space remaining in this buffer.
167   *
168   * @param src The array to copy into the buffer.
169   * @param offset The offset within the array of the first byte to be read;
170   * must be non-negative and no larger than src.length.
171   * @param length The number of bytes to be read from the given array;
172   * must be non-negative and no larger than src.length - offset.
173   *
174   * @exception BufferOverflowException If there is insufficient space in this
175   * buffer for the remaining <code>int</code>s in the source array.
176   * @exception IndexOutOfBoundsException If the preconditions on the offset
177   * and length parameters do not hold
178   * @exception ReadOnlyBufferException If this buffer is read-only.
179   */
180  public IntBuffer put (int[] src, int offset, int length)
181  {
182    checkArraySize(src.length, offset, length);
183    checkForOverflow(length);
184
185    for (int i = offset; i < offset + length; i++)
186      put (src [i]);
187
188    return this;
189  }
190
191  /**
192   * Writes the content of the the <code>int array</code> src
193   * into the buffer.
194   *
195   * @param src The array to copy into the buffer.
196   *
197   * @exception BufferOverflowException If there is insufficient space in this
198   * buffer for the remaining <code>int</code>s in the source array.
199   * @exception ReadOnlyBufferException If this buffer is read-only.
200   */
201  public final IntBuffer put (int[] src)
202  {
203    return put (src, 0, src.length);
204  }
205
206  /**
207   * Tells whether ot not this buffer is backed by an accessible
208   * <code>int</code> array.
209   */
210  public final boolean hasArray ()
211  {
212    return (backing_buffer != null
213            && !isReadOnly ());
214  }
215
216  /**
217   * Returns the <code>int</code> array that backs this buffer.
218   *
219   * @exception ReadOnlyBufferException If this buffer is read-only.
220   * @exception UnsupportedOperationException If this buffer is not backed
221   * by an accessible array.
222   */
223  public final int[] array ()
224  {
225    if (backing_buffer == null)
226      throw new UnsupportedOperationException ();
227
228    checkIfReadOnly();
229
230    return backing_buffer;
231  }
232
233  /**
234   * Returns the offset within this buffer's backing array of the first element.
235   *
236   * @exception ReadOnlyBufferException If this buffer is read-only.
237   * @exception UnsupportedOperationException If this buffer is not backed
238   * by an accessible array.
239   */
240  public final int arrayOffset ()
241  {
242    if (backing_buffer == null)
243      throw new UnsupportedOperationException ();
244
245    checkIfReadOnly();
246
247    return array_offset;
248  }
249
250  /**
251   * Calculates a hash code for this buffer.
252   *
253   * This is done with <code>int</code> arithmetic,
254   * where ** represents exponentiation, by this formula:<br>
255   * <code>s[position()] + 31 + (s[position()+1] + 30)*31**1 + ... +
256   * (s[limit()-1]+30)*31**(limit()-1)</code>.
257   * Where s is the buffer data. Note that the hashcode is dependent
258   * on buffer content, and therefore is not useful if the buffer
259   * content may change.
260   *
261   * @return the hash code
262   */
263  public int hashCode ()
264  {
265    int hashCode = get(position()) + 31;
266    int multiplier = 1;
267    for (int i = position() + 1; i < limit(); ++i)
268      {
269          multiplier *= 31;
270          hashCode += (get(i) + 30)*multiplier;
271      }
272    return hashCode;
273  }
274
275  /**
276   * Checks if this buffer is equal to obj.
277   */
278  public boolean equals (Object obj)
279  {
280    if (obj instanceof IntBuffer)
281      {
282        return compareTo ((IntBuffer) obj) == 0;
283      }
284
285    return false;
286  }
287
288  /**
289   * Compares two <code>IntBuffer</code> objects.
290   *
291   * @exception ClassCastException If obj is not an object derived from
292   * <code>IntBuffer</code>.
293   */
294  public int compareTo (IntBuffer other)
295  {
296    int num = Math.min(remaining(), other.remaining());
297    int pos_this = position();
298    int pos_other = other.position();
299
300    for (int count = 0; count < num; count++)
301      {
302         int a = get(pos_this++);
303         int b = other.get(pos_other++);
304
305         if (a == b)
306           continue;
307
308         if (a < b)
309           return -1;
310
311         return 1;
312      }
313
314     return remaining() - other.remaining();
315  }
316
317  /**
318   * Returns the byte order of this buffer.
319   */
320  public abstract ByteOrder order ();
321
322  /**
323   * Reads the <code>int</code> at this buffer's current position,
324   * and then increments the position.
325   *
326   * @exception BufferUnderflowException If there are no remaining
327   * <code>int</code>s in this buffer.
328   */
329  public abstract int get ();
330
331  /**
332   * Writes the <code>int</code> at this buffer's current position,
333   * and then increments the position.
334   *
335   * @exception BufferOverflowException If there no remaining
336   * <code>int</code>s in this buffer.
337   * @exception ReadOnlyBufferException If this buffer is read-only.
338   */
339  public abstract IntBuffer put (int b);
340
341  /**
342   * Absolute get method.
343   *
344   * @exception IndexOutOfBoundsException If index is negative or not smaller
345   * than the buffer's limit.
346   */
347  public abstract int get (int index);
348
349  /**
350   * Absolute put method.
351   *
352   * @exception IndexOutOfBoundsException If index is negative or not smaller
353   * than the buffer's limit.
354   * @exception ReadOnlyBufferException If this buffer is read-only.
355   */
356  public abstract IntBuffer put (int index, int b);
357
358  /**
359   * Compacts this buffer.
360   *
361   * @exception ReadOnlyBufferException If this buffer is read-only.
362   */
363  public abstract IntBuffer compact ();
364
365  /**
366   * Tells wether or not this buffer is direct.
367   */
368  public abstract boolean isDirect ();
369
370  /**
371   * Creates a new <code>IntBuffer</code> whose content is a shared
372   * subsequence of this buffer's content.
373   */
374  public abstract IntBuffer slice ();
375
376  /**
377   * Creates a new <code>IntBuffer</code> that shares this buffer's
378   * content.
379   */
380  public abstract IntBuffer duplicate ();
381
382  /**
383   * Creates a new read-only <code>IntBuffer</code> that shares this
384   * buffer's content.
385   */
386  public abstract IntBuffer asReadOnlyBuffer ();
387}