1/*
2 * Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26// -- This file was mechanically generated: Do not edit! -- //
27
28package java.nio;
29
30
31/**
32 * A double buffer.
33 *
34 * <p> This class defines four categories of operations upon
35 * double buffers:
36 *
37 * <ul>
38 *
39 * <li><p> Absolute and relative {@link #get() </code><i>get</i><code>} and
40 * {@link #put(double) </code><i>put</i><code>} methods that read and write
41 * single doubles; </p></li>
42 *
43 * <li><p> Relative {@link #get(double[]) </code><i>bulk get</i><code>}
44 * methods that transfer contiguous sequences of doubles from this buffer
45 * into an array; and</p></li>
46 *
47 * <li><p> Relative {@link #put(double[]) </code><i>bulk put</i><code>}
48 * methods that transfer contiguous sequences of doubles from a
49 * double array or some other double
50 * buffer into this buffer;&#32;and </p></li>
51 *
52 * <li><p> Methods for {@link #compact </code>compacting<code>}, {@link
53 * #duplicate </code>duplicating<code>}, and {@link #slice
54 * </code>slicing<code>} a double buffer.  </p></li>
55 * </ul>
56 *
57 * <p> Double buffers can be created either by {@link #allocate
58 * </code><i>allocation</i><code>}, which allocates space for the buffer's
59 * content, by {@link #wrap(double[]) </code><i>wrapping</i><code>} an existing
60 * double array  into a buffer, or by creating a
61 * <a href="ByteBuffer.html#views"><i>view</i></a> of an existing byte buffer.
62 *
63 * <p> Like a byte buffer, a double buffer is either <a
64 * href="ByteBuffer.html#direct"><i>direct</i> or <i>non-direct</i></a>.  A
65 * double buffer created via the <tt>wrap</tt> methods of this class will
66 * be non-direct.  A double buffer created as a view of a byte buffer will
67 * be direct if, and only if, the byte buffer itself is direct.  Whether or not
68 * a double buffer is direct may be determined by invoking the {@link
69 * #isDirect isDirect} method.  </p>
70 *
71 * <p> Methods in this class that do not otherwise have a value to return are
72 * specified to return the buffer upon which they are invoked.  This allows
73 * method invocations to be chained.
74 *
75 * @author Mark Reinhold
76 * @author JSR-51 Expert Group
77 * @since 1.4
78 */
79
80public abstract class DoubleBuffer
81        extends Buffer
82        implements Comparable<DoubleBuffer> {
83
84    // These fields are declared here rather than in Heap-X-Buffer in order to
85    // reduce the number of virtual method invocations needed to access these
86    // values, which is especially costly when coding small buffers.
87    //
88    final double[] hb;                  // Non-null only for heap buffers
89    final int offset;
90    boolean isReadOnly;                 // Valid only for heap buffers
91
92    // Creates a new buffer with the given mark, position, limit, capacity,
93    // backing array, and array offset
94    //
95    DoubleBuffer(int mark, int pos, int lim, int cap,   // package-private
96                 double[] hb, int offset) {
97        super(mark, pos, lim, cap, 3);
98        this.hb = hb;
99        this.offset = offset;
100    }
101
102    // Creates a new buffer with the given mark, position, limit, and capacity
103    //
104    DoubleBuffer(int mark, int pos, int lim, int cap) { // package-private
105        this(mark, pos, lim, cap, null, 0);
106    }
107
108
109    /**
110     * Allocates a new double buffer.
111     *
112     * <p> The new buffer's position will be zero, its limit will be its
113     * capacity, its mark will be undefined, and each of its elements will be
114     * initialized to zero.  It will have a {@link #array
115     * </code>backing array<code>}, and its {@link #arrayOffset </code>array
116     * offset<code>} will be zero.
117     *
118     * @param capacity The new buffer's capacity, in doubles
119     * @return The new double buffer
120     * @throws IllegalArgumentException If the <tt>capacity</tt> is a negative integer
121     */
122    public static DoubleBuffer allocate(int capacity) {
123        if (capacity < 0)
124            throw new IllegalArgumentException();
125        return new HeapDoubleBuffer(capacity, capacity);
126    }
127
128    /**
129     * Wraps a double array into a buffer.
130     *
131     * <p> The new buffer will be backed by the given double array;
132     * that is, modifications to the buffer will cause the array to be modified
133     * and vice versa.  The new buffer's capacity will be
134     * <tt>array.length</tt>, its position will be <tt>offset</tt>, its limit
135     * will be <tt>offset + length</tt>, and its mark will be undefined.  Its
136     * {@link #array </code>backing array<code>} will be the given array, and
137     * its {@link #arrayOffset </code>array offset<code>} will be zero.  </p>
138     *
139     * @param array  The array that will back the new buffer
140     * @param offset The offset of the subarray to be used; must be non-negative and
141     *               no larger than <tt>array.length</tt>.  The new buffer's position
142     *               will be set to this value.
143     * @param length The length of the subarray to be used;
144     *               must be non-negative and no larger than
145     *               <tt>array.length - offset</tt>.
146     *               The new buffer's limit will be set to <tt>offset + length</tt>.
147     * @return The new double buffer
148     * @throws IndexOutOfBoundsException If the preconditions on the <tt>offset</tt> and
149     *                                   <tt>length</tt>
150     *                                   parameters do not hold
151     */
152    public static DoubleBuffer wrap(double[] array,
153                                    int offset, int length) {
154        try {
155            return new HeapDoubleBuffer(array, offset, length);
156        } catch (IllegalArgumentException x) {
157            throw new IndexOutOfBoundsException();
158        }
159    }
160
161    /**
162     * Wraps a double array into a buffer.
163     *
164     * <p> The new buffer will be backed by the given double array;
165     * that is, modifications to the buffer will cause the array to be modified
166     * and vice versa.  The new buffer's capacity and limit will be
167     * <tt>array.length</tt>, its position will be zero, and its mark will be
168     * undefined.  Its {@link #array </code>backing array<code>} will be the
169     * given array, and its {@link #arrayOffset </code>array offset<code>} will
170     * be zero.  </p>
171     *
172     * @param array The array that will back this buffer
173     * @return The new double buffer
174     */
175    public static DoubleBuffer wrap(double[] array) {
176        return wrap(array, 0, array.length);
177    }
178
179
180    /**
181     * Creates a new double buffer whose content is a shared subsequence of
182     * this buffer's content.
183     *
184     * <p> The content of the new buffer will start at this buffer's current
185     * position.  Changes to this buffer's content will be visible in the new
186     * buffer, and vice versa; the two buffers' position, limit, and mark
187     * values will be independent.
188     *
189     * <p> The new buffer's position will be zero, its capacity and its limit
190     * will be the number of doubles remaining in this buffer, and its mark
191     * will be undefined.  The new buffer will be direct if, and only if, this
192     * buffer is direct, and it will be read-only if, and only if, this buffer
193     * is read-only.  </p>
194     *
195     * @return The new double buffer
196     */
197    public abstract DoubleBuffer slice();
198
199    /**
200     * Creates a new double buffer that shares this buffer's content.
201     *
202     * <p> The content of the new buffer will be that of this buffer.  Changes
203     * to this buffer's content will be visible in the new buffer, and vice
204     * versa; the two buffers' position, limit, and mark values will be
205     * independent.
206     *
207     * <p> The new buffer's capacity, limit, position, and mark values will be
208     * identical to those of this buffer.  The new buffer will be direct if,
209     * and only if, this buffer is direct, and it will be read-only if, and
210     * only if, this buffer is read-only.  </p>
211     *
212     * @return The new double buffer
213     */
214    public abstract DoubleBuffer duplicate();
215
216    /**
217     * Creates a new, read-only double buffer that shares this buffer's
218     * content.
219     *
220     * <p> The content of the new buffer will be that of this buffer.  Changes
221     * to this buffer's content will be visible in the new buffer; the new
222     * buffer itself, however, will be read-only and will not allow the shared
223     * content to be modified.  The two buffers' position, limit, and mark
224     * values will be independent.
225     *
226     * <p> The new buffer's capacity, limit, position, and mark values will be
227     * identical to those of this buffer.
228     *
229     * <p> If this buffer is itself read-only then this method behaves in
230     * exactly the same way as the {@link #duplicate duplicate} method.  </p>
231     *
232     * @return The new, read-only double buffer
233     */
234    public abstract DoubleBuffer asReadOnlyBuffer();
235
236
237    // -- Singleton get/put methods --
238
239    /**
240     * Relative <i>get</i> method.  Reads the double at this buffer's
241     * current position, and then increments the position. </p>
242     *
243     * @return The double at the buffer's current position
244     * @throws BufferUnderflowException If the buffer's current position is not smaller than its
245     *                                  limit
246     */
247    public abstract double get();
248
249    /**
250     * Relative <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
251     *
252     * <p> Writes the given double into this buffer at the current
253     * position, and then increments the position. </p>
254     *
255     * @param d The double to be written
256     * @return This buffer
257     * @throws BufferOverflowException If this buffer's current position is not smaller than its
258     *                                 limit
259     * @throws ReadOnlyBufferException If this buffer is read-only
260     */
261    public abstract DoubleBuffer put(double d);
262
263    /**
264     * Absolute <i>get</i> method.  Reads the double at the given
265     * index. </p>
266     *
267     * @param index The index from which the double will be read
268     * @return The double at the given index
269     * @throws IndexOutOfBoundsException If <tt>index</tt> is negative
270     *                                   or not smaller than the buffer's limit
271     */
272    public abstract double get(int index);
273
274    /**
275     * Absolute <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
276     *
277     * <p> Writes the given double into this buffer at the given
278     * index. </p>
279     *
280     * @param index The index at which the double will be written
281     * @param d     The double value to be written
282     * @return This buffer
283     * @throws IndexOutOfBoundsException If <tt>index</tt> is negative
284     *                                   or not smaller than the buffer's limit
285     * @throws ReadOnlyBufferException   If this buffer is read-only
286     */
287    public abstract DoubleBuffer put(int index, double d);
288
289
290    // -- Bulk get operations --
291
292    /**
293     * Relative bulk <i>get</i> method.
294     *
295     * <p> This method transfers doubles from this buffer into the given
296     * destination array.  If there are fewer doubles remaining in the
297     * buffer than are required to satisfy the request, that is, if
298     * <tt>length</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>, then no
299     * doubles are transferred and a {@link BufferUnderflowException} is
300     * thrown.
301     *
302     * <p> Otherwise, this method copies <tt>length</tt> doubles from this
303     * buffer into the given array, starting at the current position of this
304     * buffer and at the given offset in the array.  The position of this
305     * buffer is then incremented by <tt>length</tt>.
306     *
307     * <p> In other words, an invocation of this method of the form
308     * <tt>src.get(dst,&nbsp;off,&nbsp;len)</tt> has exactly the same effect as
309     * the loop
310     *
311     * <pre>
312     *     for (int i = off; i < off + len; i++)
313     *         dst[i] = src.get(); </pre>
314     *
315     * except that it first checks that there are sufficient doubles in
316     * this buffer and it is potentially much more efficient. </p>
317     *
318     * @param dst    The array into which doubles are to be written
319     * @param offset The offset within the array of the first double to be
320     *               written; must be non-negative and no larger than
321     *               <tt>dst.length</tt>
322     * @param length The maximum number of doubles to be written to the given
323     *               array; must be non-negative and no larger than
324     *               <tt>dst.length - offset</tt>
325     * @return This buffer
326     * @throws BufferUnderflowException  If there are fewer than <tt>length</tt> doubles
327     *                                   remaining in this buffer
328     * @throws IndexOutOfBoundsException If the preconditions on the <tt>offset</tt> and
329     *                                   <tt>length</tt>
330     *                                   parameters do not hold
331     */
332    public DoubleBuffer get(double[] dst, int offset, int length) {
333        checkBounds(offset, length, dst.length);
334        if (length > remaining())
335            throw new BufferUnderflowException();
336        int end = offset + length;
337        for (int i = offset; i < end; i++)
338            dst[i] = get();
339        return this;
340    }
341
342    /**
343     * Relative bulk <i>get</i> method.
344     *
345     * <p> This method transfers doubles from this buffer into the given
346     * destination array.  An invocation of this method of the form
347     * <tt>src.get(a)</tt> behaves in exactly the same way as the invocation
348     *
349     * <pre>
350     *     src.get(a, 0, a.length) </pre>
351     *
352     * @return This buffer
353     * @throws BufferUnderflowException If there are fewer than <tt>length</tt> doubles
354     *                                  remaining in this buffer
355     */
356    public DoubleBuffer get(double[] dst) {
357        return get(dst, 0, dst.length);
358    }
359
360
361    // -- Bulk put operations --
362
363    /**
364     * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
365     *
366     * <p> This method transfers the doubles remaining in the given source
367     * buffer into this buffer.  If there are more doubles remaining in the
368     * source buffer than in this buffer, that is, if
369     * <tt>src.remaining()</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>,
370     * then no doubles are transferred and a {@link
371     * BufferOverflowException} is thrown.
372     *
373     * <p> Otherwise, this method copies
374     * <i>n</i>&nbsp;=&nbsp;<tt>src.remaining()</tt> doubles from the given
375     * buffer into this buffer, starting at each buffer's current position.
376     * The positions of both buffers are then incremented by <i>n</i>.
377     *
378     * <p> In other words, an invocation of this method of the form
379     * <tt>dst.put(src)</tt> has exactly the same effect as the loop
380     *
381     * <pre>
382     *     while (src.hasRemaining())
383     *         dst.put(src.get()); </pre>
384     *
385     * except that it first checks that there is sufficient space in this
386     * buffer and it is potentially much more efficient. </p>
387     *
388     * @param src The source buffer from which doubles are to be read;
389     *            must not be this buffer
390     * @return This buffer
391     * @throws BufferOverflowException  If there is insufficient space in this buffer
392     *                                  for the remaining doubles in the source buffer
393     * @throws IllegalArgumentException If the source buffer is this buffer
394     * @throws ReadOnlyBufferException  If this buffer is read-only
395     */
396    public DoubleBuffer put(DoubleBuffer src) {
397        if (src == this)
398            throw new IllegalArgumentException();
399        int n = src.remaining();
400        if (n > remaining())
401            throw new BufferOverflowException();
402        for (int i = 0; i < n; i++)
403            put(src.get());
404        return this;
405    }
406
407    /**
408     * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
409     *
410     * <p> This method transfers doubles into this buffer from the given
411     * source array.  If there are more doubles to be copied from the array
412     * than remain in this buffer, that is, if
413     * <tt>length</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>, then no
414     * doubles are transferred and a {@link BufferOverflowException} is
415     * thrown.
416     *
417     * <p> Otherwise, this method copies <tt>length</tt> doubles from the
418     * given array into this buffer, starting at the given offset in the array
419     * and at the current position of this buffer.  The position of this buffer
420     * is then incremented by <tt>length</tt>.
421     *
422     * <p> In other words, an invocation of this method of the form
423     * <tt>dst.put(src,&nbsp;off,&nbsp;len)</tt> has exactly the same effect as
424     * the loop
425     *
426     * <pre>
427     *     for (int i = off; i < off + len; i++)
428     *         dst.put(a[i]); </pre>
429     *
430     * except that it first checks that there is sufficient space in this
431     * buffer and it is potentially much more efficient. </p>
432     *
433     * @param src    The array from which doubles are to be read
434     * @param offset The offset within the array of the first double to be read;
435     *               must be non-negative and no larger than <tt>array.length</tt>
436     * @param length The number of doubles to be read from the given array;
437     *               must be non-negative and no larger than
438     *               <tt>array.length - offset</tt>
439     * @return This buffer
440     * @throws BufferOverflowException   If there is insufficient space in this buffer
441     * @throws IndexOutOfBoundsException If the preconditions on the <tt>offset</tt> and
442     *                                   <tt>length</tt>
443     *                                   parameters do not hold
444     * @throws ReadOnlyBufferException   If this buffer is read-only
445     */
446    public DoubleBuffer put(double[] src, int offset, int length) {
447        checkBounds(offset, length, src.length);
448        if (length > remaining())
449            throw new BufferOverflowException();
450        int end = offset + length;
451        for (int i = offset; i < end; i++)
452            this.put(src[i]);
453        return this;
454    }
455
456    /**
457     * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
458     *
459     * <p> This method transfers the entire content of the given source
460     * double array into this buffer.  An invocation of this method of the
461     * form <tt>dst.put(a)</tt> behaves in exactly the same way as the
462     * invocation
463     *
464     * <pre>
465     *     dst.put(a, 0, a.length) </pre>
466     *
467     * @return This buffer
468     * @throws BufferOverflowException If there is insufficient space in this buffer
469     * @throws ReadOnlyBufferException If this buffer is read-only
470     */
471    public final DoubleBuffer put(double[] src) {
472        return put(src, 0, src.length);
473    }
474
475
476    // -- Other stuff --
477
478    /**
479     * Tells whether or not this buffer is backed by an accessible double
480     * array.
481     *
482     * <p> If this method returns <tt>true</tt> then the {@link #array() array}
483     * and {@link #arrayOffset() arrayOffset} methods may safely be invoked.
484     * </p>
485     *
486     * @return <tt>true</tt> if, and only if, this buffer
487     * is backed by an array and is not read-only
488     */
489    public final boolean hasArray() {
490        return (hb != null) && !isReadOnly;
491    }
492
493    /**
494     * Returns the double array that backs this
495     * buffer&nbsp;&nbsp;<i>(optional operation)</i>.
496     *
497     * <p> Modifications to this buffer's content will cause the returned
498     * array's content to be modified, and vice versa.
499     *
500     * <p> Invoke the {@link #hasArray hasArray} method before invoking this
501     * method in order to ensure that this buffer has an accessible backing
502     * array.  </p>
503     *
504     * @return The array that backs this buffer
505     * @throws ReadOnlyBufferException       If this buffer is backed by an array but is read-only
506     * @throws UnsupportedOperationException If this buffer is not backed by an accessible array
507     */
508    public final double[] array() {
509        if (hb == null)
510            throw new UnsupportedOperationException();
511        if (isReadOnly)
512            throw new ReadOnlyBufferException();
513        return hb;
514    }
515
516    /**
517     * Returns the offset within this buffer's backing array of the first
518     * element of the buffer&nbsp;&nbsp;<i>(optional operation)</i>.
519     *
520     * <p> If this buffer is backed by an array then buffer position <i>p</i>
521     * corresponds to array index <i>p</i>&nbsp;+&nbsp;<tt>arrayOffset()</tt>.
522     *
523     * <p> Invoke the {@link #hasArray hasArray} method before invoking this
524     * method in order to ensure that this buffer has an accessible backing
525     * array.  </p>
526     *
527     * @return The offset within this buffer's array
528     * of the first element of the buffer
529     * @throws ReadOnlyBufferException       If this buffer is backed by an array but is read-only
530     * @throws UnsupportedOperationException If this buffer is not backed by an accessible array
531     */
532    public final int arrayOffset() {
533        if (hb == null)
534            throw new UnsupportedOperationException();
535        if (isReadOnly)
536            throw new ReadOnlyBufferException();
537        return offset;
538    }
539
540    /**
541     * Compacts this buffer&nbsp;&nbsp;<i>(optional operation)</i>.
542     *
543     * <p> The doubles between the buffer's current position and its limit,
544     * if any, are copied to the beginning of the buffer.  That is, the
545     * double at index <i>p</i>&nbsp;=&nbsp;<tt>position()</tt> is copied
546     * to index zero, the double at index <i>p</i>&nbsp;+&nbsp;1 is copied
547     * to index one, and so forth until the double at index
548     * <tt>limit()</tt>&nbsp;-&nbsp;1 is copied to index
549     * <i>n</i>&nbsp;=&nbsp;<tt>limit()</tt>&nbsp;-&nbsp;<tt>1</tt>&nbsp;-&nbsp;<i>p</i>.
550     * The buffer's position is then set to <i>n+1</i> and its limit is set to
551     * its capacity.  The mark, if defined, is discarded.
552     *
553     * <p> The buffer's position is set to the number of doubles copied,
554     * rather than to zero, so that an invocation of this method can be
555     * followed immediately by an invocation of another relative <i>put</i>
556     * method. </p>
557     *
558     * @return This buffer
559     * @throws ReadOnlyBufferException If this buffer is read-only
560     */
561    public abstract DoubleBuffer compact();
562
563    /**
564     * Tells whether or not this double buffer is direct. </p>
565     *
566     * @return <tt>true</tt> if, and only if, this buffer is direct
567     */
568    public abstract boolean isDirect();
569
570
571    /**
572     * Returns a string summarizing the state of this buffer.  </p>
573     *
574     * @return A summary string
575     */
576    public String toString() {
577        StringBuffer sb = new StringBuffer();
578        sb.append(getClass().getName());
579        sb.append("[pos=");
580        sb.append(position());
581        sb.append(" lim=");
582        sb.append(limit());
583        sb.append(" cap=");
584        sb.append(capacity());
585        sb.append("]");
586        return sb.toString();
587    }
588
589
590    /**
591     * Returns the current hash code of this buffer.
592     *
593     * <p> The hash code of a double buffer depends only upon its remaining
594     * elements; that is, upon the elements from <tt>position()</tt> up to, and
595     * including, the element at <tt>limit()</tt>&nbsp;-&nbsp;<tt>1</tt>.
596     *
597     * <p> Because buffer hash codes are content-dependent, it is inadvisable
598     * to use buffers as keys in hash maps or similar data structures unless it
599     * is known that their contents will not change.  </p>
600     *
601     * @return The current hash code of this buffer
602     */
603    public int hashCode() {
604        int h = 1;
605        int p = position();
606        for (int i = limit() - 1; i >= p; i--)
607            h = 31 * h + (int) get(i);
608        return h;
609    }
610
611    /**
612     * Tells whether or not this buffer is equal to another object.
613     *
614     * <p> Two double buffers are equal if, and only if,
615     *
616     * <p><ol>
617     *
618     * <li><p> They have the same element type,  </p></li>
619     *
620     * <li><p> They have the same number of remaining elements, and
621     * </p></li>
622     *
623     * <li><p> The two sequences of remaining elements, considered
624     * independently of their starting positions, are pointwise equal.
625     *
626     * This method considers two double elements {@code a} and {@code b}
627     * to be equal if
628     * {@code (a == b) || (Double.isNaN(a) && Double.isNaN(b))}.
629     * The values {@code -0.0} and {@code +0.0} are considered to be
630     * equal, unlike {@link Double#equals(Object)}.
631     *
632     * </p></li>
633     *
634     * </ol>
635     *
636     * <p> A double buffer is not equal to any other type of object.  </p>
637     *
638     * @param ob The object to which this buffer is to be compared
639     * @return <tt>true</tt> if, and only if, this buffer is equal to the
640     * given object
641     */
642    public boolean equals(Object ob) {
643        if (this == ob)
644            return true;
645        if (!(ob instanceof DoubleBuffer))
646            return false;
647        DoubleBuffer that = (DoubleBuffer) ob;
648        if (this.remaining() != that.remaining())
649            return false;
650        int p = this.position();
651        for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--)
652            if (!equals(this.get(i), that.get(j)))
653                return false;
654        return true;
655    }
656
657    private static boolean equals(double x, double y) {
658
659        return (x == y) || (Double.isNaN(x) && Double.isNaN(y));
660
661
662    }
663
664    /**
665     * Compares this buffer to another.
666     *
667     * <p> Two double buffers are compared by comparing their sequences of
668     * remaining elements lexicographically, without regard to the starting
669     * position of each sequence within its corresponding buffer.
670     *
671     * Pairs of {@code double} elements are compared as if by invoking
672     * {@link Double#compare(double, double)}, except that
673     * {@code -0.0} and {@code 0.0} are considered to be equal.
674     * {@code Double.NaN} is considered by this method to be equal
675     * to itself and greater than all other {@code double} values
676     * (including {@code Double.POSITIVE_INFINITY}).
677     *
678     *
679     *
680     *
681     *
682     * <p> A double buffer is not comparable to any other type of object.
683     *
684     * @return A negative integer, zero, or a positive integer as this buffer
685     * is less than, equal to, or greater than the given buffer
686     */
687    public int compareTo(DoubleBuffer that) {
688        int n = this.position() + Math.min(this.remaining(), that.remaining());
689        for (int i = this.position(), j = that.position(); i < n; i++, j++) {
690            // Android changed : Call through to Double.compare() instead of
691            // duplicating code pointlessly.
692            int cmp = Double.compare(this.get(i), that.get(j));
693            if (cmp != 0)
694                return cmp;
695        }
696        return this.remaining() - that.remaining();
697    }
698
699    private static int compare(double x, double y) {
700
701        return ((x < y) ? -1 :
702                (x > y) ? +1 :
703                        (x == y) ? 0 :
704                                Double.isNaN(x) ? (Double.isNaN(y) ? 0 : +1) : -1);
705
706
707    }
708
709    // -- Other char stuff --
710
711
712    // -- Other byte stuff: Access to binary data --
713
714
715    /**
716     * Retrieves this buffer's byte order.
717     *
718     * <p> The byte order of a double buffer created by allocation or by
719     * wrapping an existing <tt>double</tt> array is the {@link
720     * ByteOrder#nativeOrder </code>native order<code>} of the underlying
721     * hardware.  The byte order of a double buffer created as a <a
722     * href="ByteBuffer.html#views">view</a> of a byte buffer is that of the
723     * byte buffer at the moment that the view is created.  </p>
724     *
725     * @return This buffer's byte order
726     */
727    public abstract ByteOrder order();
728
729
730}
731