ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/jsr166/jsr166/src/main/java/util/PriorityQueue.java

Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.17 by tim, Thu Jul 31 19:49:42 2003 UTC vs.
Revision 1.18 by dholmes, Mon Aug 4 01:48:39 2003 UTC

#	Line 1 | Line 1
1		package java.util;
2
3		/**
4	<	* An unbounded priority queue based on a priority heap.  This queue orders
4	>	* A priority queue based on a priority heap.  This queue orders
5		* elements according to an order specified at construction time, which is
6	<	* specified in the same manner as {@link java.util.TreeSet} and {@link java.util.TreeMap}:
7	<	* elements are ordered
6	>	* specified in the same manner as {@link java.util.TreeSet} and
7	>	* {@link java.util.TreeMap}: elements are ordered
8		* either according to their <i>natural order</i> (see {@link Comparable}), or
9	<	* according to a {@link java.util.Comparator}, depending on which constructor is used.
10	<	* The <em>head</em> of this queue is the least element with respect to the
11	<	* specified ordering. If multiple elements are tied for least value, the
9	>	* according to a {@link java.util.Comparator}, depending on which
10	>	* constructor is used.
11	>	* <p>The <em>head</em> of this queue is the <em>least</em> element with
12	>	* respect to the specified ordering.
13	>	* If multiple elements are tied for least value, the
14		* head is one of those elements. A priority queue does not permit
15		* <tt>null</tt> elements.
16		*
#	Line 20 | Line 22
22		*
23		* <p>A priority queue has a <i>capacity</i>.  The capacity is the
24		* size of the array used internally to store the elements on the
25	<	* queue.  It is always at least as large as the queue size.  As
25	>	* queue, and is limited to <tt>Integer.MAX_VALUE-1</tt>.
26	>	* It is always at least as large as the queue size.  As
27		* elements are added to a priority queue, its capacity grows
28		* automatically.  The details of the growth policy are not specified.
29		*
#	Line 38 | Line 41
41		* @author Josh Bloch
42		*/
43		public class PriorityQueue<E> extends AbstractQueue<E>
44	<	implements Queue<E>, java.io.Serializable {
44	>	implements Sorted, Queue<E>, java.io.Serializable {
45
46		private static final int DEFAULT_INITIAL_CAPACITY = 11;
47
#	Line 115 | Line 118 | public class PriorityQueue<E> extends Ab
118		/**
119		* Create a <tt>PriorityQueue</tt> containing the elements in the specified
120		* collection.  The priority queue has an initial capacity of 110% of the
121	<	* size of the specified collection; or 1 if the collection is empty.
121	>	* size of the specified collection (bounded by
122	>	* <tt>Integer.MAX_VALUE-1</tt>); or 1 if the collection is empty.
123		* If the specified collection
124		* implements the {@link Sorted} interface, the priority queue will be
125		* sorted according to the same comparator, or according to its elements'
#	Line 141 | Line 145 | public class PriorityQueue<E> extends Ab
145
146		this.queue = new Object[initialCapacity + 1];
147
148	+	// FIXME: if c is larger than Integer.MAX_VALUE we'll
149	+	// overflow the array
150	+
151		if (c instanceof Sorted) {
152	<	// FIXME: this code assumes too much
146	<	this.comparator = (Comparator<? super E>) ((Sorted)c).comparator();
147	<	for (Iterator<? extends E> i = c.iterator(); i.hasNext(); )
148	<	queue[++size] = i.next();
152	>	comparator = ((Sorted)c).comparator();
153		} else {
154		comparator = null;
151	–	for (Iterator<? extends E> i = c.iterator(); i.hasNext(); )
152	–	add(i.next());
155		}
156	+
157	+	for (Iterator<? extends E> i = c.iterator(); i.hasNext(); )
158	+	add(i.next());
159		}
160
161		// Queue Methods
#	Line 158 | Line 163 | public class PriorityQueue<E> extends Ab
163		/**
164		* Add the specified element to this priority queue.
165		*
161	–	* @param element the element to add.
166		* @return <tt>true</tt>
167		* @throws ClassCastException if the specified element cannot be compared
168		* with elements currently in the priority queue according
169		* to the priority queue's ordering.
170	<	* @throws NullPointerException if the specified element is null.
170	>	* @throws NullPointerException if the specified element is <tt>null</tt>.
171		*/
172	<	public boolean offer(E element) {
173	<	if (element == null)
172	>	public boolean offer(E o) {
173	>	if (o == null)
174		throw new NullPointerException();
175		modCount++;
176		++size;
177
178		// Grow backing store if necessary
179	+	// FIXME: watch for overflow
180	+	// FIXME: what if we're full?
181		while (size >= queue.length) {
182		Object[] newQueue = new Object[2 * queue.length];
183		System.arraycopy(queue, 0, newQueue, 0, queue.length);
184		queue = newQueue;
185		}
186
187	<	queue[size] = element;
187	>	queue[size] = o;
188		fixUp(size);
189		return true;
190		}
#	Line 203 | Line 209 | public class PriorityQueue<E> extends Ab
209		* with elements currently in the priority queue according
210		* to the priority queue's ordering.
211		*/
212	<	public boolean add(E element) {
213	<	return super.add(element);
212	>	public boolean add(E o) {
213	>	return super.add(o);
214		}
215
216		/**
211	–	* @throws NullPointerException if any element is <tt>null</tt>.
217		* @throws ClassCastException if any element cannot be compared
218		* with elements currently in the priority queue according
219		* to the priority queue's ordering.
220	+	* @throws NullPointerException if <tt>c</tt> or any element in <tt>c</tt>
221	+	* is <tt>null</tt>
222		*/
223		public boolean addAll(Collection<? extends E> c) {
224		return super.addAll(c);

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines