diff -r 53fafe384803 -r d382dacfd73f rt/emul/compact/src/main/java/java/util/HashSet.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/emul/compact/src/main/java/java/util/HashSet.java Tue Feb 26 16:54:16 2013 +0100
@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.util;
+
+/**
+ * This class implements the Set interface, backed by a hash table
+ * (actually a HashMap instance). It makes no guarantees as to the
+ * iteration order of the set; in particular, it does not guarantee that the
+ * order will remain constant over time. This class permits the null
+ * element.
+ *
+ * This class offers constant time performance for the basic operations
+ * (add, remove, contains and size),
+ * assuming the hash function disperses the elements properly among the
+ * buckets. Iterating over this set requires time proportional to the sum of
+ * the HashSet instance's size (the number of elements) plus the
+ * "capacity" of the backing HashMap instance (the number of
+ * buckets). Thus, it's very important not to set the initial capacity too
+ * high (or the load factor too low) if iteration performance is important.
+ *
+ *
Note that this implementation is not synchronized.
+ * If multiple threads access a hash set concurrently, and at least one of
+ * the threads modifies the set, it must be synchronized externally.
+ * This is typically accomplished by synchronizing on some object that
+ * naturally encapsulates the set.
+ *
+ * If no such object exists, the set should be "wrapped" using the
+ * {@link Collections#synchronizedSet Collections.synchronizedSet}
+ * method. This is best done at creation time, to prevent accidental
+ * unsynchronized access to the set:
+ * Set s = Collections.synchronizedSet(new HashSet(...));
+ *
+ * The iterators returned by this class's iterator method are
+ * fail-fast: if the set is modified at any time after the iterator is
+ * created, in any way except through the iterator's own remove
+ * method, the Iterator throws a {@link ConcurrentModificationException}.
+ * Thus, in the face of concurrent modification, the iterator fails quickly
+ * and cleanly, rather than risking arbitrary, non-deterministic behavior at
+ * an undetermined time in the future.
+ *
+ *
Note that the fail-fast behavior of an iterator cannot be guaranteed
+ * as it is, generally speaking, impossible to make any hard guarantees in the
+ * presence of unsynchronized concurrent modification. Fail-fast iterators
+ * throw ConcurrentModificationException on a best-effort basis.
+ * Therefore, it would be wrong to write a program that depended on this
+ * exception for its correctness: the fail-fast behavior of iterators
+ * should be used only to detect bugs.
+ *
+ *
This class is a member of the
+ *
+ * Java Collections Framework.
+ *
+ * @param the type of elements maintained by this set
+ *
+ * @author Josh Bloch
+ * @author Neal Gafter
+ * @see Collection
+ * @see Set
+ * @see TreeSet
+ * @see HashMap
+ * @since 1.2
+ */
+
+public class HashSet
+ extends AbstractSet
+ implements Set, Cloneable, java.io.Serializable
+{
+ static final long serialVersionUID = -5024744406713321676L;
+
+ private transient HashMap map;
+
+ // Dummy value to associate with an Object in the backing Map
+ private static final Object PRESENT = new Object();
+
+ /**
+ * Constructs a new, empty set; the backing HashMap instance has
+ * default initial capacity (16) and load factor (0.75).
+ */
+ public HashSet() {
+ map = new HashMap<>();
+ }
+
+ /**
+ * Constructs a new set containing the elements in the specified
+ * collection. The HashMap is created with default load factor
+ * (0.75) and an initial capacity sufficient to contain the elements in
+ * the specified collection.
+ *
+ * @param c the collection whose elements are to be placed into this set
+ * @throws NullPointerException if the specified collection is null
+ */
+ public HashSet(Collection c) {
+ map = new HashMap<>(Math.max((int) (c.size()/.75f) + 1, 16));
+ addAll(c);
+ }
+
+ /**
+ * Constructs a new, empty set; the backing HashMap instance has
+ * the specified initial capacity and the specified load factor.
+ *
+ * @param initialCapacity the initial capacity of the hash map
+ * @param loadFactor the load factor of the hash map
+ * @throws IllegalArgumentException if the initial capacity is less
+ * than zero, or if the load factor is nonpositive
+ */
+ public HashSet(int initialCapacity, float loadFactor) {
+ map = new HashMap<>(initialCapacity, loadFactor);
+ }
+
+ /**
+ * Constructs a new, empty set; the backing HashMap instance has
+ * the specified initial capacity and default load factor (0.75).
+ *
+ * @param initialCapacity the initial capacity of the hash table
+ * @throws IllegalArgumentException if the initial capacity is less
+ * than zero
+ */
+ public HashSet(int initialCapacity) {
+ map = new HashMap<>(initialCapacity);
+ }
+
+ /**
+ * Constructs a new, empty linked hash set. (This package private
+ * constructor is only used by LinkedHashSet.) The backing
+ * HashMap instance is a LinkedHashMap with the specified initial
+ * capacity and the specified load factor.
+ *
+ * @param initialCapacity the initial capacity of the hash map
+ * @param loadFactor the load factor of the hash map
+ * @param dummy ignored (distinguishes this
+ * constructor from other int, float constructor.)
+ * @throws IllegalArgumentException if the initial capacity is less
+ * than zero, or if the load factor is nonpositive
+ */
+ HashSet(int initialCapacity, float loadFactor, boolean dummy) {
+ map = new LinkedHashMap<>(initialCapacity, loadFactor);
+ }
+
+ /**
+ * Returns an iterator over the elements in this set. The elements
+ * are returned in no particular order.
+ *
+ * @return an Iterator over the elements in this set
+ * @see ConcurrentModificationException
+ */
+ public Iterator iterator() {
+ return map.keySet().iterator();
+ }
+
+ /**
+ * Returns the number of elements in this set (its cardinality).
+ *
+ * @return the number of elements in this set (its cardinality)
+ */
+ public int size() {
+ return map.size();
+ }
+
+ /**
+ * Returns true if this set contains no elements.
+ *
+ * @return true if this set contains no elements
+ */
+ public boolean isEmpty() {
+ return map.isEmpty();
+ }
+
+ /**
+ * Returns true if this set contains the specified element.
+ * More formally, returns true if and only if this set
+ * contains an element e such that
+ * (o==null ? e==null : o.equals(e)).
+ *
+ * @param o element whose presence in this set is to be tested
+ * @return true if this set contains the specified element
+ */
+ public boolean contains(Object o) {
+ return map.containsKey(o);
+ }
+
+ /**
+ * Adds the specified element to this set if it is not already present.
+ * More formally, adds the specified element e to this set if
+ * this set contains no element e2 such that
+ * (e==null ? e2==null : e.equals(e2)).
+ * If this set already contains the element, the call leaves the set
+ * unchanged and returns false.
+ *
+ * @param e element to be added to this set
+ * @return true if this set did not already contain the specified
+ * element
+ */
+ public boolean add(E e) {
+ return map.put(e, PRESENT)==null;
+ }
+
+ /**
+ * Removes the specified element from this set if it is present.
+ * More formally, removes an element e such that
+ * (o==null ? e==null : o.equals(e)),
+ * if this set contains such an element. Returns true if
+ * this set contained the element (or equivalently, if this set
+ * changed as a result of the call). (This set will not contain the
+ * element once the call returns.)
+ *
+ * @param o object to be removed from this set, if present
+ * @return true if the set contained the specified element
+ */
+ public boolean remove(Object o) {
+ return map.remove(o)==PRESENT;
+ }
+
+ /**
+ * Removes all of the elements from this set.
+ * The set will be empty after this call returns.
+ */
+ public void clear() {
+ map.clear();
+ }
+
+ /**
+ * Returns a shallow copy of this HashSet instance: the elements
+ * themselves are not cloned.
+ *
+ * @return a shallow copy of this set
+ */
+ public Object clone() {
+ try {
+ HashSet newSet = (HashSet) super.clone();
+ newSet.map = (HashMap) map.clone();
+ return newSet;
+ } catch (CloneNotSupportedException e) {
+ throw new InternalError();
+ }
+ }
+
+}