diff -r 53fafe384803 -r d382dacfd73f rt/emul/compact/src/main/java/java/util/HashMap.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/rt/emul/compact/src/main/java/java/util/HashMap.java Tue Feb 26 16:54:16 2013 +0100 @@ -0,0 +1,990 @@ +/* + * 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; +import java.io.*; + +/** + * Hash table based implementation of the Map interface. This + * implementation provides all of the optional map operations, and permits + * null values and the null key. (The HashMap + * class is roughly equivalent to Hashtable, except that it is + * unsynchronized and permits nulls.) This class makes no guarantees as to + * the order of the map; in particular, it does not guarantee that the order + * will remain constant over time. + * + *

This implementation provides constant-time performance for the basic + * operations (get and put), assuming the hash function + * disperses the elements properly among the buckets. Iteration over + * collection views requires time proportional to the "capacity" of the + * HashMap instance (the number of buckets) plus its size (the number + * of key-value mappings). Thus, it's very important not to set the initial + * capacity too high (or the load factor too low) if iteration performance is + * important. + * + *

An instance of HashMap has two parameters that affect its + * performance: initial capacity and load factor. The + * capacity is the number of buckets in the hash table, and the initial + * capacity is simply the capacity at the time the hash table is created. The + * load factor is a measure of how full the hash table is allowed to + * get before its capacity is automatically increased. When the number of + * entries in the hash table exceeds the product of the load factor and the + * current capacity, the hash table is rehashed (that is, internal data + * structures are rebuilt) so that the hash table has approximately twice the + * number of buckets. + * + *

As a general rule, the default load factor (.75) offers a good tradeoff + * between time and space costs. Higher values decrease the space overhead + * but increase the lookup cost (reflected in most of the operations of the + * HashMap class, including get and put). The + * expected number of entries in the map and its load factor should be taken + * into account when setting its initial capacity, so as to minimize the + * number of rehash operations. If the initial capacity is greater + * than the maximum number of entries divided by the load factor, no + * rehash operations will ever occur. + * + *

If many mappings are to be stored in a HashMap instance, + * creating it with a sufficiently large capacity will allow the mappings to + * be stored more efficiently than letting it perform automatic rehashing as + * needed to grow the table. + * + *

Note that this implementation is not synchronized. + * If multiple threads access a hash map concurrently, and at least one of + * the threads modifies the map structurally, it must be + * synchronized externally. (A structural modification is any operation + * that adds or deletes one or more mappings; merely changing the value + * associated with a key that an instance already contains is not a + * structural modification.) This is typically accomplished by + * synchronizing on some object that naturally encapsulates the map. + * + * If no such object exists, the map should be "wrapped" using the + * {@link Collections#synchronizedMap Collections.synchronizedMap} + * method. This is best done at creation time, to prevent accidental + * unsynchronized access to the map:

+ *   Map m = Collections.synchronizedMap(new HashMap(...));
+ * + *

The iterators returned by all of this class's "collection view methods" + * are fail-fast: if the map is structurally modified at any time after + * the iterator is created, in any way except through the iterator's own + * remove method, the iterator will throw 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 keys maintained by this map + * @param the type of mapped values + * + * @author Doug Lea + * @author Josh Bloch + * @author Arthur van Hoff + * @author Neal Gafter + * @see Object#hashCode() + * @see Collection + * @see Map + * @see TreeMap + * @see Hashtable + * @since 1.2 + */ + +public class HashMap + extends AbstractMap + implements Map, Cloneable, Serializable +{ + + /** + * The default initial capacity - MUST be a power of two. + */ + static final int DEFAULT_INITIAL_CAPACITY = 16; + + /** + * The maximum capacity, used if a higher value is implicitly specified + * by either of the constructors with arguments. + * MUST be a power of two <= 1<<30. + */ + static final int MAXIMUM_CAPACITY = 1 << 30; + + /** + * The load factor used when none specified in constructor. + */ + static final float DEFAULT_LOAD_FACTOR = 0.75f; + + /** + * The table, resized as necessary. Length MUST Always be a power of two. + */ + transient Entry[] table; + + /** + * The number of key-value mappings contained in this map. + */ + transient int size; + + /** + * The next size value at which to resize (capacity * load factor). + * @serial + */ + int threshold; + + /** + * The load factor for the hash table. + * + * @serial + */ + final float loadFactor; + + /** + * The number of times this HashMap has been structurally modified + * Structural modifications are those that change the number of mappings in + * the HashMap or otherwise modify its internal structure (e.g., + * rehash). This field is used to make iterators on Collection-views of + * the HashMap fail-fast. (See ConcurrentModificationException). + */ + transient int modCount; + + /** + * Constructs an empty HashMap with the specified initial + * capacity and load factor. + * + * @param initialCapacity the initial capacity + * @param loadFactor the load factor + * @throws IllegalArgumentException if the initial capacity is negative + * or the load factor is nonpositive + */ + public HashMap(int initialCapacity, float loadFactor) { + if (initialCapacity < 0) + throw new IllegalArgumentException("Illegal initial capacity: " + + initialCapacity); + if (initialCapacity > MAXIMUM_CAPACITY) + initialCapacity = MAXIMUM_CAPACITY; + if (loadFactor <= 0 || Float.isNaN(loadFactor)) + throw new IllegalArgumentException("Illegal load factor: " + + loadFactor); + + // Find a power of 2 >= initialCapacity + int capacity = 1; + while (capacity < initialCapacity) + capacity <<= 1; + + this.loadFactor = loadFactor; + threshold = (int)(capacity * loadFactor); + table = new Entry[capacity]; + init(); + } + + /** + * Constructs an empty HashMap with the specified initial + * capacity and the default load factor (0.75). + * + * @param initialCapacity the initial capacity. + * @throws IllegalArgumentException if the initial capacity is negative. + */ + public HashMap(int initialCapacity) { + this(initialCapacity, DEFAULT_LOAD_FACTOR); + } + + /** + * Constructs an empty HashMap with the default initial capacity + * (16) and the default load factor (0.75). + */ + public HashMap() { + this.loadFactor = DEFAULT_LOAD_FACTOR; + threshold = (int)(DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR); + table = new Entry[DEFAULT_INITIAL_CAPACITY]; + init(); + } + + /** + * Constructs a new HashMap with the same mappings as the + * specified Map. The HashMap is created with + * default load factor (0.75) and an initial capacity sufficient to + * hold the mappings in the specified Map. + * + * @param m the map whose mappings are to be placed in this map + * @throws NullPointerException if the specified map is null + */ + public HashMap(Map m) { + this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1, + DEFAULT_INITIAL_CAPACITY), DEFAULT_LOAD_FACTOR); + putAllForCreate(m); + } + + // internal utilities + + /** + * Initialization hook for subclasses. This method is called + * in all constructors and pseudo-constructors (clone, readObject) + * after HashMap has been initialized but before any entries have + * been inserted. (In the absence of this method, readObject would + * require explicit knowledge of subclasses.) + */ + void init() { + } + + /** + * Applies a supplemental hash function to a given hashCode, which + * defends against poor quality hash functions. This is critical + * because HashMap uses power-of-two length hash tables, that + * otherwise encounter collisions for hashCodes that do not differ + * in lower bits. Note: Null keys always map to hash 0, thus index 0. + */ + static int hash(int h) { + // This function ensures that hashCodes that differ only by + // constant multiples at each bit position have a bounded + // number of collisions (approximately 8 at default load factor). + h ^= (h >>> 20) ^ (h >>> 12); + return h ^ (h >>> 7) ^ (h >>> 4); + } + + /** + * Returns index for hash code h. + */ + static int indexFor(int h, int length) { + return h & (length-1); + } + + /** + * Returns the number of key-value mappings in this map. + * + * @return the number of key-value mappings in this map + */ + public int size() { + return size; + } + + /** + * Returns true if this map contains no key-value mappings. + * + * @return true if this map contains no key-value mappings + */ + public boolean isEmpty() { + return size == 0; + } + + /** + * Returns the value to which the specified key is mapped, + * or {@code null} if this map contains no mapping for the key. + * + *

More formally, if this map contains a mapping from a key + * {@code k} to a value {@code v} such that {@code (key==null ? k==null : + * key.equals(k))}, then this method returns {@code v}; otherwise + * it returns {@code null}. (There can be at most one such mapping.) + * + *

A return value of {@code null} does not necessarily + * indicate that the map contains no mapping for the key; it's also + * possible that the map explicitly maps the key to {@code null}. + * The {@link #containsKey containsKey} operation may be used to + * distinguish these two cases. + * + * @see #put(Object, Object) + */ + public V get(Object key) { + if (key == null) + return getForNullKey(); + int hash = hash(key.hashCode()); + for (Entry e = table[indexFor(hash, table.length)]; + e != null; + e = e.next) { + Object k; + if (e.hash == hash && ((k = e.key) == key || key.equals(k))) + return e.value; + } + return null; + } + + /** + * Offloaded version of get() to look up null keys. Null keys map + * to index 0. This null case is split out into separate methods + * for the sake of performance in the two most commonly used + * operations (get and put), but incorporated with conditionals in + * others. + */ + private V getForNullKey() { + for (Entry e = table[0]; e != null; e = e.next) { + if (e.key == null) + return e.value; + } + return null; + } + + /** + * Returns true if this map contains a mapping for the + * specified key. + * + * @param key The key whose presence in this map is to be tested + * @return true if this map contains a mapping for the specified + * key. + */ + public boolean containsKey(Object key) { + return getEntry(key) != null; + } + + /** + * Returns the entry associated with the specified key in the + * HashMap. Returns null if the HashMap contains no mapping + * for the key. + */ + final Entry getEntry(Object key) { + int hash = (key == null) ? 0 : hash(key.hashCode()); + for (Entry e = table[indexFor(hash, table.length)]; + e != null; + e = e.next) { + Object k; + if (e.hash == hash && + ((k = e.key) == key || (key != null && key.equals(k)))) + return e; + } + return null; + } + + + /** + * Associates the specified value with the specified key in this map. + * If the map previously contained a mapping for the key, the old + * value is replaced. + * + * @param key key with which the specified value is to be associated + * @param value value to be associated with the specified key + * @return the previous value associated with key, or + * null if there was no mapping for key. + * (A null return can also indicate that the map + * previously associated null with key.) + */ + public V put(K key, V value) { + if (key == null) + return putForNullKey(value); + int hash = hash(key.hashCode()); + int i = indexFor(hash, table.length); + for (Entry e = table[i]; e != null; e = e.next) { + Object k; + if (e.hash == hash && ((k = e.key) == key || key.equals(k))) { + V oldValue = e.value; + e.value = value; + e.recordAccess(this); + return oldValue; + } + } + + modCount++; + addEntry(hash, key, value, i); + return null; + } + + /** + * Offloaded version of put for null keys + */ + private V putForNullKey(V value) { + for (Entry e = table[0]; e != null; e = e.next) { + if (e.key == null) { + V oldValue = e.value; + e.value = value; + e.recordAccess(this); + return oldValue; + } + } + modCount++; + addEntry(0, null, value, 0); + return null; + } + + /** + * This method is used instead of put by constructors and + * pseudoconstructors (clone, readObject). It does not resize the table, + * check for comodification, etc. It calls createEntry rather than + * addEntry. + */ + private void putForCreate(K key, V value) { + int hash = (key == null) ? 0 : hash(key.hashCode()); + int i = indexFor(hash, table.length); + + /** + * Look for preexisting entry for key. This will never happen for + * clone or deserialize. It will only happen for construction if the + * input Map is a sorted map whose ordering is inconsistent w/ equals. + */ + for (Entry e = table[i]; e != null; e = e.next) { + Object k; + if (e.hash == hash && + ((k = e.key) == key || (key != null && key.equals(k)))) { + e.value = value; + return; + } + } + + createEntry(hash, key, value, i); + } + + private void putAllForCreate(Map m) { + for (Map.Entry e : m.entrySet()) + putForCreate(e.getKey(), e.getValue()); + } + + /** + * Rehashes the contents of this map into a new array with a + * larger capacity. This method is called automatically when the + * number of keys in this map reaches its threshold. + * + * If current capacity is MAXIMUM_CAPACITY, this method does not + * resize the map, but sets threshold to Integer.MAX_VALUE. + * This has the effect of preventing future calls. + * + * @param newCapacity the new capacity, MUST be a power of two; + * must be greater than current capacity unless current + * capacity is MAXIMUM_CAPACITY (in which case value + * is irrelevant). + */ + void resize(int newCapacity) { + Entry[] oldTable = table; + int oldCapacity = oldTable.length; + if (oldCapacity == MAXIMUM_CAPACITY) { + threshold = Integer.MAX_VALUE; + return; + } + + Entry[] newTable = new Entry[newCapacity]; + transfer(newTable); + table = newTable; + threshold = (int)(newCapacity * loadFactor); + } + + /** + * Transfers all entries from current table to newTable. + */ + void transfer(Entry[] newTable) { + Entry[] src = table; + int newCapacity = newTable.length; + for (int j = 0; j < src.length; j++) { + Entry e = src[j]; + if (e != null) { + src[j] = null; + do { + Entry next = e.next; + int i = indexFor(e.hash, newCapacity); + e.next = newTable[i]; + newTable[i] = e; + e = next; + } while (e != null); + } + } + } + + /** + * Copies all of the mappings from the specified map to this map. + * These mappings will replace any mappings that this map had for + * any of the keys currently in the specified map. + * + * @param m mappings to be stored in this map + * @throws NullPointerException if the specified map is null + */ + public void putAll(Map m) { + int numKeysToBeAdded = m.size(); + if (numKeysToBeAdded == 0) + return; + + /* + * Expand the map if the map if the number of mappings to be added + * is greater than or equal to threshold. This is conservative; the + * obvious condition is (m.size() + size) >= threshold, but this + * condition could result in a map with twice the appropriate capacity, + * if the keys to be added overlap with the keys already in this map. + * By using the conservative calculation, we subject ourself + * to at most one extra resize. + */ + if (numKeysToBeAdded > threshold) { + int targetCapacity = (int)(numKeysToBeAdded / loadFactor + 1); + if (targetCapacity > MAXIMUM_CAPACITY) + targetCapacity = MAXIMUM_CAPACITY; + int newCapacity = table.length; + while (newCapacity < targetCapacity) + newCapacity <<= 1; + if (newCapacity > table.length) + resize(newCapacity); + } + + for (Map.Entry e : m.entrySet()) + put(e.getKey(), e.getValue()); + } + + /** + * Removes the mapping for the specified key from this map if present. + * + * @param key key whose mapping is to be removed from the map + * @return the previous value associated with key, or + * null if there was no mapping for key. + * (A null return can also indicate that the map + * previously associated null with key.) + */ + public V remove(Object key) { + Entry e = removeEntryForKey(key); + return (e == null ? null : e.value); + } + + /** + * Removes and returns the entry associated with the specified key + * in the HashMap. Returns null if the HashMap contains no mapping + * for this key. + */ + final Entry removeEntryForKey(Object key) { + int hash = (key == null) ? 0 : hash(key.hashCode()); + int i = indexFor(hash, table.length); + Entry prev = table[i]; + Entry e = prev; + + while (e != null) { + Entry next = e.next; + Object k; + if (e.hash == hash && + ((k = e.key) == key || (key != null && key.equals(k)))) { + modCount++; + size--; + if (prev == e) + table[i] = next; + else + prev.next = next; + e.recordRemoval(this); + return e; + } + prev = e; + e = next; + } + + return e; + } + + /** + * Special version of remove for EntrySet. + */ + final Entry removeMapping(Object o) { + if (!(o instanceof Map.Entry)) + return null; + + Map.Entry entry = (Map.Entry) o; + Object key = entry.getKey(); + int hash = (key == null) ? 0 : hash(key.hashCode()); + int i = indexFor(hash, table.length); + Entry prev = table[i]; + Entry e = prev; + + while (e != null) { + Entry next = e.next; + if (e.hash == hash && e.equals(entry)) { + modCount++; + size--; + if (prev == e) + table[i] = next; + else + prev.next = next; + e.recordRemoval(this); + return e; + } + prev = e; + e = next; + } + + return e; + } + + /** + * Removes all of the mappings from this map. + * The map will be empty after this call returns. + */ + public void clear() { + modCount++; + Entry[] tab = table; + for (int i = 0; i < tab.length; i++) + tab[i] = null; + size = 0; + } + + /** + * Returns true if this map maps one or more keys to the + * specified value. + * + * @param value value whose presence in this map is to be tested + * @return true if this map maps one or more keys to the + * specified value + */ + public boolean containsValue(Object value) { + if (value == null) + return containsNullValue(); + + Entry[] tab = table; + for (int i = 0; i < tab.length ; i++) + for (Entry e = tab[i] ; e != null ; e = e.next) + if (value.equals(e.value)) + return true; + return false; + } + + /** + * Special-case code for containsValue with null argument + */ + private boolean containsNullValue() { + Entry[] tab = table; + for (int i = 0; i < tab.length ; i++) + for (Entry e = tab[i] ; e != null ; e = e.next) + if (e.value == null) + return true; + return false; + } + + /** + * Returns a shallow copy of this HashMap instance: the keys and + * values themselves are not cloned. + * + * @return a shallow copy of this map + */ + public Object clone() { + HashMap result = null; + try { + result = (HashMap)super.clone(); + } catch (CloneNotSupportedException e) { + // assert false; + } + result.table = new Entry[table.length]; + result.entrySet = null; + result.modCount = 0; + result.size = 0; + result.init(); + result.putAllForCreate(this); + + return result; + } + + static class Entry implements Map.Entry { + final K key; + V value; + Entry next; + final int hash; + + /** + * Creates new entry. + */ + Entry(int h, K k, V v, Entry n) { + value = v; + next = n; + key = k; + hash = h; + } + + public final K getKey() { + return key; + } + + public final V getValue() { + return value; + } + + public final V setValue(V newValue) { + V oldValue = value; + value = newValue; + return oldValue; + } + + public final boolean equals(Object o) { + if (!(o instanceof Map.Entry)) + return false; + Map.Entry e = (Map.Entry)o; + Object k1 = getKey(); + Object k2 = e.getKey(); + if (k1 == k2 || (k1 != null && k1.equals(k2))) { + Object v1 = getValue(); + Object v2 = e.getValue(); + if (v1 == v2 || (v1 != null && v1.equals(v2))) + return true; + } + return false; + } + + public final int hashCode() { + return (key==null ? 0 : key.hashCode()) ^ + (value==null ? 0 : value.hashCode()); + } + + public final String toString() { + return getKey() + "=" + getValue(); + } + + /** + * This method is invoked whenever the value in an entry is + * overwritten by an invocation of put(k,v) for a key k that's already + * in the HashMap. + */ + void recordAccess(HashMap m) { + } + + /** + * This method is invoked whenever the entry is + * removed from the table. + */ + void recordRemoval(HashMap m) { + } + } + + /** + * Adds a new entry with the specified key, value and hash code to + * the specified bucket. It is the responsibility of this + * method to resize the table if appropriate. + * + * Subclass overrides this to alter the behavior of put method. + */ + void addEntry(int hash, K key, V value, int bucketIndex) { + Entry e = table[bucketIndex]; + table[bucketIndex] = new Entry<>(hash, key, value, e); + if (size++ >= threshold) + resize(2 * table.length); + } + + /** + * Like addEntry except that this version is used when creating entries + * as part of Map construction or "pseudo-construction" (cloning, + * deserialization). This version needn't worry about resizing the table. + * + * Subclass overrides this to alter the behavior of HashMap(Map), + * clone, and readObject. + */ + void createEntry(int hash, K key, V value, int bucketIndex) { + Entry e = table[bucketIndex]; + table[bucketIndex] = new Entry<>(hash, key, value, e); + size++; + } + + private abstract class HashIterator implements Iterator { + Entry next; // next entry to return + int expectedModCount; // For fast-fail + int index; // current slot + Entry current; // current entry + + HashIterator() { + expectedModCount = modCount; + if (size > 0) { // advance to first entry + Entry[] t = table; + while (index < t.length && (next = t[index++]) == null) + ; + } + } + + public final boolean hasNext() { + return next != null; + } + + final Entry nextEntry() { + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + Entry e = next; + if (e == null) + throw new NoSuchElementException(); + + if ((next = e.next) == null) { + Entry[] t = table; + while (index < t.length && (next = t[index++]) == null) + ; + } + current = e; + return e; + } + + public void remove() { + if (current == null) + throw new IllegalStateException(); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + Object k = current.key; + current = null; + HashMap.this.removeEntryForKey(k); + expectedModCount = modCount; + } + + } + + private final class ValueIterator extends HashIterator { + public V next() { + return nextEntry().value; + } + } + + private final class KeyIterator extends HashIterator { + public K next() { + return nextEntry().getKey(); + } + } + + private final class EntryIterator extends HashIterator> { + public Map.Entry next() { + return nextEntry(); + } + } + + // Subclass overrides these to alter behavior of views' iterator() method + Iterator newKeyIterator() { + return new KeyIterator(); + } + Iterator newValueIterator() { + return new ValueIterator(); + } + Iterator> newEntryIterator() { + return new EntryIterator(); + } + + + // Views + + private transient Set> entrySet = null; + + /** + * Returns a {@link Set} view of the keys contained in this map. + * The set is backed by the map, so changes to the map are + * reflected in the set, and vice-versa. If the map is modified + * while an iteration over the set is in progress (except through + * the iterator's own remove operation), the results of + * the iteration are undefined. The set supports element removal, + * which removes the corresponding mapping from the map, via the + * Iterator.remove, Set.remove, + * removeAll, retainAll, and clear + * operations. It does not support the add or addAll + * operations. + */ + public Set keySet() { + Set ks = keySet; + return (ks != null ? ks : (keySet = new KeySet())); + } + + private final class KeySet extends AbstractSet { + public Iterator iterator() { + return newKeyIterator(); + } + public int size() { + return size; + } + public boolean contains(Object o) { + return containsKey(o); + } + public boolean remove(Object o) { + return HashMap.this.removeEntryForKey(o) != null; + } + public void clear() { + HashMap.this.clear(); + } + } + + /** + * Returns a {@link Collection} view of the values contained in this map. + * The collection is backed by the map, so changes to the map are + * reflected in the collection, and vice-versa. If the map is + * modified while an iteration over the collection is in progress + * (except through the iterator's own remove operation), + * the results of the iteration are undefined. The collection + * supports element removal, which removes the corresponding + * mapping from the map, via the Iterator.remove, + * Collection.remove, removeAll, + * retainAll and clear operations. It does not + * support the add or addAll operations. + */ + public Collection values() { + Collection vs = values; + return (vs != null ? vs : (values = new Values())); + } + + private final class Values extends AbstractCollection { + public Iterator iterator() { + return newValueIterator(); + } + public int size() { + return size; + } + public boolean contains(Object o) { + return containsValue(o); + } + public void clear() { + HashMap.this.clear(); + } + } + + /** + * Returns a {@link Set} view of the mappings contained in this map. + * The set is backed by the map, so changes to the map are + * reflected in the set, and vice-versa. If the map is modified + * while an iteration over the set is in progress (except through + * the iterator's own remove operation, or through the + * setValue operation on a map entry returned by the + * iterator) the results of the iteration are undefined. The set + * supports element removal, which removes the corresponding + * mapping from the map, via the Iterator.remove, + * Set.remove, removeAll, retainAll and + * clear operations. It does not support the + * add or addAll operations. + * + * @return a set view of the mappings contained in this map + */ + public Set> entrySet() { + return entrySet0(); + } + + private Set> entrySet0() { + Set> es = entrySet; + return es != null ? es : (entrySet = new EntrySet()); + } + + private final class EntrySet extends AbstractSet> { + public Iterator> iterator() { + return newEntryIterator(); + } + public boolean contains(Object o) { + if (!(o instanceof Map.Entry)) + return false; + Map.Entry e = (Map.Entry) o; + Entry candidate = getEntry(e.getKey()); + return candidate != null && candidate.equals(e); + } + public boolean remove(Object o) { + return removeMapping(o) != null; + } + public int size() { + return size; + } + public void clear() { + HashMap.this.clear(); + } + } + + + private static final long serialVersionUID = 362498820763181265L; + + + // These methods are used when serializing HashSets + int capacity() { return table.length; } + float loadFactor() { return loadFactor; } +}