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1338 lines
43 KiB
Java
1338 lines
43 KiB
Java
// GenericsNote: Converted -- However, null keys will now be represented in the internal structures, a big change.
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/*
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* Copyright 2003-2004 The Apache Software Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.jivesoftware.smack.util.collections;
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import java.io.IOException;
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import java.io.ObjectInputStream;
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import java.io.ObjectOutputStream;
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import java.util.*;
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/**
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* An abstract implementation of a hash-based map which provides numerous points for
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* subclasses to override.
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* <p/>
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* This class implements all the features necessary for a subclass hash-based map.
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* Key-value entries are stored in instances of the <code>HashEntry</code> class,
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* which can be overridden and replaced. The iterators can similarly be replaced,
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* without the need to replace the KeySet, EntrySet and Values view classes.
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* <p/>
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* Overridable methods are provided to change the default hashing behaviour, and
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* to change how entries are added to and removed from the map. Hopefully, all you
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* need for unusual subclasses is here.
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* <p/>
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* NOTE: From Commons Collections 3.1 this class extends AbstractMap.
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* This is to provide backwards compatibility for ReferenceMap between v3.0 and v3.1.
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* This extends clause will be removed in v4.0.
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*
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* @author java util HashMap
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* @author Matt Hall, John Watkinson, Stephen Colebourne
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* @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:32 $
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* @since Commons Collections 3.0
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*/
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public class AbstractHashedMap <K,V> extends AbstractMap<K, V> implements IterableMap<K, V> {
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protected static final String NO_NEXT_ENTRY = "No next() entry in the iteration";
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protected static final String NO_PREVIOUS_ENTRY = "No previous() entry in the iteration";
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protected static final String REMOVE_INVALID = "remove() can only be called once after next()";
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protected static final String GETKEY_INVALID = "getKey() can only be called after next() and before remove()";
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protected static final String GETVALUE_INVALID = "getValue() can only be called after next() and before remove()";
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protected static final String SETVALUE_INVALID = "setValue() can only be called after next() and before remove()";
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/**
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* The default capacity to use
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*/
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protected static final int DEFAULT_CAPACITY = 16;
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/**
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* The default threshold to use
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*/
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protected static final int DEFAULT_THRESHOLD = 12;
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/**
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* The default load factor to use
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*/
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protected static final float DEFAULT_LOAD_FACTOR = 0.75f;
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/**
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* The maximum capacity allowed
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*/
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protected static final int MAXIMUM_CAPACITY = 1 << 30;
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/**
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* An object for masking null
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*/
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protected static final Object NULL = new Object();
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/**
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* Load factor, normally 0.75
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*/
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protected transient float loadFactor;
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/**
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* The size of the map
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*/
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protected transient int size;
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/**
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* Map entries
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*/
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protected transient HashEntry<K, V>[] data;
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/**
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* Size at which to rehash
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*/
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protected transient int threshold;
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/**
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* Modification count for iterators
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*/
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protected transient int modCount;
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/**
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* Entry set
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*/
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protected transient EntrySet<K, V> entrySet;
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/**
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* Key set
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*/
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protected transient KeySet<K, V> keySet;
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/**
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* Values
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*/
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protected transient Values<K, V> values;
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/**
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* Constructor only used in deserialization, do not use otherwise.
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*/
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protected AbstractHashedMap() {
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super();
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}
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/**
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* Constructor which performs no validation on the passed in parameters.
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*
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* @param initialCapacity the initial capacity, must be a power of two
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* @param loadFactor the load factor, must be > 0.0f and generally < 1.0f
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* @param threshold the threshold, must be sensible
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*/
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protected AbstractHashedMap(int initialCapacity, float loadFactor, int threshold) {
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super();
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this.loadFactor = loadFactor;
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this.data = new HashEntry[initialCapacity];
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this.threshold = threshold;
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init();
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}
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/**
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* Constructs a new, empty map with the specified initial capacity and
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* default load factor.
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*
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* @param initialCapacity the initial capacity
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* @throws IllegalArgumentException if the initial capacity is less than one
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*/
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protected AbstractHashedMap(int initialCapacity) {
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this(initialCapacity, DEFAULT_LOAD_FACTOR);
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}
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/**
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* Constructs a new, empty map with the specified initial capacity and
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* load factor.
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*
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* @param initialCapacity the initial capacity
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* @param loadFactor the load factor
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* @throws IllegalArgumentException if the initial capacity is less than one
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* @throws IllegalArgumentException if the load factor is less than or equal to zero
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*/
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protected AbstractHashedMap(int initialCapacity, float loadFactor) {
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super();
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if (initialCapacity < 1) {
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throw new IllegalArgumentException("Initial capacity must be greater than 0");
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}
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if (loadFactor <= 0.0f || Float.isNaN(loadFactor)) {
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throw new IllegalArgumentException("Load factor must be greater than 0");
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}
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this.loadFactor = loadFactor;
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this.threshold = calculateThreshold(initialCapacity, loadFactor);
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initialCapacity = calculateNewCapacity(initialCapacity);
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this.data = new HashEntry[initialCapacity];
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init();
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}
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/**
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* Constructor copying elements from another map.
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*
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* @param map the map to copy
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* @throws NullPointerException if the map is null
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*/
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protected AbstractHashedMap(Map<? extends K, ? extends V> map) {
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this(Math.max(2 * map.size(), DEFAULT_CAPACITY), DEFAULT_LOAD_FACTOR);
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putAll(map);
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}
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/**
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* Initialise subclasses during construction, cloning or deserialization.
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*/
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protected void init() {
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}
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//-----------------------------------------------------------------------
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/**
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* Gets the value mapped to the key specified.
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*
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* @param key the key
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* @return the mapped value, null if no match
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*/
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public V get(Object key) {
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int hashCode = hash((key == null) ? NULL : key);
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HashEntry<K, V> entry = data[hashIndex(hashCode, data.length)]; // no local for hash index
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while (entry != null) {
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if (entry.hashCode == hashCode && isEqualKey(key, entry.key)) {
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return entry.getValue();
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}
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entry = entry.next;
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}
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return null;
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}
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/**
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* Gets the size of the map.
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*
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* @return the size
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*/
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public int size() {
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return size;
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}
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/**
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* Checks whether the map is currently empty.
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*
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* @return true if the map is currently size zero
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*/
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public boolean isEmpty() {
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return (size == 0);
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}
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//-----------------------------------------------------------------------
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/**
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* Checks whether the map contains the specified key.
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*
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* @param key the key to search for
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* @return true if the map contains the key
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*/
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public boolean containsKey(Object key) {
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int hashCode = hash((key == null) ? NULL : key);
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HashEntry entry = data[hashIndex(hashCode, data.length)]; // no local for hash index
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while (entry != null) {
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if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) {
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return true;
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}
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entry = entry.next;
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}
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return false;
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}
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/**
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* Checks whether the map contains the specified value.
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*
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* @param value the value to search for
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* @return true if the map contains the value
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*/
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public boolean containsValue(Object value) {
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if (value == null) {
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for (int i = 0, isize = data.length; i < isize; i++) {
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HashEntry entry = data[i];
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while (entry != null) {
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if (entry.getValue() == null) {
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return true;
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}
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entry = entry.next;
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}
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}
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} else {
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for (int i = 0, isize = data.length; i < isize; i++) {
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HashEntry entry = data[i];
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while (entry != null) {
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if (isEqualValue(value, entry.getValue())) {
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return true;
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}
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entry = entry.next;
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}
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}
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}
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return false;
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}
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//-----------------------------------------------------------------------
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/**
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* Puts a key-value mapping into this map.
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*
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* @param key the key to add
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* @param value the value to add
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* @return the value previously mapped to this key, null if none
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*/
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public V put(K key, V value) {
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int hashCode = hash((key == null) ? NULL : key);
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int index = hashIndex(hashCode, data.length);
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HashEntry<K, V> entry = data[index];
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while (entry != null) {
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if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) {
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V oldValue = entry.getValue();
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updateEntry(entry, value);
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return oldValue;
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}
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entry = entry.next;
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}
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addMapping(index, hashCode, key, value);
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return null;
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}
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/**
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* Puts all the values from the specified map into this map.
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* <p/>
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* This implementation iterates around the specified map and
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* uses {@link #put(Object, Object)}.
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*
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* @param map the map to add
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* @throws NullPointerException if the map is null
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*/
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public void putAll(Map<? extends K, ? extends V> map) {
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int mapSize = map.size();
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if (mapSize == 0) {
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return;
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}
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int newSize = (int) ((size + mapSize) / loadFactor + 1);
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ensureCapacity(calculateNewCapacity(newSize));
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// Have to cast here because of compiler inference problems.
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for (Iterator it = map.entrySet().iterator(); it.hasNext();) {
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Map.Entry<? extends K, ? extends V> entry = (Map.Entry<? extends K, ? extends V>) it.next();
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put(entry.getKey(), entry.getValue());
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}
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}
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/**
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* Removes the specified mapping from this map.
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*
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* @param key the mapping to remove
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* @return the value mapped to the removed key, null if key not in map
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*/
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public V remove(Object key) {
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int hashCode = hash((key == null) ? NULL : key);
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int index = hashIndex(hashCode, data.length);
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HashEntry<K, V> entry = data[index];
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HashEntry<K, V> previous = null;
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while (entry != null) {
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if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) {
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V oldValue = entry.getValue();
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removeMapping(entry, index, previous);
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return oldValue;
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}
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previous = entry;
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entry = entry.next;
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}
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return null;
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}
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/**
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* Clears the map, resetting the size to zero and nullifying references
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* to avoid garbage collection issues.
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*/
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public void clear() {
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modCount++;
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HashEntry[] data = this.data;
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for (int i = data.length - 1; i >= 0; i--) {
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data[i] = null;
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}
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size = 0;
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}
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/**
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* Gets the hash code for the key specified.
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* This implementation uses the additional hashing routine from JDK1.4.
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* Subclasses can override this to return alternate hash codes.
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*
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* @param key the key to get a hash code for
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* @return the hash code
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*/
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protected int hash(Object key) {
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// same as JDK 1.4
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int h = key.hashCode();
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h += ~(h << 9);
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h ^= (h >>> 14);
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h += (h << 4);
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h ^= (h >>> 10);
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return h;
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}
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/**
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* Compares two keys, in internal converted form, to see if they are equal.
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* This implementation uses the equals method.
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* Subclasses can override this to match differently.
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*
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* @param key1 the first key to compare passed in from outside
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* @param key2 the second key extracted from the entry via <code>entry.key</code>
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* @return true if equal
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*/
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protected boolean isEqualKey(Object key1, Object key2) {
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return (key1 == key2 || ((key1 != null) && key1.equals(key2)));
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}
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/**
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* Compares two values, in external form, to see if they are equal.
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* This implementation uses the equals method and assumes neither value is null.
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* Subclasses can override this to match differently.
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*
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* @param value1 the first value to compare passed in from outside
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* @param value2 the second value extracted from the entry via <code>getValue()</code>
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* @return true if equal
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*/
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protected boolean isEqualValue(Object value1, Object value2) {
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return (value1 == value2 || value1.equals(value2));
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}
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/**
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* Gets the index into the data storage for the hashCode specified.
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* This implementation uses the least significant bits of the hashCode.
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* Subclasses can override this to return alternate bucketing.
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*
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* @param hashCode the hash code to use
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* @param dataSize the size of the data to pick a bucket from
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* @return the bucket index
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*/
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protected int hashIndex(int hashCode, int dataSize) {
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return hashCode & (dataSize - 1);
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}
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//-----------------------------------------------------------------------
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/**
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* Gets the entry mapped to the key specified.
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* <p/>
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* This method exists for subclasses that may need to perform a multi-step
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* process accessing the entry. The public methods in this class don't use this
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* method to gain a small performance boost.
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*
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* @param key the key
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* @return the entry, null if no match
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*/
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protected HashEntry<K, V> getEntry(Object key) {
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int hashCode = hash((key == null) ? NULL : key);
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HashEntry<K, V> entry = data[hashIndex(hashCode, data.length)]; // no local for hash index
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while (entry != null) {
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if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) {
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return entry;
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}
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entry = entry.next;
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}
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return null;
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}
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//-----------------------------------------------------------------------
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/**
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* Updates an existing key-value mapping to change the value.
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* <p/>
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* This implementation calls <code>setValue()</code> on the entry.
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* Subclasses could override to handle changes to the map.
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*
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* @param entry the entry to update
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* @param newValue the new value to store
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*/
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protected void updateEntry(HashEntry<K, V> entry, V newValue) {
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entry.setValue(newValue);
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}
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/**
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* Reuses an existing key-value mapping, storing completely new data.
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* <p/>
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* This implementation sets all the data fields on the entry.
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* Subclasses could populate additional entry fields.
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*
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* @param entry the entry to update, not null
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* @param hashIndex the index in the data array
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* @param hashCode the hash code of the key to add
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* @param key the key to add
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* @param value the value to add
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*/
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protected void reuseEntry(HashEntry<K, V> entry, int hashIndex, int hashCode, K key, V value) {
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entry.next = data[hashIndex];
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entry.hashCode = hashCode;
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entry.key = key;
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entry.value = value;
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}
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//-----------------------------------------------------------------------
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/**
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* Adds a new key-value mapping into this map.
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* <p/>
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* This implementation calls <code>createEntry()</code>, <code>addEntry()</code>
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* and <code>checkCapacity()</code>.
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* It also handles changes to <code>modCount</code> and <code>size</code>.
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* Subclasses could override to fully control adds to the map.
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*
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* @param hashIndex the index into the data array to store at
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* @param hashCode the hash code of the key to add
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* @param key the key to add
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* @param value the value to add
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*/
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protected void addMapping(int hashIndex, int hashCode, K key, V value) {
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modCount++;
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HashEntry<K, V> entry = createEntry(data[hashIndex], hashCode, key, value);
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addEntry(entry, hashIndex);
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size++;
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checkCapacity();
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}
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/**
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* Creates an entry to store the key-value data.
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* <p/>
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* This implementation creates a new HashEntry instance.
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* Subclasses can override this to return a different storage class,
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* or implement caching.
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*
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* @param next the next entry in sequence
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* @param hashCode the hash code to use
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* @param key the key to store
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* @param value the value to store
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* @return the newly created entry
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*/
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protected HashEntry<K, V> createEntry(HashEntry<K, V> next, int hashCode, K key, V value) {
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return new HashEntry<K, V>(next, hashCode, key, value);
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}
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/**
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* Adds an entry into this map.
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* <p/>
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* This implementation adds the entry to the data storage table.
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* Subclasses could override to handle changes to the map.
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*
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* @param entry the entry to add
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* @param hashIndex the index into the data array to store at
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*/
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protected void addEntry(HashEntry<K, V> entry, int hashIndex) {
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data[hashIndex] = entry;
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}
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//-----------------------------------------------------------------------
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/**
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* Removes a mapping from the map.
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* <p/>
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* This implementation calls <code>removeEntry()</code> and <code>destroyEntry()</code>.
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* It also handles changes to <code>modCount</code> and <code>size</code>.
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* Subclasses could override to fully control removals from the map.
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*
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* @param entry the entry to remove
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* @param hashIndex the index into the data structure
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* @param previous the previous entry in the chain
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*/
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protected void removeMapping(HashEntry<K, V> entry, int hashIndex, HashEntry<K, V> previous) {
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modCount++;
|
|
removeEntry(entry, hashIndex, previous);
|
|
size--;
|
|
destroyEntry(entry);
|
|
}
|
|
|
|
/**
|
|
* Removes an entry from the chain stored in a particular index.
|
|
* <p/>
|
|
* This implementation removes the entry from the data storage table.
|
|
* The size is not updated.
|
|
* Subclasses could override to handle changes to the map.
|
|
*
|
|
* @param entry the entry to remove
|
|
* @param hashIndex the index into the data structure
|
|
* @param previous the previous entry in the chain
|
|
*/
|
|
protected void removeEntry(HashEntry<K, V> entry, int hashIndex, HashEntry<K, V> previous) {
|
|
if (previous == null) {
|
|
data[hashIndex] = entry.next;
|
|
} else {
|
|
previous.next = entry.next;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Kills an entry ready for the garbage collector.
|
|
* <p/>
|
|
* This implementation prepares the HashEntry for garbage collection.
|
|
* Subclasses can override this to implement caching (override clear as well).
|
|
*
|
|
* @param entry the entry to destroy
|
|
*/
|
|
protected void destroyEntry(HashEntry<K, V> entry) {
|
|
entry.next = null;
|
|
entry.key = null;
|
|
entry.value = null;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Checks the capacity of the map and enlarges it if necessary.
|
|
* <p/>
|
|
* This implementation uses the threshold to check if the map needs enlarging
|
|
*/
|
|
protected void checkCapacity() {
|
|
if (size >= threshold) {
|
|
int newCapacity = data.length * 2;
|
|
if (newCapacity <= MAXIMUM_CAPACITY) {
|
|
ensureCapacity(newCapacity);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Changes the size of the data structure to the capacity proposed.
|
|
*
|
|
* @param newCapacity the new capacity of the array (a power of two, less or equal to max)
|
|
*/
|
|
protected void ensureCapacity(int newCapacity) {
|
|
int oldCapacity = data.length;
|
|
if (newCapacity <= oldCapacity) {
|
|
return;
|
|
}
|
|
if (size == 0) {
|
|
threshold = calculateThreshold(newCapacity, loadFactor);
|
|
data = new HashEntry[newCapacity];
|
|
} else {
|
|
HashEntry<K, V> oldEntries[] = data;
|
|
HashEntry<K, V> newEntries[] = new HashEntry[newCapacity];
|
|
|
|
modCount++;
|
|
for (int i = oldCapacity - 1; i >= 0; i--) {
|
|
HashEntry<K, V> entry = oldEntries[i];
|
|
if (entry != null) {
|
|
oldEntries[i] = null; // gc
|
|
do {
|
|
HashEntry<K, V> next = entry.next;
|
|
int index = hashIndex(entry.hashCode, newCapacity);
|
|
entry.next = newEntries[index];
|
|
newEntries[index] = entry;
|
|
entry = next;
|
|
} while (entry != null);
|
|
}
|
|
}
|
|
threshold = calculateThreshold(newCapacity, loadFactor);
|
|
data = newEntries;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Calculates the new capacity of the map.
|
|
* This implementation normalizes the capacity to a power of two.
|
|
*
|
|
* @param proposedCapacity the proposed capacity
|
|
* @return the normalized new capacity
|
|
*/
|
|
protected int calculateNewCapacity(int proposedCapacity) {
|
|
int newCapacity = 1;
|
|
if (proposedCapacity > MAXIMUM_CAPACITY) {
|
|
newCapacity = MAXIMUM_CAPACITY;
|
|
} else {
|
|
while (newCapacity < proposedCapacity) {
|
|
newCapacity <<= 1; // multiply by two
|
|
}
|
|
if (newCapacity > MAXIMUM_CAPACITY) {
|
|
newCapacity = MAXIMUM_CAPACITY;
|
|
}
|
|
}
|
|
return newCapacity;
|
|
}
|
|
|
|
/**
|
|
* Calculates the new threshold of the map, where it will be resized.
|
|
* This implementation uses the load factor.
|
|
*
|
|
* @param newCapacity the new capacity
|
|
* @param factor the load factor
|
|
* @return the new resize threshold
|
|
*/
|
|
protected int calculateThreshold(int newCapacity, float factor) {
|
|
return (int) (newCapacity * factor);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Gets the <code>next</code> field from a <code>HashEntry</code>.
|
|
* Used in subclasses that have no visibility of the field.
|
|
*
|
|
* @param entry the entry to query, must not be null
|
|
* @return the <code>next</code> field of the entry
|
|
* @throws NullPointerException if the entry is null
|
|
* @since Commons Collections 3.1
|
|
*/
|
|
protected HashEntry<K, V> entryNext(HashEntry<K, V> entry) {
|
|
return entry.next;
|
|
}
|
|
|
|
/**
|
|
* Gets the <code>hashCode</code> field from a <code>HashEntry</code>.
|
|
* Used in subclasses that have no visibility of the field.
|
|
*
|
|
* @param entry the entry to query, must not be null
|
|
* @return the <code>hashCode</code> field of the entry
|
|
* @throws NullPointerException if the entry is null
|
|
* @since Commons Collections 3.1
|
|
*/
|
|
protected int entryHashCode(HashEntry<K, V> entry) {
|
|
return entry.hashCode;
|
|
}
|
|
|
|
/**
|
|
* Gets the <code>key</code> field from a <code>HashEntry</code>.
|
|
* Used in subclasses that have no visibility of the field.
|
|
*
|
|
* @param entry the entry to query, must not be null
|
|
* @return the <code>key</code> field of the entry
|
|
* @throws NullPointerException if the entry is null
|
|
* @since Commons Collections 3.1
|
|
*/
|
|
protected K entryKey(HashEntry<K, V> entry) {
|
|
return entry.key;
|
|
}
|
|
|
|
/**
|
|
* Gets the <code>value</code> field from a <code>HashEntry</code>.
|
|
* Used in subclasses that have no visibility of the field.
|
|
*
|
|
* @param entry the entry to query, must not be null
|
|
* @return the <code>value</code> field of the entry
|
|
* @throws NullPointerException if the entry is null
|
|
* @since Commons Collections 3.1
|
|
*/
|
|
protected V entryValue(HashEntry<K, V> entry) {
|
|
return entry.value;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Gets an iterator over the map.
|
|
* Changes made to the iterator affect this map.
|
|
* <p/>
|
|
* A MapIterator returns the keys in the map. It also provides convenient
|
|
* methods to get the key and value, and set the value.
|
|
* It avoids the need to create an entrySet/keySet/values object.
|
|
* It also avoids creating the Map.Entry object.
|
|
*
|
|
* @return the map iterator
|
|
*/
|
|
public MapIterator<K, V> mapIterator() {
|
|
if (size == 0) {
|
|
return EmptyMapIterator.INSTANCE;
|
|
}
|
|
return new HashMapIterator<K, V>(this);
|
|
}
|
|
|
|
/**
|
|
* MapIterator implementation.
|
|
*/
|
|
protected static class HashMapIterator <K,V> extends HashIterator<K, V> implements MapIterator<K, V> {
|
|
|
|
protected HashMapIterator(AbstractHashedMap<K, V> parent) {
|
|
super(parent);
|
|
}
|
|
|
|
public K next() {
|
|
return super.nextEntry().getKey();
|
|
}
|
|
|
|
public K getKey() {
|
|
HashEntry<K, V> current = currentEntry();
|
|
if (current == null) {
|
|
throw new IllegalStateException(AbstractHashedMap.GETKEY_INVALID);
|
|
}
|
|
return current.getKey();
|
|
}
|
|
|
|
public V getValue() {
|
|
HashEntry<K, V> current = currentEntry();
|
|
if (current == null) {
|
|
throw new IllegalStateException(AbstractHashedMap.GETVALUE_INVALID);
|
|
}
|
|
return current.getValue();
|
|
}
|
|
|
|
public V setValue(V value) {
|
|
HashEntry<K, V> current = currentEntry();
|
|
if (current == null) {
|
|
throw new IllegalStateException(AbstractHashedMap.SETVALUE_INVALID);
|
|
}
|
|
return current.setValue(value);
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Gets the entrySet view of the map.
|
|
* Changes made to the view affect this map.
|
|
* To simply iterate through the entries, use {@link #mapIterator()}.
|
|
*
|
|
* @return the entrySet view
|
|
*/
|
|
public Set<Map.Entry<K, V>> entrySet() {
|
|
if (entrySet == null) {
|
|
entrySet = new EntrySet<K, V>(this);
|
|
}
|
|
return entrySet;
|
|
}
|
|
|
|
/**
|
|
* Creates an entry set iterator.
|
|
* Subclasses can override this to return iterators with different properties.
|
|
*
|
|
* @return the entrySet iterator
|
|
*/
|
|
protected Iterator<Map.Entry<K, V>> createEntrySetIterator() {
|
|
if (size() == 0) {
|
|
return EmptyIterator.INSTANCE;
|
|
}
|
|
return new EntrySetIterator<K, V>(this);
|
|
}
|
|
|
|
/**
|
|
* EntrySet implementation.
|
|
*/
|
|
protected static class EntrySet <K,V> extends AbstractSet<Map.Entry<K, V>> {
|
|
/**
|
|
* The parent map
|
|
*/
|
|
protected final AbstractHashedMap<K, V> parent;
|
|
|
|
protected EntrySet(AbstractHashedMap<K, V> parent) {
|
|
super();
|
|
this.parent = parent;
|
|
}
|
|
|
|
public int size() {
|
|
return parent.size();
|
|
}
|
|
|
|
public void clear() {
|
|
parent.clear();
|
|
}
|
|
|
|
public boolean contains(Map.Entry<K, V> entry) {
|
|
Map.Entry<K, V> e = entry;
|
|
Entry<K, V> match = parent.getEntry(e.getKey());
|
|
return (match != null && match.equals(e));
|
|
}
|
|
|
|
public boolean remove(Object obj) {
|
|
if (obj instanceof Map.Entry == false) {
|
|
return false;
|
|
}
|
|
if (contains(obj) == false) {
|
|
return false;
|
|
}
|
|
Map.Entry<K, V> entry = (Map.Entry<K, V>) obj;
|
|
K key = entry.getKey();
|
|
parent.remove(key);
|
|
return true;
|
|
}
|
|
|
|
public Iterator<Map.Entry<K, V>> iterator() {
|
|
return parent.createEntrySetIterator();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* EntrySet iterator.
|
|
*/
|
|
protected static class EntrySetIterator <K,V> extends HashIterator<K, V> implements Iterator<Map.Entry<K, V>> {
|
|
|
|
protected EntrySetIterator(AbstractHashedMap<K, V> parent) {
|
|
super(parent);
|
|
}
|
|
|
|
public HashEntry<K, V> next() {
|
|
return super.nextEntry();
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Gets the keySet view of the map.
|
|
* Changes made to the view affect this map.
|
|
* To simply iterate through the keys, use {@link #mapIterator()}.
|
|
*
|
|
* @return the keySet view
|
|
*/
|
|
public Set<K> keySet() {
|
|
if (keySet == null) {
|
|
keySet = new KeySet<K, V>(this);
|
|
}
|
|
return keySet;
|
|
}
|
|
|
|
/**
|
|
* Creates a key set iterator.
|
|
* Subclasses can override this to return iterators with different properties.
|
|
*
|
|
* @return the keySet iterator
|
|
*/
|
|
protected Iterator<K> createKeySetIterator() {
|
|
if (size() == 0) {
|
|
return EmptyIterator.INSTANCE;
|
|
}
|
|
return new KeySetIterator<K, V>(this);
|
|
}
|
|
|
|
/**
|
|
* KeySet implementation.
|
|
*/
|
|
protected static class KeySet <K,V> extends AbstractSet<K> {
|
|
/**
|
|
* The parent map
|
|
*/
|
|
protected final AbstractHashedMap<K, V> parent;
|
|
|
|
protected KeySet(AbstractHashedMap<K, V> parent) {
|
|
super();
|
|
this.parent = parent;
|
|
}
|
|
|
|
public int size() {
|
|
return parent.size();
|
|
}
|
|
|
|
public void clear() {
|
|
parent.clear();
|
|
}
|
|
|
|
public boolean contains(Object key) {
|
|
return parent.containsKey(key);
|
|
}
|
|
|
|
public boolean remove(Object key) {
|
|
boolean result = parent.containsKey(key);
|
|
parent.remove(key);
|
|
return result;
|
|
}
|
|
|
|
public Iterator<K> iterator() {
|
|
return parent.createKeySetIterator();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* KeySet iterator.
|
|
*/
|
|
protected static class KeySetIterator <K,V> extends HashIterator<K, V> implements Iterator<K> {
|
|
|
|
protected KeySetIterator(AbstractHashedMap<K, V> parent) {
|
|
super(parent);
|
|
}
|
|
|
|
public K next() {
|
|
return super.nextEntry().getKey();
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Gets the values view of the map.
|
|
* Changes made to the view affect this map.
|
|
* To simply iterate through the values, use {@link #mapIterator()}.
|
|
*
|
|
* @return the values view
|
|
*/
|
|
public Collection<V> values() {
|
|
if (values == null) {
|
|
values = new Values(this);
|
|
}
|
|
return values;
|
|
}
|
|
|
|
/**
|
|
* Creates a values iterator.
|
|
* Subclasses can override this to return iterators with different properties.
|
|
*
|
|
* @return the values iterator
|
|
*/
|
|
protected Iterator<V> createValuesIterator() {
|
|
if (size() == 0) {
|
|
return EmptyIterator.INSTANCE;
|
|
}
|
|
return new ValuesIterator<K, V>(this);
|
|
}
|
|
|
|
/**
|
|
* Values implementation.
|
|
*/
|
|
protected static class Values <K,V> extends AbstractCollection<V> {
|
|
/**
|
|
* The parent map
|
|
*/
|
|
protected final AbstractHashedMap<K, V> parent;
|
|
|
|
protected Values(AbstractHashedMap<K, V> parent) {
|
|
super();
|
|
this.parent = parent;
|
|
}
|
|
|
|
public int size() {
|
|
return parent.size();
|
|
}
|
|
|
|
public void clear() {
|
|
parent.clear();
|
|
}
|
|
|
|
public boolean contains(Object value) {
|
|
return parent.containsValue(value);
|
|
}
|
|
|
|
public Iterator<V> iterator() {
|
|
return parent.createValuesIterator();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Values iterator.
|
|
*/
|
|
protected static class ValuesIterator <K,V> extends HashIterator<K, V> implements Iterator<V> {
|
|
|
|
protected ValuesIterator(AbstractHashedMap<K, V> parent) {
|
|
super(parent);
|
|
}
|
|
|
|
public V next() {
|
|
return super.nextEntry().getValue();
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* HashEntry used to store the data.
|
|
* <p/>
|
|
* If you subclass <code>AbstractHashedMap</code> but not <code>HashEntry</code>
|
|
* then you will not be able to access the protected fields.
|
|
* The <code>entryXxx()</code> methods on <code>AbstractHashedMap</code> exist
|
|
* to provide the necessary access.
|
|
*/
|
|
protected static class HashEntry <K,V> implements Map.Entry<K, V>, KeyValue<K, V> {
|
|
/**
|
|
* The next entry in the hash chain
|
|
*/
|
|
protected HashEntry<K, V> next;
|
|
/**
|
|
* The hash code of the key
|
|
*/
|
|
protected int hashCode;
|
|
/**
|
|
* The key
|
|
*/
|
|
private K key;
|
|
/**
|
|
* The value
|
|
*/
|
|
private V value;
|
|
|
|
protected HashEntry(HashEntry<K, V> next, int hashCode, K key, V value) {
|
|
super();
|
|
this.next = next;
|
|
this.hashCode = hashCode;
|
|
this.key = key;
|
|
this.value = value;
|
|
}
|
|
|
|
public K getKey() {
|
|
return key;
|
|
}
|
|
|
|
public void setKey(K key) {
|
|
this.key = key;
|
|
}
|
|
|
|
public V getValue() {
|
|
return value;
|
|
}
|
|
|
|
public V setValue(V value) {
|
|
V old = this.value;
|
|
this.value = value;
|
|
return old;
|
|
}
|
|
|
|
public boolean equals(Object obj) {
|
|
if (obj == this) {
|
|
return true;
|
|
}
|
|
if (obj instanceof Map.Entry == false) {
|
|
return false;
|
|
}
|
|
Map.Entry other = (Map.Entry) obj;
|
|
return (getKey() == null ? other.getKey() == null : getKey().equals(other.getKey())) && (getValue() == null ? other.getValue() == null : getValue().equals(other.getValue()));
|
|
}
|
|
|
|
public int hashCode() {
|
|
return (getKey() == null ? 0 : getKey().hashCode()) ^ (getValue() == null ? 0 : getValue().hashCode());
|
|
}
|
|
|
|
public String toString() {
|
|
return new StringBuffer().append(getKey()).append('=').append(getValue()).toString();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Base Iterator
|
|
*/
|
|
protected static abstract class HashIterator <K,V> {
|
|
|
|
/**
|
|
* The parent map
|
|
*/
|
|
protected final AbstractHashedMap parent;
|
|
/**
|
|
* The current index into the array of buckets
|
|
*/
|
|
protected int hashIndex;
|
|
/**
|
|
* The last returned entry
|
|
*/
|
|
protected HashEntry<K, V> last;
|
|
/**
|
|
* The next entry
|
|
*/
|
|
protected HashEntry<K, V> next;
|
|
/**
|
|
* The modification count expected
|
|
*/
|
|
protected int expectedModCount;
|
|
|
|
protected HashIterator(AbstractHashedMap<K, V> parent) {
|
|
super();
|
|
this.parent = parent;
|
|
HashEntry<K, V>[] data = parent.data;
|
|
int i = data.length;
|
|
HashEntry<K, V> next = null;
|
|
while (i > 0 && next == null) {
|
|
next = data[--i];
|
|
}
|
|
this.next = next;
|
|
this.hashIndex = i;
|
|
this.expectedModCount = parent.modCount;
|
|
}
|
|
|
|
public boolean hasNext() {
|
|
return (next != null);
|
|
}
|
|
|
|
protected HashEntry<K, V> nextEntry() {
|
|
if (parent.modCount != expectedModCount) {
|
|
throw new ConcurrentModificationException();
|
|
}
|
|
HashEntry<K, V> newCurrent = next;
|
|
if (newCurrent == null) {
|
|
throw new NoSuchElementException(AbstractHashedMap.NO_NEXT_ENTRY);
|
|
}
|
|
HashEntry<K, V>[] data = parent.data;
|
|
int i = hashIndex;
|
|
HashEntry<K, V> n = newCurrent.next;
|
|
while (n == null && i > 0) {
|
|
n = data[--i];
|
|
}
|
|
next = n;
|
|
hashIndex = i;
|
|
last = newCurrent;
|
|
return newCurrent;
|
|
}
|
|
|
|
protected HashEntry<K, V> currentEntry() {
|
|
return last;
|
|
}
|
|
|
|
public void remove() {
|
|
if (last == null) {
|
|
throw new IllegalStateException(AbstractHashedMap.REMOVE_INVALID);
|
|
}
|
|
if (parent.modCount != expectedModCount) {
|
|
throw new ConcurrentModificationException();
|
|
}
|
|
parent.remove(last.getKey());
|
|
last = null;
|
|
expectedModCount = parent.modCount;
|
|
}
|
|
|
|
public String toString() {
|
|
if (last != null) {
|
|
return "Iterator[" + last.getKey() + "=" + last.getValue() + "]";
|
|
} else {
|
|
return "Iterator[]";
|
|
}
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Writes the map data to the stream. This method must be overridden if a
|
|
* subclass must be setup before <code>put()</code> is used.
|
|
* <p/>
|
|
* Serialization is not one of the JDK's nicest topics. Normal serialization will
|
|
* initialise the superclass before the subclass. Sometimes however, this isn't
|
|
* what you want, as in this case the <code>put()</code> method on read can be
|
|
* affected by subclass state.
|
|
* <p/>
|
|
* The solution adopted here is to serialize the state data of this class in
|
|
* this protected method. This method must be called by the
|
|
* <code>writeObject()</code> of the first serializable subclass.
|
|
* <p/>
|
|
* Subclasses may override if they have a specific field that must be present
|
|
* on read before this implementation will work. Generally, the read determines
|
|
* what must be serialized here, if anything.
|
|
*
|
|
* @param out the output stream
|
|
*/
|
|
protected void doWriteObject(ObjectOutputStream out) throws IOException {
|
|
out.writeFloat(loadFactor);
|
|
out.writeInt(data.length);
|
|
out.writeInt(size);
|
|
for (MapIterator it = mapIterator(); it.hasNext();) {
|
|
out.writeObject(it.next());
|
|
out.writeObject(it.getValue());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Reads the map data from the stream. This method must be overridden if a
|
|
* subclass must be setup before <code>put()</code> is used.
|
|
* <p/>
|
|
* Serialization is not one of the JDK's nicest topics. Normal serialization will
|
|
* initialise the superclass before the subclass. Sometimes however, this isn't
|
|
* what you want, as in this case the <code>put()</code> method on read can be
|
|
* affected by subclass state.
|
|
* <p/>
|
|
* The solution adopted here is to deserialize the state data of this class in
|
|
* this protected method. This method must be called by the
|
|
* <code>readObject()</code> of the first serializable subclass.
|
|
* <p/>
|
|
* Subclasses may override if the subclass has a specific field that must be present
|
|
* before <code>put()</code> or <code>calculateThreshold()</code> will work correctly.
|
|
*
|
|
* @param in the input stream
|
|
*/
|
|
protected void doReadObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
|
|
loadFactor = in.readFloat();
|
|
int capacity = in.readInt();
|
|
int size = in.readInt();
|
|
init();
|
|
data = new HashEntry[capacity];
|
|
for (int i = 0; i < size; i++) {
|
|
K key = (K) in.readObject();
|
|
V value = (V) in.readObject();
|
|
put(key, value);
|
|
}
|
|
threshold = calculateThreshold(data.length, loadFactor);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* Clones the map without cloning the keys or values.
|
|
* <p/>
|
|
* To implement <code>clone()</code>, a subclass must implement the
|
|
* <code>Cloneable</code> interface and make this method public.
|
|
*
|
|
* @return a shallow clone
|
|
*/
|
|
protected Object clone() {
|
|
try {
|
|
AbstractHashedMap cloned = (AbstractHashedMap) super.clone();
|
|
cloned.data = new HashEntry[data.length];
|
|
cloned.entrySet = null;
|
|
cloned.keySet = null;
|
|
cloned.values = null;
|
|
cloned.modCount = 0;
|
|
cloned.size = 0;
|
|
cloned.init();
|
|
cloned.putAll(this);
|
|
return cloned;
|
|
|
|
} catch (CloneNotSupportedException ex) {
|
|
return null; // should never happen
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Compares this map with another.
|
|
*
|
|
* @param obj the object to compare to
|
|
* @return true if equal
|
|
*/
|
|
public boolean equals(Object obj) {
|
|
if (obj == this) {
|
|
return true;
|
|
}
|
|
if (obj instanceof Map == false) {
|
|
return false;
|
|
}
|
|
Map map = (Map) obj;
|
|
if (map.size() != size()) {
|
|
return false;
|
|
}
|
|
MapIterator it = mapIterator();
|
|
try {
|
|
while (it.hasNext()) {
|
|
Object key = it.next();
|
|
Object value = it.getValue();
|
|
if (value == null) {
|
|
if (map.get(key) != null || map.containsKey(key) == false) {
|
|
return false;
|
|
}
|
|
} else {
|
|
if (value.equals(map.get(key)) == false) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
} catch (ClassCastException ignored) {
|
|
return false;
|
|
} catch (NullPointerException ignored) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Gets the standard Map hashCode.
|
|
*
|
|
* @return the hash code defined in the Map interface
|
|
*/
|
|
public int hashCode() {
|
|
int total = 0;
|
|
Iterator it = createEntrySetIterator();
|
|
while (it.hasNext()) {
|
|
total += it.next().hashCode();
|
|
}
|
|
return total;
|
|
}
|
|
|
|
/**
|
|
* Gets the map as a String.
|
|
*
|
|
* @return a string version of the map
|
|
*/
|
|
public String toString() {
|
|
if (size() == 0) {
|
|
return "{}";
|
|
}
|
|
StringBuffer buf = new StringBuffer(32 * size());
|
|
buf.append('{');
|
|
|
|
MapIterator it = mapIterator();
|
|
boolean hasNext = it.hasNext();
|
|
while (hasNext) {
|
|
Object key = it.next();
|
|
Object value = it.getValue();
|
|
buf.append(key == this ? "(this Map)" : key).append('=').append(value == this ? "(this Map)" : value);
|
|
|
|
hasNext = it.hasNext();
|
|
if (hasNext) {
|
|
buf.append(',').append(' ');
|
|
}
|
|
}
|
|
|
|
buf.append('}');
|
|
return buf.toString();
|
|
}
|
|
}
|