| /* |
| * Copyright (c) 1997, 2013, 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.util.function.Consumer; |
| import java.util.function.BiConsumer; |
| import java.util.function.BiFunction; |
| import java.io.IOException; |
| |
| // Android-added: Note about spliterator order b/33945212 in Android N |
| /** |
| * <p>Hash table and linked list implementation of the <tt>Map</tt> interface, |
| * with predictable iteration order. This implementation differs from |
| * <tt>HashMap</tt> in that it maintains a doubly-linked list running through |
| * all of its entries. This linked list defines the iteration ordering, |
| * which is normally the order in which keys were inserted into the map |
| * (<i>insertion-order</i>). Note that insertion order is not affected |
| * if a key is <i>re-inserted</i> into the map. (A key <tt>k</tt> is |
| * reinserted into a map <tt>m</tt> if <tt>m.put(k, v)</tt> is invoked when |
| * <tt>m.containsKey(k)</tt> would return <tt>true</tt> immediately prior to |
| * the invocation.) |
| * |
| * <p>This implementation spares its clients from the unspecified, generally |
| * chaotic ordering provided by {@link HashMap} (and {@link Hashtable}), |
| * without incurring the increased cost associated with {@link TreeMap}. It |
| * can be used to produce a copy of a map that has the same order as the |
| * original, regardless of the original map's implementation: |
| * <pre> |
| * void foo(Map m) { |
| * Map copy = new LinkedHashMap(m); |
| * ... |
| * } |
| * </pre> |
| * This technique is particularly useful if a module takes a map on input, |
| * copies it, and later returns results whose order is determined by that of |
| * the copy. (Clients generally appreciate having things returned in the same |
| * order they were presented.) |
| * |
| * <p>A special {@link #LinkedHashMap(int,float,boolean) constructor} is |
| * provided to create a linked hash map whose order of iteration is the order |
| * in which its entries were last accessed, from least-recently accessed to |
| * most-recently (<i>access-order</i>). This kind of map is well-suited to |
| * building LRU caches. Invoking the {@code put}, {@code putIfAbsent}, |
| * {@code get}, {@code getOrDefault}, {@code compute}, {@code computeIfAbsent}, |
| * {@code computeIfPresent}, or {@code merge} methods results |
| * in an access to the corresponding entry (assuming it exists after the |
| * invocation completes). The {@code replace} methods only result in an access |
| * of the entry if the value is replaced. The {@code putAll} method generates one |
| * entry access for each mapping in the specified map, in the order that |
| * key-value mappings are provided by the specified map's entry set iterator. |
| * <i>No other methods generate entry accesses.</i> In particular, operations |
| * on collection-views do <i>not</i> affect the order of iteration of the |
| * backing map. |
| * |
| * <p>The {@link #removeEldestEntry(Map.Entry)} method may be overridden to |
| * impose a policy for removing stale mappings automatically when new mappings |
| * are added to the map. |
| * |
| * <p>This class provides all of the optional <tt>Map</tt> operations, and |
| * permits null elements. Like <tt>HashMap</tt>, it provides constant-time |
| * performance for the basic operations (<tt>add</tt>, <tt>contains</tt> and |
| * <tt>remove</tt>), assuming the hash function disperses elements |
| * properly among the buckets. Performance is likely to be just slightly |
| * below that of <tt>HashMap</tt>, due to the added expense of maintaining the |
| * linked list, with one exception: Iteration over the collection-views |
| * of a <tt>LinkedHashMap</tt> requires time proportional to the <i>size</i> |
| * of the map, regardless of its capacity. Iteration over a <tt>HashMap</tt> |
| * is likely to be more expensive, requiring time proportional to its |
| * <i>capacity</i>. |
| * |
| * <p>A linked hash map has two parameters that affect its performance: |
| * <i>initial capacity</i> and <i>load factor</i>. They are defined precisely |
| * as for <tt>HashMap</tt>. Note, however, that the penalty for choosing an |
| * excessively high value for initial capacity is less severe for this class |
| * than for <tt>HashMap</tt>, as iteration times for this class are unaffected |
| * by capacity. |
| * |
| * <p><strong>Note that this implementation is not synchronized.</strong> |
| * If multiple threads access a linked hash map concurrently, and at least |
| * one of the threads modifies the map structurally, it <em>must</em> be |
| * synchronized externally. 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:<pre> |
| * Map m = Collections.synchronizedMap(new LinkedHashMap(...));</pre> |
| * |
| * A structural modification is any operation that adds or deletes one or more |
| * mappings or, in the case of access-ordered linked hash maps, affects |
| * iteration order. In insertion-ordered linked hash maps, merely changing |
| * the value associated with a key that is already contained in the map is not |
| * a structural modification. <strong>In access-ordered linked hash maps, |
| * merely querying the map with <tt>get</tt> is a structural modification. |
| * </strong>) |
| * |
| * <p>The iterators returned by the <tt>iterator</tt> method of the collections |
| * returned by all of this class's collection view methods are |
| * <em>fail-fast</em>: if the map is structurally modified at any time after |
| * the iterator is created, in any way except through the iterator's own |
| * <tt>remove</tt> 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. |
| * |
| * <p>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 <tt>ConcurrentModificationException</tt> on a best-effort basis. |
| * Therefore, it would be wrong to write a program that depended on this |
| * exception for its correctness: <i>the fail-fast behavior of iterators |
| * should be used only to detect bugs.</i> |
| * |
| * <p>The spliterators returned by the spliterator method of the collections |
| * returned by all of this class's collection view methods are |
| * <em><a href="Spliterator.html#binding">late-binding</a></em>, |
| * <em>fail-fast</em>, and additionally report {@link Spliterator#ORDERED}. |
| * <em>Note</em>: The implementation of these spliterators in Android Nougat |
| * (API levels 24 and 25) uses the wrong order (inconsistent with the |
| * iterators, which use the correct order), despite reporting |
| * {@link Spliterator#ORDERED}. You may use the following code fragments |
| * to obtain a correctly ordered Spliterator on API level 24 and 25: |
| * <ul> |
| * <li>For a Collection view {@code c = lhm.keySet()}, |
| * {@code c = lhm.keySet()} or {@code c = lhm.values()}, use |
| * {@code java.util.Spliterators.spliterator(c, c.spliterator().characteristics())} |
| * instead of {@code c.spliterator()}. |
| * <li>Instead of {@code lhm.stream()} or {@code lhm.parallelStream()}, use |
| * {@code java.util.stream.StreamSupport.stream(spliterator, false)} |
| * to construct a (nonparallel) {@link java.util.stream.Stream} from |
| * such a {@code Spliterator}. |
| * </ul> |
| * Note that these workarounds are only suggested where {@code lhm} is a |
| * {@code LinkedHashMap}. |
| * |
| * <p>This class is a member of the |
| * <a href="{@docRoot}/openjdk-redirect.html?v=8&path=/technotes/guides/collections/index.html"> |
| * Java Collections Framework</a>. |
| * |
| * @implNote |
| * The spliterators returned by the spliterator method of the collections |
| * returned by all of this class's collection view methods are created from |
| * the iterators of the corresponding collections. |
| * |
| * @param <K> the type of keys maintained by this map |
| * @param <V> the type of mapped values |
| * |
| * @author Josh Bloch |
| * @see Object#hashCode() |
| * @see Collection |
| * @see Map |
| * @see HashMap |
| * @see TreeMap |
| * @see Hashtable |
| * @since 1.4 |
| */ |
| public class LinkedHashMap<K,V> |
| extends HashMap<K,V> |
| implements Map<K,V> |
| { |
| |
| /* |
| * Implementation note. A previous version of this class was |
| * internally structured a little differently. Because superclass |
| * HashMap now uses trees for some of its nodes, class |
| * LinkedHashMap.Entry is now treated as intermediary node class |
| * that can also be converted to tree form. |
| * |
| // BEGIN Android-changed |
| * LinkedHashMapEntry should not be renamed. Specifically, for |
| * source compatibility with earlier versions of Android, this |
| * nested class must not be named "Entry". Otherwise, it would |
| * hide Map.Entry which would break compilation of code like: |
| * |
| * LinkedHashMap.Entry<K, V> entry = map.entrySet().iterator.next() |
| * |
| * To compile, that code snippet's "LinkedHashMap.Entry" must |
| * mean java.util.Map.Entry which is the compile time type of |
| * entrySet()'s elements. |
| // END Android-changed |
| * |
| * The changes in node classes also require using two fields |
| * (head, tail) rather than a pointer to a header node to maintain |
| * the doubly-linked before/after list. This class also |
| * previously used a different style of callback methods upon |
| * access, insertion, and removal. |
| */ |
| |
| /** |
| * HashMap.Node subclass for normal LinkedHashMap entries. |
| */ |
| static class LinkedHashMapEntry<K,V> extends HashMap.Node<K,V> { |
| LinkedHashMapEntry<K,V> before, after; |
| LinkedHashMapEntry(int hash, K key, V value, Node<K,V> next) { |
| super(hash, key, value, next); |
| } |
| } |
| |
| private static final long serialVersionUID = 3801124242820219131L; |
| |
| /** |
| * The head (eldest) of the doubly linked list. |
| */ |
| transient LinkedHashMapEntry<K,V> head; |
| |
| /** |
| * The tail (youngest) of the doubly linked list. |
| */ |
| transient LinkedHashMapEntry<K,V> tail; |
| |
| /** |
| * The iteration ordering method for this linked hash map: <tt>true</tt> |
| * for access-order, <tt>false</tt> for insertion-order. |
| * |
| * @serial |
| */ |
| final boolean accessOrder; |
| |
| // internal utilities |
| |
| // link at the end of list |
| private void linkNodeLast(LinkedHashMapEntry<K,V> p) { |
| LinkedHashMapEntry<K,V> last = tail; |
| tail = p; |
| if (last == null) |
| head = p; |
| else { |
| p.before = last; |
| last.after = p; |
| } |
| } |
| |
| // apply src's links to dst |
| private void transferLinks(LinkedHashMapEntry<K,V> src, |
| LinkedHashMapEntry<K,V> dst) { |
| LinkedHashMapEntry<K,V> b = dst.before = src.before; |
| LinkedHashMapEntry<K,V> a = dst.after = src.after; |
| if (b == null) |
| head = dst; |
| else |
| b.after = dst; |
| if (a == null) |
| tail = dst; |
| else |
| a.before = dst; |
| } |
| |
| // overrides of HashMap hook methods |
| |
| void reinitialize() { |
| super.reinitialize(); |
| head = tail = null; |
| } |
| |
| Node<K,V> newNode(int hash, K key, V value, Node<K,V> e) { |
| LinkedHashMapEntry<K,V> p = |
| new LinkedHashMapEntry<K,V>(hash, key, value, e); |
| linkNodeLast(p); |
| return p; |
| } |
| |
| Node<K,V> replacementNode(Node<K,V> p, Node<K,V> next) { |
| LinkedHashMapEntry<K,V> q = (LinkedHashMapEntry<K,V>)p; |
| LinkedHashMapEntry<K,V> t = |
| new LinkedHashMapEntry<K,V>(q.hash, q.key, q.value, next); |
| transferLinks(q, t); |
| return t; |
| } |
| |
| TreeNode<K,V> newTreeNode(int hash, K key, V value, Node<K,V> next) { |
| TreeNode<K,V> p = new TreeNode<K,V>(hash, key, value, next); |
| linkNodeLast(p); |
| return p; |
| } |
| |
| TreeNode<K,V> replacementTreeNode(Node<K,V> p, Node<K,V> next) { |
| LinkedHashMapEntry<K,V> q = (LinkedHashMapEntry<K,V>)p; |
| TreeNode<K,V> t = new TreeNode<K,V>(q.hash, q.key, q.value, next); |
| transferLinks(q, t); |
| return t; |
| } |
| |
| void afterNodeRemoval(Node<K,V> e) { // unlink |
| LinkedHashMapEntry<K,V> p = |
| (LinkedHashMapEntry<K,V>)e, b = p.before, a = p.after; |
| p.before = p.after = null; |
| if (b == null) |
| head = a; |
| else |
| b.after = a; |
| if (a == null) |
| tail = b; |
| else |
| a.before = b; |
| } |
| |
| void afterNodeInsertion(boolean evict) { // possibly remove eldest |
| LinkedHashMapEntry<K,V> first; |
| if (evict && (first = head) != null && removeEldestEntry(first)) { |
| K key = first.key; |
| removeNode(hash(key), key, null, false, true); |
| } |
| } |
| |
| void afterNodeAccess(Node<K,V> e) { // move node to last |
| LinkedHashMapEntry<K,V> last; |
| if (accessOrder && (last = tail) != e) { |
| LinkedHashMapEntry<K,V> p = |
| (LinkedHashMapEntry<K,V>)e, b = p.before, a = p.after; |
| p.after = null; |
| if (b == null) |
| head = a; |
| else |
| b.after = a; |
| if (a != null) |
| a.before = b; |
| else |
| last = b; |
| if (last == null) |
| head = p; |
| else { |
| p.before = last; |
| last.after = p; |
| } |
| tail = p; |
| ++modCount; |
| } |
| } |
| |
| void internalWriteEntries(java.io.ObjectOutputStream s) throws IOException { |
| for (LinkedHashMapEntry<K,V> e = head; e != null; e = e.after) { |
| s.writeObject(e.key); |
| s.writeObject(e.value); |
| } |
| } |
| |
| /** |
| * Constructs an empty insertion-ordered <tt>LinkedHashMap</tt> instance |
| * 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 LinkedHashMap(int initialCapacity, float loadFactor) { |
| super(initialCapacity, loadFactor); |
| accessOrder = false; |
| } |
| |
| /** |
| * Constructs an empty insertion-ordered <tt>LinkedHashMap</tt> instance |
| * with the specified initial capacity and a default load factor (0.75). |
| * |
| * @param initialCapacity the initial capacity |
| * @throws IllegalArgumentException if the initial capacity is negative |
| */ |
| public LinkedHashMap(int initialCapacity) { |
| super(initialCapacity); |
| accessOrder = false; |
| } |
| |
| /** |
| * Constructs an empty insertion-ordered <tt>LinkedHashMap</tt> instance |
| * with the default initial capacity (16) and load factor (0.75). |
| */ |
| public LinkedHashMap() { |
| super(); |
| accessOrder = false; |
| } |
| |
| /** |
| * Constructs an insertion-ordered <tt>LinkedHashMap</tt> instance with |
| * the same mappings as the specified map. The <tt>LinkedHashMap</tt> |
| * instance is created with a 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 LinkedHashMap(Map<? extends K, ? extends V> m) { |
| super(); |
| accessOrder = false; |
| putMapEntries(m, false); |
| } |
| |
| /** |
| * Constructs an empty <tt>LinkedHashMap</tt> instance with the |
| * specified initial capacity, load factor and ordering mode. |
| * |
| * @param initialCapacity the initial capacity |
| * @param loadFactor the load factor |
| * @param accessOrder the ordering mode - <tt>true</tt> for |
| * access-order, <tt>false</tt> for insertion-order |
| * @throws IllegalArgumentException if the initial capacity is negative |
| * or the load factor is nonpositive |
| */ |
| public LinkedHashMap(int initialCapacity, |
| float loadFactor, |
| boolean accessOrder) { |
| super(initialCapacity, loadFactor); |
| this.accessOrder = accessOrder; |
| } |
| |
| |
| /** |
| * Returns <tt>true</tt> 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 <tt>true</tt> if this map maps one or more keys to the |
| * specified value |
| */ |
| public boolean containsValue(Object value) { |
| for (LinkedHashMapEntry<K,V> e = head; e != null; e = e.after) { |
| V v = e.value; |
| if (v == value || (value != null && value.equals(v))) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Returns the value to which the specified key is mapped, |
| * or {@code null} if this map contains no mapping for the key. |
| * |
| * <p>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.) |
| * |
| * <p>A return value of {@code null} does not <i>necessarily</i> |
| * 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. |
| */ |
| public V get(Object key) { |
| Node<K,V> e; |
| if ((e = getNode(hash(key), key)) == null) |
| return null; |
| if (accessOrder) |
| afterNodeAccess(e); |
| return e.value; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public V getOrDefault(Object key, V defaultValue) { |
| Node<K,V> e; |
| if ((e = getNode(hash(key), key)) == null) |
| return defaultValue; |
| if (accessOrder) |
| afterNodeAccess(e); |
| return e.value; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void clear() { |
| super.clear(); |
| head = tail = null; |
| } |
| |
| // Android-added: eldest(), for internal use in LRU caches |
| /** |
| * Returns the eldest entry in the map, or {@code null} if the map is empty. |
| * @hide |
| */ |
| public Map.Entry<K, V> eldest() { |
| return head; |
| } |
| |
| /** |
| * Returns <tt>true</tt> if this map should remove its eldest entry. |
| * This method is invoked by <tt>put</tt> and <tt>putAll</tt> after |
| * inserting a new entry into the map. It provides the implementor |
| * with the opportunity to remove the eldest entry each time a new one |
| * is added. This is useful if the map represents a cache: it allows |
| * the map to reduce memory consumption by deleting stale entries. |
| * |
| * <p>Sample use: this override will allow the map to grow up to 100 |
| * entries and then delete the eldest entry each time a new entry is |
| * added, maintaining a steady state of 100 entries. |
| * <pre> |
| * private static final int MAX_ENTRIES = 100; |
| * |
| * protected boolean removeEldestEntry(Map.Entry eldest) { |
| * return size() > MAX_ENTRIES; |
| * } |
| * </pre> |
| * |
| * <p>This method typically does not modify the map in any way, |
| * instead allowing the map to modify itself as directed by its |
| * return value. It <i>is</i> permitted for this method to modify |
| * the map directly, but if it does so, it <i>must</i> return |
| * <tt>false</tt> (indicating that the map should not attempt any |
| * further modification). The effects of returning <tt>true</tt> |
| * after modifying the map from within this method are unspecified. |
| * |
| * <p>This implementation merely returns <tt>false</tt> (so that this |
| * map acts like a normal map - the eldest element is never removed). |
| * |
| * @param eldest The least recently inserted entry in the map, or if |
| * this is an access-ordered map, the least recently accessed |
| * entry. This is the entry that will be removed it this |
| * method returns <tt>true</tt>. If the map was empty prior |
| * to the <tt>put</tt> or <tt>putAll</tt> invocation resulting |
| * in this invocation, this will be the entry that was just |
| * inserted; in other words, if the map contains a single |
| * entry, the eldest entry is also the newest. |
| * @return <tt>true</tt> if the eldest entry should be removed |
| * from the map; <tt>false</tt> if it should be retained. |
| */ |
| protected boolean removeEldestEntry(Map.Entry<K,V> eldest) { |
| return false; |
| } |
| |
| /** |
| * 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 <tt>remove</tt> operation), the results of |
| * the iteration are undefined. The set supports element removal, |
| * which removes the corresponding mapping from the map, via the |
| * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
| * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> |
| * operations. It does not support the <tt>add</tt> or <tt>addAll</tt> |
| * operations. |
| * Its {@link Spliterator} typically provides faster sequential |
| * performance but much poorer parallel performance than that of |
| * {@code HashMap}. |
| * |
| * @return a set view of the keys contained in this map |
| */ |
| public Set<K> keySet() { |
| Set<K> ks = keySet; |
| if (ks == null) { |
| ks = new LinkedKeySet(); |
| keySet = ks; |
| } |
| return ks; |
| } |
| |
| final class LinkedKeySet extends AbstractSet<K> { |
| public final int size() { return size; } |
| public final void clear() { LinkedHashMap.this.clear(); } |
| public final Iterator<K> iterator() { |
| return new LinkedKeyIterator(); |
| } |
| public final boolean contains(Object o) { return containsKey(o); } |
| public final boolean remove(Object key) { |
| return removeNode(hash(key), key, null, false, true) != null; |
| } |
| public final Spliterator<K> spliterator() { |
| return Spliterators.spliterator(this, Spliterator.SIZED | |
| Spliterator.ORDERED | |
| Spliterator.DISTINCT); |
| } |
| public final void forEach(Consumer<? super K> action) { |
| if (action == null) |
| throw new NullPointerException(); |
| int mc = modCount; |
| // Android-changed: Detect changes to modCount early. |
| for (LinkedHashMapEntry<K,V> e = head; (e != null && modCount == mc); e = e.after) |
| action.accept(e.key); |
| if (modCount != mc) |
| throw new ConcurrentModificationException(); |
| } |
| } |
| |
| /** |
| * 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 <tt>remove</tt> operation), |
| * the results of the iteration are undefined. The collection |
| * supports element removal, which removes the corresponding |
| * mapping from the map, via the <tt>Iterator.remove</tt>, |
| * <tt>Collection.remove</tt>, <tt>removeAll</tt>, |
| * <tt>retainAll</tt> and <tt>clear</tt> operations. It does not |
| * support the <tt>add</tt> or <tt>addAll</tt> operations. |
| * Its {@link Spliterator} typically provides faster sequential |
| * performance but much poorer parallel performance than that of |
| * {@code HashMap}. |
| * |
| * @return a view of the values contained in this map |
| */ |
| public Collection<V> values() { |
| Collection<V> vs = values; |
| if (vs == null) { |
| vs = new LinkedValues(); |
| values = vs; |
| } |
| return vs; |
| } |
| |
| final class LinkedValues extends AbstractCollection<V> { |
| public final int size() { return size; } |
| public final void clear() { LinkedHashMap.this.clear(); } |
| public final Iterator<V> iterator() { |
| return new LinkedValueIterator(); |
| } |
| public final boolean contains(Object o) { return containsValue(o); } |
| public final Spliterator<V> spliterator() { |
| return Spliterators.spliterator(this, Spliterator.SIZED | |
| Spliterator.ORDERED); |
| } |
| public final void forEach(Consumer<? super V> action) { |
| if (action == null) |
| throw new NullPointerException(); |
| int mc = modCount; |
| // Android-changed: Detect changes to modCount early. |
| for (LinkedHashMapEntry<K,V> e = head; (e != null && modCount == mc); e = e.after) |
| action.accept(e.value); |
| if (modCount != mc) |
| throw new ConcurrentModificationException(); |
| } |
| } |
| |
| /** |
| * 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 <tt>remove</tt> operation, or through the |
| * <tt>setValue</tt> 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 <tt>Iterator.remove</tt>, |
| * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and |
| * <tt>clear</tt> operations. It does not support the |
| * <tt>add</tt> or <tt>addAll</tt> operations. |
| * Its {@link Spliterator} typically provides faster sequential |
| * performance but much poorer parallel performance than that of |
| * {@code HashMap}. |
| * |
| * @return a set view of the mappings contained in this map |
| */ |
| public Set<Map.Entry<K,V>> entrySet() { |
| Set<Map.Entry<K,V>> es; |
| return (es = entrySet) == null ? (entrySet = new LinkedEntrySet()) : es; |
| } |
| |
| final class LinkedEntrySet extends AbstractSet<Map.Entry<K,V>> { |
| public final int size() { return size; } |
| public final void clear() { LinkedHashMap.this.clear(); } |
| public final Iterator<Map.Entry<K,V>> iterator() { |
| return new LinkedEntryIterator(); |
| } |
| public final boolean contains(Object o) { |
| if (!(o instanceof Map.Entry)) |
| return false; |
| Map.Entry<?,?> e = (Map.Entry<?,?>) o; |
| Object key = e.getKey(); |
| Node<K,V> candidate = getNode(hash(key), key); |
| return candidate != null && candidate.equals(e); |
| } |
| public final boolean remove(Object o) { |
| if (o instanceof Map.Entry) { |
| Map.Entry<?,?> e = (Map.Entry<?,?>) o; |
| Object key = e.getKey(); |
| Object value = e.getValue(); |
| return removeNode(hash(key), key, value, true, true) != null; |
| } |
| return false; |
| } |
| public final Spliterator<Map.Entry<K,V>> spliterator() { |
| return Spliterators.spliterator(this, Spliterator.SIZED | |
| Spliterator.ORDERED | |
| Spliterator.DISTINCT); |
| } |
| public final void forEach(Consumer<? super Map.Entry<K,V>> action) { |
| if (action == null) |
| throw new NullPointerException(); |
| int mc = modCount; |
| // Android-changed: Detect changes to modCount early. |
| for (LinkedHashMapEntry<K,V> e = head; (e != null && mc == modCount); e = e.after) |
| action.accept(e); |
| if (modCount != mc) |
| throw new ConcurrentModificationException(); |
| } |
| } |
| |
| // Map overrides |
| |
| public void forEach(BiConsumer<? super K, ? super V> action) { |
| if (action == null) |
| throw new NullPointerException(); |
| int mc = modCount; |
| // Android-changed: Detect changes to modCount early. |
| for (LinkedHashMapEntry<K,V> e = head; modCount == mc && e != null; e = e.after) |
| action.accept(e.key, e.value); |
| if (modCount != mc) |
| throw new ConcurrentModificationException(); |
| } |
| |
| public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) { |
| if (function == null) |
| throw new NullPointerException(); |
| int mc = modCount; |
| // Android-changed: Detect changes to modCount early. |
| for (LinkedHashMapEntry<K,V> e = head; modCount == mc && e != null; e = e.after) |
| e.value = function.apply(e.key, e.value); |
| if (modCount != mc) |
| throw new ConcurrentModificationException(); |
| } |
| |
| // Iterators |
| |
| abstract class LinkedHashIterator { |
| LinkedHashMapEntry<K,V> next; |
| LinkedHashMapEntry<K,V> current; |
| int expectedModCount; |
| |
| LinkedHashIterator() { |
| next = head; |
| expectedModCount = modCount; |
| current = null; |
| } |
| |
| public final boolean hasNext() { |
| return next != null; |
| } |
| |
| final LinkedHashMapEntry<K,V> nextNode() { |
| LinkedHashMapEntry<K,V> e = next; |
| if (modCount != expectedModCount) |
| throw new ConcurrentModificationException(); |
| if (e == null) |
| throw new NoSuchElementException(); |
| current = e; |
| next = e.after; |
| return e; |
| } |
| |
| public final void remove() { |
| Node<K,V> p = current; |
| if (p == null) |
| throw new IllegalStateException(); |
| if (modCount != expectedModCount) |
| throw new ConcurrentModificationException(); |
| current = null; |
| K key = p.key; |
| removeNode(hash(key), key, null, false, false); |
| expectedModCount = modCount; |
| } |
| } |
| |
| final class LinkedKeyIterator extends LinkedHashIterator |
| implements Iterator<K> { |
| public final K next() { return nextNode().getKey(); } |
| } |
| |
| final class LinkedValueIterator extends LinkedHashIterator |
| implements Iterator<V> { |
| public final V next() { return nextNode().value; } |
| } |
| |
| final class LinkedEntryIterator extends LinkedHashIterator |
| implements Iterator<Map.Entry<K,V>> { |
| public final Map.Entry<K,V> next() { return nextNode(); } |
| } |
| |
| |
| } |
