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/* |
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* Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Sun designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Sun in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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* CA 95054 USA or visit www.sun.com if you need additional information or |
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* have any questions. |
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*/ |
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|
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package java.util; |
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|
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/** |
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* A Red-Black tree based {@link NavigableMap} implementation. |
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* The map is sorted according to the {@linkplain Comparable natural |
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* ordering} of its keys, or by a {@link Comparator} provided at map |
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* creation time, depending on which constructor is used. |
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* |
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* <p>This implementation provides guaranteed log(n) time cost for the |
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* <tt>containsKey</tt>, <tt>get</tt>, <tt>put</tt> and <tt>remove</tt> |
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* operations. Algorithms are adaptations of those in Cormen, Leiserson, and |
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* Rivest's <I>Introduction to Algorithms</I>. |
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* |
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* <p>Note that the ordering maintained by a sorted map (whether or not an |
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* explicit comparator is provided) must be <i>consistent with equals</i> if |
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* this sorted map is to correctly implement the <tt>Map</tt> interface. (See |
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* <tt>Comparable</tt> or <tt>Comparator</tt> for a precise definition of |
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* <i>consistent with equals</i>.) This is so because the <tt>Map</tt> |
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* interface is defined in terms of the equals operation, but a map performs |
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* all key comparisons using its <tt>compareTo</tt> (or <tt>compare</tt>) |
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* method, so two keys that are deemed equal by this method are, from the |
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* standpoint of the sorted map, equal. The behavior of a sorted map |
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* <i>is</i> well-defined even if its ordering is inconsistent with equals; it |
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* just fails to obey the general contract of the <tt>Map</tt> interface. |
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* |
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* <p><strong>Note that this implementation is not synchronized.</strong> |
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* If multiple threads access a map concurrently, and at least one of the |
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* threads modifies the map structurally, it <i>must</i> be synchronized |
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* externally. (A structural modification is any operation that adds or |
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* deletes one or more mappings; merely changing the value associated |
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* with an existing key is not a structural modification.) This is |
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* typically accomplished by synchronizing on some object that naturally |
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* encapsulates the map. |
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* If no such object exists, the map should be "wrapped" using the |
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* {@link Collections#synchronizedSortedMap Collections.synchronizedSortedMap} |
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* method. This is best done at creation time, to prevent accidental |
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* unsynchronized access to the map: <pre> |
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* SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));</pre> |
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* |
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* <p>The iterators returned by the <tt>iterator</tt> method of the collections |
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* returned by all of this class's "collection view methods" are |
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* <i>fail-fast</i>: if the map is structurally modified at any time after the |
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* iterator is created, in any way except through the iterator's own |
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* <tt>remove</tt> method, the iterator will throw a {@link |
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* ConcurrentModificationException}. Thus, in the face of concurrent |
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* modification, the iterator fails quickly and cleanly, rather than risking |
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* arbitrary, non-deterministic behavior at an undetermined time in the future. |
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* |
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* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
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* as it is, generally speaking, impossible to make any hard guarantees in the |
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* presence of unsynchronized concurrent modification. Fail-fast iterators |
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* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
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* Therefore, it would be wrong to write a program that depended on this |
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* exception for its correctness: <i>the fail-fast behavior of iterators |
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* should be used only to detect bugs.</i> |
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* |
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* <p>All <tt>Map.Entry</tt> pairs returned by methods in this class |
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* and its views represent snapshots of mappings at the time they were |
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* produced. They do <em>not</em> support the <tt>Entry.setValue</tt> |
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* method. (Note however that it is possible to change mappings in the |
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* associated map using <tt>put</tt>.) |
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* |
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* <p>This class is a member of the |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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* Java Collections Framework</a>. |
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* |
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* @param <K> the type of keys maintained by this map |
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* @param <V> the type of mapped values |
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* |
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* @author Josh Bloch and Doug Lea |
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* @version %I%, %G% |
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* @see Map |
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* @see HashMap |
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* @see Hashtable |
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* @see Comparable |
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* @see Comparator |
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* @see Collection |
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* @since 1.2 |
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*/ |
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|
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public class TreeMap<K,V> |
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extends AbstractMap<K,V> |
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implements NavigableMap<K,V>, Cloneable, java.io.Serializable |
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{ |
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/** |
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* The comparator used to maintain order in this tree map, or |
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* null if it uses the natural ordering of its keys. |
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* |
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* @serial |
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*/ |
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private final Comparator<? super K> comparator; |
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|
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private transient Entry<K,V> root = null; |
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|
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/** |
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* The number of entries in the tree |
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*/ |
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private transient int size = 0; |
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|
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/** |
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* The number of structural modifications to the tree. |
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*/ |
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private transient int modCount = 0; |
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|
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/** |
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* Constructs a new, empty tree map, using the natural ordering of its |
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* keys. All keys inserted into the map must implement the {@link |
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* Comparable} interface. Furthermore, all such keys must be |
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* <i>mutually comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw |
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* a <tt>ClassCastException</tt> for any keys <tt>k1</tt> and |
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* <tt>k2</tt> in the map. If the user attempts to put a key into the |
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* map that violates this constraint (for example, the user attempts to |
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* put a string key into a map whose keys are integers), the |
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* <tt>put(Object key, Object value)</tt> call will throw a |
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* <tt>ClassCastException</tt>. |
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*/ |
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public TreeMap() { |
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comparator = null; |
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} |
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|
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/** |
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* Constructs a new, empty tree map, ordered according to the given |
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* comparator. All keys inserted into the map must be <i>mutually |
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* comparable</i> by the given comparator: <tt>comparator.compare(k1, |
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* k2)</tt> must not throw a <tt>ClassCastException</tt> for any keys |
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* <tt>k1</tt> and <tt>k2</tt> in the map. If the user attempts to put |
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* a key into the map that violates this constraint, the <tt>put(Object |
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* key, Object value)</tt> call will throw a |
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* <tt>ClassCastException</tt>. |
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* |
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* @param comparator the comparator that will be used to order this map. |
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* If <tt>null</tt>, the {@linkplain Comparable natural |
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* ordering} of the keys will be used. |
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*/ |
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public TreeMap(Comparator<? super K> comparator) { |
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this.comparator = comparator; |
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} |
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|
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/** |
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* Constructs a new tree map containing the same mappings as the given |
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* map, ordered according to the <i>natural ordering</i> of its keys. |
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* All keys inserted into the new map must implement the {@link |
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* Comparable} interface. Furthermore, all such keys must be |
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* <i>mutually comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw |
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* a <tt>ClassCastException</tt> for any keys <tt>k1</tt> and |
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* <tt>k2</tt> in the map. This method runs in n*log(n) time. |
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* |
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* @param m the map whose mappings are to be placed in this map |
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* @throws ClassCastException if the keys in m are not {@link Comparable}, |
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* or are not mutually comparable |
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* @throws NullPointerException if the specified map is null |
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*/ |
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public TreeMap(Map<? extends K, ? extends V> m) { |
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comparator = null; |
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putAll(m); |
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} |
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|
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/** |
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* Constructs a new tree map containing the same mappings and |
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* using the same ordering as the specified sorted map. This |
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* method runs in linear time. |
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* |
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* @param m the sorted map whose mappings are to be placed in this map, |
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* and whose comparator is to be used to sort this map |
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* @throws NullPointerException if the specified map is null |
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*/ |
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public TreeMap(SortedMap<K, ? extends V> m) { |
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comparator = m.comparator(); |
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try { |
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buildFromSorted(m.size(), m.entrySet().iterator(), null, null); |
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} catch (java.io.IOException cannotHappen) { |
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} catch (ClassNotFoundException cannotHappen) { |
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} |
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} |
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|
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|
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// Query Operations |
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|
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/** |
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* Returns the number of key-value mappings in this map. |
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* |
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* @return the number of key-value mappings in this map |
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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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/** |
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* Returns <tt>true</tt> if this map contains a mapping for the specified |
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* key. |
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* |
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* @param key key whose presence in this map is to be tested |
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* @return <tt>true</tt> if this map contains a mapping for the |
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* specified key |
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* @throws ClassCastException if the specified key cannot be compared |
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* with the keys currently in the map |
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* @throws NullPointerException if the specified key is null |
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* and this map uses natural ordering, or its comparator |
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* does not permit null keys |
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*/ |
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public boolean containsKey(Object key) { |
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return getEntry(key) != null; |
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} |
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|
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/** |
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* Returns <tt>true</tt> if this map maps one or more keys to the |
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* specified value. More formally, returns <tt>true</tt> if and only if |
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* this map contains at least one mapping to a value <tt>v</tt> such |
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* that <tt>(value==null ? v==null : value.equals(v))</tt>. This |
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* operation will probably require time linear in the map size for |
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* most implementations. |
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* |
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* @param value value whose presence in this map is to be tested |
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* @return <tt>true</tt> if a mapping to <tt>value</tt> exists; |
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* <tt>false</tt> otherwise |
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* @since 1.2 |
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*/ |
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public boolean containsValue(Object value) { |
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for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e)) |
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if (valEquals(value, e.value)) |
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return true; |
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return false; |
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} |
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|
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/** |
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* Returns the value to which the specified key is mapped, |
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* or {@code null} if this map contains no mapping for the key. |
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* |
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* <p>More formally, if this map contains a mapping from a key |
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* {@code k} to a value {@code v} such that {@code key} compares |
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* equal to {@code k} according to the map's ordering, then this |
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* method returns {@code v}; otherwise it returns {@code null}. |
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* (There can be at most one such mapping.) |
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* |
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* <p>A return value of {@code null} does not <i>necessarily</i> |
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* indicate that the map contains no mapping for the key; it's also |
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* possible that the map explicitly maps the key to {@code null}. |
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* The {@link #containsKey containsKey} operation may be used to |
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* distinguish these two cases. |
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* |
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* @throws ClassCastException if the specified key cannot be compared |
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* with the keys currently in the map |
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* @throws NullPointerException if the specified key is null |
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* and this map uses natural ordering, or its comparator |
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* does not permit null keys |
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*/ |
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public V get(Object key) { |
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Entry<K,V> p = getEntry(key); |
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return (p==null ? null : p.value); |
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} |
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|
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public Comparator<? super K> comparator() { |
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return comparator; |
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} |
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|
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/** |
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* @throws NoSuchElementException {@inheritDoc} |
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*/ |
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public K firstKey() { |
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return key(getFirstEntry()); |
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} |
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|
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/** |
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* @throws NoSuchElementException {@inheritDoc} |
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*/ |
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public K lastKey() { |
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return key(getLastEntry()); |
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} |
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|
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/** |
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* Copies all of the mappings from the specified map to this map. |
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* These mappings replace any mappings that this map had for any |
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* of the keys currently in the specified map. |
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* |
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* @param map mappings to be stored in this map |
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* @throws ClassCastException if the class of a key or value in |
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* the specified map prevents it from being stored in this map |
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* @throws NullPointerException if the specified map is null or |
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* the specified map contains a null key and this map does not |
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* permit null keys |
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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 (size==0 && mapSize!=0 && map instanceof SortedMap) { |
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Comparator c = ((SortedMap)map).comparator(); |
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if (c == comparator || (c != null && c.equals(comparator))) { |
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++modCount; |
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try { |
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buildFromSorted(mapSize, map.entrySet().iterator(), |
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null, null); |
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} catch (java.io.IOException cannotHappen) { |
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} catch (ClassNotFoundException cannotHappen) { |
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} |
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return; |
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} |
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} |
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super.putAll(map); |
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} |
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|
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/** |
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* Returns this map's entry for the given key, or <tt>null</tt> if the map |
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* does not contain an entry for the key. |
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* |
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* @return this map's entry for the given key, or <tt>null</tt> if the map |
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* does not contain an entry for the key |
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* @throws ClassCastException if the specified key cannot be compared |
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* with the keys currently in the map |
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* @throws NullPointerException if the specified key is null |
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* and this map uses natural ordering, or its comparator |
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* does not permit null keys |
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*/ |
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final Entry<K,V> getEntry(Object key) { |
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// Offload comparator-based version for sake of performance |
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if (comparator != null) |
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return getEntryUsingComparator(key); |
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if (key == null) |
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throw new NullPointerException(); |
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Comparable<? super K> k = (Comparable<? super K>) key; |
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Entry<K,V> p = root; |
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while (p != null) { |
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int cmp = k.compareTo(p.key); |
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if (cmp < 0) |
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p = p.left; |
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else if (cmp > 0) |
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p = p.right; |
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else |
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return p; |
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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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* Version of getEntry using comparator. Split off from getEntry |
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* for performance. (This is not worth doing for most methods, |
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* that are less dependent on comparator performance, but is |
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* worthwhile here.) |
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*/ |
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final Entry<K,V> getEntryUsingComparator(Object key) { |
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K k = (K) key; |
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Comparator<? super K> cpr = comparator; |
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if (cpr != null) { |
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Entry<K,V> p = root; |
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while (p != null) { |
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int cmp = cpr.compare(k, p.key); |
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if (cmp < 0) |
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p = p.left; |
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else if (cmp > 0) |
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p = p.right; |
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else |
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return p; |
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} |
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} |
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return null; |
379 |
} |
380 |
|
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/** |
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* Gets the entry corresponding to the specified key; if no such entry |
383 |
* exists, returns the entry for the least key greater than the specified |
384 |
* key; if no such entry exists (i.e., the greatest key in the Tree is less |
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* than the specified key), returns <tt>null</tt>. |
386 |
*/ |
387 |
final Entry<K,V> getCeilingEntry(K key) { |
388 |
Entry<K,V> p = root; |
389 |
while (p != null) { |
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int cmp = compare(key, p.key); |
391 |
if (cmp < 0) { |
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if (p.left != null) |
393 |
p = p.left; |
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else |
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return p; |
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} else if (cmp > 0) { |
397 |
if (p.right != null) { |
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p = p.right; |
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} else { |
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Entry<K,V> parent = p.parent; |
401 |
Entry<K,V> ch = p; |
402 |
while (parent != null && ch == parent.right) { |
403 |
ch = parent; |
404 |
parent = parent.parent; |
405 |
} |
406 |
return parent; |
407 |
} |
408 |
} else |
409 |
return p; |
410 |
} |
411 |
return null; |
412 |
} |
413 |
|
414 |
/** |
415 |
* Gets the entry corresponding to the specified key; if no such entry |
416 |
* exists, returns the entry for the greatest key less than the specified |
417 |
* key; if no such entry exists, returns <tt>null</tt>. |
418 |
*/ |
419 |
final Entry<K,V> getFloorEntry(K key) { |
420 |
Entry<K,V> p = root; |
421 |
while (p != null) { |
422 |
int cmp = compare(key, p.key); |
423 |
if (cmp > 0) { |
424 |
if (p.right != null) |
425 |
p = p.right; |
426 |
else |
427 |
return p; |
428 |
} else if (cmp < 0) { |
429 |
if (p.left != null) { |
430 |
p = p.left; |
431 |
} else { |
432 |
Entry<K,V> parent = p.parent; |
433 |
Entry<K,V> ch = p; |
434 |
while (parent != null && ch == parent.left) { |
435 |
ch = parent; |
436 |
parent = parent.parent; |
437 |
} |
438 |
return parent; |
439 |
} |
440 |
} else |
441 |
return p; |
442 |
|
443 |
} |
444 |
return null; |
445 |
} |
446 |
|
447 |
/** |
448 |
* Gets the entry for the least key greater than the specified |
449 |
* key; if no such entry exists, returns the entry for the least |
450 |
* key greater than the specified key; if no such entry exists |
451 |
* returns <tt>null</tt>. |
452 |
*/ |
453 |
final Entry<K,V> getHigherEntry(K key) { |
454 |
Entry<K,V> p = root; |
455 |
while (p != null) { |
456 |
int cmp = compare(key, p.key); |
457 |
if (cmp < 0) { |
458 |
if (p.left != null) |
459 |
p = p.left; |
460 |
else |
461 |
return p; |
462 |
} else { |
463 |
if (p.right != null) { |
464 |
p = p.right; |
465 |
} else { |
466 |
Entry<K,V> parent = p.parent; |
467 |
Entry<K,V> ch = p; |
468 |
while (parent != null && ch == parent.right) { |
469 |
ch = parent; |
470 |
parent = parent.parent; |
471 |
} |
472 |
return parent; |
473 |
} |
474 |
} |
475 |
} |
476 |
return null; |
477 |
} |
478 |
|
479 |
/** |
480 |
* Returns the entry for the greatest key less than the specified key; if |
481 |
* no such entry exists (i.e., the least key in the Tree is greater than |
482 |
* the specified key), returns <tt>null</tt>. |
483 |
*/ |
484 |
final Entry<K,V> getLowerEntry(K key) { |
485 |
Entry<K,V> p = root; |
486 |
while (p != null) { |
487 |
int cmp = compare(key, p.key); |
488 |
if (cmp > 0) { |
489 |
if (p.right != null) |
490 |
p = p.right; |
491 |
else |
492 |
return p; |
493 |
} else { |
494 |
if (p.left != null) { |
495 |
p = p.left; |
496 |
} else { |
497 |
Entry<K,V> parent = p.parent; |
498 |
Entry<K,V> ch = p; |
499 |
while (parent != null && ch == parent.left) { |
500 |
ch = parent; |
501 |
parent = parent.parent; |
502 |
} |
503 |
return parent; |
504 |
} |
505 |
} |
506 |
} |
507 |
return null; |
508 |
} |
509 |
|
510 |
/** |
511 |
* Associates the specified value with the specified key in this map. |
512 |
* If the map previously contained a mapping for the key, the old |
513 |
* value is replaced. |
514 |
* |
515 |
* @param key key with which the specified value is to be associated |
516 |
* @param value value to be associated with the specified key |
517 |
* |
518 |
* @return the previous value associated with <tt>key</tt>, or |
519 |
* <tt>null</tt> if there was no mapping for <tt>key</tt>. |
520 |
* (A <tt>null</tt> return can also indicate that the map |
521 |
* previously associated <tt>null</tt> with <tt>key</tt>.) |
522 |
* @throws ClassCastException if the specified key cannot be compared |
523 |
* with the keys currently in the map |
524 |
* @throws NullPointerException if the specified key is null |
525 |
* and this map uses natural ordering, or its comparator |
526 |
* does not permit null keys |
527 |
*/ |
528 |
public V put(K key, V value) { |
529 |
Entry<K,V> t = root; |
530 |
if (t == null) { |
531 |
// TBD: |
532 |
// 5045147: (coll) Adding null to an empty TreeSet should |
533 |
// throw NullPointerException |
534 |
// |
535 |
// compare(key, key); // type check |
536 |
root = new Entry<K,V>(key, value, null); |
537 |
size = 1; |
538 |
modCount++; |
539 |
return null; |
540 |
} |
541 |
int cmp; |
542 |
Entry<K,V> parent; |
543 |
// split comparator and comparable paths |
544 |
Comparator<? super K> cpr = comparator; |
545 |
if (cpr != null) { |
546 |
do { |
547 |
parent = t; |
548 |
cmp = cpr.compare(key, t.key); |
549 |
if (cmp < 0) |
550 |
t = t.left; |
551 |
else if (cmp > 0) |
552 |
t = t.right; |
553 |
else |
554 |
return t.setValue(value); |
555 |
} while (t != null); |
556 |
} |
557 |
else { |
558 |
if (key == null) |
559 |
throw new NullPointerException(); |
560 |
Comparable<? super K> k = (Comparable<? super K>) key; |
561 |
do { |
562 |
parent = t; |
563 |
cmp = k.compareTo(t.key); |
564 |
if (cmp < 0) |
565 |
t = t.left; |
566 |
else if (cmp > 0) |
567 |
t = t.right; |
568 |
else |
569 |
return t.setValue(value); |
570 |
} while (t != null); |
571 |
} |
572 |
Entry<K,V> e = new Entry<K,V>(key, value, parent); |
573 |
if (cmp < 0) |
574 |
parent.left = e; |
575 |
else |
576 |
parent.right = e; |
577 |
fixAfterInsertion(e); |
578 |
size++; |
579 |
modCount++; |
580 |
return null; |
581 |
} |
582 |
|
583 |
/** |
584 |
* Removes the mapping for this key from this TreeMap if present. |
585 |
* |
586 |
* @param key key for which mapping should be removed |
587 |
* @return the previous value associated with <tt>key</tt>, or |
588 |
* <tt>null</tt> if there was no mapping for <tt>key</tt>. |
589 |
* (A <tt>null</tt> return can also indicate that the map |
590 |
* previously associated <tt>null</tt> with <tt>key</tt>.) |
591 |
* @throws ClassCastException if the specified key cannot be compared |
592 |
* with the keys currently in the map |
593 |
* @throws NullPointerException if the specified key is null |
594 |
* and this map uses natural ordering, or its comparator |
595 |
* does not permit null keys |
596 |
*/ |
597 |
public V remove(Object key) { |
598 |
Entry<K,V> p = getEntry(key); |
599 |
if (p == null) |
600 |
return null; |
601 |
|
602 |
V oldValue = p.value; |
603 |
deleteEntry(p); |
604 |
return oldValue; |
605 |
} |
606 |
|
607 |
/** |
608 |
* Removes all of the mappings from this map. |
609 |
* The map will be empty after this call returns. |
610 |
*/ |
611 |
public void clear() { |
612 |
modCount++; |
613 |
size = 0; |
614 |
root = null; |
615 |
} |
616 |
|
617 |
/** |
618 |
* Returns a shallow copy of this <tt>TreeMap</tt> instance. (The keys and |
619 |
* values themselves are not cloned.) |
620 |
* |
621 |
* @return a shallow copy of this map |
622 |
*/ |
623 |
public Object clone() { |
624 |
TreeMap<K,V> clone = null; |
625 |
try { |
626 |
clone = (TreeMap<K,V>) super.clone(); |
627 |
} catch (CloneNotSupportedException e) { |
628 |
throw new InternalError(); |
629 |
} |
630 |
|
631 |
// Put clone into "virgin" state (except for comparator) |
632 |
clone.root = null; |
633 |
clone.size = 0; |
634 |
clone.modCount = 0; |
635 |
clone.entrySet = null; |
636 |
clone.navigableKeySet = null; |
637 |
clone.descendingMap = null; |
638 |
|
639 |
// Initialize clone with our mappings |
640 |
try { |
641 |
clone.buildFromSorted(size, entrySet().iterator(), null, null); |
642 |
} catch (java.io.IOException cannotHappen) { |
643 |
} catch (ClassNotFoundException cannotHappen) { |
644 |
} |
645 |
|
646 |
return clone; |
647 |
} |
648 |
|
649 |
// NavigableMap API methods |
650 |
|
651 |
/** |
652 |
* @since 1.6 |
653 |
*/ |
654 |
public Map.Entry<K,V> firstEntry() { |
655 |
return exportEntry(getFirstEntry()); |
656 |
} |
657 |
|
658 |
/** |
659 |
* @since 1.6 |
660 |
*/ |
661 |
public Map.Entry<K,V> lastEntry() { |
662 |
return exportEntry(getLastEntry()); |
663 |
} |
664 |
|
665 |
/** |
666 |
* @since 1.6 |
667 |
*/ |
668 |
public Map.Entry<K,V> pollFirstEntry() { |
669 |
Entry<K,V> p = getFirstEntry(); |
670 |
Map.Entry<K,V> result = exportEntry(p); |
671 |
if (p != null) |
672 |
deleteEntry(p); |
673 |
return result; |
674 |
} |
675 |
|
676 |
/** |
677 |
* @since 1.6 |
678 |
*/ |
679 |
public Map.Entry<K,V> pollLastEntry() { |
680 |
Entry<K,V> p = getLastEntry(); |
681 |
Map.Entry<K,V> result = exportEntry(p); |
682 |
if (p != null) |
683 |
deleteEntry(p); |
684 |
return result; |
685 |
} |
686 |
|
687 |
/** |
688 |
* @throws ClassCastException {@inheritDoc} |
689 |
* @throws NullPointerException if the specified key is null |
690 |
* and this map uses natural ordering, or its comparator |
691 |
* does not permit null keys |
692 |
* @since 1.6 |
693 |
*/ |
694 |
public Map.Entry<K,V> lowerEntry(K key) { |
695 |
return exportEntry(getLowerEntry(key)); |
696 |
} |
697 |
|
698 |
/** |
699 |
* @throws ClassCastException {@inheritDoc} |
700 |
* @throws NullPointerException if the specified key is null |
701 |
* and this map uses natural ordering, or its comparator |
702 |
* does not permit null keys |
703 |
* @since 1.6 |
704 |
*/ |
705 |
public K lowerKey(K key) { |
706 |
return keyOrNull(getLowerEntry(key)); |
707 |
} |
708 |
|
709 |
/** |
710 |
* @throws ClassCastException {@inheritDoc} |
711 |
* @throws NullPointerException if the specified key is null |
712 |
* and this map uses natural ordering, or its comparator |
713 |
* does not permit null keys |
714 |
* @since 1.6 |
715 |
*/ |
716 |
public Map.Entry<K,V> floorEntry(K key) { |
717 |
return exportEntry(getFloorEntry(key)); |
718 |
} |
719 |
|
720 |
/** |
721 |
* @throws ClassCastException {@inheritDoc} |
722 |
* @throws NullPointerException if the specified key is null |
723 |
* and this map uses natural ordering, or its comparator |
724 |
* does not permit null keys |
725 |
* @since 1.6 |
726 |
*/ |
727 |
public K floorKey(K key) { |
728 |
return keyOrNull(getFloorEntry(key)); |
729 |
} |
730 |
|
731 |
/** |
732 |
* @throws ClassCastException {@inheritDoc} |
733 |
* @throws NullPointerException if the specified key is null |
734 |
* and this map uses natural ordering, or its comparator |
735 |
* does not permit null keys |
736 |
* @since 1.6 |
737 |
*/ |
738 |
public Map.Entry<K,V> ceilingEntry(K key) { |
739 |
return exportEntry(getCeilingEntry(key)); |
740 |
} |
741 |
|
742 |
/** |
743 |
* @throws ClassCastException {@inheritDoc} |
744 |
* @throws NullPointerException if the specified key is null |
745 |
* and this map uses natural ordering, or its comparator |
746 |
* does not permit null keys |
747 |
* @since 1.6 |
748 |
*/ |
749 |
public K ceilingKey(K key) { |
750 |
return keyOrNull(getCeilingEntry(key)); |
751 |
} |
752 |
|
753 |
/** |
754 |
* @throws ClassCastException {@inheritDoc} |
755 |
* @throws NullPointerException if the specified key is null |
756 |
* and this map uses natural ordering, or its comparator |
757 |
* does not permit null keys |
758 |
* @since 1.6 |
759 |
*/ |
760 |
public Map.Entry<K,V> higherEntry(K key) { |
761 |
return exportEntry(getHigherEntry(key)); |
762 |
} |
763 |
|
764 |
/** |
765 |
* @throws ClassCastException {@inheritDoc} |
766 |
* @throws NullPointerException if the specified key is null |
767 |
* and this map uses natural ordering, or its comparator |
768 |
* does not permit null keys |
769 |
* @since 1.6 |
770 |
*/ |
771 |
public K higherKey(K key) { |
772 |
return keyOrNull(getHigherEntry(key)); |
773 |
} |
774 |
|
775 |
// Views |
776 |
|
777 |
/** |
778 |
* Fields initialized to contain an instance of the entry set view |
779 |
* the first time this view is requested. Views are stateless, so |
780 |
* there's no reason to create more than one. |
781 |
*/ |
782 |
private transient EntrySet entrySet = null; |
783 |
private transient KeySet<K> navigableKeySet = null; |
784 |
private transient NavigableMap<K,V> descendingMap = null; |
785 |
|
786 |
/** |
787 |
* Returns a {@link Set} view of the keys contained in this map. |
788 |
* The set's iterator returns the keys in ascending order. |
789 |
* The set is backed by the map, so changes to the map are |
790 |
* reflected in the set, and vice-versa. If the map is modified |
791 |
* while an iteration over the set is in progress (except through |
792 |
* the iterator's own <tt>remove</tt> operation), the results of |
793 |
* the iteration are undefined. The set supports element removal, |
794 |
* which removes the corresponding mapping from the map, via the |
795 |
* <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
796 |
* <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> |
797 |
* operations. It does not support the <tt>add</tt> or <tt>addAll</tt> |
798 |
* operations. |
799 |
*/ |
800 |
public Set<K> keySet() { |
801 |
return navigableKeySet(); |
802 |
} |
803 |
|
804 |
/** |
805 |
* @since 1.6 |
806 |
*/ |
807 |
public NavigableSet<K> navigableKeySet() { |
808 |
KeySet<K> nks = navigableKeySet; |
809 |
return (nks != null) ? nks : (navigableKeySet = new KeySet(this)); |
810 |
} |
811 |
|
812 |
/** |
813 |
* @since 1.6 |
814 |
*/ |
815 |
public NavigableSet<K> descendingKeySet() { |
816 |
return descendingMap().navigableKeySet(); |
817 |
} |
818 |
|
819 |
/** |
820 |
* Returns a {@link Collection} view of the values contained in this map. |
821 |
* The collection's iterator returns the values in ascending order |
822 |
* of the corresponding keys. |
823 |
* The collection is backed by the map, so changes to the map are |
824 |
* reflected in the collection, and vice-versa. If the map is |
825 |
* modified while an iteration over the collection is in progress |
826 |
* (except through the iterator's own <tt>remove</tt> operation), |
827 |
* the results of the iteration are undefined. The collection |
828 |
* supports element removal, which removes the corresponding |
829 |
* mapping from the map, via the <tt>Iterator.remove</tt>, |
830 |
* <tt>Collection.remove</tt>, <tt>removeAll</tt>, |
831 |
* <tt>retainAll</tt> and <tt>clear</tt> operations. It does not |
832 |
* support the <tt>add</tt> or <tt>addAll</tt> operations. |
833 |
*/ |
834 |
public Collection<V> values() { |
835 |
Collection<V> vs = values; |
836 |
return (vs != null) ? vs : (values = new Values()); |
837 |
} |
838 |
|
839 |
/** |
840 |
* Returns a {@link Set} view of the mappings contained in this map. |
841 |
* The set's iterator returns the entries in ascending key order. |
842 |
* The set is backed by the map, so changes to the map are |
843 |
* reflected in the set, and vice-versa. If the map is modified |
844 |
* while an iteration over the set is in progress (except through |
845 |
* the iterator's own <tt>remove</tt> operation, or through the |
846 |
* <tt>setValue</tt> operation on a map entry returned by the |
847 |
* iterator) the results of the iteration are undefined. The set |
848 |
* supports element removal, which removes the corresponding |
849 |
* mapping from the map, via the <tt>Iterator.remove</tt>, |
850 |
* <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and |
851 |
* <tt>clear</tt> operations. It does not support the |
852 |
* <tt>add</tt> or <tt>addAll</tt> operations. |
853 |
*/ |
854 |
public Set<Map.Entry<K,V>> entrySet() { |
855 |
EntrySet es = entrySet; |
856 |
return (es != null) ? es : (entrySet = new EntrySet()); |
857 |
} |
858 |
|
859 |
/** |
860 |
* @since 1.6 |
861 |
*/ |
862 |
public NavigableMap<K, V> descendingMap() { |
863 |
NavigableMap<K, V> km = descendingMap; |
864 |
return (km != null) ? km : |
865 |
(descendingMap = new DescendingSubMap(this, |
866 |
true, null, true, |
867 |
true, null, true)); |
868 |
} |
869 |
|
870 |
/** |
871 |
* @throws ClassCastException {@inheritDoc} |
872 |
* @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> is |
873 |
* null and this map uses natural ordering, or its comparator |
874 |
* does not permit null keys |
875 |
* @throws IllegalArgumentException {@inheritDoc} |
876 |
* @since 1.6 |
877 |
*/ |
878 |
public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, |
879 |
K toKey, boolean toInclusive) { |
880 |
return new AscendingSubMap(this, |
881 |
false, fromKey, fromInclusive, |
882 |
false, toKey, toInclusive); |
883 |
} |
884 |
|
885 |
/** |
886 |
* @throws ClassCastException {@inheritDoc} |
887 |
* @throws NullPointerException if <tt>toKey</tt> is null |
888 |
* and this map uses natural ordering, or its comparator |
889 |
* does not permit null keys |
890 |
* @throws IllegalArgumentException {@inheritDoc} |
891 |
* @since 1.6 |
892 |
*/ |
893 |
public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { |
894 |
return new AscendingSubMap(this, |
895 |
true, null, true, |
896 |
false, toKey, inclusive); |
897 |
} |
898 |
|
899 |
/** |
900 |
* @throws ClassCastException {@inheritDoc} |
901 |
* @throws NullPointerException if <tt>fromKey</tt> is null |
902 |
* and this map uses natural ordering, or its comparator |
903 |
* does not permit null keys |
904 |
* @throws IllegalArgumentException {@inheritDoc} |
905 |
* @since 1.6 |
906 |
*/ |
907 |
public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) { |
908 |
return new AscendingSubMap(this, |
909 |
false, fromKey, inclusive, |
910 |
true, null, true); |
911 |
} |
912 |
|
913 |
/** |
914 |
* @throws ClassCastException {@inheritDoc} |
915 |
* @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> is |
916 |
* null and this map uses natural ordering, or its comparator |
917 |
* does not permit null keys |
918 |
* @throws IllegalArgumentException {@inheritDoc} |
919 |
*/ |
920 |
public SortedMap<K,V> subMap(K fromKey, K toKey) { |
921 |
return subMap(fromKey, true, toKey, false); |
922 |
} |
923 |
|
924 |
/** |
925 |
* @throws ClassCastException {@inheritDoc} |
926 |
* @throws NullPointerException if <tt>toKey</tt> is null |
927 |
* and this map uses natural ordering, or its comparator |
928 |
* does not permit null keys |
929 |
* @throws IllegalArgumentException {@inheritDoc} |
930 |
*/ |
931 |
public SortedMap<K,V> headMap(K toKey) { |
932 |
return headMap(toKey, false); |
933 |
} |
934 |
|
935 |
/** |
936 |
* @throws ClassCastException {@inheritDoc} |
937 |
* @throws NullPointerException if <tt>fromKey</tt> is null |
938 |
* and this map uses natural ordering, or its comparator |
939 |
* does not permit null keys |
940 |
* @throws IllegalArgumentException {@inheritDoc} |
941 |
*/ |
942 |
public SortedMap<K,V> tailMap(K fromKey) { |
943 |
return tailMap(fromKey, true); |
944 |
} |
945 |
|
946 |
// View class support |
947 |
|
948 |
class Values extends AbstractCollection<V> { |
949 |
public Iterator<V> iterator() { |
950 |
return new ValueIterator(getFirstEntry()); |
951 |
} |
952 |
|
953 |
public int size() { |
954 |
return TreeMap.this.size(); |
955 |
} |
956 |
|
957 |
public boolean contains(Object o) { |
958 |
return TreeMap.this.containsValue(o); |
959 |
} |
960 |
|
961 |
public boolean remove(Object o) { |
962 |
for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e)) { |
963 |
if (valEquals(e.getValue(), o)) { |
964 |
deleteEntry(e); |
965 |
return true; |
966 |
} |
967 |
} |
968 |
return false; |
969 |
} |
970 |
|
971 |
public void clear() { |
972 |
TreeMap.this.clear(); |
973 |
} |
974 |
} |
975 |
|
976 |
class EntrySet extends AbstractSet<Map.Entry<K,V>> { |
977 |
public Iterator<Map.Entry<K,V>> iterator() { |
978 |
return new EntryIterator(getFirstEntry()); |
979 |
} |
980 |
|
981 |
public boolean contains(Object o) { |
982 |
if (!(o instanceof Map.Entry)) |
983 |
return false; |
984 |
Map.Entry<K,V> entry = (Map.Entry<K,V>) o; |
985 |
V value = entry.getValue(); |
986 |
Entry<K,V> p = getEntry(entry.getKey()); |
987 |
return p != null && valEquals(p.getValue(), value); |
988 |
} |
989 |
|
990 |
public boolean remove(Object o) { |
991 |
if (!(o instanceof Map.Entry)) |
992 |
return false; |
993 |
Map.Entry<K,V> entry = (Map.Entry<K,V>) o; |
994 |
V value = entry.getValue(); |
995 |
Entry<K,V> p = getEntry(entry.getKey()); |
996 |
if (p != null && valEquals(p.getValue(), value)) { |
997 |
deleteEntry(p); |
998 |
return true; |
999 |
} |
1000 |
return false; |
1001 |
} |
1002 |
|
1003 |
public int size() { |
1004 |
return TreeMap.this.size(); |
1005 |
} |
1006 |
|
1007 |
public void clear() { |
1008 |
TreeMap.this.clear(); |
1009 |
} |
1010 |
} |
1011 |
|
1012 |
/* |
1013 |
* Unlike Values and EntrySet, the KeySet class is static, |
1014 |
* delegating to a NavigableMap to allow use by SubMaps, which |
1015 |
* outweighs the ugliness of needing type-tests for the following |
1016 |
* Iterator methods that are defined appropriately in main versus |
1017 |
* submap classes. |
1018 |
*/ |
1019 |
|
1020 |
Iterator<K> keyIterator() { |
1021 |
return new KeyIterator(getFirstEntry()); |
1022 |
} |
1023 |
|
1024 |
Iterator<K> descendingKeyIterator() { |
1025 |
return new DescendingKeyIterator(getFirstEntry()); |
1026 |
} |
1027 |
|
1028 |
static final class KeySet<E> extends AbstractSet<E> implements NavigableSet<E> { |
1029 |
private final NavigableMap<E, Object> m; |
1030 |
KeySet(NavigableMap<E,Object> map) { m = map; } |
1031 |
|
1032 |
public Iterator<E> iterator() { |
1033 |
if (m instanceof TreeMap) |
1034 |
return ((TreeMap<E,Object>)m).keyIterator(); |
1035 |
else |
1036 |
return (Iterator<E>)(((TreeMap.NavigableSubMap)m).keyIterator()); |
1037 |
} |
1038 |
|
1039 |
public Iterator<E> descendingIterator() { |
1040 |
if (m instanceof TreeMap) |
1041 |
return ((TreeMap<E,Object>)m).descendingKeyIterator(); |
1042 |
else |
1043 |
return (Iterator<E>)(((TreeMap.NavigableSubMap)m).descendingKeyIterator()); |
1044 |
} |
1045 |
|
1046 |
public int size() { return m.size(); } |
1047 |
public boolean isEmpty() { return m.isEmpty(); } |
1048 |
public boolean contains(Object o) { return m.containsKey(o); } |
1049 |
public void clear() { m.clear(); } |
1050 |
public E lower(E e) { return m.lowerKey(e); } |
1051 |
public E floor(E e) { return m.floorKey(e); } |
1052 |
public E ceiling(E e) { return m.ceilingKey(e); } |
1053 |
public E higher(E e) { return m.higherKey(e); } |
1054 |
public E first() { return m.firstKey(); } |
1055 |
public E last() { return m.lastKey(); } |
1056 |
public Comparator<? super E> comparator() { return m.comparator(); } |
1057 |
public E pollFirst() { |
1058 |
Map.Entry<E,Object> e = m.pollFirstEntry(); |
1059 |
return e == null? null : e.getKey(); |
1060 |
} |
1061 |
public E pollLast() { |
1062 |
Map.Entry<E,Object> e = m.pollLastEntry(); |
1063 |
return e == null? null : e.getKey(); |
1064 |
} |
1065 |
public boolean remove(Object o) { |
1066 |
int oldSize = size(); |
1067 |
m.remove(o); |
1068 |
return size() != oldSize; |
1069 |
} |
1070 |
public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, |
1071 |
E toElement, boolean toInclusive) { |
1072 |
return new TreeSet<E>(m.subMap(fromElement, fromInclusive, |
1073 |
toElement, toInclusive)); |
1074 |
} |
1075 |
public NavigableSet<E> headSet(E toElement, boolean inclusive) { |
1076 |
return new TreeSet<E>(m.headMap(toElement, inclusive)); |
1077 |
} |
1078 |
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) { |
1079 |
return new TreeSet<E>(m.tailMap(fromElement, inclusive)); |
1080 |
} |
1081 |
public SortedSet<E> subSet(E fromElement, E toElement) { |
1082 |
return subSet(fromElement, true, toElement, false); |
1083 |
} |
1084 |
public SortedSet<E> headSet(E toElement) { |
1085 |
return headSet(toElement, false); |
1086 |
} |
1087 |
public SortedSet<E> tailSet(E fromElement) { |
1088 |
return tailSet(fromElement, true); |
1089 |
} |
1090 |
public NavigableSet<E> descendingSet() { |
1091 |
return new TreeSet(m.descendingMap()); |
1092 |
} |
1093 |
} |
1094 |
|
1095 |
/** |
1096 |
* Base class for TreeMap Iterators |
1097 |
*/ |
1098 |
abstract class PrivateEntryIterator<T> implements Iterator<T> { |
1099 |
Entry<K,V> next; |
1100 |
Entry<K,V> lastReturned; |
1101 |
int expectedModCount; |
1102 |
|
1103 |
PrivateEntryIterator(Entry<K,V> first) { |
1104 |
expectedModCount = modCount; |
1105 |
lastReturned = null; |
1106 |
next = first; |
1107 |
} |
1108 |
|
1109 |
public final boolean hasNext() { |
1110 |
return next != null; |
1111 |
} |
1112 |
|
1113 |
final Entry<K,V> nextEntry() { |
1114 |
Entry<K,V> e = next; |
1115 |
if (e == null) |
1116 |
throw new NoSuchElementException(); |
1117 |
if (modCount != expectedModCount) |
1118 |
throw new ConcurrentModificationException(); |
1119 |
next = successor(e); |
1120 |
lastReturned = e; |
1121 |
return e; |
1122 |
} |
1123 |
|
1124 |
final Entry<K,V> prevEntry() { |
1125 |
Entry<K,V> e = next; |
1126 |
if (e == null) |
1127 |
throw new NoSuchElementException(); |
1128 |
if (modCount != expectedModCount) |
1129 |
throw new ConcurrentModificationException(); |
1130 |
next = predecessor(e); |
1131 |
lastReturned = e; |
1132 |
return e; |
1133 |
} |
1134 |
|
1135 |
public void remove() { |
1136 |
if (lastReturned == null) |
1137 |
throw new IllegalStateException(); |
1138 |
if (modCount != expectedModCount) |
1139 |
throw new ConcurrentModificationException(); |
1140 |
// deleted entries are replaced by their successors |
1141 |
if (lastReturned.left != null && lastReturned.right != null) |
1142 |
next = lastReturned; |
1143 |
deleteEntry(lastReturned); |
1144 |
expectedModCount = modCount; |
1145 |
lastReturned = null; |
1146 |
} |
1147 |
} |
1148 |
|
1149 |
final class EntryIterator extends PrivateEntryIterator<Map.Entry<K,V>> { |
1150 |
EntryIterator(Entry<K,V> first) { |
1151 |
super(first); |
1152 |
} |
1153 |
public Map.Entry<K,V> next() { |
1154 |
return nextEntry(); |
1155 |
} |
1156 |
} |
1157 |
|
1158 |
final class ValueIterator extends PrivateEntryIterator<V> { |
1159 |
ValueIterator(Entry<K,V> first) { |
1160 |
super(first); |
1161 |
} |
1162 |
public V next() { |
1163 |
return nextEntry().value; |
1164 |
} |
1165 |
} |
1166 |
|
1167 |
final class KeyIterator extends PrivateEntryIterator<K> { |
1168 |
KeyIterator(Entry<K,V> first) { |
1169 |
super(first); |
1170 |
} |
1171 |
public K next() { |
1172 |
return nextEntry().key; |
1173 |
} |
1174 |
} |
1175 |
|
1176 |
final class DescendingKeyIterator extends PrivateEntryIterator<K> { |
1177 |
DescendingKeyIterator(Entry<K,V> first) { |
1178 |
super(first); |
1179 |
} |
1180 |
public K next() { |
1181 |
return prevEntry().key; |
1182 |
} |
1183 |
} |
1184 |
|
1185 |
// Little utilities |
1186 |
|
1187 |
/** |
1188 |
* Compares two keys using the correct comparison method for this TreeMap. |
1189 |
*/ |
1190 |
final int compare(Object k1, Object k2) { |
1191 |
return comparator==null ? ((Comparable<? super K>)k1).compareTo((K)k2) |
1192 |
: comparator.compare((K)k1, (K)k2); |
1193 |
} |
1194 |
|
1195 |
/** |
1196 |
* Test two values for equality. Differs from o1.equals(o2) only in |
1197 |
* that it copes with <tt>null</tt> o1 properly. |
1198 |
*/ |
1199 |
final static boolean valEquals(Object o1, Object o2) { |
1200 |
return (o1==null ? o2==null : o1.equals(o2)); |
1201 |
} |
1202 |
|
1203 |
/** |
1204 |
* Return SimpleImmutableEntry for entry, or null if null |
1205 |
*/ |
1206 |
static <K,V> Map.Entry<K,V> exportEntry(TreeMap.Entry<K,V> e) { |
1207 |
return e == null? null : |
1208 |
new AbstractMap.SimpleImmutableEntry<K,V>(e); |
1209 |
} |
1210 |
|
1211 |
/** |
1212 |
* Return key for entry, or null if null |
1213 |
*/ |
1214 |
static <K,V> K keyOrNull(TreeMap.Entry<K,V> e) { |
1215 |
return e == null? null : e.key; |
1216 |
} |
1217 |
|
1218 |
/** |
1219 |
* Returns the key corresponding to the specified Entry. |
1220 |
* @throws NoSuchElementException if the Entry is null |
1221 |
*/ |
1222 |
static <K> K key(Entry<K,?> e) { |
1223 |
if (e==null) |
1224 |
throw new NoSuchElementException(); |
1225 |
return e.key; |
1226 |
} |
1227 |
|
1228 |
|
1229 |
// SubMaps |
1230 |
|
1231 |
/** |
1232 |
* Dummy value serving as unmatchable fence key for unbounded |
1233 |
* SubMapIterators |
1234 |
*/ |
1235 |
private static final Object UNBOUNDED = new Object(); |
1236 |
|
1237 |
/** |
1238 |
* @serial include |
1239 |
*/ |
1240 |
static abstract class NavigableSubMap<K,V> extends AbstractMap<K,V> |
1241 |
implements NavigableMap<K,V>, java.io.Serializable { |
1242 |
/** |
1243 |
* The backing map. |
1244 |
*/ |
1245 |
final TreeMap<K,V> m; |
1246 |
|
1247 |
/** |
1248 |
* Endpoints are represented as triples (fromStart, lo, |
1249 |
* loInclusive) and (toEnd, hi, hiInclusive). If fromStart is |
1250 |
* true, then the low (absolute) bound is the start of the |
1251 |
* backing map, and the other values are ignored. Otherwise, |
1252 |
* if loInclusive is true, lo is the inclusive bound, else lo |
1253 |
* is the exclusive bound. Similarly for the upper bound. |
1254 |
*/ |
1255 |
final K lo, hi; |
1256 |
final boolean fromStart, toEnd; |
1257 |
final boolean loInclusive, hiInclusive; |
1258 |
|
1259 |
NavigableSubMap(TreeMap<K,V> m, |
1260 |
boolean fromStart, K lo, boolean loInclusive, |
1261 |
boolean toEnd, K hi, boolean hiInclusive) { |
1262 |
if (!fromStart && !toEnd) { |
1263 |
if (m.compare(lo, hi) > 0) |
1264 |
throw new IllegalArgumentException("fromKey > toKey"); |
1265 |
} else { |
1266 |
if (!fromStart) // type check |
1267 |
m.compare(lo, lo); |
1268 |
if (!toEnd) |
1269 |
m.compare(hi, hi); |
1270 |
} |
1271 |
|
1272 |
this.m = m; |
1273 |
this.fromStart = fromStart; |
1274 |
this.lo = lo; |
1275 |
this.loInclusive = loInclusive; |
1276 |
this.toEnd = toEnd; |
1277 |
this.hi = hi; |
1278 |
this.hiInclusive = hiInclusive; |
1279 |
} |
1280 |
|
1281 |
// internal utilities |
1282 |
|
1283 |
final boolean tooLow(Object key) { |
1284 |
if (!fromStart) { |
1285 |
int c = m.compare(key, lo); |
1286 |
if (c < 0 || (c == 0 && !loInclusive)) |
1287 |
return true; |
1288 |
} |
1289 |
return false; |
1290 |
} |
1291 |
|
1292 |
final boolean tooHigh(Object key) { |
1293 |
if (!toEnd) { |
1294 |
int c = m.compare(key, hi); |
1295 |
if (c > 0 || (c == 0 && !hiInclusive)) |
1296 |
return true; |
1297 |
} |
1298 |
return false; |
1299 |
} |
1300 |
|
1301 |
final boolean inRange(Object key) { |
1302 |
return !tooLow(key) && !tooHigh(key); |
1303 |
} |
1304 |
|
1305 |
final boolean inClosedRange(Object key) { |
1306 |
return (fromStart || m.compare(key, lo) >= 0) |
1307 |
&& (toEnd || m.compare(hi, key) >= 0); |
1308 |
} |
1309 |
|
1310 |
final boolean inRange(Object key, boolean inclusive) { |
1311 |
return inclusive ? inRange(key) : inClosedRange(key); |
1312 |
} |
1313 |
|
1314 |
/* |
1315 |
* Absolute versions of relation operations. |
1316 |
* Subclasses map to these using like-named "sub" |
1317 |
* versions that invert senses for descending maps |
1318 |
*/ |
1319 |
|
1320 |
final TreeMap.Entry<K,V> absLowest() { |
1321 |
TreeMap.Entry<K,V> e = |
1322 |
(fromStart ? m.getFirstEntry() : |
1323 |
(loInclusive ? m.getCeilingEntry(lo) : |
1324 |
m.getHigherEntry(lo))); |
1325 |
return (e == null || tooHigh(e.key)) ? null : e; |
1326 |
} |
1327 |
|
1328 |
final TreeMap.Entry<K,V> absHighest() { |
1329 |
TreeMap.Entry<K,V> e = |
1330 |
(toEnd ? m.getLastEntry() : |
1331 |
(hiInclusive ? m.getFloorEntry(hi) : |
1332 |
m.getLowerEntry(hi))); |
1333 |
return (e == null || tooLow(e.key)) ? null : e; |
1334 |
} |
1335 |
|
1336 |
final TreeMap.Entry<K,V> absCeiling(K key) { |
1337 |
if (tooLow(key)) |
1338 |
return absLowest(); |
1339 |
TreeMap.Entry<K,V> e = m.getCeilingEntry(key); |
1340 |
return (e == null || tooHigh(e.key)) ? null : e; |
1341 |
} |
1342 |
|
1343 |
final TreeMap.Entry<K,V> absHigher(K key) { |
1344 |
if (tooLow(key)) |
1345 |
return absLowest(); |
1346 |
TreeMap.Entry<K,V> e = m.getHigherEntry(key); |
1347 |
return (e == null || tooHigh(e.key)) ? null : e; |
1348 |
} |
1349 |
|
1350 |
final TreeMap.Entry<K,V> absFloor(K key) { |
1351 |
if (tooHigh(key)) |
1352 |
return absHighest(); |
1353 |
TreeMap.Entry<K,V> e = m.getFloorEntry(key); |
1354 |
return (e == null || tooLow(e.key)) ? null : e; |
1355 |
} |
1356 |
|
1357 |
final TreeMap.Entry<K,V> absLower(K key) { |
1358 |
if (tooHigh(key)) |
1359 |
return absHighest(); |
1360 |
TreeMap.Entry<K,V> e = m.getLowerEntry(key); |
1361 |
return (e == null || tooLow(e.key)) ? null : e; |
1362 |
} |
1363 |
|
1364 |
/** Returns the absolute high fence for ascending traversal */ |
1365 |
final TreeMap.Entry<K,V> absHighFence() { |
1366 |
return (toEnd ? null : (hiInclusive ? |
1367 |
m.getHigherEntry(hi) : |
1368 |
m.getCeilingEntry(hi))); |
1369 |
} |
1370 |
|
1371 |
/** Return the absolute low fence for descending traversal */ |
1372 |
final TreeMap.Entry<K,V> absLowFence() { |
1373 |
return (fromStart ? null : (loInclusive ? |
1374 |
m.getLowerEntry(lo) : |
1375 |
m.getFloorEntry(lo))); |
1376 |
} |
1377 |
|
1378 |
// Abstract methods defined in ascending vs descending classes |
1379 |
// These relay to the appropriate absolute versions |
1380 |
|
1381 |
abstract TreeMap.Entry<K,V> subLowest(); |
1382 |
abstract TreeMap.Entry<K,V> subHighest(); |
1383 |
abstract TreeMap.Entry<K,V> subCeiling(K key); |
1384 |
abstract TreeMap.Entry<K,V> subHigher(K key); |
1385 |
abstract TreeMap.Entry<K,V> subFloor(K key); |
1386 |
abstract TreeMap.Entry<K,V> subLower(K key); |
1387 |
|
1388 |
/** Returns ascending iterator from the perspective of this submap */ |
1389 |
abstract Iterator<K> keyIterator(); |
1390 |
|
1391 |
/** Returns descending iterator from the perspective of this submap */ |
1392 |
abstract Iterator<K> descendingKeyIterator(); |
1393 |
|
1394 |
// public methods |
1395 |
|
1396 |
public boolean isEmpty() { |
1397 |
return (fromStart && toEnd) ? m.isEmpty() : entrySet().isEmpty(); |
1398 |
} |
1399 |
|
1400 |
public int size() { |
1401 |
return (fromStart && toEnd) ? m.size() : entrySet().size(); |
1402 |
} |
1403 |
|
1404 |
public final boolean containsKey(Object key) { |
1405 |
return inRange(key) && m.containsKey(key); |
1406 |
} |
1407 |
|
1408 |
public final V put(K key, V value) { |
1409 |
if (!inRange(key)) |
1410 |
throw new IllegalArgumentException("key out of range"); |
1411 |
return m.put(key, value); |
1412 |
} |
1413 |
|
1414 |
public final V get(Object key) { |
1415 |
return !inRange(key)? null : m.get(key); |
1416 |
} |
1417 |
|
1418 |
public final V remove(Object key) { |
1419 |
return !inRange(key)? null : m.remove(key); |
1420 |
} |
1421 |
|
1422 |
public final Map.Entry<K,V> ceilingEntry(K key) { |
1423 |
return exportEntry(subCeiling(key)); |
1424 |
} |
1425 |
|
1426 |
public final K ceilingKey(K key) { |
1427 |
return keyOrNull(subCeiling(key)); |
1428 |
} |
1429 |
|
1430 |
public final Map.Entry<K,V> higherEntry(K key) { |
1431 |
return exportEntry(subHigher(key)); |
1432 |
} |
1433 |
|
1434 |
public final K higherKey(K key) { |
1435 |
return keyOrNull(subHigher(key)); |
1436 |
} |
1437 |
|
1438 |
public final Map.Entry<K,V> floorEntry(K key) { |
1439 |
return exportEntry(subFloor(key)); |
1440 |
} |
1441 |
|
1442 |
public final K floorKey(K key) { |
1443 |
return keyOrNull(subFloor(key)); |
1444 |
} |
1445 |
|
1446 |
public final Map.Entry<K,V> lowerEntry(K key) { |
1447 |
return exportEntry(subLower(key)); |
1448 |
} |
1449 |
|
1450 |
public final K lowerKey(K key) { |
1451 |
return keyOrNull(subLower(key)); |
1452 |
} |
1453 |
|
1454 |
public final K firstKey() { |
1455 |
return key(subLowest()); |
1456 |
} |
1457 |
|
1458 |
public final K lastKey() { |
1459 |
return key(subHighest()); |
1460 |
} |
1461 |
|
1462 |
public final Map.Entry<K,V> firstEntry() { |
1463 |
return exportEntry(subLowest()); |
1464 |
} |
1465 |
|
1466 |
public final Map.Entry<K,V> lastEntry() { |
1467 |
return exportEntry(subHighest()); |
1468 |
} |
1469 |
|
1470 |
public final Map.Entry<K,V> pollFirstEntry() { |
1471 |
TreeMap.Entry<K,V> e = subLowest(); |
1472 |
Map.Entry<K,V> result = exportEntry(e); |
1473 |
if (e != null) |
1474 |
m.deleteEntry(e); |
1475 |
return result; |
1476 |
} |
1477 |
|
1478 |
public final Map.Entry<K,V> pollLastEntry() { |
1479 |
TreeMap.Entry<K,V> e = subHighest(); |
1480 |
Map.Entry<K,V> result = exportEntry(e); |
1481 |
if (e != null) |
1482 |
m.deleteEntry(e); |
1483 |
return result; |
1484 |
} |
1485 |
|
1486 |
// Views |
1487 |
transient NavigableMap<K,V> descendingMapView = null; |
1488 |
transient EntrySetView entrySetView = null; |
1489 |
transient KeySet<K> navigableKeySetView = null; |
1490 |
|
1491 |
public final NavigableSet<K> navigableKeySet() { |
1492 |
KeySet<K> nksv = navigableKeySetView; |
1493 |
return (nksv != null) ? nksv : |
1494 |
(navigableKeySetView = new TreeMap.KeySet(this)); |
1495 |
} |
1496 |
|
1497 |
public final Set<K> keySet() { |
1498 |
return navigableKeySet(); |
1499 |
} |
1500 |
|
1501 |
public NavigableSet<K> descendingKeySet() { |
1502 |
return descendingMap().navigableKeySet(); |
1503 |
} |
1504 |
|
1505 |
public final SortedMap<K,V> subMap(K fromKey, K toKey) { |
1506 |
return subMap(fromKey, true, toKey, false); |
1507 |
} |
1508 |
|
1509 |
public final SortedMap<K,V> headMap(K toKey) { |
1510 |
return headMap(toKey, false); |
1511 |
} |
1512 |
|
1513 |
public final SortedMap<K,V> tailMap(K fromKey) { |
1514 |
return tailMap(fromKey, true); |
1515 |
} |
1516 |
|
1517 |
// View classes |
1518 |
|
1519 |
abstract class EntrySetView extends AbstractSet<Map.Entry<K,V>> { |
1520 |
private transient int size = -1, sizeModCount; |
1521 |
|
1522 |
public int size() { |
1523 |
if (fromStart && toEnd) |
1524 |
return m.size(); |
1525 |
if (size == -1 || sizeModCount != m.modCount) { |
1526 |
sizeModCount = m.modCount; |
1527 |
size = 0; |
1528 |
Iterator i = iterator(); |
1529 |
while (i.hasNext()) { |
1530 |
size++; |
1531 |
i.next(); |
1532 |
} |
1533 |
} |
1534 |
return size; |
1535 |
} |
1536 |
|
1537 |
public boolean isEmpty() { |
1538 |
TreeMap.Entry<K,V> n = absLowest(); |
1539 |
return n == null || tooHigh(n.key); |
1540 |
} |
1541 |
|
1542 |
public boolean contains(Object o) { |
1543 |
if (!(o instanceof Map.Entry)) |
1544 |
return false; |
1545 |
Map.Entry<K,V> entry = (Map.Entry<K,V>) o; |
1546 |
K key = entry.getKey(); |
1547 |
if (!inRange(key)) |
1548 |
return false; |
1549 |
TreeMap.Entry node = m.getEntry(key); |
1550 |
return node != null && |
1551 |
valEquals(node.getValue(), entry.getValue()); |
1552 |
} |
1553 |
|
1554 |
public boolean remove(Object o) { |
1555 |
if (!(o instanceof Map.Entry)) |
1556 |
return false; |
1557 |
Map.Entry<K,V> entry = (Map.Entry<K,V>) o; |
1558 |
K key = entry.getKey(); |
1559 |
if (!inRange(key)) |
1560 |
return false; |
1561 |
TreeMap.Entry<K,V> node = m.getEntry(key); |
1562 |
if (node!=null && valEquals(node.getValue(),entry.getValue())){ |
1563 |
m.deleteEntry(node); |
1564 |
return true; |
1565 |
} |
1566 |
return false; |
1567 |
} |
1568 |
} |
1569 |
|
1570 |
/** |
1571 |
* Iterators for SubMaps |
1572 |
*/ |
1573 |
abstract class SubMapIterator<T> implements Iterator<T> { |
1574 |
TreeMap.Entry<K,V> lastReturned; |
1575 |
TreeMap.Entry<K,V> next; |
1576 |
final Object fenceKey; |
1577 |
int expectedModCount; |
1578 |
|
1579 |
SubMapIterator(TreeMap.Entry<K,V> first, |
1580 |
TreeMap.Entry<K,V> fence) { |
1581 |
expectedModCount = m.modCount; |
1582 |
lastReturned = null; |
1583 |
next = first; |
1584 |
fenceKey = fence == null ? UNBOUNDED : fence.key; |
1585 |
} |
1586 |
|
1587 |
public final boolean hasNext() { |
1588 |
return next != null && next.key != fenceKey; |
1589 |
} |
1590 |
|
1591 |
final TreeMap.Entry<K,V> nextEntry() { |
1592 |
TreeMap.Entry<K,V> e = next; |
1593 |
if (e == null || e.key == fenceKey) |
1594 |
throw new NoSuchElementException(); |
1595 |
if (m.modCount != expectedModCount) |
1596 |
throw new ConcurrentModificationException(); |
1597 |
next = successor(e); |
1598 |
lastReturned = e; |
1599 |
return e; |
1600 |
} |
1601 |
|
1602 |
final TreeMap.Entry<K,V> prevEntry() { |
1603 |
TreeMap.Entry<K,V> e = next; |
1604 |
if (e == null || e.key == fenceKey) |
1605 |
throw new NoSuchElementException(); |
1606 |
if (m.modCount != expectedModCount) |
1607 |
throw new ConcurrentModificationException(); |
1608 |
next = predecessor(e); |
1609 |
lastReturned = e; |
1610 |
return e; |
1611 |
} |
1612 |
|
1613 |
final void removeAscending() { |
1614 |
if (lastReturned == null) |
1615 |
throw new IllegalStateException(); |
1616 |
if (m.modCount != expectedModCount) |
1617 |
throw new ConcurrentModificationException(); |
1618 |
// deleted entries are replaced by their successors |
1619 |
if (lastReturned.left != null && lastReturned.right != null) |
1620 |
next = lastReturned; |
1621 |
m.deleteEntry(lastReturned); |
1622 |
lastReturned = null; |
1623 |
expectedModCount = m.modCount; |
1624 |
} |
1625 |
|
1626 |
final void removeDescending() { |
1627 |
if (lastReturned == null) |
1628 |
throw new IllegalStateException(); |
1629 |
if (m.modCount != expectedModCount) |
1630 |
throw new ConcurrentModificationException(); |
1631 |
m.deleteEntry(lastReturned); |
1632 |
lastReturned = null; |
1633 |
expectedModCount = m.modCount; |
1634 |
} |
1635 |
|
1636 |
} |
1637 |
|
1638 |
final class SubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> { |
1639 |
SubMapEntryIterator(TreeMap.Entry<K,V> first, |
1640 |
TreeMap.Entry<K,V> fence) { |
1641 |
super(first, fence); |
1642 |
} |
1643 |
public Map.Entry<K,V> next() { |
1644 |
return nextEntry(); |
1645 |
} |
1646 |
public void remove() { |
1647 |
removeAscending(); |
1648 |
} |
1649 |
} |
1650 |
|
1651 |
final class SubMapKeyIterator extends SubMapIterator<K> { |
1652 |
SubMapKeyIterator(TreeMap.Entry<K,V> first, |
1653 |
TreeMap.Entry<K,V> fence) { |
1654 |
super(first, fence); |
1655 |
} |
1656 |
public K next() { |
1657 |
return nextEntry().key; |
1658 |
} |
1659 |
public void remove() { |
1660 |
removeAscending(); |
1661 |
} |
1662 |
} |
1663 |
|
1664 |
final class DescendingSubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> { |
1665 |
DescendingSubMapEntryIterator(TreeMap.Entry<K,V> last, |
1666 |
TreeMap.Entry<K,V> fence) { |
1667 |
super(last, fence); |
1668 |
} |
1669 |
|
1670 |
public Map.Entry<K,V> next() { |
1671 |
return prevEntry(); |
1672 |
} |
1673 |
public void remove() { |
1674 |
removeDescending(); |
1675 |
} |
1676 |
} |
1677 |
|
1678 |
final class DescendingSubMapKeyIterator extends SubMapIterator<K> { |
1679 |
DescendingSubMapKeyIterator(TreeMap.Entry<K,V> last, |
1680 |
TreeMap.Entry<K,V> fence) { |
1681 |
super(last, fence); |
1682 |
} |
1683 |
public K next() { |
1684 |
return prevEntry().key; |
1685 |
} |
1686 |
public void remove() { |
1687 |
removeDescending(); |
1688 |
} |
1689 |
} |
1690 |
} |
1691 |
|
1692 |
/** |
1693 |
* @serial include |
1694 |
*/ |
1695 |
static final class AscendingSubMap<K,V> extends NavigableSubMap<K,V> { |
1696 |
private static final long serialVersionUID = 912986545866124060L; |
1697 |
|
1698 |
AscendingSubMap(TreeMap<K,V> m, |
1699 |
boolean fromStart, K lo, boolean loInclusive, |
1700 |
boolean toEnd, K hi, boolean hiInclusive) { |
1701 |
super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive); |
1702 |
} |
1703 |
|
1704 |
public Comparator<? super K> comparator() { |
1705 |
return m.comparator(); |
1706 |
} |
1707 |
|
1708 |
public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, |
1709 |
K toKey, boolean toInclusive) { |
1710 |
if (!inRange(fromKey, fromInclusive)) |
1711 |
throw new IllegalArgumentException("fromKey out of range"); |
1712 |
if (!inRange(toKey, toInclusive)) |
1713 |
throw new IllegalArgumentException("toKey out of range"); |
1714 |
return new AscendingSubMap(m, |
1715 |
false, fromKey, fromInclusive, |
1716 |
false, toKey, toInclusive); |
1717 |
} |
1718 |
|
1719 |
public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { |
1720 |
if (!inRange(toKey, inclusive)) |
1721 |
throw new IllegalArgumentException("toKey out of range"); |
1722 |
return new AscendingSubMap(m, |
1723 |
fromStart, lo, loInclusive, |
1724 |
false, toKey, inclusive); |
1725 |
} |
1726 |
|
1727 |
public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive){ |
1728 |
if (!inRange(fromKey, inclusive)) |
1729 |
throw new IllegalArgumentException("fromKey out of range"); |
1730 |
return new AscendingSubMap(m, |
1731 |
false, fromKey, inclusive, |
1732 |
toEnd, hi, hiInclusive); |
1733 |
} |
1734 |
|
1735 |
public NavigableMap<K,V> descendingMap() { |
1736 |
NavigableMap<K,V> mv = descendingMapView; |
1737 |
return (mv != null) ? mv : |
1738 |
(descendingMapView = |
1739 |
new DescendingSubMap(m, |
1740 |
fromStart, lo, loInclusive, |
1741 |
toEnd, hi, hiInclusive)); |
1742 |
} |
1743 |
|
1744 |
Iterator<K> keyIterator() { |
1745 |
return new SubMapKeyIterator(absLowest(), absHighFence()); |
1746 |
} |
1747 |
|
1748 |
Iterator<K> descendingKeyIterator() { |
1749 |
return new DescendingSubMapKeyIterator(absHighest(), absLowFence()); |
1750 |
} |
1751 |
|
1752 |
final class AscendingEntrySetView extends EntrySetView { |
1753 |
public Iterator<Map.Entry<K,V>> iterator() { |
1754 |
return new SubMapEntryIterator(absLowest(), absHighFence()); |
1755 |
} |
1756 |
} |
1757 |
|
1758 |
public Set<Map.Entry<K,V>> entrySet() { |
1759 |
EntrySetView es = entrySetView; |
1760 |
return (es != null) ? es : new AscendingEntrySetView(); |
1761 |
} |
1762 |
|
1763 |
TreeMap.Entry<K,V> subLowest() { return absLowest(); } |
1764 |
TreeMap.Entry<K,V> subHighest() { return absHighest(); } |
1765 |
TreeMap.Entry<K,V> subCeiling(K key) { return absCeiling(key); } |
1766 |
TreeMap.Entry<K,V> subHigher(K key) { return absHigher(key); } |
1767 |
TreeMap.Entry<K,V> subFloor(K key) { return absFloor(key); } |
1768 |
TreeMap.Entry<K,V> subLower(K key) { return absLower(key); } |
1769 |
} |
1770 |
|
1771 |
/** |
1772 |
* @serial include |
1773 |
*/ |
1774 |
static final class DescendingSubMap<K,V> extends NavigableSubMap<K,V> { |
1775 |
private static final long serialVersionUID = 912986545866120460L; |
1776 |
DescendingSubMap(TreeMap<K,V> m, |
1777 |
boolean fromStart, K lo, boolean loInclusive, |
1778 |
boolean toEnd, K hi, boolean hiInclusive) { |
1779 |
super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive); |
1780 |
} |
1781 |
|
1782 |
private final Comparator<? super K> reverseComparator = |
1783 |
Collections.reverseOrder(m.comparator); |
1784 |
|
1785 |
public Comparator<? super K> comparator() { |
1786 |
return reverseComparator; |
1787 |
} |
1788 |
|
1789 |
public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, |
1790 |
K toKey, boolean toInclusive) { |
1791 |
if (!inRange(fromKey, fromInclusive)) |
1792 |
throw new IllegalArgumentException("fromKey out of range"); |
1793 |
if (!inRange(toKey, toInclusive)) |
1794 |
throw new IllegalArgumentException("toKey out of range"); |
1795 |
return new DescendingSubMap(m, |
1796 |
false, toKey, toInclusive, |
1797 |
false, fromKey, fromInclusive); |
1798 |
} |
1799 |
|
1800 |
public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { |
1801 |
if (!inRange(toKey, inclusive)) |
1802 |
throw new IllegalArgumentException("toKey out of range"); |
1803 |
return new DescendingSubMap(m, |
1804 |
false, toKey, inclusive, |
1805 |
toEnd, hi, hiInclusive); |
1806 |
} |
1807 |
|
1808 |
public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive){ |
1809 |
if (!inRange(fromKey, inclusive)) |
1810 |
throw new IllegalArgumentException("fromKey out of range"); |
1811 |
return new DescendingSubMap(m, |
1812 |
fromStart, lo, loInclusive, |
1813 |
false, fromKey, inclusive); |
1814 |
} |
1815 |
|
1816 |
public NavigableMap<K,V> descendingMap() { |
1817 |
NavigableMap<K,V> mv = descendingMapView; |
1818 |
return (mv != null) ? mv : |
1819 |
(descendingMapView = |
1820 |
new AscendingSubMap(m, |
1821 |
fromStart, lo, loInclusive, |
1822 |
toEnd, hi, hiInclusive)); |
1823 |
} |
1824 |
|
1825 |
Iterator<K> keyIterator() { |
1826 |
return new DescendingSubMapKeyIterator(absHighest(), absLowFence()); |
1827 |
} |
1828 |
|
1829 |
Iterator<K> descendingKeyIterator() { |
1830 |
return new SubMapKeyIterator(absLowest(), absHighFence()); |
1831 |
} |
1832 |
|
1833 |
final class DescendingEntrySetView extends EntrySetView { |
1834 |
public Iterator<Map.Entry<K,V>> iterator() { |
1835 |
return new DescendingSubMapEntryIterator(absHighest(), absLowFence()); |
1836 |
} |
1837 |
} |
1838 |
|
1839 |
public Set<Map.Entry<K,V>> entrySet() { |
1840 |
EntrySetView es = entrySetView; |
1841 |
return (es != null) ? es : new DescendingEntrySetView(); |
1842 |
} |
1843 |
|
1844 |
TreeMap.Entry<K,V> subLowest() { return absHighest(); } |
1845 |
TreeMap.Entry<K,V> subHighest() { return absLowest(); } |
1846 |
TreeMap.Entry<K,V> subCeiling(K key) { return absFloor(key); } |
1847 |
TreeMap.Entry<K,V> subHigher(K key) { return absLower(key); } |
1848 |
TreeMap.Entry<K,V> subFloor(K key) { return absCeiling(key); } |
1849 |
TreeMap.Entry<K,V> subLower(K key) { return absHigher(key); } |
1850 |
} |
1851 |
|
1852 |
/** |
1853 |
* This class exists solely for the sake of serialization |
1854 |
* compatibility with previous releases of TreeMap that did not |
1855 |
* support NavigableMap. It translates an old-version SubMap into |
1856 |
* a new-version AscendingSubMap. This class is never otherwise |
1857 |
* used. |
1858 |
* |
1859 |
* @serial include |
1860 |
*/ |
1861 |
private class SubMap extends AbstractMap<K,V> |
1862 |
implements SortedMap<K,V>, java.io.Serializable { |
1863 |
private static final long serialVersionUID = -6520786458950516097L; |
1864 |
private boolean fromStart = false, toEnd = false; |
1865 |
private K fromKey, toKey; |
1866 |
private Object readResolve() { |
1867 |
return new AscendingSubMap(TreeMap.this, |
1868 |
fromStart, fromKey, true, |
1869 |
toEnd, toKey, false); |
1870 |
} |
1871 |
public Set<Map.Entry<K,V>> entrySet() { throw new InternalError(); } |
1872 |
public K lastKey() { throw new InternalError(); } |
1873 |
public K firstKey() { throw new InternalError(); } |
1874 |
public SortedMap<K,V> subMap(K fromKey, K toKey) { throw new InternalError(); } |
1875 |
public SortedMap<K,V> headMap(K toKey) { throw new InternalError(); } |
1876 |
public SortedMap<K,V> tailMap(K fromKey) { throw new InternalError(); } |
1877 |
public Comparator<? super K> comparator() { throw new InternalError(); } |
1878 |
} |
1879 |
|
1880 |
|
1881 |
// Red-black mechanics |
1882 |
|
1883 |
private static final boolean RED = false; |
1884 |
private static final boolean BLACK = true; |
1885 |
|
1886 |
/** |
1887 |
* Node in the Tree. Doubles as a means to pass key-value pairs back to |
1888 |
* user (see Map.Entry). |
1889 |
*/ |
1890 |
|
1891 |
static final class Entry<K,V> implements Map.Entry<K,V> { |
1892 |
K key; |
1893 |
V value; |
1894 |
Entry<K,V> left = null; |
1895 |
Entry<K,V> right = null; |
1896 |
Entry<K,V> parent; |
1897 |
boolean color = BLACK; |
1898 |
|
1899 |
/** |
1900 |
* Make a new cell with given key, value, and parent, and with |
1901 |
* <tt>null</tt> child links, and BLACK color. |
1902 |
*/ |
1903 |
Entry(K key, V value, Entry<K,V> parent) { |
1904 |
this.key = key; |
1905 |
this.value = value; |
1906 |
this.parent = parent; |
1907 |
} |
1908 |
|
1909 |
/** |
1910 |
* Returns the key. |
1911 |
* |
1912 |
* @return the key |
1913 |
*/ |
1914 |
public K getKey() { |
1915 |
return key; |
1916 |
} |
1917 |
|
1918 |
/** |
1919 |
* Returns the value associated with the key. |
1920 |
* |
1921 |
* @return the value associated with the key |
1922 |
*/ |
1923 |
public V getValue() { |
1924 |
return value; |
1925 |
} |
1926 |
|
1927 |
/** |
1928 |
* Replaces the value currently associated with the key with the given |
1929 |
* value. |
1930 |
* |
1931 |
* @return the value associated with the key before this method was |
1932 |
* called |
1933 |
*/ |
1934 |
public V setValue(V value) { |
1935 |
V oldValue = this.value; |
1936 |
this.value = value; |
1937 |
return oldValue; |
1938 |
} |
1939 |
|
1940 |
public boolean equals(Object o) { |
1941 |
if (!(o instanceof Map.Entry)) |
1942 |
return false; |
1943 |
Map.Entry<?,?> e = (Map.Entry<?,?>)o; |
1944 |
|
1945 |
return valEquals(key,e.getKey()) && valEquals(value,e.getValue()); |
1946 |
} |
1947 |
|
1948 |
public int hashCode() { |
1949 |
int keyHash = (key==null ? 0 : key.hashCode()); |
1950 |
int valueHash = (value==null ? 0 : value.hashCode()); |
1951 |
return keyHash ^ valueHash; |
1952 |
} |
1953 |
|
1954 |
public String toString() { |
1955 |
return key + "=" + value; |
1956 |
} |
1957 |
} |
1958 |
|
1959 |
/** |
1960 |
* Returns the first Entry in the TreeMap (according to the TreeMap's |
1961 |
* key-sort function). Returns null if the TreeMap is empty. |
1962 |
*/ |
1963 |
final Entry<K,V> getFirstEntry() { |
1964 |
Entry<K,V> p = root; |
1965 |
if (p != null) |
1966 |
while (p.left != null) |
1967 |
p = p.left; |
1968 |
return p; |
1969 |
} |
1970 |
|
1971 |
/** |
1972 |
* Returns the last Entry in the TreeMap (according to the TreeMap's |
1973 |
* key-sort function). Returns null if the TreeMap is empty. |
1974 |
*/ |
1975 |
final Entry<K,V> getLastEntry() { |
1976 |
Entry<K,V> p = root; |
1977 |
if (p != null) |
1978 |
while (p.right != null) |
1979 |
p = p.right; |
1980 |
return p; |
1981 |
} |
1982 |
|
1983 |
/** |
1984 |
* Returns the successor of the specified Entry, or null if no such. |
1985 |
*/ |
1986 |
static <K,V> TreeMap.Entry<K,V> successor(Entry<K,V> t) { |
1987 |
if (t == null) |
1988 |
return null; |
1989 |
else if (t.right != null) { |
1990 |
Entry<K,V> p = t.right; |
1991 |
while (p.left != null) |
1992 |
p = p.left; |
1993 |
return p; |
1994 |
} else { |
1995 |
Entry<K,V> p = t.parent; |
1996 |
Entry<K,V> ch = t; |
1997 |
while (p != null && ch == p.right) { |
1998 |
ch = p; |
1999 |
p = p.parent; |
2000 |
} |
2001 |
return p; |
2002 |
} |
2003 |
} |
2004 |
|
2005 |
/** |
2006 |
* Returns the predecessor of the specified Entry, or null if no such. |
2007 |
*/ |
2008 |
static <K,V> Entry<K,V> predecessor(Entry<K,V> t) { |
2009 |
if (t == null) |
2010 |
return null; |
2011 |
else if (t.left != null) { |
2012 |
Entry<K,V> p = t.left; |
2013 |
while (p.right != null) |
2014 |
p = p.right; |
2015 |
return p; |
2016 |
} else { |
2017 |
Entry<K,V> p = t.parent; |
2018 |
Entry<K,V> ch = t; |
2019 |
while (p != null && ch == p.left) { |
2020 |
ch = p; |
2021 |
p = p.parent; |
2022 |
} |
2023 |
return p; |
2024 |
} |
2025 |
} |
2026 |
|
2027 |
/** |
2028 |
* Balancing operations. |
2029 |
* |
2030 |
* Implementations of rebalancings during insertion and deletion are |
2031 |
* slightly different than the CLR version. Rather than using dummy |
2032 |
* nilnodes, we use a set of accessors that deal properly with null. They |
2033 |
* are used to avoid messiness surrounding nullness checks in the main |
2034 |
* algorithms. |
2035 |
*/ |
2036 |
|
2037 |
private static <K,V> boolean colorOf(Entry<K,V> p) { |
2038 |
return (p == null ? BLACK : p.color); |
2039 |
} |
2040 |
|
2041 |
private static <K,V> Entry<K,V> parentOf(Entry<K,V> p) { |
2042 |
return (p == null ? null: p.parent); |
2043 |
} |
2044 |
|
2045 |
private static <K,V> void setColor(Entry<K,V> p, boolean c) { |
2046 |
if (p != null) |
2047 |
p.color = c; |
2048 |
} |
2049 |
|
2050 |
private static <K,V> Entry<K,V> leftOf(Entry<K,V> p) { |
2051 |
return (p == null) ? null: p.left; |
2052 |
} |
2053 |
|
2054 |
private static <K,V> Entry<K,V> rightOf(Entry<K,V> p) { |
2055 |
return (p == null) ? null: p.right; |
2056 |
} |
2057 |
|
2058 |
/** From CLR */ |
2059 |
private void rotateLeft(Entry<K,V> p) { |
2060 |
if (p != null) { |
2061 |
Entry<K,V> r = p.right; |
2062 |
p.right = r.left; |
2063 |
if (r.left != null) |
2064 |
r.left.parent = p; |
2065 |
r.parent = p.parent; |
2066 |
if (p.parent == null) |
2067 |
root = r; |
2068 |
else if (p.parent.left == p) |
2069 |
p.parent.left = r; |
2070 |
else |
2071 |
p.parent.right = r; |
2072 |
r.left = p; |
2073 |
p.parent = r; |
2074 |
} |
2075 |
} |
2076 |
|
2077 |
/** From CLR */ |
2078 |
private void rotateRight(Entry<K,V> p) { |
2079 |
if (p != null) { |
2080 |
Entry<K,V> l = p.left; |
2081 |
p.left = l.right; |
2082 |
if (l.right != null) l.right.parent = p; |
2083 |
l.parent = p.parent; |
2084 |
if (p.parent == null) |
2085 |
root = l; |
2086 |
else if (p.parent.right == p) |
2087 |
p.parent.right = l; |
2088 |
else p.parent.left = l; |
2089 |
l.right = p; |
2090 |
p.parent = l; |
2091 |
} |
2092 |
} |
2093 |
|
2094 |
/** From CLR */ |
2095 |
private void fixAfterInsertion(Entry<K,V> x) { |
2096 |
x.color = RED; |
2097 |
|
2098 |
while (x != null && x != root && x.parent.color == RED) { |
2099 |
if (parentOf(x) == leftOf(parentOf(parentOf(x)))) { |
2100 |
Entry<K,V> y = rightOf(parentOf(parentOf(x))); |
2101 |
if (colorOf(y) == RED) { |
2102 |
setColor(parentOf(x), BLACK); |
2103 |
setColor(y, BLACK); |
2104 |
setColor(parentOf(parentOf(x)), RED); |
2105 |
x = parentOf(parentOf(x)); |
2106 |
} else { |
2107 |
if (x == rightOf(parentOf(x))) { |
2108 |
x = parentOf(x); |
2109 |
rotateLeft(x); |
2110 |
} |
2111 |
setColor(parentOf(x), BLACK); |
2112 |
setColor(parentOf(parentOf(x)), RED); |
2113 |
rotateRight(parentOf(parentOf(x))); |
2114 |
} |
2115 |
} else { |
2116 |
Entry<K,V> y = leftOf(parentOf(parentOf(x))); |
2117 |
if (colorOf(y) == RED) { |
2118 |
setColor(parentOf(x), BLACK); |
2119 |
setColor(y, BLACK); |
2120 |
setColor(parentOf(parentOf(x)), RED); |
2121 |
x = parentOf(parentOf(x)); |
2122 |
} else { |
2123 |
if (x == leftOf(parentOf(x))) { |
2124 |
x = parentOf(x); |
2125 |
rotateRight(x); |
2126 |
} |
2127 |
setColor(parentOf(x), BLACK); |
2128 |
setColor(parentOf(parentOf(x)), RED); |
2129 |
rotateLeft(parentOf(parentOf(x))); |
2130 |
} |
2131 |
} |
2132 |
} |
2133 |
root.color = BLACK; |
2134 |
} |
2135 |
|
2136 |
/** |
2137 |
* Delete node p, and then rebalance the tree. |
2138 |
*/ |
2139 |
private void deleteEntry(Entry<K,V> p) { |
2140 |
modCount++; |
2141 |
size--; |
2142 |
|
2143 |
// If strictly internal, copy successor's element to p and then make p |
2144 |
// point to successor. |
2145 |
if (p.left != null && p.right != null) { |
2146 |
Entry<K,V> s = successor (p); |
2147 |
p.key = s.key; |
2148 |
p.value = s.value; |
2149 |
p = s; |
2150 |
} // p has 2 children |
2151 |
|
2152 |
// Start fixup at replacement node, if it exists. |
2153 |
Entry<K,V> replacement = (p.left != null ? p.left : p.right); |
2154 |
|
2155 |
if (replacement != null) { |
2156 |
// Link replacement to parent |
2157 |
replacement.parent = p.parent; |
2158 |
if (p.parent == null) |
2159 |
root = replacement; |
2160 |
else if (p == p.parent.left) |
2161 |
p.parent.left = replacement; |
2162 |
else |
2163 |
p.parent.right = replacement; |
2164 |
|
2165 |
// Null out links so they are OK to use by fixAfterDeletion. |
2166 |
p.left = p.right = p.parent = null; |
2167 |
|
2168 |
// Fix replacement |
2169 |
if (p.color == BLACK) |
2170 |
fixAfterDeletion(replacement); |
2171 |
} else if (p.parent == null) { // return if we are the only node. |
2172 |
root = null; |
2173 |
} else { // No children. Use self as phantom replacement and unlink. |
2174 |
if (p.color == BLACK) |
2175 |
fixAfterDeletion(p); |
2176 |
|
2177 |
if (p.parent != null) { |
2178 |
if (p == p.parent.left) |
2179 |
p.parent.left = null; |
2180 |
else if (p == p.parent.right) |
2181 |
p.parent.right = null; |
2182 |
p.parent = null; |
2183 |
} |
2184 |
} |
2185 |
} |
2186 |
|
2187 |
/** From CLR */ |
2188 |
private void fixAfterDeletion(Entry<K,V> x) { |
2189 |
while (x != root && colorOf(x) == BLACK) { |
2190 |
if (x == leftOf(parentOf(x))) { |
2191 |
Entry<K,V> sib = rightOf(parentOf(x)); |
2192 |
|
2193 |
if (colorOf(sib) == RED) { |
2194 |
setColor(sib, BLACK); |
2195 |
setColor(parentOf(x), RED); |
2196 |
rotateLeft(parentOf(x)); |
2197 |
sib = rightOf(parentOf(x)); |
2198 |
} |
2199 |
|
2200 |
if (colorOf(leftOf(sib)) == BLACK && |
2201 |
colorOf(rightOf(sib)) == BLACK) { |
2202 |
setColor(sib, RED); |
2203 |
x = parentOf(x); |
2204 |
} else { |
2205 |
if (colorOf(rightOf(sib)) == BLACK) { |
2206 |
setColor(leftOf(sib), BLACK); |
2207 |
setColor(sib, RED); |
2208 |
rotateRight(sib); |
2209 |
sib = rightOf(parentOf(x)); |
2210 |
} |
2211 |
setColor(sib, colorOf(parentOf(x))); |
2212 |
setColor(parentOf(x), BLACK); |
2213 |
setColor(rightOf(sib), BLACK); |
2214 |
rotateLeft(parentOf(x)); |
2215 |
x = root; |
2216 |
} |
2217 |
} else { // symmetric |
2218 |
Entry<K,V> sib = leftOf(parentOf(x)); |
2219 |
|
2220 |
if (colorOf(sib) == RED) { |
2221 |
setColor(sib, BLACK); |
2222 |
setColor(parentOf(x), RED); |
2223 |
rotateRight(parentOf(x)); |
2224 |
sib = leftOf(parentOf(x)); |
2225 |
} |
2226 |
|
2227 |
if (colorOf(rightOf(sib)) == BLACK && |
2228 |
colorOf(leftOf(sib)) == BLACK) { |
2229 |
setColor(sib, RED); |
2230 |
x = parentOf(x); |
2231 |
} else { |
2232 |
if (colorOf(leftOf(sib)) == BLACK) { |
2233 |
setColor(rightOf(sib), BLACK); |
2234 |
setColor(sib, RED); |
2235 |
rotateLeft(sib); |
2236 |
sib = leftOf(parentOf(x)); |
2237 |
} |
2238 |
setColor(sib, colorOf(parentOf(x))); |
2239 |
setColor(parentOf(x), BLACK); |
2240 |
setColor(leftOf(sib), BLACK); |
2241 |
rotateRight(parentOf(x)); |
2242 |
x = root; |
2243 |
} |
2244 |
} |
2245 |
} |
2246 |
|
2247 |
setColor(x, BLACK); |
2248 |
} |
2249 |
|
2250 |
private static final long serialVersionUID = 919286545866124006L; |
2251 |
|
2252 |
/** |
2253 |
* Save the state of the <tt>TreeMap</tt> instance to a stream (i.e., |
2254 |
* serialize it). |
2255 |
* |
2256 |
* @serialData The <i>size</i> of the TreeMap (the number of key-value |
2257 |
* mappings) is emitted (int), followed by the key (Object) |
2258 |
* and value (Object) for each key-value mapping represented |
2259 |
* by the TreeMap. The key-value mappings are emitted in |
2260 |
* key-order (as determined by the TreeMap's Comparator, |
2261 |
* or by the keys' natural ordering if the TreeMap has no |
2262 |
* Comparator). |
2263 |
*/ |
2264 |
private void writeObject(java.io.ObjectOutputStream s) |
2265 |
throws java.io.IOException { |
2266 |
// Write out the Comparator and any hidden stuff |
2267 |
s.defaultWriteObject(); |
2268 |
|
2269 |
// Write out size (number of Mappings) |
2270 |
s.writeInt(size); |
2271 |
|
2272 |
// Write out keys and values (alternating) |
2273 |
for (Iterator<Map.Entry<K,V>> i = entrySet().iterator(); i.hasNext(); ) { |
2274 |
Map.Entry<K,V> e = i.next(); |
2275 |
s.writeObject(e.getKey()); |
2276 |
s.writeObject(e.getValue()); |
2277 |
} |
2278 |
} |
2279 |
|
2280 |
/** |
2281 |
* Reconstitute the <tt>TreeMap</tt> instance from a stream (i.e., |
2282 |
* deserialize it). |
2283 |
*/ |
2284 |
private void readObject(final java.io.ObjectInputStream s) |
2285 |
throws java.io.IOException, ClassNotFoundException { |
2286 |
// Read in the Comparator and any hidden stuff |
2287 |
s.defaultReadObject(); |
2288 |
|
2289 |
// Read in size |
2290 |
int size = s.readInt(); |
2291 |
|
2292 |
buildFromSorted(size, null, s, null); |
2293 |
} |
2294 |
|
2295 |
/** Intended to be called only from TreeSet.readObject */ |
2296 |
void readTreeSet(int size, java.io.ObjectInputStream s, V defaultVal) |
2297 |
throws java.io.IOException, ClassNotFoundException { |
2298 |
buildFromSorted(size, null, s, defaultVal); |
2299 |
} |
2300 |
|
2301 |
/** Intended to be called only from TreeSet.addAll */ |
2302 |
void addAllForTreeSet(SortedSet<? extends K> set, V defaultVal) { |
2303 |
try { |
2304 |
buildFromSorted(set.size(), set.iterator(), null, defaultVal); |
2305 |
} catch (java.io.IOException cannotHappen) { |
2306 |
} catch (ClassNotFoundException cannotHappen) { |
2307 |
} |
2308 |
} |
2309 |
|
2310 |
|
2311 |
/** |
2312 |
* Linear time tree building algorithm from sorted data. Can accept keys |
2313 |
* and/or values from iterator or stream. This leads to too many |
2314 |
* parameters, but seems better than alternatives. The four formats |
2315 |
* that this method accepts are: |
2316 |
* |
2317 |
* 1) An iterator of Map.Entries. (it != null, defaultVal == null). |
2318 |
* 2) An iterator of keys. (it != null, defaultVal != null). |
2319 |
* 3) A stream of alternating serialized keys and values. |
2320 |
* (it == null, defaultVal == null). |
2321 |
* 4) A stream of serialized keys. (it == null, defaultVal != null). |
2322 |
* |
2323 |
* It is assumed that the comparator of the TreeMap is already set prior |
2324 |
* to calling this method. |
2325 |
* |
2326 |
* @param size the number of keys (or key-value pairs) to be read from |
2327 |
* the iterator or stream |
2328 |
* @param it If non-null, new entries are created from entries |
2329 |
* or keys read from this iterator. |
2330 |
* @param str If non-null, new entries are created from keys and |
2331 |
* possibly values read from this stream in serialized form. |
2332 |
* Exactly one of it and str should be non-null. |
2333 |
* @param defaultVal if non-null, this default value is used for |
2334 |
* each value in the map. If null, each value is read from |
2335 |
* iterator or stream, as described above. |
2336 |
* @throws IOException propagated from stream reads. This cannot |
2337 |
* occur if str is null. |
2338 |
* @throws ClassNotFoundException propagated from readObject. |
2339 |
* This cannot occur if str is null. |
2340 |
*/ |
2341 |
private void buildFromSorted(int size, Iterator it, |
2342 |
java.io.ObjectInputStream str, |
2343 |
V defaultVal) |
2344 |
throws java.io.IOException, ClassNotFoundException { |
2345 |
this.size = size; |
2346 |
root = buildFromSorted(0, 0, size-1, computeRedLevel(size), |
2347 |
it, str, defaultVal); |
2348 |
} |
2349 |
|
2350 |
/** |
2351 |
* Recursive "helper method" that does the real work of the |
2352 |
* previous method. Identically named parameters have |
2353 |
* identical definitions. Additional parameters are documented below. |
2354 |
* It is assumed that the comparator and size fields of the TreeMap are |
2355 |
* already set prior to calling this method. (It ignores both fields.) |
2356 |
* |
2357 |
* @param level the current level of tree. Initial call should be 0. |
2358 |
* @param lo the first element index of this subtree. Initial should be 0. |
2359 |
* @param hi the last element index of this subtree. Initial should be |
2360 |
* size-1. |
2361 |
* @param redLevel the level at which nodes should be red. |
2362 |
* Must be equal to computeRedLevel for tree of this size. |
2363 |
*/ |
2364 |
private final Entry<K,V> buildFromSorted(int level, int lo, int hi, |
2365 |
int redLevel, |
2366 |
Iterator it, |
2367 |
java.io.ObjectInputStream str, |
2368 |
V defaultVal) |
2369 |
throws java.io.IOException, ClassNotFoundException { |
2370 |
/* |
2371 |
* Strategy: The root is the middlemost element. To get to it, we |
2372 |
* have to first recursively construct the entire left subtree, |
2373 |
* so as to grab all of its elements. We can then proceed with right |
2374 |
* subtree. |
2375 |
* |
2376 |
* The lo and hi arguments are the minimum and maximum |
2377 |
* indices to pull out of the iterator or stream for current subtree. |
2378 |
* They are not actually indexed, we just proceed sequentially, |
2379 |
* ensuring that items are extracted in corresponding order. |
2380 |
*/ |
2381 |
|
2382 |
if (hi < lo) return null; |
2383 |
|
2384 |
int mid = (lo + hi) >>> 1; |
2385 |
|
2386 |
Entry<K,V> left = null; |
2387 |
if (lo < mid) |
2388 |
left = buildFromSorted(level+1, lo, mid - 1, redLevel, |
2389 |
it, str, defaultVal); |
2390 |
|
2391 |
// extract key and/or value from iterator or stream |
2392 |
K key; |
2393 |
V value; |
2394 |
if (it != null) { |
2395 |
if (defaultVal==null) { |
2396 |
Map.Entry<K,V> entry = (Map.Entry<K,V>)it.next(); |
2397 |
key = entry.getKey(); |
2398 |
value = entry.getValue(); |
2399 |
} else { |
2400 |
key = (K)it.next(); |
2401 |
value = defaultVal; |
2402 |
} |
2403 |
} else { // use stream |
2404 |
key = (K) str.readObject(); |
2405 |
value = (defaultVal != null ? defaultVal : (V) str.readObject()); |
2406 |
} |
2407 |
|
2408 |
Entry<K,V> middle = new Entry<K,V>(key, value, null); |
2409 |
|
2410 |
// color nodes in non-full bottommost level red |
2411 |
if (level == redLevel) |
2412 |
middle.color = RED; |
2413 |
|
2414 |
if (left != null) { |
2415 |
middle.left = left; |
2416 |
left.parent = middle; |
2417 |
} |
2418 |
|
2419 |
if (mid < hi) { |
2420 |
Entry<K,V> right = buildFromSorted(level+1, mid+1, hi, redLevel, |
2421 |
it, str, defaultVal); |
2422 |
middle.right = right; |
2423 |
right.parent = middle; |
2424 |
} |
2425 |
|
2426 |
return middle; |
2427 |
} |
2428 |
|
2429 |
/** |
2430 |
* Find the level down to which to assign all nodes BLACK. This is the |
2431 |
* last `full' level of the complete binary tree produced by |
2432 |
* buildTree. The remaining nodes are colored RED. (This makes a `nice' |
2433 |
* set of color assignments wrt future insertions.) This level number is |
2434 |
* computed by finding the number of splits needed to reach the zeroeth |
2435 |
* node. (The answer is ~lg(N), but in any case must be computed by same |
2436 |
* quick O(lg(N)) loop.) |
2437 |
*/ |
2438 |
private static int computeRedLevel(int sz) { |
2439 |
int level = 0; |
2440 |
for (int m = sz - 1; m >= 0; m = m / 2 - 1) |
2441 |
level++; |
2442 |
return level; |
2443 |
} |
2444 |
} |