--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/TreeMap.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,2443 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.util;
+
+/**
+ * A Red-Black tree based {@link NavigableMap} implementation.
+ * The map is sorted according to the {@linkplain Comparable natural
+ * ordering} of its keys, or by a {@link Comparator} provided at map
+ * creation time, depending on which constructor is used.
+ *
+ * <p>This implementation provides guaranteed log(n) time cost for the
+ * <tt>containsKey</tt>, <tt>get</tt>, <tt>put</tt> and <tt>remove</tt>
+ * operations. Algorithms are adaptations of those in Cormen, Leiserson, and
+ * Rivest's <I>Introduction to Algorithms</I>.
+ *
+ * <p>Note that the ordering maintained by a sorted map (whether or not an
+ * explicit comparator is provided) must be <i>consistent with equals</i> if
+ * this sorted map is to correctly implement the <tt>Map</tt> interface. (See
+ * <tt>Comparable</tt> or <tt>Comparator</tt> for a precise definition of
+ * <i>consistent with equals</i>.) This is so because the <tt>Map</tt>
+ * interface is defined in terms of the equals operation, but a map performs
+ * all key comparisons using its <tt>compareTo</tt> (or <tt>compare</tt>)
+ * method, so two keys that are deemed equal by this method are, from the
+ * standpoint of the sorted map, equal. The behavior of a sorted map
+ * <i>is</i> well-defined even if its ordering is inconsistent with equals; it
+ * just fails to obey the general contract of the <tt>Map</tt> interface.
+ *
+ * <p><strong>Note that this implementation is not synchronized.</strong>
+ * If multiple threads access a map concurrently, and at least one of the
+ * threads modifies the map structurally, it <i>must</i> be synchronized
+ * externally. (A structural modification is any operation that adds or
+ * deletes one or more mappings; merely changing the value associated
+ * with an existing key is not a structural modification.) This is
+ * typically accomplished by synchronizing on some object that naturally
+ * encapsulates the map.
+ * If no such object exists, the map should be "wrapped" using the
+ * {@link Collections#synchronizedSortedMap Collections.synchronizedSortedMap}
+ * method. This is best done at creation time, to prevent accidental
+ * unsynchronized access to the map: <pre>
+ * SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));</pre>
+ *
+ * <p>The iterators returned by the <tt>iterator</tt> method of the collections
+ * returned by all of this class's "collection view methods" are
+ * <i>fail-fast</i>: if the map is structurally modified at any time after the
+ * iterator is created, in any way except through the iterator's own
+ * <tt>remove</tt> method, the iterator will throw a {@link
+ * ConcurrentModificationException}. Thus, in the face of concurrent
+ * modification, the iterator fails quickly and cleanly, rather than risking
+ * arbitrary, non-deterministic behavior at an undetermined time in the future.
+ *
+ * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
+ * as it is, generally speaking, impossible to make any hard guarantees in the
+ * presence of unsynchronized concurrent modification. Fail-fast iterators
+ * throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
+ * Therefore, it would be wrong to write a program that depended on this
+ * exception for its correctness: <i>the fail-fast behavior of iterators
+ * should be used only to detect bugs.</i>
+ *
+ * <p>All <tt>Map.Entry</tt> pairs returned by methods in this class
+ * and its views represent snapshots of mappings at the time they were
+ * produced. They do <em>not</em> support the <tt>Entry.setValue</tt>
+ * method. (Note however that it is possible to change mappings in the
+ * associated map using <tt>put</tt>.)
+ *
+ * <p>This class is a member of the
+ * <a href="{@docRoot}/../technotes/guides/collections/index.html">
+ * Java Collections Framework</a>.
+ *
+ * @param <K> the type of keys maintained by this map
+ * @param <V> the type of mapped values
+ *
+ * @author Josh Bloch and Doug Lea
+ * @see Map
+ * @see HashMap
+ * @see Hashtable
+ * @see Comparable
+ * @see Comparator
+ * @see Collection
+ * @since 1.2
+ */
+
+public class TreeMap<K,V>
+ extends AbstractMap<K,V>
+ implements NavigableMap<K,V>, Cloneable, java.io.Serializable
+{
+ /**
+ * The comparator used to maintain order in this tree map, or
+ * null if it uses the natural ordering of its keys.
+ *
+ * @serial
+ */
+ private final Comparator<? super K> comparator;
+
+ private transient Entry<K,V> root = null;
+
+ /**
+ * The number of entries in the tree
+ */
+ private transient int size = 0;
+
+ /**
+ * The number of structural modifications to the tree.
+ */
+ private transient int modCount = 0;
+
+ /**
+ * Constructs a new, empty tree map, using the natural ordering of its
+ * keys. All keys inserted into the map must implement the {@link
+ * Comparable} interface. Furthermore, all such keys must be
+ * <i>mutually comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw
+ * a <tt>ClassCastException</tt> for any keys <tt>k1</tt> and
+ * <tt>k2</tt> in the map. If the user attempts to put a key into the
+ * map that violates this constraint (for example, the user attempts to
+ * put a string key into a map whose keys are integers), the
+ * <tt>put(Object key, Object value)</tt> call will throw a
+ * <tt>ClassCastException</tt>.
+ */
+ public TreeMap() {
+ comparator = null;
+ }
+
+ /**
+ * Constructs a new, empty tree map, ordered according to the given
+ * comparator. All keys inserted into the map must be <i>mutually
+ * comparable</i> by the given comparator: <tt>comparator.compare(k1,
+ * k2)</tt> must not throw a <tt>ClassCastException</tt> for any keys
+ * <tt>k1</tt> and <tt>k2</tt> in the map. If the user attempts to put
+ * a key into the map that violates this constraint, the <tt>put(Object
+ * key, Object value)</tt> call will throw a
+ * <tt>ClassCastException</tt>.
+ *
+ * @param comparator the comparator that will be used to order this map.
+ * If <tt>null</tt>, the {@linkplain Comparable natural
+ * ordering} of the keys will be used.
+ */
+ public TreeMap(Comparator<? super K> comparator) {
+ this.comparator = comparator;
+ }
+
+ /**
+ * Constructs a new tree map containing the same mappings as the given
+ * map, ordered according to the <i>natural ordering</i> of its keys.
+ * All keys inserted into the new map must implement the {@link
+ * Comparable} interface. Furthermore, all such keys must be
+ * <i>mutually comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw
+ * a <tt>ClassCastException</tt> for any keys <tt>k1</tt> and
+ * <tt>k2</tt> in the map. This method runs in n*log(n) time.
+ *
+ * @param m the map whose mappings are to be placed in this map
+ * @throws ClassCastException if the keys in m are not {@link Comparable},
+ * or are not mutually comparable
+ * @throws NullPointerException if the specified map is null
+ */
+ public TreeMap(Map<? extends K, ? extends V> m) {
+ comparator = null;
+ putAll(m);
+ }
+
+ /**
+ * Constructs a new tree map containing the same mappings and
+ * using the same ordering as the specified sorted map. This
+ * method runs in linear time.
+ *
+ * @param m the sorted map whose mappings are to be placed in this map,
+ * and whose comparator is to be used to sort this map
+ * @throws NullPointerException if the specified map is null
+ */
+ public TreeMap(SortedMap<K, ? extends V> m) {
+ comparator = m.comparator();
+ try {
+ buildFromSorted(m.size(), m.entrySet().iterator(), null, null);
+ } catch (java.io.IOException cannotHappen) {
+ } catch (ClassNotFoundException cannotHappen) {
+ }
+ }
+
+
+ // Query Operations
+
+ /**
+ * Returns the number of key-value mappings in this map.
+ *
+ * @return the number of key-value mappings in this map
+ */
+ public int size() {
+ return size;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this map contains a mapping for the specified
+ * key.
+ *
+ * @param key key whose presence in this map is to be tested
+ * @return <tt>true</tt> if this map contains a mapping for the
+ * specified key
+ * @throws ClassCastException if the specified key cannot be compared
+ * with the keys currently in the map
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ */
+ public boolean containsKey(Object key) {
+ return getEntry(key) != null;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this map maps one or more keys to the
+ * specified value. More formally, returns <tt>true</tt> if and only if
+ * this map contains at least one mapping to a value <tt>v</tt> such
+ * that <tt>(value==null ? v==null : value.equals(v))</tt>. This
+ * operation will probably require time linear in the map size for
+ * most implementations.
+ *
+ * @param value value whose presence in this map is to be tested
+ * @return <tt>true</tt> if a mapping to <tt>value</tt> exists;
+ * <tt>false</tt> otherwise
+ * @since 1.2
+ */
+ public boolean containsValue(Object value) {
+ for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e))
+ if (valEquals(value, e.value))
+ return true;
+ return false;
+ }
+
+ /**
+ * Returns the value to which the specified key is mapped,
+ * or {@code null} if this map contains no mapping for the key.
+ *
+ * <p>More formally, if this map contains a mapping from a key
+ * {@code k} to a value {@code v} such that {@code key} compares
+ * equal to {@code k} according to the map's ordering, then this
+ * method returns {@code v}; otherwise it returns {@code null}.
+ * (There can be at most one such mapping.)
+ *
+ * <p>A return value of {@code null} does not <i>necessarily</i>
+ * indicate that the map contains no mapping for the key; it's also
+ * possible that the map explicitly maps the key to {@code null}.
+ * The {@link #containsKey containsKey} operation may be used to
+ * distinguish these two cases.
+ *
+ * @throws ClassCastException if the specified key cannot be compared
+ * with the keys currently in the map
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ */
+ public V get(Object key) {
+ Entry<K,V> p = getEntry(key);
+ return (p==null ? null : p.value);
+ }
+
+ public Comparator<? super K> comparator() {
+ return comparator;
+ }
+
+ /**
+ * @throws NoSuchElementException {@inheritDoc}
+ */
+ public K firstKey() {
+ return key(getFirstEntry());
+ }
+
+ /**
+ * @throws NoSuchElementException {@inheritDoc}
+ */
+ public K lastKey() {
+ return key(getLastEntry());
+ }
+
+ /**
+ * Copies all of the mappings from the specified map to this map.
+ * These mappings replace any mappings that this map had for any
+ * of the keys currently in the specified map.
+ *
+ * @param map mappings to be stored in this map
+ * @throws ClassCastException if the class of a key or value in
+ * the specified map prevents it from being stored in this map
+ * @throws NullPointerException if the specified map is null or
+ * the specified map contains a null key and this map does not
+ * permit null keys
+ */
+ public void putAll(Map<? extends K, ? extends V> map) {
+ int mapSize = map.size();
+ if (size==0 && mapSize!=0 && map instanceof SortedMap) {
+ Comparator c = ((SortedMap)map).comparator();
+ if (c == comparator || (c != null && c.equals(comparator))) {
+ ++modCount;
+ try {
+ buildFromSorted(mapSize, map.entrySet().iterator(),
+ null, null);
+ } catch (java.io.IOException cannotHappen) {
+ } catch (ClassNotFoundException cannotHappen) {
+ }
+ return;
+ }
+ }
+ super.putAll(map);
+ }
+
+ /**
+ * Returns this map's entry for the given key, or <tt>null</tt> if the map
+ * does not contain an entry for the key.
+ *
+ * @return this map's entry for the given key, or <tt>null</tt> if the map
+ * does not contain an entry for the key
+ * @throws ClassCastException if the specified key cannot be compared
+ * with the keys currently in the map
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ */
+ final Entry<K,V> getEntry(Object key) {
+ // Offload comparator-based version for sake of performance
+ if (comparator != null)
+ return getEntryUsingComparator(key);
+ if (key == null)
+ throw new NullPointerException();
+ Comparable<? super K> k = (Comparable<? super K>) key;
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = k.compareTo(p.key);
+ if (cmp < 0)
+ p = p.left;
+ else if (cmp > 0)
+ p = p.right;
+ else
+ return p;
+ }
+ return null;
+ }
+
+ /**
+ * Version of getEntry using comparator. Split off from getEntry
+ * for performance. (This is not worth doing for most methods,
+ * that are less dependent on comparator performance, but is
+ * worthwhile here.)
+ */
+ final Entry<K,V> getEntryUsingComparator(Object key) {
+ K k = (K) key;
+ Comparator<? super K> cpr = comparator;
+ if (cpr != null) {
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = cpr.compare(k, p.key);
+ if (cmp < 0)
+ p = p.left;
+ else if (cmp > 0)
+ p = p.right;
+ else
+ return p;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Gets the entry corresponding to the specified key; if no such entry
+ * exists, returns the entry for the least key greater than the specified
+ * key; if no such entry exists (i.e., the greatest key in the Tree is less
+ * than the specified key), returns <tt>null</tt>.
+ */
+ final Entry<K,V> getCeilingEntry(K key) {
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = compare(key, p.key);
+ if (cmp < 0) {
+ if (p.left != null)
+ p = p.left;
+ else
+ return p;
+ } else if (cmp > 0) {
+ if (p.right != null) {
+ p = p.right;
+ } else {
+ Entry<K,V> parent = p.parent;
+ Entry<K,V> ch = p;
+ while (parent != null && ch == parent.right) {
+ ch = parent;
+ parent = parent.parent;
+ }
+ return parent;
+ }
+ } else
+ return p;
+ }
+ return null;
+ }
+
+ /**
+ * Gets the entry corresponding to the specified key; if no such entry
+ * exists, returns the entry for the greatest key less than the specified
+ * key; if no such entry exists, returns <tt>null</tt>.
+ */
+ final Entry<K,V> getFloorEntry(K key) {
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = compare(key, p.key);
+ if (cmp > 0) {
+ if (p.right != null)
+ p = p.right;
+ else
+ return p;
+ } else if (cmp < 0) {
+ if (p.left != null) {
+ p = p.left;
+ } else {
+ Entry<K,V> parent = p.parent;
+ Entry<K,V> ch = p;
+ while (parent != null && ch == parent.left) {
+ ch = parent;
+ parent = parent.parent;
+ }
+ return parent;
+ }
+ } else
+ return p;
+
+ }
+ return null;
+ }
+
+ /**
+ * Gets the entry for the least key greater than the specified
+ * key; if no such entry exists, returns the entry for the least
+ * key greater than the specified key; if no such entry exists
+ * returns <tt>null</tt>.
+ */
+ final Entry<K,V> getHigherEntry(K key) {
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = compare(key, p.key);
+ if (cmp < 0) {
+ if (p.left != null)
+ p = p.left;
+ else
+ return p;
+ } else {
+ if (p.right != null) {
+ p = p.right;
+ } else {
+ Entry<K,V> parent = p.parent;
+ Entry<K,V> ch = p;
+ while (parent != null && ch == parent.right) {
+ ch = parent;
+ parent = parent.parent;
+ }
+ return parent;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns the entry for the greatest key less than the specified key; if
+ * no such entry exists (i.e., the least key in the Tree is greater than
+ * the specified key), returns <tt>null</tt>.
+ */
+ final Entry<K,V> getLowerEntry(K key) {
+ Entry<K,V> p = root;
+ while (p != null) {
+ int cmp = compare(key, p.key);
+ if (cmp > 0) {
+ if (p.right != null)
+ p = p.right;
+ else
+ return p;
+ } else {
+ if (p.left != null) {
+ p = p.left;
+ } else {
+ Entry<K,V> parent = p.parent;
+ Entry<K,V> ch = p;
+ while (parent != null && ch == parent.left) {
+ ch = parent;
+ parent = parent.parent;
+ }
+ return parent;
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Associates the specified value with the specified key in this map.
+ * If the map previously contained a mapping for the key, the old
+ * value is replaced.
+ *
+ * @param key key with which the specified value is to be associated
+ * @param value value to be associated with the specified key
+ *
+ * @return the previous value associated with <tt>key</tt>, or
+ * <tt>null</tt> if there was no mapping for <tt>key</tt>.
+ * (A <tt>null</tt> return can also indicate that the map
+ * previously associated <tt>null</tt> with <tt>key</tt>.)
+ * @throws ClassCastException if the specified key cannot be compared
+ * with the keys currently in the map
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ */
+ public V put(K key, V value) {
+ Entry<K,V> t = root;
+ if (t == null) {
+ // TBD:
+ // 5045147: (coll) Adding null to an empty TreeSet should
+ // throw NullPointerException
+ //
+ // compare(key, key); // type check
+ root = new Entry<K,V>(key, value, null);
+ size = 1;
+ modCount++;
+ return null;
+ }
+ int cmp;
+ Entry<K,V> parent;
+ // split comparator and comparable paths
+ Comparator<? super K> cpr = comparator;
+ if (cpr != null) {
+ do {
+ parent = t;
+ cmp = cpr.compare(key, t.key);
+ if (cmp < 0)
+ t = t.left;
+ else if (cmp > 0)
+ t = t.right;
+ else
+ return t.setValue(value);
+ } while (t != null);
+ }
+ else {
+ if (key == null)
+ throw new NullPointerException();
+ Comparable<? super K> k = (Comparable<? super K>) key;
+ do {
+ parent = t;
+ cmp = k.compareTo(t.key);
+ if (cmp < 0)
+ t = t.left;
+ else if (cmp > 0)
+ t = t.right;
+ else
+ return t.setValue(value);
+ } while (t != null);
+ }
+ Entry<K,V> e = new Entry<K,V>(key, value, parent);
+ if (cmp < 0)
+ parent.left = e;
+ else
+ parent.right = e;
+ fixAfterInsertion(e);
+ size++;
+ modCount++;
+ return null;
+ }
+
+ /**
+ * Removes the mapping for this key from this TreeMap if present.
+ *
+ * @param key key for which mapping should be removed
+ * @return the previous value associated with <tt>key</tt>, or
+ * <tt>null</tt> if there was no mapping for <tt>key</tt>.
+ * (A <tt>null</tt> return can also indicate that the map
+ * previously associated <tt>null</tt> with <tt>key</tt>.)
+ * @throws ClassCastException if the specified key cannot be compared
+ * with the keys currently in the map
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ */
+ public V remove(Object key) {
+ Entry<K,V> p = getEntry(key);
+ if (p == null)
+ return null;
+
+ V oldValue = p.value;
+ deleteEntry(p);
+ return oldValue;
+ }
+
+ /**
+ * Removes all of the mappings from this map.
+ * The map will be empty after this call returns.
+ */
+ public void clear() {
+ modCount++;
+ size = 0;
+ root = null;
+ }
+
+ /**
+ * Returns a shallow copy of this <tt>TreeMap</tt> instance. (The keys and
+ * values themselves are not cloned.)
+ *
+ * @return a shallow copy of this map
+ */
+ public Object clone() {
+ TreeMap<K,V> clone = null;
+ try {
+ clone = (TreeMap<K,V>) super.clone();
+ } catch (CloneNotSupportedException e) {
+ throw new InternalError();
+ }
+
+ // Put clone into "virgin" state (except for comparator)
+ clone.root = null;
+ clone.size = 0;
+ clone.modCount = 0;
+ clone.entrySet = null;
+ clone.navigableKeySet = null;
+ clone.descendingMap = null;
+
+ // Initialize clone with our mappings
+ try {
+ clone.buildFromSorted(size, entrySet().iterator(), null, null);
+ } catch (java.io.IOException cannotHappen) {
+ } catch (ClassNotFoundException cannotHappen) {
+ }
+
+ return clone;
+ }
+
+ // NavigableMap API methods
+
+ /**
+ * @since 1.6
+ */
+ public Map.Entry<K,V> firstEntry() {
+ return exportEntry(getFirstEntry());
+ }
+
+ /**
+ * @since 1.6
+ */
+ public Map.Entry<K,V> lastEntry() {
+ return exportEntry(getLastEntry());
+ }
+
+ /**
+ * @since 1.6
+ */
+ public Map.Entry<K,V> pollFirstEntry() {
+ Entry<K,V> p = getFirstEntry();
+ Map.Entry<K,V> result = exportEntry(p);
+ if (p != null)
+ deleteEntry(p);
+ return result;
+ }
+
+ /**
+ * @since 1.6
+ */
+ public Map.Entry<K,V> pollLastEntry() {
+ Entry<K,V> p = getLastEntry();
+ Map.Entry<K,V> result = exportEntry(p);
+ if (p != null)
+ deleteEntry(p);
+ return result;
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public Map.Entry<K,V> lowerEntry(K key) {
+ return exportEntry(getLowerEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public K lowerKey(K key) {
+ return keyOrNull(getLowerEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public Map.Entry<K,V> floorEntry(K key) {
+ return exportEntry(getFloorEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public K floorKey(K key) {
+ return keyOrNull(getFloorEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public Map.Entry<K,V> ceilingEntry(K key) {
+ return exportEntry(getCeilingEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public K ceilingKey(K key) {
+ return keyOrNull(getCeilingEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public Map.Entry<K,V> higherEntry(K key) {
+ return exportEntry(getHigherEntry(key));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if the specified key is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @since 1.6
+ */
+ public K higherKey(K key) {
+ return keyOrNull(getHigherEntry(key));
+ }
+
+ // Views
+
+ /**
+ * Fields initialized to contain an instance of the entry set view
+ * the first time this view is requested. Views are stateless, so
+ * there's no reason to create more than one.
+ */
+ private transient EntrySet entrySet = null;
+ private transient KeySet<K> navigableKeySet = null;
+ private transient NavigableMap<K,V> descendingMap = null;
+
+ /**
+ * Returns a {@link Set} view of the keys contained in this map.
+ * The set's iterator returns the keys in ascending order.
+ * The set is backed by the map, so changes to the map are
+ * reflected in the set, and vice-versa. If the map is modified
+ * while an iteration over the set is in progress (except through
+ * the iterator's own <tt>remove</tt> operation), the results of
+ * the iteration are undefined. The set supports element removal,
+ * which removes the corresponding mapping from the map, via the
+ * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>,
+ * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt>
+ * operations. It does not support the <tt>add</tt> or <tt>addAll</tt>
+ * operations.
+ */
+ public Set<K> keySet() {
+ return navigableKeySet();
+ }
+
+ /**
+ * @since 1.6
+ */
+ public NavigableSet<K> navigableKeySet() {
+ KeySet<K> nks = navigableKeySet;
+ return (nks != null) ? nks : (navigableKeySet = new KeySet(this));
+ }
+
+ /**
+ * @since 1.6
+ */
+ public NavigableSet<K> descendingKeySet() {
+ return descendingMap().navigableKeySet();
+ }
+
+ /**
+ * Returns a {@link Collection} view of the values contained in this map.
+ * The collection's iterator returns the values in ascending order
+ * of the corresponding keys.
+ * The collection is backed by the map, so changes to the map are
+ * reflected in the collection, and vice-versa. If the map is
+ * modified while an iteration over the collection is in progress
+ * (except through the iterator's own <tt>remove</tt> operation),
+ * the results of the iteration are undefined. The collection
+ * supports element removal, which removes the corresponding
+ * mapping from the map, via the <tt>Iterator.remove</tt>,
+ * <tt>Collection.remove</tt>, <tt>removeAll</tt>,
+ * <tt>retainAll</tt> and <tt>clear</tt> operations. It does not
+ * support the <tt>add</tt> or <tt>addAll</tt> operations.
+ */
+ public Collection<V> values() {
+ Collection<V> vs = values;
+ return (vs != null) ? vs : (values = new Values());
+ }
+
+ /**
+ * Returns a {@link Set} view of the mappings contained in this map.
+ * The set's iterator returns the entries in ascending key order.
+ * The set is backed by the map, so changes to the map are
+ * reflected in the set, and vice-versa. If the map is modified
+ * while an iteration over the set is in progress (except through
+ * the iterator's own <tt>remove</tt> operation, or through the
+ * <tt>setValue</tt> operation on a map entry returned by the
+ * iterator) the results of the iteration are undefined. The set
+ * supports element removal, which removes the corresponding
+ * mapping from the map, via the <tt>Iterator.remove</tt>,
+ * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and
+ * <tt>clear</tt> operations. It does not support the
+ * <tt>add</tt> or <tt>addAll</tt> operations.
+ */
+ public Set<Map.Entry<K,V>> entrySet() {
+ EntrySet es = entrySet;
+ return (es != null) ? es : (entrySet = new EntrySet());
+ }
+
+ /**
+ * @since 1.6
+ */
+ public NavigableMap<K, V> descendingMap() {
+ NavigableMap<K, V> km = descendingMap;
+ return (km != null) ? km :
+ (descendingMap = new DescendingSubMap(this,
+ true, null, true,
+ true, null, true));
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> is
+ * null and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @since 1.6
+ */
+ public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
+ K toKey, boolean toInclusive) {
+ return new AscendingSubMap(this,
+ false, fromKey, fromInclusive,
+ false, toKey, toInclusive);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>toKey</tt> is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @since 1.6
+ */
+ public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
+ return new AscendingSubMap(this,
+ true, null, true,
+ false, toKey, inclusive);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>fromKey</tt> is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @since 1.6
+ */
+ public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) {
+ return new AscendingSubMap(this,
+ false, fromKey, inclusive,
+ true, null, true);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> is
+ * null and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public SortedMap<K,V> subMap(K fromKey, K toKey) {
+ return subMap(fromKey, true, toKey, false);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>toKey</tt> is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public SortedMap<K,V> headMap(K toKey) {
+ return headMap(toKey, false);
+ }
+
+ /**
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException if <tt>fromKey</tt> is null
+ * and this map uses natural ordering, or its comparator
+ * does not permit null keys
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public SortedMap<K,V> tailMap(K fromKey) {
+ return tailMap(fromKey, true);
+ }
+
+ // View class support
+
+ class Values extends AbstractCollection<V> {
+ public Iterator<V> iterator() {
+ return new ValueIterator(getFirstEntry());
+ }
+
+ public int size() {
+ return TreeMap.this.size();
+ }
+
+ public boolean contains(Object o) {
+ return TreeMap.this.containsValue(o);
+ }
+
+ public boolean remove(Object o) {
+ for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e)) {
+ if (valEquals(e.getValue(), o)) {
+ deleteEntry(e);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ public void clear() {
+ TreeMap.this.clear();
+ }
+ }
+
+ class EntrySet extends AbstractSet<Map.Entry<K,V>> {
+ public Iterator<Map.Entry<K,V>> iterator() {
+ return new EntryIterator(getFirstEntry());
+ }
+
+ public boolean contains(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<K,V> entry = (Map.Entry<K,V>) o;
+ V value = entry.getValue();
+ Entry<K,V> p = getEntry(entry.getKey());
+ return p != null && valEquals(p.getValue(), value);
+ }
+
+ public boolean remove(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<K,V> entry = (Map.Entry<K,V>) o;
+ V value = entry.getValue();
+ Entry<K,V> p = getEntry(entry.getKey());
+ if (p != null && valEquals(p.getValue(), value)) {
+ deleteEntry(p);
+ return true;
+ }
+ return false;
+ }
+
+ public int size() {
+ return TreeMap.this.size();
+ }
+
+ public void clear() {
+ TreeMap.this.clear();
+ }
+ }
+
+ /*
+ * Unlike Values and EntrySet, the KeySet class is static,
+ * delegating to a NavigableMap to allow use by SubMaps, which
+ * outweighs the ugliness of needing type-tests for the following
+ * Iterator methods that are defined appropriately in main versus
+ * submap classes.
+ */
+
+ Iterator<K> keyIterator() {
+ return new KeyIterator(getFirstEntry());
+ }
+
+ Iterator<K> descendingKeyIterator() {
+ return new DescendingKeyIterator(getFirstEntry());
+ }
+
+ static final class KeySet<E> extends AbstractSet<E> implements NavigableSet<E> {
+ private final NavigableMap<E, Object> m;
+ KeySet(NavigableMap<E,Object> map) { m = map; }
+
+ public Iterator<E> iterator() {
+ if (m instanceof TreeMap)
+ return ((TreeMap<E,Object>)m).keyIterator();
+ else
+ return (Iterator<E>)(((TreeMap.NavigableSubMap)m).keyIterator());
+ }
+
+ public Iterator<E> descendingIterator() {
+ if (m instanceof TreeMap)
+ return ((TreeMap<E,Object>)m).descendingKeyIterator();
+ else
+ return (Iterator<E>)(((TreeMap.NavigableSubMap)m).descendingKeyIterator());
+ }
+
+ public int size() { return m.size(); }
+ public boolean isEmpty() { return m.isEmpty(); }
+ public boolean contains(Object o) { return m.containsKey(o); }
+ public void clear() { m.clear(); }
+ public E lower(E e) { return m.lowerKey(e); }
+ public E floor(E e) { return m.floorKey(e); }
+ public E ceiling(E e) { return m.ceilingKey(e); }
+ public E higher(E e) { return m.higherKey(e); }
+ public E first() { return m.firstKey(); }
+ public E last() { return m.lastKey(); }
+ public Comparator<? super E> comparator() { return m.comparator(); }
+ public E pollFirst() {
+ Map.Entry<E,Object> e = m.pollFirstEntry();
+ return e == null? null : e.getKey();
+ }
+ public E pollLast() {
+ Map.Entry<E,Object> e = m.pollLastEntry();
+ return e == null? null : e.getKey();
+ }
+ public boolean remove(Object o) {
+ int oldSize = size();
+ m.remove(o);
+ return size() != oldSize;
+ }
+ public NavigableSet<E> subSet(E fromElement, boolean fromInclusive,
+ E toElement, boolean toInclusive) {
+ return new TreeSet<E>(m.subMap(fromElement, fromInclusive,
+ toElement, toInclusive));
+ }
+ public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+ return new TreeSet<E>(m.headMap(toElement, inclusive));
+ }
+ public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+ return new TreeSet<E>(m.tailMap(fromElement, inclusive));
+ }
+ public SortedSet<E> subSet(E fromElement, E toElement) {
+ return subSet(fromElement, true, toElement, false);
+ }
+ public SortedSet<E> headSet(E toElement) {
+ return headSet(toElement, false);
+ }
+ public SortedSet<E> tailSet(E fromElement) {
+ return tailSet(fromElement, true);
+ }
+ public NavigableSet<E> descendingSet() {
+ return new TreeSet(m.descendingMap());
+ }
+ }
+
+ /**
+ * Base class for TreeMap Iterators
+ */
+ abstract class PrivateEntryIterator<T> implements Iterator<T> {
+ Entry<K,V> next;
+ Entry<K,V> lastReturned;
+ int expectedModCount;
+
+ PrivateEntryIterator(Entry<K,V> first) {
+ expectedModCount = modCount;
+ lastReturned = null;
+ next = first;
+ }
+
+ public final boolean hasNext() {
+ return next != null;
+ }
+
+ final Entry<K,V> nextEntry() {
+ Entry<K,V> e = next;
+ if (e == null)
+ throw new NoSuchElementException();
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ next = successor(e);
+ lastReturned = e;
+ return e;
+ }
+
+ final Entry<K,V> prevEntry() {
+ Entry<K,V> e = next;
+ if (e == null)
+ throw new NoSuchElementException();
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ next = predecessor(e);
+ lastReturned = e;
+ return e;
+ }
+
+ public void remove() {
+ if (lastReturned == null)
+ throw new IllegalStateException();
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ // deleted entries are replaced by their successors
+ if (lastReturned.left != null && lastReturned.right != null)
+ next = lastReturned;
+ deleteEntry(lastReturned);
+ expectedModCount = modCount;
+ lastReturned = null;
+ }
+ }
+
+ final class EntryIterator extends PrivateEntryIterator<Map.Entry<K,V>> {
+ EntryIterator(Entry<K,V> first) {
+ super(first);
+ }
+ public Map.Entry<K,V> next() {
+ return nextEntry();
+ }
+ }
+
+ final class ValueIterator extends PrivateEntryIterator<V> {
+ ValueIterator(Entry<K,V> first) {
+ super(first);
+ }
+ public V next() {
+ return nextEntry().value;
+ }
+ }
+
+ final class KeyIterator extends PrivateEntryIterator<K> {
+ KeyIterator(Entry<K,V> first) {
+ super(first);
+ }
+ public K next() {
+ return nextEntry().key;
+ }
+ }
+
+ final class DescendingKeyIterator extends PrivateEntryIterator<K> {
+ DescendingKeyIterator(Entry<K,V> first) {
+ super(first);
+ }
+ public K next() {
+ return prevEntry().key;
+ }
+ }
+
+ // Little utilities
+
+ /**
+ * Compares two keys using the correct comparison method for this TreeMap.
+ */
+ final int compare(Object k1, Object k2) {
+ return comparator==null ? ((Comparable<? super K>)k1).compareTo((K)k2)
+ : comparator.compare((K)k1, (K)k2);
+ }
+
+ /**
+ * Test two values for equality. Differs from o1.equals(o2) only in
+ * that it copes with <tt>null</tt> o1 properly.
+ */
+ final static boolean valEquals(Object o1, Object o2) {
+ return (o1==null ? o2==null : o1.equals(o2));
+ }
+
+ /**
+ * Return SimpleImmutableEntry for entry, or null if null
+ */
+ static <K,V> Map.Entry<K,V> exportEntry(TreeMap.Entry<K,V> e) {
+ return e == null? null :
+ new AbstractMap.SimpleImmutableEntry<K,V>(e);
+ }
+
+ /**
+ * Return key for entry, or null if null
+ */
+ static <K,V> K keyOrNull(TreeMap.Entry<K,V> e) {
+ return e == null? null : e.key;
+ }
+
+ /**
+ * Returns the key corresponding to the specified Entry.
+ * @throws NoSuchElementException if the Entry is null
+ */
+ static <K> K key(Entry<K,?> e) {
+ if (e==null)
+ throw new NoSuchElementException();
+ return e.key;
+ }
+
+
+ // SubMaps
+
+ /**
+ * Dummy value serving as unmatchable fence key for unbounded
+ * SubMapIterators
+ */
+ private static final Object UNBOUNDED = new Object();
+
+ /**
+ * @serial include
+ */
+ static abstract class NavigableSubMap<K,V> extends AbstractMap<K,V>
+ implements NavigableMap<K,V>, java.io.Serializable {
+ /**
+ * The backing map.
+ */
+ final TreeMap<K,V> m;
+
+ /**
+ * Endpoints are represented as triples (fromStart, lo,
+ * loInclusive) and (toEnd, hi, hiInclusive). If fromStart is
+ * true, then the low (absolute) bound is the start of the
+ * backing map, and the other values are ignored. Otherwise,
+ * if loInclusive is true, lo is the inclusive bound, else lo
+ * is the exclusive bound. Similarly for the upper bound.
+ */
+ final K lo, hi;
+ final boolean fromStart, toEnd;
+ final boolean loInclusive, hiInclusive;
+
+ NavigableSubMap(TreeMap<K,V> m,
+ boolean fromStart, K lo, boolean loInclusive,
+ boolean toEnd, K hi, boolean hiInclusive) {
+ if (!fromStart && !toEnd) {
+ if (m.compare(lo, hi) > 0)
+ throw new IllegalArgumentException("fromKey > toKey");
+ } else {
+ if (!fromStart) // type check
+ m.compare(lo, lo);
+ if (!toEnd)
+ m.compare(hi, hi);
+ }
+
+ this.m = m;
+ this.fromStart = fromStart;
+ this.lo = lo;
+ this.loInclusive = loInclusive;
+ this.toEnd = toEnd;
+ this.hi = hi;
+ this.hiInclusive = hiInclusive;
+ }
+
+ // internal utilities
+
+ final boolean tooLow(Object key) {
+ if (!fromStart) {
+ int c = m.compare(key, lo);
+ if (c < 0 || (c == 0 && !loInclusive))
+ return true;
+ }
+ return false;
+ }
+
+ final boolean tooHigh(Object key) {
+ if (!toEnd) {
+ int c = m.compare(key, hi);
+ if (c > 0 || (c == 0 && !hiInclusive))
+ return true;
+ }
+ return false;
+ }
+
+ final boolean inRange(Object key) {
+ return !tooLow(key) && !tooHigh(key);
+ }
+
+ final boolean inClosedRange(Object key) {
+ return (fromStart || m.compare(key, lo) >= 0)
+ && (toEnd || m.compare(hi, key) >= 0);
+ }
+
+ final boolean inRange(Object key, boolean inclusive) {
+ return inclusive ? inRange(key) : inClosedRange(key);
+ }
+
+ /*
+ * Absolute versions of relation operations.
+ * Subclasses map to these using like-named "sub"
+ * versions that invert senses for descending maps
+ */
+
+ final TreeMap.Entry<K,V> absLowest() {
+ TreeMap.Entry<K,V> e =
+ (fromStart ? m.getFirstEntry() :
+ (loInclusive ? m.getCeilingEntry(lo) :
+ m.getHigherEntry(lo)));
+ return (e == null || tooHigh(e.key)) ? null : e;
+ }
+
+ final TreeMap.Entry<K,V> absHighest() {
+ TreeMap.Entry<K,V> e =
+ (toEnd ? m.getLastEntry() :
+ (hiInclusive ? m.getFloorEntry(hi) :
+ m.getLowerEntry(hi)));
+ return (e == null || tooLow(e.key)) ? null : e;
+ }
+
+ final TreeMap.Entry<K,V> absCeiling(K key) {
+ if (tooLow(key))
+ return absLowest();
+ TreeMap.Entry<K,V> e = m.getCeilingEntry(key);
+ return (e == null || tooHigh(e.key)) ? null : e;
+ }
+
+ final TreeMap.Entry<K,V> absHigher(K key) {
+ if (tooLow(key))
+ return absLowest();
+ TreeMap.Entry<K,V> e = m.getHigherEntry(key);
+ return (e == null || tooHigh(e.key)) ? null : e;
+ }
+
+ final TreeMap.Entry<K,V> absFloor(K key) {
+ if (tooHigh(key))
+ return absHighest();
+ TreeMap.Entry<K,V> e = m.getFloorEntry(key);
+ return (e == null || tooLow(e.key)) ? null : e;
+ }
+
+ final TreeMap.Entry<K,V> absLower(K key) {
+ if (tooHigh(key))
+ return absHighest();
+ TreeMap.Entry<K,V> e = m.getLowerEntry(key);
+ return (e == null || tooLow(e.key)) ? null : e;
+ }
+
+ /** Returns the absolute high fence for ascending traversal */
+ final TreeMap.Entry<K,V> absHighFence() {
+ return (toEnd ? null : (hiInclusive ?
+ m.getHigherEntry(hi) :
+ m.getCeilingEntry(hi)));
+ }
+
+ /** Return the absolute low fence for descending traversal */
+ final TreeMap.Entry<K,V> absLowFence() {
+ return (fromStart ? null : (loInclusive ?
+ m.getLowerEntry(lo) :
+ m.getFloorEntry(lo)));
+ }
+
+ // Abstract methods defined in ascending vs descending classes
+ // These relay to the appropriate absolute versions
+
+ abstract TreeMap.Entry<K,V> subLowest();
+ abstract TreeMap.Entry<K,V> subHighest();
+ abstract TreeMap.Entry<K,V> subCeiling(K key);
+ abstract TreeMap.Entry<K,V> subHigher(K key);
+ abstract TreeMap.Entry<K,V> subFloor(K key);
+ abstract TreeMap.Entry<K,V> subLower(K key);
+
+ /** Returns ascending iterator from the perspective of this submap */
+ abstract Iterator<K> keyIterator();
+
+ /** Returns descending iterator from the perspective of this submap */
+ abstract Iterator<K> descendingKeyIterator();
+
+ // public methods
+
+ public boolean isEmpty() {
+ return (fromStart && toEnd) ? m.isEmpty() : entrySet().isEmpty();
+ }
+
+ public int size() {
+ return (fromStart && toEnd) ? m.size() : entrySet().size();
+ }
+
+ public final boolean containsKey(Object key) {
+ return inRange(key) && m.containsKey(key);
+ }
+
+ public final V put(K key, V value) {
+ if (!inRange(key))
+ throw new IllegalArgumentException("key out of range");
+ return m.put(key, value);
+ }
+
+ public final V get(Object key) {
+ return !inRange(key)? null : m.get(key);
+ }
+
+ public final V remove(Object key) {
+ return !inRange(key)? null : m.remove(key);
+ }
+
+ public final Map.Entry<K,V> ceilingEntry(K key) {
+ return exportEntry(subCeiling(key));
+ }
+
+ public final K ceilingKey(K key) {
+ return keyOrNull(subCeiling(key));
+ }
+
+ public final Map.Entry<K,V> higherEntry(K key) {
+ return exportEntry(subHigher(key));
+ }
+
+ public final K higherKey(K key) {
+ return keyOrNull(subHigher(key));
+ }
+
+ public final Map.Entry<K,V> floorEntry(K key) {
+ return exportEntry(subFloor(key));
+ }
+
+ public final K floorKey(K key) {
+ return keyOrNull(subFloor(key));
+ }
+
+ public final Map.Entry<K,V> lowerEntry(K key) {
+ return exportEntry(subLower(key));
+ }
+
+ public final K lowerKey(K key) {
+ return keyOrNull(subLower(key));
+ }
+
+ public final K firstKey() {
+ return key(subLowest());
+ }
+
+ public final K lastKey() {
+ return key(subHighest());
+ }
+
+ public final Map.Entry<K,V> firstEntry() {
+ return exportEntry(subLowest());
+ }
+
+ public final Map.Entry<K,V> lastEntry() {
+ return exportEntry(subHighest());
+ }
+
+ public final Map.Entry<K,V> pollFirstEntry() {
+ TreeMap.Entry<K,V> e = subLowest();
+ Map.Entry<K,V> result = exportEntry(e);
+ if (e != null)
+ m.deleteEntry(e);
+ return result;
+ }
+
+ public final Map.Entry<K,V> pollLastEntry() {
+ TreeMap.Entry<K,V> e = subHighest();
+ Map.Entry<K,V> result = exportEntry(e);
+ if (e != null)
+ m.deleteEntry(e);
+ return result;
+ }
+
+ // Views
+ transient NavigableMap<K,V> descendingMapView = null;
+ transient EntrySetView entrySetView = null;
+ transient KeySet<K> navigableKeySetView = null;
+
+ public final NavigableSet<K> navigableKeySet() {
+ KeySet<K> nksv = navigableKeySetView;
+ return (nksv != null) ? nksv :
+ (navigableKeySetView = new TreeMap.KeySet(this));
+ }
+
+ public final Set<K> keySet() {
+ return navigableKeySet();
+ }
+
+ public NavigableSet<K> descendingKeySet() {
+ return descendingMap().navigableKeySet();
+ }
+
+ public final SortedMap<K,V> subMap(K fromKey, K toKey) {
+ return subMap(fromKey, true, toKey, false);
+ }
+
+ public final SortedMap<K,V> headMap(K toKey) {
+ return headMap(toKey, false);
+ }
+
+ public final SortedMap<K,V> tailMap(K fromKey) {
+ return tailMap(fromKey, true);
+ }
+
+ // View classes
+
+ abstract class EntrySetView extends AbstractSet<Map.Entry<K,V>> {
+ private transient int size = -1, sizeModCount;
+
+ public int size() {
+ if (fromStart && toEnd)
+ return m.size();
+ if (size == -1 || sizeModCount != m.modCount) {
+ sizeModCount = m.modCount;
+ size = 0;
+ Iterator i = iterator();
+ while (i.hasNext()) {
+ size++;
+ i.next();
+ }
+ }
+ return size;
+ }
+
+ public boolean isEmpty() {
+ TreeMap.Entry<K,V> n = absLowest();
+ return n == null || tooHigh(n.key);
+ }
+
+ public boolean contains(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<K,V> entry = (Map.Entry<K,V>) o;
+ K key = entry.getKey();
+ if (!inRange(key))
+ return false;
+ TreeMap.Entry node = m.getEntry(key);
+ return node != null &&
+ valEquals(node.getValue(), entry.getValue());
+ }
+
+ public boolean remove(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<K,V> entry = (Map.Entry<K,V>) o;
+ K key = entry.getKey();
+ if (!inRange(key))
+ return false;
+ TreeMap.Entry<K,V> node = m.getEntry(key);
+ if (node!=null && valEquals(node.getValue(),entry.getValue())){
+ m.deleteEntry(node);
+ return true;
+ }
+ return false;
+ }
+ }
+
+ /**
+ * Iterators for SubMaps
+ */
+ abstract class SubMapIterator<T> implements Iterator<T> {
+ TreeMap.Entry<K,V> lastReturned;
+ TreeMap.Entry<K,V> next;
+ final Object fenceKey;
+ int expectedModCount;
+
+ SubMapIterator(TreeMap.Entry<K,V> first,
+ TreeMap.Entry<K,V> fence) {
+ expectedModCount = m.modCount;
+ lastReturned = null;
+ next = first;
+ fenceKey = fence == null ? UNBOUNDED : fence.key;
+ }
+
+ public final boolean hasNext() {
+ return next != null && next.key != fenceKey;
+ }
+
+ final TreeMap.Entry<K,V> nextEntry() {
+ TreeMap.Entry<K,V> e = next;
+ if (e == null || e.key == fenceKey)
+ throw new NoSuchElementException();
+ if (m.modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ next = successor(e);
+ lastReturned = e;
+ return e;
+ }
+
+ final TreeMap.Entry<K,V> prevEntry() {
+ TreeMap.Entry<K,V> e = next;
+ if (e == null || e.key == fenceKey)
+ throw new NoSuchElementException();
+ if (m.modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ next = predecessor(e);
+ lastReturned = e;
+ return e;
+ }
+
+ final void removeAscending() {
+ if (lastReturned == null)
+ throw new IllegalStateException();
+ if (m.modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ // deleted entries are replaced by their successors
+ if (lastReturned.left != null && lastReturned.right != null)
+ next = lastReturned;
+ m.deleteEntry(lastReturned);
+ lastReturned = null;
+ expectedModCount = m.modCount;
+ }
+
+ final void removeDescending() {
+ if (lastReturned == null)
+ throw new IllegalStateException();
+ if (m.modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ m.deleteEntry(lastReturned);
+ lastReturned = null;
+ expectedModCount = m.modCount;
+ }
+
+ }
+
+ final class SubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> {
+ SubMapEntryIterator(TreeMap.Entry<K,V> first,
+ TreeMap.Entry<K,V> fence) {
+ super(first, fence);
+ }
+ public Map.Entry<K,V> next() {
+ return nextEntry();
+ }
+ public void remove() {
+ removeAscending();
+ }
+ }
+
+ final class SubMapKeyIterator extends SubMapIterator<K> {
+ SubMapKeyIterator(TreeMap.Entry<K,V> first,
+ TreeMap.Entry<K,V> fence) {
+ super(first, fence);
+ }
+ public K next() {
+ return nextEntry().key;
+ }
+ public void remove() {
+ removeAscending();
+ }
+ }
+
+ final class DescendingSubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> {
+ DescendingSubMapEntryIterator(TreeMap.Entry<K,V> last,
+ TreeMap.Entry<K,V> fence) {
+ super(last, fence);
+ }
+
+ public Map.Entry<K,V> next() {
+ return prevEntry();
+ }
+ public void remove() {
+ removeDescending();
+ }
+ }
+
+ final class DescendingSubMapKeyIterator extends SubMapIterator<K> {
+ DescendingSubMapKeyIterator(TreeMap.Entry<K,V> last,
+ TreeMap.Entry<K,V> fence) {
+ super(last, fence);
+ }
+ public K next() {
+ return prevEntry().key;
+ }
+ public void remove() {
+ removeDescending();
+ }
+ }
+ }
+
+ /**
+ * @serial include
+ */
+ static final class AscendingSubMap<K,V> extends NavigableSubMap<K,V> {
+ private static final long serialVersionUID = 912986545866124060L;
+
+ AscendingSubMap(TreeMap<K,V> m,
+ boolean fromStart, K lo, boolean loInclusive,
+ boolean toEnd, K hi, boolean hiInclusive) {
+ super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive);
+ }
+
+ public Comparator<? super K> comparator() {
+ return m.comparator();
+ }
+
+ public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
+ K toKey, boolean toInclusive) {
+ if (!inRange(fromKey, fromInclusive))
+ throw new IllegalArgumentException("fromKey out of range");
+ if (!inRange(toKey, toInclusive))
+ throw new IllegalArgumentException("toKey out of range");
+ return new AscendingSubMap(m,
+ false, fromKey, fromInclusive,
+ false, toKey, toInclusive);
+ }
+
+ public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
+ if (!inRange(toKey, inclusive))
+ throw new IllegalArgumentException("toKey out of range");
+ return new AscendingSubMap(m,
+ fromStart, lo, loInclusive,
+ false, toKey, inclusive);
+ }
+
+ public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive){
+ if (!inRange(fromKey, inclusive))
+ throw new IllegalArgumentException("fromKey out of range");
+ return new AscendingSubMap(m,
+ false, fromKey, inclusive,
+ toEnd, hi, hiInclusive);
+ }
+
+ public NavigableMap<K,V> descendingMap() {
+ NavigableMap<K,V> mv = descendingMapView;
+ return (mv != null) ? mv :
+ (descendingMapView =
+ new DescendingSubMap(m,
+ fromStart, lo, loInclusive,
+ toEnd, hi, hiInclusive));
+ }
+
+ Iterator<K> keyIterator() {
+ return new SubMapKeyIterator(absLowest(), absHighFence());
+ }
+
+ Iterator<K> descendingKeyIterator() {
+ return new DescendingSubMapKeyIterator(absHighest(), absLowFence());
+ }
+
+ final class AscendingEntrySetView extends EntrySetView {
+ public Iterator<Map.Entry<K,V>> iterator() {
+ return new SubMapEntryIterator(absLowest(), absHighFence());
+ }
+ }
+
+ public Set<Map.Entry<K,V>> entrySet() {
+ EntrySetView es = entrySetView;
+ return (es != null) ? es : new AscendingEntrySetView();
+ }
+
+ TreeMap.Entry<K,V> subLowest() { return absLowest(); }
+ TreeMap.Entry<K,V> subHighest() { return absHighest(); }
+ TreeMap.Entry<K,V> subCeiling(K key) { return absCeiling(key); }
+ TreeMap.Entry<K,V> subHigher(K key) { return absHigher(key); }
+ TreeMap.Entry<K,V> subFloor(K key) { return absFloor(key); }
+ TreeMap.Entry<K,V> subLower(K key) { return absLower(key); }
+ }
+
+ /**
+ * @serial include
+ */
+ static final class DescendingSubMap<K,V> extends NavigableSubMap<K,V> {
+ private static final long serialVersionUID = 912986545866120460L;
+ DescendingSubMap(TreeMap<K,V> m,
+ boolean fromStart, K lo, boolean loInclusive,
+ boolean toEnd, K hi, boolean hiInclusive) {
+ super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive);
+ }
+
+ private final Comparator<? super K> reverseComparator =
+ Collections.reverseOrder(m.comparator);
+
+ public Comparator<? super K> comparator() {
+ return reverseComparator;
+ }
+
+ public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
+ K toKey, boolean toInclusive) {
+ if (!inRange(fromKey, fromInclusive))
+ throw new IllegalArgumentException("fromKey out of range");
+ if (!inRange(toKey, toInclusive))
+ throw new IllegalArgumentException("toKey out of range");
+ return new DescendingSubMap(m,
+ false, toKey, toInclusive,
+ false, fromKey, fromInclusive);
+ }
+
+ public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
+ if (!inRange(toKey, inclusive))
+ throw new IllegalArgumentException("toKey out of range");
+ return new DescendingSubMap(m,
+ false, toKey, inclusive,
+ toEnd, hi, hiInclusive);
+ }
+
+ public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive){
+ if (!inRange(fromKey, inclusive))
+ throw new IllegalArgumentException("fromKey out of range");
+ return new DescendingSubMap(m,
+ fromStart, lo, loInclusive,
+ false, fromKey, inclusive);
+ }
+
+ public NavigableMap<K,V> descendingMap() {
+ NavigableMap<K,V> mv = descendingMapView;
+ return (mv != null) ? mv :
+ (descendingMapView =
+ new AscendingSubMap(m,
+ fromStart, lo, loInclusive,
+ toEnd, hi, hiInclusive));
+ }
+
+ Iterator<K> keyIterator() {
+ return new DescendingSubMapKeyIterator(absHighest(), absLowFence());
+ }
+
+ Iterator<K> descendingKeyIterator() {
+ return new SubMapKeyIterator(absLowest(), absHighFence());
+ }
+
+ final class DescendingEntrySetView extends EntrySetView {
+ public Iterator<Map.Entry<K,V>> iterator() {
+ return new DescendingSubMapEntryIterator(absHighest(), absLowFence());
+ }
+ }
+
+ public Set<Map.Entry<K,V>> entrySet() {
+ EntrySetView es = entrySetView;
+ return (es != null) ? es : new DescendingEntrySetView();
+ }
+
+ TreeMap.Entry<K,V> subLowest() { return absHighest(); }
+ TreeMap.Entry<K,V> subHighest() { return absLowest(); }
+ TreeMap.Entry<K,V> subCeiling(K key) { return absFloor(key); }
+ TreeMap.Entry<K,V> subHigher(K key) { return absLower(key); }
+ TreeMap.Entry<K,V> subFloor(K key) { return absCeiling(key); }
+ TreeMap.Entry<K,V> subLower(K key) { return absHigher(key); }
+ }
+
+ /**
+ * This class exists solely for the sake of serialization
+ * compatibility with previous releases of TreeMap that did not
+ * support NavigableMap. It translates an old-version SubMap into
+ * a new-version AscendingSubMap. This class is never otherwise
+ * used.
+ *
+ * @serial include
+ */
+ private class SubMap extends AbstractMap<K,V>
+ implements SortedMap<K,V>, java.io.Serializable {
+ private static final long serialVersionUID = -6520786458950516097L;
+ private boolean fromStart = false, toEnd = false;
+ private K fromKey, toKey;
+ private Object readResolve() {
+ return new AscendingSubMap(TreeMap.this,
+ fromStart, fromKey, true,
+ toEnd, toKey, false);
+ }
+ public Set<Map.Entry<K,V>> entrySet() { throw new InternalError(); }
+ public K lastKey() { throw new InternalError(); }
+ public K firstKey() { throw new InternalError(); }
+ public SortedMap<K,V> subMap(K fromKey, K toKey) { throw new InternalError(); }
+ public SortedMap<K,V> headMap(K toKey) { throw new InternalError(); }
+ public SortedMap<K,V> tailMap(K fromKey) { throw new InternalError(); }
+ public Comparator<? super K> comparator() { throw new InternalError(); }
+ }
+
+
+ // Red-black mechanics
+
+ private static final boolean RED = false;
+ private static final boolean BLACK = true;
+
+ /**
+ * Node in the Tree. Doubles as a means to pass key-value pairs back to
+ * user (see Map.Entry).
+ */
+
+ static final class Entry<K,V> implements Map.Entry<K,V> {
+ K key;
+ V value;
+ Entry<K,V> left = null;
+ Entry<K,V> right = null;
+ Entry<K,V> parent;
+ boolean color = BLACK;
+
+ /**
+ * Make a new cell with given key, value, and parent, and with
+ * <tt>null</tt> child links, and BLACK color.
+ */
+ Entry(K key, V value, Entry<K,V> parent) {
+ this.key = key;
+ this.value = value;
+ this.parent = parent;
+ }
+
+ /**
+ * Returns the key.
+ *
+ * @return the key
+ */
+ public K getKey() {
+ return key;
+ }
+
+ /**
+ * Returns the value associated with the key.
+ *
+ * @return the value associated with the key
+ */
+ public V getValue() {
+ return value;
+ }
+
+ /**
+ * Replaces the value currently associated with the key with the given
+ * value.
+ *
+ * @return the value associated with the key before this method was
+ * called
+ */
+ public V setValue(V value) {
+ V oldValue = this.value;
+ this.value = value;
+ return oldValue;
+ }
+
+ public boolean equals(Object o) {
+ if (!(o instanceof Map.Entry))
+ return false;
+ Map.Entry<?,?> e = (Map.Entry<?,?>)o;
+
+ return valEquals(key,e.getKey()) && valEquals(value,e.getValue());
+ }
+
+ public int hashCode() {
+ int keyHash = (key==null ? 0 : key.hashCode());
+ int valueHash = (value==null ? 0 : value.hashCode());
+ return keyHash ^ valueHash;
+ }
+
+ public String toString() {
+ return key + "=" + value;
+ }
+ }
+
+ /**
+ * Returns the first Entry in the TreeMap (according to the TreeMap's
+ * key-sort function). Returns null if the TreeMap is empty.
+ */
+ final Entry<K,V> getFirstEntry() {
+ Entry<K,V> p = root;
+ if (p != null)
+ while (p.left != null)
+ p = p.left;
+ return p;
+ }
+
+ /**
+ * Returns the last Entry in the TreeMap (according to the TreeMap's
+ * key-sort function). Returns null if the TreeMap is empty.
+ */
+ final Entry<K,V> getLastEntry() {
+ Entry<K,V> p = root;
+ if (p != null)
+ while (p.right != null)
+ p = p.right;
+ return p;
+ }
+
+ /**
+ * Returns the successor of the specified Entry, or null if no such.
+ */
+ static <K,V> TreeMap.Entry<K,V> successor(Entry<K,V> t) {
+ if (t == null)
+ return null;
+ else if (t.right != null) {
+ Entry<K,V> p = t.right;
+ while (p.left != null)
+ p = p.left;
+ return p;
+ } else {
+ Entry<K,V> p = t.parent;
+ Entry<K,V> ch = t;
+ while (p != null && ch == p.right) {
+ ch = p;
+ p = p.parent;
+ }
+ return p;
+ }
+ }
+
+ /**
+ * Returns the predecessor of the specified Entry, or null if no such.
+ */
+ static <K,V> Entry<K,V> predecessor(Entry<K,V> t) {
+ if (t == null)
+ return null;
+ else if (t.left != null) {
+ Entry<K,V> p = t.left;
+ while (p.right != null)
+ p = p.right;
+ return p;
+ } else {
+ Entry<K,V> p = t.parent;
+ Entry<K,V> ch = t;
+ while (p != null && ch == p.left) {
+ ch = p;
+ p = p.parent;
+ }
+ return p;
+ }
+ }
+
+ /**
+ * Balancing operations.
+ *
+ * Implementations of rebalancings during insertion and deletion are
+ * slightly different than the CLR version. Rather than using dummy
+ * nilnodes, we use a set of accessors that deal properly with null. They
+ * are used to avoid messiness surrounding nullness checks in the main
+ * algorithms.
+ */
+
+ private static <K,V> boolean colorOf(Entry<K,V> p) {
+ return (p == null ? BLACK : p.color);
+ }
+
+ private static <K,V> Entry<K,V> parentOf(Entry<K,V> p) {
+ return (p == null ? null: p.parent);
+ }
+
+ private static <K,V> void setColor(Entry<K,V> p, boolean c) {
+ if (p != null)
+ p.color = c;
+ }
+
+ private static <K,V> Entry<K,V> leftOf(Entry<K,V> p) {
+ return (p == null) ? null: p.left;
+ }
+
+ private static <K,V> Entry<K,V> rightOf(Entry<K,V> p) {
+ return (p == null) ? null: p.right;
+ }
+
+ /** From CLR */
+ private void rotateLeft(Entry<K,V> p) {
+ if (p != null) {
+ Entry<K,V> r = p.right;
+ p.right = r.left;
+ if (r.left != null)
+ r.left.parent = p;
+ r.parent = p.parent;
+ if (p.parent == null)
+ root = r;
+ else if (p.parent.left == p)
+ p.parent.left = r;
+ else
+ p.parent.right = r;
+ r.left = p;
+ p.parent = r;
+ }
+ }
+
+ /** From CLR */
+ private void rotateRight(Entry<K,V> p) {
+ if (p != null) {
+ Entry<K,V> l = p.left;
+ p.left = l.right;
+ if (l.right != null) l.right.parent = p;
+ l.parent = p.parent;
+ if (p.parent == null)
+ root = l;
+ else if (p.parent.right == p)
+ p.parent.right = l;
+ else p.parent.left = l;
+ l.right = p;
+ p.parent = l;
+ }
+ }
+
+ /** From CLR */
+ private void fixAfterInsertion(Entry<K,V> x) {
+ x.color = RED;
+
+ while (x != null && x != root && x.parent.color == RED) {
+ if (parentOf(x) == leftOf(parentOf(parentOf(x)))) {
+ Entry<K,V> y = rightOf(parentOf(parentOf(x)));
+ if (colorOf(y) == RED) {
+ setColor(parentOf(x), BLACK);
+ setColor(y, BLACK);
+ setColor(parentOf(parentOf(x)), RED);
+ x = parentOf(parentOf(x));
+ } else {
+ if (x == rightOf(parentOf(x))) {
+ x = parentOf(x);
+ rotateLeft(x);
+ }
+ setColor(parentOf(x), BLACK);
+ setColor(parentOf(parentOf(x)), RED);
+ rotateRight(parentOf(parentOf(x)));
+ }
+ } else {
+ Entry<K,V> y = leftOf(parentOf(parentOf(x)));
+ if (colorOf(y) == RED) {
+ setColor(parentOf(x), BLACK);
+ setColor(y, BLACK);
+ setColor(parentOf(parentOf(x)), RED);
+ x = parentOf(parentOf(x));
+ } else {
+ if (x == leftOf(parentOf(x))) {
+ x = parentOf(x);
+ rotateRight(x);
+ }
+ setColor(parentOf(x), BLACK);
+ setColor(parentOf(parentOf(x)), RED);
+ rotateLeft(parentOf(parentOf(x)));
+ }
+ }
+ }
+ root.color = BLACK;
+ }
+
+ /**
+ * Delete node p, and then rebalance the tree.
+ */
+ private void deleteEntry(Entry<K,V> p) {
+ modCount++;
+ size--;
+
+ // If strictly internal, copy successor's element to p and then make p
+ // point to successor.
+ if (p.left != null && p.right != null) {
+ Entry<K,V> s = successor (p);
+ p.key = s.key;
+ p.value = s.value;
+ p = s;
+ } // p has 2 children
+
+ // Start fixup at replacement node, if it exists.
+ Entry<K,V> replacement = (p.left != null ? p.left : p.right);
+
+ if (replacement != null) {
+ // Link replacement to parent
+ replacement.parent = p.parent;
+ if (p.parent == null)
+ root = replacement;
+ else if (p == p.parent.left)
+ p.parent.left = replacement;
+ else
+ p.parent.right = replacement;
+
+ // Null out links so they are OK to use by fixAfterDeletion.
+ p.left = p.right = p.parent = null;
+
+ // Fix replacement
+ if (p.color == BLACK)
+ fixAfterDeletion(replacement);
+ } else if (p.parent == null) { // return if we are the only node.
+ root = null;
+ } else { // No children. Use self as phantom replacement and unlink.
+ if (p.color == BLACK)
+ fixAfterDeletion(p);
+
+ if (p.parent != null) {
+ if (p == p.parent.left)
+ p.parent.left = null;
+ else if (p == p.parent.right)
+ p.parent.right = null;
+ p.parent = null;
+ }
+ }
+ }
+
+ /** From CLR */
+ private void fixAfterDeletion(Entry<K,V> x) {
+ while (x != root && colorOf(x) == BLACK) {
+ if (x == leftOf(parentOf(x))) {
+ Entry<K,V> sib = rightOf(parentOf(x));
+
+ if (colorOf(sib) == RED) {
+ setColor(sib, BLACK);
+ setColor(parentOf(x), RED);
+ rotateLeft(parentOf(x));
+ sib = rightOf(parentOf(x));
+ }
+
+ if (colorOf(leftOf(sib)) == BLACK &&
+ colorOf(rightOf(sib)) == BLACK) {
+ setColor(sib, RED);
+ x = parentOf(x);
+ } else {
+ if (colorOf(rightOf(sib)) == BLACK) {
+ setColor(leftOf(sib), BLACK);
+ setColor(sib, RED);
+ rotateRight(sib);
+ sib = rightOf(parentOf(x));
+ }
+ setColor(sib, colorOf(parentOf(x)));
+ setColor(parentOf(x), BLACK);
+ setColor(rightOf(sib), BLACK);
+ rotateLeft(parentOf(x));
+ x = root;
+ }
+ } else { // symmetric
+ Entry<K,V> sib = leftOf(parentOf(x));
+
+ if (colorOf(sib) == RED) {
+ setColor(sib, BLACK);
+ setColor(parentOf(x), RED);
+ rotateRight(parentOf(x));
+ sib = leftOf(parentOf(x));
+ }
+
+ if (colorOf(rightOf(sib)) == BLACK &&
+ colorOf(leftOf(sib)) == BLACK) {
+ setColor(sib, RED);
+ x = parentOf(x);
+ } else {
+ if (colorOf(leftOf(sib)) == BLACK) {
+ setColor(rightOf(sib), BLACK);
+ setColor(sib, RED);
+ rotateLeft(sib);
+ sib = leftOf(parentOf(x));
+ }
+ setColor(sib, colorOf(parentOf(x)));
+ setColor(parentOf(x), BLACK);
+ setColor(leftOf(sib), BLACK);
+ rotateRight(parentOf(x));
+ x = root;
+ }
+ }
+ }
+
+ setColor(x, BLACK);
+ }
+
+ private static final long serialVersionUID = 919286545866124006L;
+
+ /**
+ * Save the state of the <tt>TreeMap</tt> instance to a stream (i.e.,
+ * serialize it).
+ *
+ * @serialData The <i>size</i> of the TreeMap (the number of key-value
+ * mappings) is emitted (int), followed by the key (Object)
+ * and value (Object) for each key-value mapping represented
+ * by the TreeMap. The key-value mappings are emitted in
+ * key-order (as determined by the TreeMap's Comparator,
+ * or by the keys' natural ordering if the TreeMap has no
+ * Comparator).
+ */
+ private void writeObject(java.io.ObjectOutputStream s)
+ throws java.io.IOException {
+ // Write out the Comparator and any hidden stuff
+ s.defaultWriteObject();
+
+ // Write out size (number of Mappings)
+ s.writeInt(size);
+
+ // Write out keys and values (alternating)
+ for (Iterator<Map.Entry<K,V>> i = entrySet().iterator(); i.hasNext(); ) {
+ Map.Entry<K,V> e = i.next();
+ s.writeObject(e.getKey());
+ s.writeObject(e.getValue());
+ }
+ }
+
+ /**
+ * Reconstitute the <tt>TreeMap</tt> instance from a stream (i.e.,
+ * deserialize it).
+ */
+ private void readObject(final java.io.ObjectInputStream s)
+ throws java.io.IOException, ClassNotFoundException {
+ // Read in the Comparator and any hidden stuff
+ s.defaultReadObject();
+
+ // Read in size
+ int size = s.readInt();
+
+ buildFromSorted(size, null, s, null);
+ }
+
+ /** Intended to be called only from TreeSet.readObject */
+ void readTreeSet(int size, java.io.ObjectInputStream s, V defaultVal)
+ throws java.io.IOException, ClassNotFoundException {
+ buildFromSorted(size, null, s, defaultVal);
+ }
+
+ /** Intended to be called only from TreeSet.addAll */
+ void addAllForTreeSet(SortedSet<? extends K> set, V defaultVal) {
+ try {
+ buildFromSorted(set.size(), set.iterator(), null, defaultVal);
+ } catch (java.io.IOException cannotHappen) {
+ } catch (ClassNotFoundException cannotHappen) {
+ }
+ }
+
+
+ /**
+ * Linear time tree building algorithm from sorted data. Can accept keys
+ * and/or values from iterator or stream. This leads to too many
+ * parameters, but seems better than alternatives. The four formats
+ * that this method accepts are:
+ *
+ * 1) An iterator of Map.Entries. (it != null, defaultVal == null).
+ * 2) An iterator of keys. (it != null, defaultVal != null).
+ * 3) A stream of alternating serialized keys and values.
+ * (it == null, defaultVal == null).
+ * 4) A stream of serialized keys. (it == null, defaultVal != null).
+ *
+ * It is assumed that the comparator of the TreeMap is already set prior
+ * to calling this method.
+ *
+ * @param size the number of keys (or key-value pairs) to be read from
+ * the iterator or stream
+ * @param it If non-null, new entries are created from entries
+ * or keys read from this iterator.
+ * @param str If non-null, new entries are created from keys and
+ * possibly values read from this stream in serialized form.
+ * Exactly one of it and str should be non-null.
+ * @param defaultVal if non-null, this default value is used for
+ * each value in the map. If null, each value is read from
+ * iterator or stream, as described above.
+ * @throws IOException propagated from stream reads. This cannot
+ * occur if str is null.
+ * @throws ClassNotFoundException propagated from readObject.
+ * This cannot occur if str is null.
+ */
+ private void buildFromSorted(int size, Iterator it,
+ java.io.ObjectInputStream str,
+ V defaultVal)
+ throws java.io.IOException, ClassNotFoundException {
+ this.size = size;
+ root = buildFromSorted(0, 0, size-1, computeRedLevel(size),
+ it, str, defaultVal);
+ }
+
+ /**
+ * Recursive "helper method" that does the real work of the
+ * previous method. Identically named parameters have
+ * identical definitions. Additional parameters are documented below.
+ * It is assumed that the comparator and size fields of the TreeMap are
+ * already set prior to calling this method. (It ignores both fields.)
+ *
+ * @param level the current level of tree. Initial call should be 0.
+ * @param lo the first element index of this subtree. Initial should be 0.
+ * @param hi the last element index of this subtree. Initial should be
+ * size-1.
+ * @param redLevel the level at which nodes should be red.
+ * Must be equal to computeRedLevel for tree of this size.
+ */
+ private final Entry<K,V> buildFromSorted(int level, int lo, int hi,
+ int redLevel,
+ Iterator it,
+ java.io.ObjectInputStream str,
+ V defaultVal)
+ throws java.io.IOException, ClassNotFoundException {
+ /*
+ * Strategy: The root is the middlemost element. To get to it, we
+ * have to first recursively construct the entire left subtree,
+ * so as to grab all of its elements. We can then proceed with right
+ * subtree.
+ *
+ * The lo and hi arguments are the minimum and maximum
+ * indices to pull out of the iterator or stream for current subtree.
+ * They are not actually indexed, we just proceed sequentially,
+ * ensuring that items are extracted in corresponding order.
+ */
+
+ if (hi < lo) return null;
+
+ int mid = (lo + hi) >>> 1;
+
+ Entry<K,V> left = null;
+ if (lo < mid)
+ left = buildFromSorted(level+1, lo, mid - 1, redLevel,
+ it, str, defaultVal);
+
+ // extract key and/or value from iterator or stream
+ K key;
+ V value;
+ if (it != null) {
+ if (defaultVal==null) {
+ Map.Entry<K,V> entry = (Map.Entry<K,V>)it.next();
+ key = entry.getKey();
+ value = entry.getValue();
+ } else {
+ key = (K)it.next();
+ value = defaultVal;
+ }
+ } else { // use stream
+ key = (K) str.readObject();
+ value = (defaultVal != null ? defaultVal : (V) str.readObject());
+ }
+
+ Entry<K,V> middle = new Entry<K,V>(key, value, null);
+
+ // color nodes in non-full bottommost level red
+ if (level == redLevel)
+ middle.color = RED;
+
+ if (left != null) {
+ middle.left = left;
+ left.parent = middle;
+ }
+
+ if (mid < hi) {
+ Entry<K,V> right = buildFromSorted(level+1, mid+1, hi, redLevel,
+ it, str, defaultVal);
+ middle.right = right;
+ right.parent = middle;
+ }
+
+ return middle;
+ }
+
+ /**
+ * Find the level down to which to assign all nodes BLACK. This is the
+ * last `full' level of the complete binary tree produced by
+ * buildTree. The remaining nodes are colored RED. (This makes a `nice'
+ * set of color assignments wrt future insertions.) This level number is
+ * computed by finding the number of splits needed to reach the zeroeth
+ * node. (The answer is ~lg(N), but in any case must be computed by same
+ * quick O(lg(N)) loop.)
+ */
+ private static int computeRedLevel(int sz) {
+ int level = 0;
+ for (int m = sz - 1; m >= 0; m = m / 2 - 1)
+ level++;
+ return level;
+ }
+}