/*
* 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
* @version 1.73, 05/10/06
* @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;
}
}
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