/*
* %W% %E%
*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.util;
import java.util.*; // for javadoc (till 6280605 is fixed)
/**
* 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.
*
* This implementation provides guaranteed log(n) time cost for the
* containsKey, get, put and remove
* operations. Algorithms are adaptations of those in Cormen, Leiserson, and
* Rivest's Introduction to Algorithms.
*
*
Note that the ordering maintained by a sorted map (whether or not an
* explicit comparator is provided) must be consistent with equals if
* this sorted map is to correctly implement the Map interface. (See
* Comparable or Comparator for a precise definition of
* consistent with equals.) This is so because the Map
* interface is defined in terms of the equals operation, but a map performs
* all key comparisons using its compareTo (or compare)
* 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
* is well-defined even if its ordering is inconsistent with equals; it
* just fails to obey the general contract of the Map interface.
*
*
Note that this implementation is not synchronized.
* If multiple threads access a map concurrently, and at least one of the
* threads modifies the map structurally, it must 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:
* SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));
*
* The iterators returned by the iterator method of the collections
* returned by all of this class's "collection view methods" are
* fail-fast: if the map is structurally modified at any time after the
* iterator is created, in any way except through the iterator's own
* remove 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.
*
*
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 ConcurrentModificationException on a best-effort basis.
* Therefore, it would be wrong to write a program that depended on this
* exception for its correctness: the fail-fast behavior of iterators
* should be used only to detect bugs.
*
*
All Map.Entry pairs returned by methods in this class
* and its views represent snapshots of mappings at the time they were
* produced. They do not support the Entry.setValue
* method. (Note however that it is possible to change mappings in the
* associated map using put.)
*
*
This class is a member of the
*
* Java Collections Framework.
*
* @param the type of keys maintained by this map
* @param the type of mapped values
*
* @author Josh Bloch and Doug Lea
* @version %I%, %G%
* @see Map
* @see HashMap
* @see Hashtable
* @see Comparable
* @see Comparator
* @see Collection
* @since 1.2
*/
public class TreeMap
extends AbstractMap
implements NavigableMap, 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 Comparator comparator = null;
private transient Entry 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;
private void incrementSize() { modCount++; size++; }
private void decrementSize() { modCount++; size--; }
/**
* 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
* mutually comparable: k1.compareTo(k2) must not throw
* a ClassCastException for any keys k1 and
* k2 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
* put(Object key, Object value) call will throw a
* ClassCastException.
*/
public TreeMap() {
}
/**
* Constructs a new, empty tree map, ordered according to the given
* comparator. All keys inserted into the map must be mutually
* comparable by the given comparator: comparator.compare(k1,
* k2) must not throw a ClassCastException for any keys
* k1 and k2 in the map. If the user attempts to put
* a key into the map that violates this constraint, the put(Object
* key, Object value) call will throw a
* ClassCastException.
*
* @param comparator the comparator that will be used to order this map.
* If null, the {@linkplain Comparable natural
* ordering} of the keys will be used.
*/
public TreeMap(Comparator comparator) {
this.comparator = comparator;
}
/**
* Constructs a new tree map containing the same mappings as the given
* map, ordered according to the natural ordering of its keys.
* All keys inserted into the new map must implement the {@link
* Comparable} interface. Furthermore, all such keys must be
* mutually comparable: k1.compareTo(k2) must not throw
* a ClassCastException for any keys k1 and
* k2 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 m) {
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 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 true if this map contains a mapping for the specified
* key.
*
* @param key key whose presence in this map is to be tested
* @return true 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 true if this map maps one or more keys to the
* specified value. More formally, returns true if and only if
* this map contains at least one mapping to a value v such
* that (value==null ? v==null : value.equals(v)). 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 true if a mapping to value exists;
* false otherwise
* @since 1.2
*/
public boolean containsValue(Object value) {
return (root==null ? false :
(value==null ? valueSearchNull(root)
: valueSearchNonNull(root, value)));
}
private boolean valueSearchNull(Entry n) {
if (n.value == null)
return true;
// Check left and right subtrees for value
return (n.left != null && valueSearchNull(n.left)) ||
(n.right != null && valueSearchNull(n.right));
}
private boolean valueSearchNonNull(Entry n, Object value) {
// Check this node for the value
if (value.equals(n.value))
return true;
// Check left and right subtrees for value
return (n.left != null && valueSearchNonNull(n.left, value)) ||
(n.right != null && valueSearchNonNull(n.right, value));
}
/**
* Returns the value to which the specified key is mapped,
* or {@code null} if this map contains no mapping for the key.
*
* 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.)
*
*
A return value of {@code null} does not necessarily
* 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 p = getEntry(key);
return (p==null ? null : p.value);
}
public Comparator 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 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 null if the map
* does not contain an entry for the key.
*
* @return this map's entry for the given key, or null 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
*/
private Entry getEntry(Object key) {
// Offload comparator-based version for sake of performance
if (comparator != null)
return getEntryUsingComparator(key);
Comparable k = (Comparable) key;
Entry 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.)
*/
private Entry getEntryUsingComparator(Object key) {
K k = (K) key;
Comparator cpr = comparator;
Entry 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 null.
*/
private Entry getCeilingEntry(K key) {
Entry p = root;
if (p==null)
return null;
while (true) {
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 parent = p.parent;
Entry ch = p;
while (parent != null && ch == parent.right) {
ch = parent;
parent = parent.parent;
}
return parent;
}
} else
return p;
}
}
/**
* 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 null.
*/
private Entry getFloorEntry(K key) {
Entry p = root;
if (p==null)
return null;
while (true) {
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 parent = p.parent;
Entry ch = p;
while (parent != null && ch == parent.left) {
ch = parent;
parent = parent.parent;
}
return parent;
}
} else
return p;
}
}
/**
* 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 null.
*/
private Entry getHigherEntry(K key) {
Entry p = root;
if (p==null)
return null;
while (true) {
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 parent = p.parent;
Entry ch = p;
while (parent != null && ch == parent.right) {
ch = parent;
parent = parent.parent;
}
return parent;
}
}
}
}
/**
* 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 null.
*/
private Entry getLowerEntry(K key) {
Entry p = root;
if (p==null)
return null;
while (true) {
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 parent = p.parent;
Entry ch = p;
while (parent != null && ch == parent.left) {
ch = parent;
parent = parent.parent;
}
return parent;
}
}
}
}
/**
* Returns the key corresponding to the specified Entry.
* @throws NoSuchElementException if the Entry is null
*/
private static K key(Entry e) {
if (e==null)
throw new NoSuchElementException();
return e.key;
}
/**
* 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 key, or
* null if there was no mapping for key.
* (A null return can also indicate that the map
* previously associated null with 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 V put(K key, V value) {
Entry t = root;
if (t == null) {
// TBD
// if (key == null) {
// if (comparator == null)
// throw new NullPointerException();
// comparator.compare(key, key);
// }
incrementSize();
root = new Entry(key, value, null);
return null;
}
while (true) {
int cmp = compare(key, t.key);
if (cmp == 0) {
return t.setValue(value);
} else if (cmp < 0) {
if (t.left != null) {
t = t.left;
} else {
incrementSize();
t.left = new Entry(key, value, t);
fixAfterInsertion(t.left);
return null;
}
} else { // cmp > 0
if (t.right != null) {
t = t.right;
} else {
incrementSize();
t.right = new Entry(key, value, t);
fixAfterInsertion(t.right);
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 key, or
* null if there was no mapping for key.
* (A null return can also indicate that the map
* previously associated null with 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 V remove(Object key) {
Entry 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 TreeMap instance. (The keys and
* values themselves are not cloned.)
*
* @return a shallow copy of this map
*/
public Object clone() {
TreeMap clone = null;
try {
clone = (TreeMap) 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.descendingEntrySet = null;
clone.descendingKeySet = 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 firstEntry() {
Entry e = getFirstEntry();
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @since 1.6
*/
public Map.Entry lastEntry() {
Entry e = getLastEntry();
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @since 1.6
*/
public Map.Entry pollFirstEntry() {
Entry p = getFirstEntry();
if (p == null)
return null;
Map.Entry result = new AbstractMap.SimpleImmutableEntry(p);
deleteEntry(p);
return result;
}
/**
* @since 1.6
*/
public Map.Entry pollLastEntry() {
Entry p = getLastEntry();
if (p == null)
return null;
Map.Entry result = new AbstractMap.SimpleImmutableEntry(p);
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 lowerEntry(K key) {
Entry e = getLowerEntry(key);
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @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) {
Entry e = getLowerEntry(key);
return (e == null)? null : e.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 floorEntry(K key) {
Entry e = getFloorEntry(key);
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @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) {
Entry e = getFloorEntry(key);
return (e == null)? null : e.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 ceilingEntry(K key) {
Entry e = getCeilingEntry(key);
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @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) {
Entry e = getCeilingEntry(key);
return (e == null)? null : e.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 higherEntry(K key) {
Entry e = getHigherEntry(key);
return (e == null)? null : new AbstractMap.SimpleImmutableEntry(e);
}
/**
* @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) {
Entry e = getHigherEntry(key);
return (e == null)? null : e.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 Set> entrySet = null;
private transient Set> descendingEntrySet = null;
private transient Set descendingKeySet = 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 remove operation), the results of
* the iteration are undefined. The set supports element removal,
* which removes the corresponding mapping from the map, via the
* Iterator.remove, Set.remove,
* removeAll, retainAll, and clear
* operations. It does not support the add or addAll
* operations.
*/
public Set keySet() {
Set ks = keySet;
return (ks != null) ? ks : (keySet = new KeySet());
}
class KeySet extends AbstractSet {
public Iterator iterator() {
return new KeyIterator(getFirstEntry());
}
public int size() {
return TreeMap.this.size();
}
public boolean contains(Object o) {
return containsKey(o);
}
public boolean remove(Object o) {
int oldSize = size;
TreeMap.this.remove(o);
return size != oldSize;
}
public void clear() {
TreeMap.this.clear();
}
}
/**
* 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 remove operation),
* the results of the iteration are undefined. The collection
* supports element removal, which removes the corresponding
* mapping from the map, via the Iterator.remove,
* Collection.remove, removeAll,
* retainAll and clear operations. It does not
* support the add or addAll operations.
*/
public Collection values() {
Collection vs = values;
return (vs != null) ? vs : (values = new Values());
}
class Values extends AbstractCollection {
public Iterator iterator() {
return new ValueIterator(getFirstEntry());
}
public int size() {
return TreeMap.this.size();
}
public boolean contains(Object o) {
for (Entry e = getFirstEntry(); e != null; e = successor(e))
if (valEquals(e.getValue(), o))
return true;
return false;
}
public boolean remove(Object o) {
for (Entry e = getFirstEntry(); e != null; e = successor(e)) {
if (valEquals(e.getValue(), o)) {
deleteEntry(e);
return true;
}
}
return false;
}
public void clear() {
TreeMap.this.clear();
}
}
/**
* 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 remove operation, or through the
* setValue 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 Iterator.remove,
* Set.remove, removeAll, retainAll and
* clear operations. It does not support the
* add or addAll operations.
*/
public Set> entrySet() {
Set> es = entrySet;
return (es != null) ? es : (entrySet = new EntrySet());
}
class EntrySet extends AbstractSet> {
public Iterator> iterator() {
return new EntryIterator(getFirstEntry());
}
public boolean contains(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry entry = (Map.Entry) o;
V value = entry.getValue();
Entry 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 entry = (Map.Entry) o;
V value = entry.getValue();
Entry 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();
}
}
/**
* @since 1.6
*/
public Set> descendingEntrySet() {
Set> es = descendingEntrySet;
return (es != null) ? es : (descendingEntrySet = new DescendingEntrySet());
}
class DescendingEntrySet extends EntrySet {
public Iterator> iterator() {
return new DescendingEntryIterator(getLastEntry());
}
}
/**
* @since 1.6
*/
public Set descendingKeySet() {
Set ks = descendingKeySet;
return (ks != null) ? ks : (descendingKeySet = new DescendingKeySet());
}
class DescendingKeySet extends KeySet {
public Iterator iterator() {
return new DescendingKeyIterator(getLastEntry());
}
}
/**
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if fromKey or toKey is
* null and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
* @since 1.6
*/
public NavigableMap navigableSubMap(K fromKey, K toKey) {
return new SubMap(fromKey, toKey);
}
/**
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if toKey is null
* and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
* @since 1.6
*/
public NavigableMap navigableHeadMap(K toKey) {
return new SubMap(toKey, true);
}
/**
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if fromKey is null
* and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
* @since 1.6
*/
public NavigableMap navigableTailMap(K fromKey) {
return new SubMap(fromKey, false);
}
/**
* Equivalent to {@link #navigableSubMap} but with a return type
* conforming to the SortedMap interface.
*
* {@inheritDoc}
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if fromKey or toKey is
* null and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
*/
public SortedMap subMap(K fromKey, K toKey) {
return new SubMap(fromKey, toKey);
}
/**
* Equivalent to {@link #navigableHeadMap} but with a return type
* conforming to the SortedMap interface.
*
* {@inheritDoc}
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if toKey is null
* and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
*/
public SortedMap headMap(K toKey) {
return new SubMap(toKey, true);
}
/**
* Equivalent to {@link #navigableTailMap} but with a return type
* conforming to the SortedMap interface.
*
* {@inheritDoc}
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException if fromKey is null
* and this map uses natural ordering, or its comparator
* does not permit null keys
* @throws IllegalArgumentException {@inheritDoc}
*/
public SortedMap tailMap(K fromKey) {
return new SubMap(fromKey, false);
}
private class SubMap
extends AbstractMap
implements NavigableMap, java.io.Serializable {
private static final long serialVersionUID = -6520786458950516097L;
/**
* fromKey is significant only if fromStart is false. Similarly,
* toKey is significant only if toStart is false.
*/
private boolean fromStart = false, toEnd = false;
private K fromKey, toKey;
SubMap(K fromKey, K toKey) {
if (compare(fromKey, toKey) > 0)
throw new IllegalArgumentException("fromKey > toKey");
this.fromKey = fromKey;
this.toKey = toKey;
}
SubMap(K key, boolean headMap) {
compare(key, key); // Type-check key
if (headMap) {
fromStart = true;
toKey = key;
} else {
toEnd = true;
fromKey = key;
}
}
SubMap(boolean fromStart, K fromKey, boolean toEnd, K toKey) {
this.fromStart = fromStart;
this.fromKey= fromKey;
this.toEnd = toEnd;
this.toKey = toKey;
}
public boolean isEmpty() {
return entrySet().isEmpty();
}
public boolean containsKey(Object key) {
return inRange(key) && TreeMap.this.containsKey(key);
}
public V get(Object key) {
if (!inRange(key))
return null;
return TreeMap.this.get(key);
}
public V put(K key, V value) {
if (!inRange(key))
throw new IllegalArgumentException("key out of range");
return TreeMap.this.put(key, value);
}
public V remove(Object key) {
if (!inRange(key))
return null;
return TreeMap.this.remove(key);
}
public Comparator comparator() {
return comparator;
}
public K firstKey() {
TreeMap.Entry e = fromStart ? getFirstEntry() : getCeilingEntry(fromKey);
K first = key(e);
if (!toEnd && compare(first, toKey) >= 0)
throw new NoSuchElementException();
return first;
}
public K lastKey() {
TreeMap.Entry e = toEnd ? getLastEntry() : getLowerEntry(toKey);
K last = key(e);
if (!fromStart && compare(last, fromKey) < 0)
throw new NoSuchElementException();
return last;
}
public Map.Entry firstEntry() {
TreeMap.Entry e = fromStart ?
getFirstEntry() : getCeilingEntry(fromKey);
if (e == null || (!toEnd && compare(e.key, toKey) >= 0))
return null;
return e;
}
public Map.Entry lastEntry() {
TreeMap.Entry e = toEnd ?
getLastEntry() : getLowerEntry(toKey);
if (e == null || (!fromStart && compare(e.key, fromKey) < 0))
return null;
return e;
}
public Map.Entry pollFirstEntry() {
TreeMap.Entry e = fromStart ?
getFirstEntry() : getCeilingEntry(fromKey);
if (e == null || (!toEnd && compare(e.key, toKey) >= 0))
return null;
Map.Entry result = new AbstractMap.SimpleImmutableEntry(e);
deleteEntry(e);
return result;
}
public Map.Entry pollLastEntry() {
TreeMap.Entry e = toEnd ?
getLastEntry() : getLowerEntry(toKey);
if (e == null || (!fromStart && compare(e.key, fromKey) < 0))
return null;
Map.Entry result = new AbstractMap.SimpleImmutableEntry(e);
deleteEntry(e);
return result;
}
private TreeMap.Entry subceiling(K key) {
TreeMap.Entry e = (!fromStart && compare(key, fromKey) < 0)?
getCeilingEntry(fromKey) : getCeilingEntry(key);
if (e == null || (!toEnd && compare(e.key, toKey) >= 0))
return null;
return e;
}
public Map.Entry ceilingEntry(K key) {
TreeMap.Entry e = subceiling(key);
return e == null? null : new AbstractMap.SimpleImmutableEntry(e);
}
public K ceilingKey(K key) {
TreeMap.Entry e = subceiling(key);
return e == null? null : e.key;
}
private TreeMap.Entry subhigher(K key) {
TreeMap.Entry e = (!fromStart && compare(key, fromKey) < 0)?
getCeilingEntry(fromKey) : getHigherEntry(key);
if (e == null || (!toEnd && compare(e.key, toKey) >= 0))
return null;
return e;
}
public Map.Entry higherEntry(K key) {
TreeMap.Entry e = subhigher(key);
return e == null? null : new AbstractMap.SimpleImmutableEntry(e);
}
public K higherKey(K key) {
TreeMap.Entry e = subhigher(key);
return e == null? null : e.key;
}
private TreeMap.Entry subfloor(K key) {
TreeMap.Entry e = (!toEnd && compare(key, toKey) >= 0)?
getLowerEntry(toKey) : getFloorEntry(key);
if (e == null || (!fromStart && compare(e.key, fromKey) < 0))
return null;
return e;
}
public Map.Entry floorEntry(K key) {
TreeMap.Entry e = subfloor(key);
return e == null? null : new AbstractMap.SimpleImmutableEntry(e);
}
public K floorKey(K key) {
TreeMap.Entry e = subfloor(key);
return e == null? null : e.key;
}
private TreeMap.Entry sublower(K key) {
TreeMap.Entry e = (!toEnd && compare(key, toKey) >= 0)?
getLowerEntry(toKey) : getLowerEntry(key);
if (e == null || (!fromStart && compare(e.key, fromKey) < 0))
return null;
return e;
}
public Map.Entry lowerEntry(K key) {
TreeMap.Entry e = sublower(key);
return e == null? null : new AbstractMap.SimpleImmutableEntry(e);
}
public K lowerKey(K key) {
TreeMap.Entry e = sublower(key);
return e == null? null : e.key;
}
private transient Set> entrySet = null;
public Set> entrySet() {
Set> es = entrySet;
return (es != null)? es : (entrySet = new EntrySetView());
}
private class EntrySetView extends AbstractSet> {
private transient int size = -1, sizeModCount;
public int size() {
if (size == -1 || sizeModCount != TreeMap.this.modCount) {
size = 0; sizeModCount = TreeMap.this.modCount;
Iterator i = iterator();
while (i.hasNext()) {
size++;
i.next();
}
}
return size;
}
public boolean isEmpty() {
return !iterator().hasNext();
}
public boolean contains(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry entry = (Map.Entry) o;
K key = entry.getKey();
if (!inRange(key))
return false;
TreeMap.Entry node = getEntry(key);
return node != null &&
valEquals(node.getValue(), entry.getValue());
}
public boolean remove(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry entry = (Map.Entry) o;
K key = entry.getKey();
if (!inRange(key))
return false;
TreeMap.Entry node = getEntry(key);
if (node!=null && valEquals(node.getValue(),entry.getValue())){
deleteEntry(node);
return true;
}
return false;
}
public Iterator> iterator() {
return new SubMapEntryIterator(
(fromStart ? getFirstEntry() : getCeilingEntry(fromKey)),
(toEnd ? null : getCeilingEntry(toKey)));
}
}
private transient Set> descendingEntrySetView = null;
private transient Set descendingKeySetView = null;
public Set> descendingEntrySet() {
Set> es = descendingEntrySetView;
return (es != null) ? es :
(descendingEntrySetView = new DescendingEntrySetView());
}
public Set descendingKeySet() {
Set ks = descendingKeySetView;
return (ks != null) ? ks :
(descendingKeySetView = new DescendingKeySetView());
}
private class DescendingEntrySetView extends EntrySetView {
public Iterator> iterator() {
return new DescendingSubMapEntryIterator
((toEnd ? getLastEntry() : getLowerEntry(toKey)),
(fromStart ? null : getLowerEntry(fromKey)));
}
}
private class DescendingKeySetView extends AbstractSet {
public Iterator iterator() {
return new Iterator() {
private Iterator> i = descendingEntrySet().iterator();
public boolean hasNext() { return i.hasNext(); }
public K next() { return i.next().getKey(); }
public void remove() { i.remove(); }
};
}
public int size() {
return SubMap.this.size();
}
public boolean contains(Object k) {
return SubMap.this.containsKey(k);
}
}
public NavigableMap navigableSubMap(K fromKey, K toKey) {
if (!inRange2(fromKey))
throw new IllegalArgumentException("fromKey out of range");
if (!inRange2(toKey))
throw new IllegalArgumentException("toKey out of range");
return new SubMap(fromKey, toKey);
}
public NavigableMap navigableHeadMap(K toKey) {
if (!inRange2(toKey))
throw new IllegalArgumentException("toKey out of range");
return new SubMap(fromStart, fromKey, false, toKey);
}
public NavigableMap navigableTailMap(K fromKey) {
if (!inRange2(fromKey))
throw new IllegalArgumentException("fromKey out of range");
return new SubMap(false, fromKey, toEnd, toKey);
}
public SortedMap subMap(K fromKey, K toKey) {
return navigableSubMap(fromKey, toKey);
}
public SortedMap headMap(K toKey) {
return navigableHeadMap(toKey);
}
public SortedMap tailMap(K fromKey) {
return navigableTailMap(fromKey);
}
private boolean inRange(Object key) {
return (fromStart || compare(key, fromKey) >= 0) &&
(toEnd || compare(key, toKey) < 0);
}
// This form allows the high endpoint (as well as all legit keys)
private boolean inRange2(Object key) {
return (fromStart || compare(key, fromKey) >= 0) &&
(toEnd || compare(key, toKey) <= 0);
}
}
/**
* TreeMap Iterator.
*/
abstract class PrivateEntryIterator implements Iterator {
int expectedModCount = TreeMap.this.modCount;
Entry lastReturned = null;
Entry next;
PrivateEntryIterator(Entry first) {
next = first;
}
public boolean hasNext() {
return next != null;
}
Entry nextEntry() {
if (next == null)
throw new NoSuchElementException();
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
lastReturned = next;
next = successor(next);
return lastReturned;
}
public void remove() {
if (lastReturned == null)
throw new IllegalStateException();
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
if (lastReturned.left != null && lastReturned.right != null)
next = lastReturned;
deleteEntry(lastReturned);
expectedModCount++;
lastReturned = null;
}
}
class EntryIterator extends PrivateEntryIterator> {
EntryIterator(Entry first) {
super(first);
}
public Map.Entry next() {
return nextEntry();
}
}
class KeyIterator extends PrivateEntryIterator {
KeyIterator(Entry first) {
super(first);
}
public K next() {
return nextEntry().key;
}
}
class ValueIterator extends PrivateEntryIterator {
ValueIterator(Entry first) {
super(first);
}
public V next() {
return nextEntry().value;
}
}
class SubMapEntryIterator extends PrivateEntryIterator> {
private final K firstExcludedKey;
SubMapEntryIterator(Entry first, Entry firstExcluded) {
super(first);
firstExcludedKey = (firstExcluded == null
? null
: firstExcluded.key);
}
public boolean hasNext() {
return next != null && next.key != firstExcludedKey;
}
public Map.Entry next() {
if (next == null || next.key == firstExcludedKey)
throw new NoSuchElementException();
return nextEntry();
}
}
/**
* Base for Descending Iterators.
*/
abstract class DescendingPrivateEntryIterator extends PrivateEntryIterator {
DescendingPrivateEntryIterator(Entry first) {
super(first);
}
Entry nextEntry() {
if (next == null)
throw new NoSuchElementException();
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
lastReturned = next;
next = predecessor(next);
return lastReturned;
}
}
class DescendingEntryIterator extends DescendingPrivateEntryIterator> {
DescendingEntryIterator(Entry first) {
super(first);
}
public Map.Entry next() {
return nextEntry();
}
}
class DescendingKeyIterator extends DescendingPrivateEntryIterator {
DescendingKeyIterator(Entry first) {
super(first);
}
public K next() {
return nextEntry().key;
}
}
class DescendingSubMapEntryIterator extends DescendingPrivateEntryIterator> {
private final K lastExcludedKey;
DescendingSubMapEntryIterator(Entry last, Entry lastExcluded) {
super(last);
lastExcludedKey = (lastExcluded == null
? null
: lastExcluded.key);
}
public boolean hasNext() {
return next != null && next.key != lastExcludedKey;
}
public Map.Entry next() {
if (next == null || next.key == lastExcludedKey)
throw new NoSuchElementException();
return nextEntry();
}
}
/**
* Compares two keys using the correct comparison method for this TreeMap.
*/
private int compare(Object k1, Object k2) {
return comparator==null ? ((Comparable)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 null o1 properly.
*/
private static boolean valEquals(Object o1, Object o2) {
return (o1==null ? o2==null : o1.equals(o2));
}
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 class Entry implements Map.Entry {
K key;
V value;
Entry left = null;
Entry right = null;
Entry parent;
boolean color = BLACK;
/**
* Make a new cell with given key, value, and parent, and with
* null child links, and BLACK color.
*/
Entry(K key, V value, Entry 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.
*/
private Entry getFirstEntry() {
Entry 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.
*/
private Entry getLastEntry() {
Entry 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.
*/
private Entry successor(Entry t) {
if (t == null)
return null;
else if (t.right != null) {
Entry p = t.right;
while (p.left != null)
p = p.left;
return p;
} else {
Entry p = t.parent;
Entry 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.
*/
private Entry predecessor(Entry t) {
if (t == null)
return null;
else if (t.left != null) {
Entry p = t.left;
while (p.right != null)
p = p.right;
return p;
} else {
Entry p = t.parent;
Entry 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 boolean colorOf(Entry p) {
return (p == null ? BLACK : p.color);
}
private static Entry parentOf(Entry p) {
return (p == null ? null: p.parent);
}
private static void setColor(Entry p, boolean c) {
if (p != null)
p.color = c;
}
private static Entry leftOf(Entry p) {
return (p == null) ? null: p.left;
}
private static Entry rightOf(Entry p) {
return (p == null) ? null: p.right;
}
/** From CLR **/
private void rotateLeft(Entry p) {
Entry 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 p) {
Entry 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 x) {
x.color = RED;
while (x != null && x != root && x.parent.color == RED) {
if (parentOf(x) == leftOf(parentOf(parentOf(x)))) {
Entry 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);
if (parentOf(parentOf(x)) != null)
rotateRight(parentOf(parentOf(x)));
}
} else {
Entry 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);
if (parentOf(parentOf(x)) != null)
rotateLeft(parentOf(parentOf(x)));
}
}
}
root.color = BLACK;
}
/**
* Delete node p, and then rebalance the tree.
*/
private void deleteEntry(Entry p) {
decrementSize();
// If strictly internal, copy successor's element to p and then make p
// point to successor.
if (p.left != null && p.right != null) {
Entry 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 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 x) {
while (x != root && colorOf(x) == BLACK) {
if (x == leftOf(parentOf(x))) {
Entry 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 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 TreeMap instance to a stream (i.e.,
* serialize it).
*
* @serialData The size 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> i = entrySet().iterator(); i.hasNext(); ) {
Map.Entry e = i.next();
s.writeObject(e.getKey());
s.writeObject(e.getValue());
}
}
/**
* Reconstitute the