com.blazebit.collection

Class TrieMap<V>

java.lang.Object

java.util.AbstractMap<CharSequence,V>

com.blazebit.collection.TrieMap<V>

Type Parameters:

V - The value type that the trie holds.

All Implemented Interfaces:

Serializable, Map<CharSequence,V>

public class TrieMap<V>
extends AbstractMap<CharSequence,V>
implements Serializable, Map<CharSequence,V>

A trie implementation that can be used as map. This map implementation is especially thought to be used when having char sequence keys. Additionally to the standard methods of the Map interface, this implementation offers methods to check if a key prefix is contained, get the best matching key from an example key and retrieve prefixed views on the map. This map does not support null keys, instead an empty string should be used. The implementation uses nested HashMaps with Character keys internally to ensure O(k) performance where k is the length of an existing key, keyLen is the key which is used for retrieval or modification operations and k ≤ keyLen.

Author:

Christian Beikov

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
TrieMap() Constructs an empty TrieMap
TrieMap(Map<CharSequence,? extends V> map) Constructs a new TrieMap with the values from the given map.
TrieMap(TrieMap<? extends V> map) Constructs a new TrieMap by deep cloning the internally used nodes.

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object key)
boolean	containsKeyPrefix(CharSequence prefix) Returns true when an entry exists that that has the given prefix.
Set<Map.Entry<CharSequence,V>>	entrySet()
V	get(Object key)
String	getBestMatch(CharSequence str)
Set<CharSequence>	keySet()
V	put(CharSequence key, V value)
V	remove(Object o)
int	size()
TrieMap<V>	subMap(CharSequence prefix) Returns a view on the current map that acts like if every method call to the current map where a key is involved would be prefixed with the given prefix.
Collection<V>	values()

Methods inherited from class java.util.AbstractMap

clone, containsValue, equals, hashCode, isEmpty, putAll, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, containsValue, equals, forEach, getOrDefault, hashCode, isEmpty, merge, putAll, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

TrieMap

public TrieMap()

Constructs an empty TrieMap

TrieMap

public TrieMap(Map<CharSequence,? extends V> map)

Constructs a new TrieMap with the values from the given map.

Parameters:

map - The map from which to construct this TrieMap

TrieMap

public TrieMap(TrieMap<? extends V> map)

Constructs a new TrieMap by deep cloning the internally used nodes.

Parameters:

map - The map from which to construct this TrieMap

Method Detail

put

public V put(CharSequence key,
             V value)

Specified by:

put in interface Map<CharSequence,V>

Overrides:

put in class AbstractMap<CharSequence,V>

get

public V get(Object key)

Specified by:

get in interface Map<CharSequence,V>

Overrides:

get in class AbstractMap<CharSequence,V>

getBestMatch

public String getBestMatch(CharSequence str)

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<CharSequence,V>

Overrides:

containsKey in class AbstractMap<CharSequence,V>

containsKeyPrefix

public boolean containsKeyPrefix(CharSequence prefix)

Returns true when an entry exists that that has the given prefix.

Parameters:

prefix - The prefix for which to check if an entry is contained.

Returns:

True when an entry with the given prefix exists, otherwise false.

remove

public V remove(Object o)

Specified by:

remove in interface Map<CharSequence,V>

Overrides:

remove in class AbstractMap<CharSequence,V>

clear

public void clear()

Specified by:

clear in interface Map<CharSequence,V>

Overrides:

clear in class AbstractMap<CharSequence,V>

size

public int size()

Specified by:

size in interface Map<CharSequence,V>

Overrides:

size in class AbstractMap<CharSequence,V>

keySet

public Set<CharSequence> keySet()

Specified by:

keySet in interface Map<CharSequence,V>

Overrides:

keySet in class AbstractMap<CharSequence,V>

entrySet

public Set<Map.Entry<CharSequence,V>> entrySet()

Specified by:

entrySet in interface Map<CharSequence,V>

Specified by:

entrySet in class AbstractMap<CharSequence,V>

values

public Collection<V> values()

Specified by:

values in interface Map<CharSequence,V>

Overrides:

values in class AbstractMap<CharSequence,V>

subMap

public TrieMap<V> subMap(CharSequence prefix)

Returns a view on the current map that acts like if every method call to the current map where a key is involved would be prefixed with the given prefix. Although the implementation behaves like described, it makes the calls in a more performant way.

Parameters:

prefix - The prefix which to use for the sub map.

Returns:

A prefixed view on the current map.