it.unimi.dsi.fastutil.chars
Class Char2ReferenceLinkedOpenHashMap<V>

java.lang.Object
  it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceFunction<V>
      it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceMap<V>
          it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceSortedMap<V>
              it.unimi.dsi.fastutil.chars.Char2ReferenceLinkedOpenHashMap<V>

All Implemented Interfaces:

Char2ReferenceFunction<V>, Char2ReferenceMap<V>, Char2ReferenceSortedMap<V>, Function<Character,V>, Hash, Serializable, Cloneable, Map<Character,V>, SortedMap<Character,V>

public class Char2ReferenceLinkedOpenHashMap<V>
extends AbstractChar2ReferenceSortedMap<V>
implements Serializable, Cloneable, Hash

A type-specific linked hash map with with a fast, small-footprint implementation.

Instances of this class use a hash table to represent a map. The table is enlarged as needed by doubling its size when new entries are created, but it is never made smaller (even on a clear()). A family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

Iterators generated by this map will enumerate pairs in the same order in which they have been added to the map (addition of pairs whose key is already present in the set does not change the iteration order). Note that this order has nothing in common with the natural order of the keys. The order is kept by means of a doubly linked list, represented via an array of longs parallel to the table.

This class implements the interface of a sorted map, so to allow easy access of the iteration order: for instance, you can get the first key in iteration order with AbstractChar2ReferenceSortedMap.firstKey() without having to create an iterator; however, this class partially violates the SortedMap contract because all submap methods throw an exception and comparator() returns always null.

Additional methods, such as getAndMoveToFirst(), make it easy to use instances of this class as a cache (e.g., with LRU policy).

The iterators provided by the views of this class using are type-specific list iterators, and can be started at any element which is a key of the map, or a NoSuchElementException exception will be thrown. If, however, the provided element is not the first or last key in the set, the first access to the list index will require linear time, as in the worst case the entire key set must be scanned in iteration order to retrieve the positional index of the starting key. If you use just the methods of a type-specific BidirectionalIterator, however, all operations will be performed in constant time.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceMap

AbstractChar2ReferenceMap.BasicEntry<V>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Hash.Strategy<K>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.chars.Char2ReferenceSortedMap

Char2ReferenceSortedMap.FastSortedEntrySet<V>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.chars.Char2ReferenceMap

Char2ReferenceMap.Entry<V>, Char2ReferenceMap.FastEntrySet<V>

Field Summary

static long

serialVersionUID

Fields inherited from interface it.unimi.dsi.fastutil.Hash

DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR

Constructor Summary

Char2ReferenceLinkedOpenHashMap()
Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.

Char2ReferenceLinkedOpenHashMap(char[] k, V[] v)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.

Char2ReferenceLinkedOpenHashMap(char[] k, V[] v, float f)
Creates a new hash map using the elements of two parallel arrays.

Char2ReferenceLinkedOpenHashMap(Char2ReferenceMap<V> m)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.

Char2ReferenceLinkedOpenHashMap(Char2ReferenceMap<V> m, float f)
Creates a new hash map copying a given type-specific one.

Char2ReferenceLinkedOpenHashMap(int expected)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.

Char2ReferenceLinkedOpenHashMap(int expected, float f)
Creates a new hash map.

Char2ReferenceLinkedOpenHashMap(Map<? extends Character,? extends V> m)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.

Char2ReferenceLinkedOpenHashMap(Map<? extends Character,? extends V> m, float f)
Creates a new hash map copying a given one.

Method Summary

Char2ReferenceSortedMap.FastSortedEntrySet<V>	char2ReferenceEntrySet() Returns a type-specific sorted-set view of the mappings contained in this map.
void	clear() Removes all associations from this function (optional operation).
Char2ReferenceLinkedOpenHashMap<V>	clone() Returns a deep copy of this map.
CharComparator	comparator() Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.
boolean	containsKey(char k) Checks whether the given value is contained in AbstractChar2ReferenceMap.keySet().
boolean	containsValue(Object v) Checks whether the given value is contained in AbstractChar2ReferenceMap.values().
char	firstCharKey() Returns the first key of this map in iteration order.
V	get(char k) Returns the value to which the given key is mapped.
V	get(Character ok)
V	getAndMoveToFirst(char k) Returns the value to which the given key is mapped; if the key is present, it is moved to the first position of the iteration order.
V	getAndMoveToLast(char k) Returns the value to which the given key is mapped; if the key is present, it is moved to the last position of the iteration order.
int	growthFactor() Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.
void	growthFactor(int growthFactor) Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.
int	hashCode() Returns a hash code for this map.
Char2ReferenceSortedMap<V>	headMap(char to) Returns a view of the portion of this sorted map whose keys are strictly less than toKey.
boolean	isEmpty()
CharSortedSet	keySet() Returns a type-specific-sorted-set view of the keys of this map.
char	lastCharKey() Returns the last key of this map in iteration order.
V	put(Character ok, V ov) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
V	put(char k, V v) Adds a pair to the map.
V	putAndMoveToFirst(char k, V v) Adds a pair to the map; if the key is already present, it is moved to the first position of the iteration order.
V	putAndMoveToLast(char k, V v) Adds a pair to the map; if the key is already present, it is moved to the last position of the iteration order.
boolean	rehash() Deprecated. A no-op.
V	remove(char k) Removes the mapping with the given key.
V	remove(Object ok) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
V	removeFirst() Removes the mapping associated with the first key in iteration order.
V	removeLast() Removes the mapping associated with the last key in iteration order.
int	size() Returns the intended number of keys in this function, or -1 if no such number exists.
Char2ReferenceSortedMap<V>	subMap(char from, char to) Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.
Char2ReferenceSortedMap<V>	tailMap(char from) Returns a view of the portion of this sorted map whose keys are greater than or equal to fromKey.
boolean	trim() Rehashes the map, making the table as small as possible.
boolean	trim(int n) Rehashes this map if the table is too large.
ReferenceCollection<V>	values() Returns a type-specific collection view of the values contained in this map.

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceSortedMap

entrySet, firstKey, headMap, lastKey, subMap, tailMap

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceMap

equals, putAll, toString

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ReferenceFunction

containsKey, defaultReturnValue, defaultReturnValue, get

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.chars.Char2ReferenceFunction

defaultReturnValue, defaultReturnValue

Methods inherited from interface it.unimi.dsi.fastutil.Function

containsKey, get

Methods inherited from interface java.util.Map

containsKey, equals, get, putAll

Field Detail

serialVersionUID

public static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(int expected,
                                       float f)

Creates a new hash map.

The actual table size will be the least power of two greater than expected/f.

Parameters:

expected - the expected number of elements in the hash set.

f - the load factor.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(int expected)

Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.

Parameters:

expected - the expected number of elements in the hash map.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap()

Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(Map<? extends Character,? extends V> m,
                                       float f)

Creates a new hash map copying a given one.

Parameters:

m - a Map to be copied into the new hash map.

f - the load factor.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(Map<? extends Character,? extends V> m)

Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.

Parameters:

m - a Map to be copied into the new hash map.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(Char2ReferenceMap<V> m,
                                       float f)

Creates a new hash map copying a given type-specific one.

Parameters:

m - a type-specific map to be copied into the new hash map.

f - the load factor.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(Char2ReferenceMap<V> m)

Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.

Parameters:

m - a type-specific map to be copied into the new hash map.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(char[] k,
                                       V[] v,
                                       float f)

Creates a new hash map using the elements of two parallel arrays.

Parameters:

k - the array of keys of the new hash map.

v - the array of corresponding values in the new hash map.

f - the load factor.

Throws:

IllegalArgumentException - if k and v have different lengths.

Char2ReferenceLinkedOpenHashMap

public Char2ReferenceLinkedOpenHashMap(char[] k,
                                       V[] v)

Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.

Parameters:

k - the array of keys of the new hash map.

v - the array of corresponding values in the new hash map.

Throws:

IllegalArgumentException - if k and v have different lengths.

Method Detail

put

public V put(char k,
             V v)

Description copied from interface: Char2ReferenceFunction

Adds a pair to the map.

Specified by:

put in interface Char2ReferenceFunction<V>

Overrides:

put in class AbstractChar2ReferenceFunction<V>

Parameters:

k - the key.

v - the value.

Returns:

the old value, or the default return value if no value was present for the given key.

See Also:

Function.put(Object,Object)

put

public V put(Character ok,
             V ov)

Description copied from class: AbstractChar2ReferenceFunction

Delegates to the corresponding type-specific method, taking care of returning null on a missing key.

This method must check whether the provided key is in the map using containsKey(). Thus, it probes the map twice. Implementors of subclasses should override it with a more efficient method.

Specified by:

put in interface Function<Character,V>

Specified by:

put in interface Map<Character,V>

Overrides:

put in class AbstractChar2ReferenceFunction<V>

Parameters:

ok - the key.

ov - the value.

Returns:

the old value, or null if no value was present for the given key.

See Also:

Map.put(Object,Object)

remove

public V remove(char k)

Description copied from interface: Char2ReferenceFunction

Removes the mapping with the given key.

Specified by:

remove in interface Char2ReferenceFunction<V>

Overrides:

remove in class AbstractChar2ReferenceFunction<V>

Returns:

the old value, or the default return value if no value was present for the given key.

See Also:

Function.remove(Object)

remove

public V remove(Object ok)

Description copied from class: AbstractChar2ReferenceFunction

Delegates to the corresponding type-specific method, taking care of returning null on a missing key.

This method must check whether the provided key is in the map using containsKey(). Thus, it probes the map twice. Implementors of subclasses should override it with a more efficient method.

Specified by:

remove in interface Function<Character,V>

Specified by:

remove in interface Map<Character,V>

Overrides:

remove in class AbstractChar2ReferenceFunction<V>

Returns:

the old value, or null if no value was present for the given key.

See Also:

Map.remove(Object)

removeFirst

public V removeFirst()

Removes the mapping associated with the first key in iteration order.

Returns:

the value previously associated with the first key in iteration order.

Throws:

NoSuchElementException - is this map is empty.

removeLast

public V removeLast()

Removes the mapping associated with the last key in iteration order.

Returns:

the value previously associated with the last key in iteration order.

Throws:

NoSuchElementException - is this map is empty.

getAndMoveToFirst

public V getAndMoveToFirst(char k)

Returns the value to which the given key is mapped; if the key is present, it is moved to the first position of the iteration order.

Parameters:

k - the key.

Returns:

the corresponding value, or the default return value if no value was present for the given key.

getAndMoveToLast

public V getAndMoveToLast(char k)

Returns the value to which the given key is mapped; if the key is present, it is moved to the last position of the iteration order.

Parameters:

k - the key.

Returns:

the corresponding value, or the default return value if no value was present for the given key.

putAndMoveToFirst

public V putAndMoveToFirst(char k,
                           V v)

Adds a pair to the map; if the key is already present, it is moved to the first position of the iteration order.

Parameters:

k - the key.

v - the value.

Returns:

the old value, or the default return value if no value was present for the given key.

putAndMoveToLast

public V putAndMoveToLast(char k,
                          V v)

Adds a pair to the map; if the key is already present, it is moved to the last position of the iteration order.

Parameters:

k - the key.

v - the value.

Returns:

the old value, or the default return value if no value was present for the given key.

get

public V get(Character ok)

get

public V get(char k)

Description copied from interface: Char2ReferenceFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Char2ReferenceFunction<V>

Parameters:

k - the key.

Returns:

the corresponding value, or the default return value if no value was present for the given key.

See Also:

Function.get(Object)

containsKey

public boolean containsKey(char k)

Description copied from class: AbstractChar2ReferenceMap

Checks whether the given value is contained in AbstractChar2ReferenceMap.keySet().

Specified by:

containsKey in interface Char2ReferenceFunction<V>

Overrides:

containsKey in class AbstractChar2ReferenceMap<V>

See Also:

Function.containsKey(Object)

containsValue

public boolean containsValue(Object v)

Description copied from class: AbstractChar2ReferenceMap

Checks whether the given value is contained in AbstractChar2ReferenceMap.values().

Specified by:

containsValue in interface Map<Character,V>

Overrides:

containsValue in class AbstractChar2ReferenceMap<V>

clear

public void clear()

Description copied from interface: Function

Removes all associations from this function (optional operation).

Specified by:

clear in interface Function<Character,V>

Specified by:

clear in interface Map<Character,V>

Overrides:

clear in class AbstractChar2ReferenceFunction<V>

See Also:

Map.clear()

size

public int size()

Description copied from interface: Function

Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.

Specified by:

size in interface Function<Character,V>

Specified by:

size in interface Map<Character,V>

Returns:

the intended number of keys in this function, or -1 if that number is not available.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<Character,V>

Overrides:

isEmpty in class AbstractChar2ReferenceMap<V>

growthFactor

@Deprecated
public void growthFactor(int growthFactor)

Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

A no-op for backward compatibility.

Parameters:

growthFactor - unused.

growthFactor

@Deprecated
public int growthFactor()

Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

Gets the growth factor (2).

Returns:

the growth factor of this set, which is fixed (2).

See Also:

growthFactor(int)

firstCharKey

public char firstCharKey()

Returns the first key of this map in iteration order.

Specified by:

firstCharKey in interface Char2ReferenceSortedMap<V>

Returns:

the first key in iteration order.

See Also:

SortedMap.firstKey()

lastCharKey

public char lastCharKey()

Returns the last key of this map in iteration order.

Specified by:

lastCharKey in interface Char2ReferenceSortedMap<V>

Returns:

the last key in iteration order.

See Also:

SortedMap.lastKey()

comparator

public CharComparator comparator()

Description copied from interface: Char2ReferenceSortedMap

Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.

Note that this specification strengthens the one given in SortedMap.comparator().

Specified by:

comparator in interface Char2ReferenceSortedMap<V>

Specified by:

comparator in interface SortedMap<Character,V>

See Also:

SortedMap.comparator()

tailMap

public Char2ReferenceSortedMap<V> tailMap(char from)

Description copied from interface: Char2ReferenceSortedMap

Returns a view of the portion of this sorted map whose keys are greater than or equal to fromKey.

Specified by:

tailMap in interface Char2ReferenceSortedMap<V>

See Also:

SortedMap.tailMap(Object)

headMap

public Char2ReferenceSortedMap<V> headMap(char to)

Description copied from interface: Char2ReferenceSortedMap

Returns a view of the portion of this sorted map whose keys are strictly less than toKey.

Specified by:

headMap in interface Char2ReferenceSortedMap<V>

See Also:

SortedMap.headMap(Object)

subMap

public Char2ReferenceSortedMap<V> subMap(char from,
                                         char to)

Description copied from interface: Char2ReferenceSortedMap

Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.

Specified by:

subMap in interface Char2ReferenceSortedMap<V>

See Also:

SortedMap.subMap(Object,Object)

char2ReferenceEntrySet

public Char2ReferenceSortedMap.FastSortedEntrySet<V> char2ReferenceEntrySet()

Description copied from interface: Char2ReferenceSortedMap

Returns a type-specific sorted-set view of the mappings contained in this map. Note that this specification strengthens the one given in the corresponding type-specific unsorted map.

Specified by:

char2ReferenceEntrySet in interface Char2ReferenceMap<V>

Specified by:

char2ReferenceEntrySet in interface Char2ReferenceSortedMap<V>

Returns:

a type-specific sorted-set view of the mappings contained in this map.

See Also:

Char2ReferenceSortedMap.entrySet()

keySet

public CharSortedSet keySet()

Description copied from class: AbstractChar2ReferenceSortedMap

Returns a type-specific-sorted-set view of the keys of this map.

The view is backed by the sorted set returned by AbstractChar2ReferenceSortedMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

Specified by:

keySet in interface Char2ReferenceMap<V>

Specified by:

keySet in interface Char2ReferenceSortedMap<V>

Specified by:

keySet in interface Map<Character,V>

Specified by:

keySet in interface SortedMap<Character,V>

Overrides:

keySet in class AbstractChar2ReferenceSortedMap<V>

Returns:

a sorted set view of the keys of this map; it may be safely cast to a type-specific interface.

See Also:

Map.keySet()

values

public ReferenceCollection<V> values()

Description copied from class: AbstractChar2ReferenceSortedMap

Returns a type-specific collection view of the values contained in this map.

The view is backed by the sorted set returned by AbstractChar2ReferenceSortedMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

Specified by:

values in interface Char2ReferenceMap<V>

Specified by:

values in interface Char2ReferenceSortedMap<V>

Specified by:

values in interface Map<Character,V>

Specified by:

values in interface SortedMap<Character,V>

Overrides:

values in class AbstractChar2ReferenceSortedMap<V>

Returns:

a type-specific collection view of the values contained in this map.

See Also:

Map.values()

rehash

@Deprecated
public boolean rehash()

Deprecated. A no-op.

A no-op for backward compatibility. The kind of tables implemented by this class never need rehashing.

If you need to reduce the table size to fit exactly this set, use trim().

Returns:

true.

See Also:

trim()

trim

public boolean trim()

Rehashes the map, making the table as small as possible.

This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.

If the table size is already the minimum possible, this method does nothing.

Returns:

true if there was enough memory to trim the map.

See Also:

trim(int)

trim

public boolean trim(int n)

Rehashes this map if the table is too large.

Let N be the smallest table size that can hold max(n,size()) entries, still satisfying the load factor. If the current table size is smaller than or equal to N, this method does nothing. Otherwise, it rehashes this map in a table of size N.

This method is useful when reusing maps. Clearing a map leaves the table size untouched. If you are reusing a map many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient maps.

Parameters:

n - the threshold for the trimming.

Returns:

true if there was enough memory to trim the map.

See Also:

trim()

clone

public Char2ReferenceLinkedOpenHashMap<V> clone()

Returns a deep copy of this map.

This method performs a deep copy of this hash map; the data stored in the map, however, is not cloned. Note that this makes a difference only for object keys.

Overrides:

clone in class Object

Returns:

a deep copy of this map.

hashCode

public int hashCode()

Returns a hash code for this map. This method overrides the generic method provided by the superclass. Since equals() is not overriden, it is important that the value returned by this method is the same value as the one returned by the overriden method.

Specified by:

hashCode in interface Map<Character,V>

Overrides:

hashCode in class AbstractChar2ReferenceMap<V>

Returns:

a hash code for this map.