it.unimi.dsi.fastutil.objects

Class Reference2IntArrayMap<K>

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractReference2IntFunction<K>

it.unimi.dsi.fastutil.objects.AbstractReference2IntMap<K>

it.unimi.dsi.fastutil.objects.Reference2IntArrayMap<K>

All Implemented Interfaces:

Reference2IntFunction<K>, Reference2IntMap<K>, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<K,java.lang.Integer>, java.util.function.ToIntFunction<K>, java.util.Map<K,java.lang.Integer>

public class Reference2IntArrayMap<K>
extends AbstractReference2IntMap<K>
implements java.io.Serializable, java.lang.Cloneable

A simple, brute-force implementation of a map based on two parallel backing arrays.

The main purpose of this implementation is that of wrapping cleanly the brute-force approach to the storage of a very small number of pairs: just put them into two parallel arrays and scan linearly to find an item.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntMap

AbstractReference2IntMap.BasicEntry<K>, AbstractReference2IntMap.BasicEntrySet<K>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2IntMap

Reference2IntMap.Entry<K>, Reference2IntMap.FastEntrySet<K>

Constructor Summary

Constructors

Constructor and Description
Reference2IntArrayMap() Creates a new empty array map.
Reference2IntArrayMap(int capacity) Creates a new empty array map of given capacity.
Reference2IntArrayMap(java.util.Map<? extends K,? extends java.lang.Integer> m) Creates a new empty array map copying the entries of a given map.
Reference2IntArrayMap(java.lang.Object[] key, int[] value) Creates a new empty array map with given key and value backing arrays.
Reference2IntArrayMap(java.lang.Object[] key, int[] value, int size) Creates a new array map with given key and value backing arrays, using the given number of elements.
Reference2IntArrayMap(Reference2IntMap<K> m) Creates a new empty array map copying the entries of a given map.

Method Summary

Modifier and Type	Method and Description
void	clear() Removes all of the mappings from this map (optional operation).
Reference2IntArrayMap<K>	clone() Returns a deep copy of this map.
boolean	containsKey(java.lang.Object k) Returns true if this function contains a mapping for the specified key.
boolean	containsValue(int v) Returns true if this map maps one or more keys to the specified value.
int	getInt(java.lang.Object k) Returns the value to which the given key is mapped.
boolean	isEmpty()
ReferenceSet<K>	keySet() Returns a type-specific-set view of the keys of this map.
int	put(K k, int v) Adds a pair to the map (optional operation).
Reference2IntMap.FastEntrySet<K>	reference2IntEntrySet() Returns a type-specific set view of the mappings contained in this map.
int	removeInt(java.lang.Object k) Removes the mapping with the given key (optional operation).
int	size() Returns the number of key/value mappings in this map.
IntCollection	values() Returns a type-specific-set view of the values of this map.

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntMap

equals, hashCode, putAll, toString

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntFunction

defaultReturnValue, defaultReturnValue

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2IntMap

computeInt, computeIntIfAbsent, computeIntIfAbsentPartial, computeIntIfPresent, containsValue, defaultReturnValue, defaultReturnValue, entrySet, get, getOrDefault, getOrDefault, merge, mergeInt, put, putIfAbsent, putIfAbsent, remove, remove, remove, replace, replace, replace, replace

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2IntFunction

applyAsInt

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

apply

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, replaceAll

Constructor Detail

Reference2IntArrayMap

public Reference2IntArrayMap(java.lang.Object[] key,
                             int[] value)

Creates a new empty array map with given key and value backing arrays. The resulting map will have as many entries as the given arrays.

It is responsibility of the caller that the elements of key are distinct.

Parameters:

key - the key array.

value - the value array (it must have the same length as key).

Reference2IntArrayMap

public Reference2IntArrayMap()

Creates a new empty array map.

Reference2IntArrayMap

public Reference2IntArrayMap(int capacity)

Creates a new empty array map of given capacity.

Parameters:

capacity - the initial capacity.

Reference2IntArrayMap

public Reference2IntArrayMap(Reference2IntMap<K> m)

Creates a new empty array map copying the entries of a given map.

Parameters:

m - a map.

Reference2IntArrayMap

public Reference2IntArrayMap(java.util.Map<? extends K,? extends java.lang.Integer> m)

Creates a new empty array map copying the entries of a given map.

Parameters:

m - a map.

Reference2IntArrayMap

public Reference2IntArrayMap(java.lang.Object[] key,
                             int[] value,
                             int size)

Creates a new array map with given key and value backing arrays, using the given number of elements.

It is responsibility of the caller that the first size elements of key are distinct.

Parameters:

key - the key array.

value - the value array (it must have the same length as key).

size - the number of valid elements in key and value.

Method Detail

reference2IntEntrySet

public Reference2IntMap.FastEntrySet<K> reference2IntEntrySet()

Description copied from interface: Reference2IntMap

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

This method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Map.entrySet() so that it returns an ObjectSet of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).

Specified by:

reference2IntEntrySet in interface Reference2IntMap<K>

Returns:

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

See Also:

Map.entrySet()

getInt

public int getInt(java.lang.Object k)

Description copied from interface: Reference2IntFunction

Returns the value to which the given key is mapped.

Specified by:

getInt in interface Reference2IntFunction<K>

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)

size

public int size()

Description copied from interface: Reference2IntMap

Returns the number of key/value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Specified by:

size in interface Reference2IntMap<K>

Specified by:

size in interface java.util.Map<K,java.lang.Integer>

Returns:

the number of key-value mappings in this map.

See Also:

Size64

clear

public void clear()

Description copied from interface: Reference2IntMap

Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.

Specified by:

clear in interface Reference2IntMap<K>

Specified by:

clear in interface java.util.Map<K,java.lang.Integer>

See Also:

Map.clear()

containsKey

public boolean containsKey(java.lang.Object k)

Description copied from interface: Reference2IntMap

Returns true if this function contains a mapping for the specified key.

Specified by:

containsKey in interface Reference2IntMap<K>

Specified by:

containsKey in interface java.util.Map<K,java.lang.Integer>

Overrides:

containsKey in class AbstractReference2IntMap<K>

Parameters:

k - the key.

Returns:

true if this function associates a value to key.

See Also:

Map.containsKey(Object)

containsValue

public boolean containsValue(int v)

Description copied from interface: Reference2IntMap

Returns true if this map maps one or more keys to the specified value.

Specified by:

containsValue in interface Reference2IntMap<K>

Overrides:

containsValue in class AbstractReference2IntMap<K>

See Also:

Map.containsValue(Object)

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<K,java.lang.Integer>

Overrides:

isEmpty in class AbstractReference2IntMap<K>

put

public int put(K k,
               int v)

Description copied from interface: Reference2IntFunction

Adds a pair to the map (optional operation).

Specified by:

put in interface Reference2IntFunction<K>

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)

removeInt

public int removeInt(java.lang.Object k)

Description copied from interface: Reference2IntFunction

Removes the mapping with the given key (optional operation).

Specified by:

removeInt in interface Reference2IntFunction<K>

Parameters:

k - the key.

Returns:

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

See Also:

Function.remove(Object)

keySet

public ReferenceSet<K> keySet()

Description copied from class: AbstractReference2IntMap

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

The view is backed by the set returned by Map.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 Reference2IntMap<K>

Specified by:

keySet in interface java.util.Map<K,java.lang.Integer>

Overrides:

keySet in class AbstractReference2IntMap<K>

Returns:

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

See Also:

Map.keySet()

values

public IntCollection values()

Description copied from class: AbstractReference2IntMap

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

The view is backed by the set returned by Map.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 Reference2IntMap<K>

Specified by:

values in interface java.util.Map<K,java.lang.Integer>

Overrides:

values in class AbstractReference2IntMap<K>

Returns:

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

See Also:

Map.values()

clone

public Reference2IntArrayMap<K> 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 java.lang.Object

Returns:

a deep copy of this map.