Package it.unimi.dsi.fastutil.objects

Class Reference2ObjectArrayMap<K,V>

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractReference2ObjectFunction<K,V>

it.unimi.dsi.fastutil.objects.AbstractReference2ObjectMap<K,V>

it.unimi.dsi.fastutil.objects.Reference2ObjectArrayMap<K,V>

All Implemented Interfaces:

Function<K,V>, Reference2ObjectFunction<K,V>, Reference2ObjectMap<K,V>, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<K,V>, java.util.Map<K,V>

public class Reference2ObjectArrayMap<K,V>
extends AbstractReference2ObjectMap<K,V>
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.AbstractReference2ObjectMap

AbstractReference2ObjectMap.BasicEntry<K,V>, AbstractReference2ObjectMap.BasicEntrySet<K,V>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2ObjectMap

Reference2ObjectMap.Entry<K,V>, Reference2ObjectMap.FastEntrySet<K,V>

Constructor Summary

Constructors

Constructor	Description
Reference2ObjectArrayMap()	Creates a new empty array map.
Reference2ObjectArrayMap(int capacity)	Creates a new empty array map of given capacity.
Reference2ObjectArrayMap(Reference2ObjectMap<K,V> m)	Creates a new empty array map copying the entries of a given map.
Reference2ObjectArrayMap(java.lang.Object[] key, java.lang.Object[] value)	Creates a new empty array map with given key and value backing arrays.
Reference2ObjectArrayMap(java.lang.Object[] key, java.lang.Object[] value, int size)	Creates a new array map with given key and value backing arrays, using the given number of elements.
Reference2ObjectArrayMap(java.util.Map<? extends K,? extends V> m)	Creates a new empty array map copying the entries of a given map.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all of the mappings from this map (optional operation).
Reference2ObjectArrayMap<K,V>	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(java.lang.Object v)
V	get(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.
V	put(K k, V v)	Adds a pair to the map (optional operation).
Reference2ObjectMap.FastEntrySet<K,V>	reference2ObjectEntrySet()	Returns a type-specific set view of the mappings contained in this map.
V	remove(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.
ObjectCollection<V>	values()	Returns a type-specific-set view of the values of this map.

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2ObjectFunction

defaultReturnValue, defaultReturnValue

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2ObjectMap

equals, hashCode, putAll, toString

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

apply

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2ObjectMap

defaultReturnValue, defaultReturnValue, entrySet

Constructor Detail

Reference2ObjectArrayMap

public Reference2ObjectArrayMap(java.lang.Object[] key,
                                java.lang.Object[] 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).

Reference2ObjectArrayMap

public Reference2ObjectArrayMap()

Creates a new empty array map.

Reference2ObjectArrayMap

public Reference2ObjectArrayMap(int capacity)

Creates a new empty array map of given capacity.

Parameters:

capacity - the initial capacity.

Reference2ObjectArrayMap

public Reference2ObjectArrayMap(Reference2ObjectMap<K,V> m)

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

Parameters:

m - a map.

Reference2ObjectArrayMap

public Reference2ObjectArrayMap(java.util.Map<? extends K,? extends V> m)

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

Parameters:

m - a map.

Reference2ObjectArrayMap

public Reference2ObjectArrayMap(java.lang.Object[] key,
                                java.lang.Object[] 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

reference2ObjectEntrySet

public Reference2ObjectMap.FastEntrySet<K,V> reference2ObjectEntrySet()

Description copied from interface: Reference2ObjectMap

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:

reference2ObjectEntrySet in interface Reference2ObjectMap<K,V>

Returns:

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

See Also:

Map.entrySet()

get

public V get(java.lang.Object k)

Description copied from interface: Reference2ObjectFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Function<K,V>

Specified by:

get in interface java.util.Map<K,V>

Specified by:

get in interface Reference2ObjectFunction<K,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)

size

public int size()

Description copied from interface: Reference2ObjectMap

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 Function<K,V>

Specified by:

size in interface java.util.Map<K,V>

Specified by:

size in interface Reference2ObjectMap<K,V>

Returns:

the number of key-value mappings in this map.

See Also:

Size64

clear

public void clear()

Description copied from interface: Reference2ObjectMap

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

Specified by:

clear in interface Function<K,V>

Specified by:

clear in interface java.util.Map<K,V>

Specified by:

clear in interface Reference2ObjectMap<K,V>

See Also:

Map.clear()

containsKey

public boolean containsKey(java.lang.Object k)

Description copied from interface: Reference2ObjectMap

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

Specified by:

containsKey in interface Function<K,V>

Specified by:

containsKey in interface java.util.Map<K,V>

Specified by:

containsKey in interface Reference2ObjectMap<K,V>

Overrides:

containsKey in class AbstractReference2ObjectMap<K,V>

Parameters:

k - the key.

Returns:

true if this function associates a value to key.

See Also:

Map.containsKey(Object)

containsValue

public boolean containsValue(java.lang.Object v)

Specified by:

containsValue in interface java.util.Map<K,V>

Overrides:

containsValue in class AbstractReference2ObjectMap<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<K,V>

Overrides:

isEmpty in class AbstractReference2ObjectMap<K,V>

put

public V put(K k,
             V v)

Description copied from interface: Reference2ObjectMap

Adds a pair to the map (optional operation).

This default implementation just delegates to the corresponding function method.

Specified by:

put in interface Function<K,V>

Specified by:

put in interface java.util.Map<K,V>

Specified by:

put in interface Reference2ObjectFunction<K,V>

Specified by:

put in interface Reference2ObjectMap<K,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)

remove

public V remove(java.lang.Object k)

Description copied from interface: Reference2ObjectMap

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

This default implementation just delegates to the corresponding type-specific–function method.

Specified by:

remove in interface Function<K,V>

Specified by:

remove in interface java.util.Map<K,V>

Specified by:

remove in interface Reference2ObjectFunction<K,V>

Specified by:

remove in interface Reference2ObjectMap<K,V>

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: AbstractReference2ObjectMap

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 java.util.Map<K,V>

Specified by:

keySet in interface Reference2ObjectMap<K,V>

Overrides:

keySet in class AbstractReference2ObjectMap<K,V>

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 ObjectCollection<V> values()

Description copied from class: AbstractReference2ObjectMap

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 java.util.Map<K,V>

Specified by:

values in interface Reference2ObjectMap<K,V>

Overrides:

values in class AbstractReference2ObjectMap<K,V>

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 Reference2ObjectArrayMap<K,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.

Returns:

a deep copy of this map.