org.apache.arrow.memory

クラス LowCostIdentityHashMap<K,V extends ValueWithKeyIncluded<K>>

java.lang.Object

org.apache.arrow.memory.LowCostIdentityHashMap<K,V>

型パラメータ:

V -

public class LowCostIdentityHashMap<K,V extends ValueWithKeyIncluded<K>>
extends Object

Highly specialized IdentityHashMap that implements only partial Map APIs It incurs low initial cost (just two elements by default) It assumes Value includes the Key - Implements @ValueWithKeyIncluded iface that provides "getKey" method

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
LowCostIdentityHashMap() Creates an Map with default expected maximum size.
LowCostIdentityHashMap(int maxSize) Creates an Map with the specified maximum size parameter.

メソッドのサマリー

修飾子とタイプ	メソッドと説明
void	clear() Removes all elements from this map, leaving it empty.
boolean	containsKey(K key) Returns whether this map contains the specified key.
boolean	containsValue(V value) Returns whether this map contains the specified value.
V	get(K key) Returns the value of the mapping with the specified key.
V	getNextValue() Special API to return next value - substitute of regular Map.values.iterator().next()
boolean	isEmpty() Returns whether this Map has no elements.
V	put(V value) Maps the specified key to the specified value.
V	remove(K key) Removes the mapping with the specified key from this map.
int	size() Returns the number of mappings in this Map.

クラスから継承されたメソッド java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

コンストラクタの詳細

LowCostIdentityHashMap

public LowCostIdentityHashMap()

Creates an Map with default expected maximum size.

LowCostIdentityHashMap

public LowCostIdentityHashMap(int maxSize)

Creates an Map with the specified maximum size parameter.

パラメータ:

maxSize - The estimated maximum number of entries that will be put in this map.

メソッドの詳細

clear

public void clear()

Removes all elements from this map, leaving it empty.

関連項目:

isEmpty(), size()

containsKey

public boolean containsKey(K key)

Returns whether this map contains the specified key.

パラメータ:

key - the key to search for.

戻り値:

true if this map contains the specified key, false otherwise.

containsValue

public boolean containsValue(V value)

Returns whether this map contains the specified value.

パラメータ:

value - the value to search for.

戻り値:

true if this map contains the specified value, false otherwise.

get

public V get(K key)

Returns the value of the mapping with the specified key.

パラメータ:

key - the key.

戻り値:

the value of the mapping with the specified key.

put

public V put(V value)

Maps the specified key to the specified value.

パラメータ:

value - the value.

戻り値:

the value of any previous mapping with the specified key or null if there was no such mapping.

remove

public V remove(K key)

Removes the mapping with the specified key from this map.

パラメータ:

key - the key of the mapping to remove.

戻り値:

the value of the removed mapping, or null if no mapping for the specified key was found.

isEmpty

public boolean isEmpty()

Returns whether this Map has no elements.

戻り値:

true if this Map has no elements, false otherwise.

関連項目:

size()

size

public int size()

Returns the number of mappings in this Map.

戻り値:

the number of mappings in this Map.

getNextValue

public V getNextValue()

Special API to return next value - substitute of regular Map.values.iterator().next()

戻り値:

next available value or null if none available