Package com.apple.foundationdb.record.util

Class MapUtils

java.lang.Object

com.apple.foundationdb.record.util.MapUtils

public class MapUtils
extends Object

Utility functions for manipulating maps.

Method Summary

Modifier and Type	Method	Description
static <K,V> V	computeIfAbsent(Map<K,V> map, K key, Function<K,V> supplier)	In older versions of java ConcurrentHashMap.computeIfAbsent() has an issue where threads can contend on reads even when the value is present.

Methods inherited from class java.lang.Object

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

Method Detail

computeIfAbsent

public static <K,V> V computeIfAbsent(Map<K,V> map,
                                            K key,
                                            Function<K,V> supplier)

In older versions of java ConcurrentHashMap.computeIfAbsent() has an issue where threads can contend on reads even when the value is present. This method provides the same behavior as computeIfAbsent but avoids such contention.

Type Parameters:

K - the key type

V - the value type

Parameters:

map - the map to use for the operation

key - the key to look up

supplier - a supplier to be used to generate a new value if one is not already present

Returns:

the existing value from the map or the newly added value if no value was previously present