io.rsocket.internal

Class CollectionUtil

java.lang.Object

io.rsocket.internal.CollectionUtil

public class CollectionUtil
extends Object

Utility functions for collection objects.

Constructor Summary

Constructors

Constructor and Description
CollectionUtil()

Method Summary

Modifier and Type	Method and Description
static <K,V> V	getOrDefault(Map<K,V> map, K key, Function<K,V> supplier) A getOrDefault that doesn't create garbage if its suppler is non-capturing.
static <T> int	removeIf(List<T> values, Predicate<T> predicate) Remove element from a list if it matches a predicate.
static <V> int	sum(List<V> values, ToIntFunction<V> function) Garbage free sum function.
static void	validateLoadFactor(float loadFactor) Validate that a load factor is in the range of 0.1 to 0.9.
static void	validatePositivePowerOfTwo(int value) Validate that a number is a power of two.

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionUtil

public CollectionUtil()

Method Detail

getOrDefault

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

A getOrDefault that doesn't create garbage if its suppler is non-capturing.

Type Parameters:

K - type of the key

V - type of the value

Parameters:

map - to perform the lookup on.

key - on which the lookup is done.

supplier - of the default value if one is not found.

Returns:

the value if found or a new default which as been added to the map.

sum

public static <V> int sum(List<V> values,
                          ToIntFunction<V> function)

Garbage free sum function.

Note: the list must implement RandomAccess to be efficient.

Type Parameters:

V - the value to add up

Parameters:

values - the list of input values

function - function that map each value to an int

Returns:

the sum of all the int values returned for each member of the list.

validateLoadFactor

public static void validateLoadFactor(float loadFactor)

Validate that a load factor is in the range of 0.1 to 0.9.

Load factors in the range 0.5 - 0.7 are recommended for open-addressing with linear probing.

Parameters:

loadFactor - to be validated.

validatePositivePowerOfTwo

public static void validatePositivePowerOfTwo(int value)

Validate that a number is a power of two.

Parameters:

value - to be validated.

removeIf

public static <T> int removeIf(List<T> values,
                               Predicate<T> predicate)

Remove element from a list if it matches a predicate.

Note: the list must implement RandomAccess to be efficient.

Type Parameters:

T - type of the value.

Parameters:

values - to be iterated over.

predicate - to test the value against

Returns:

the number of items remove.