Package org.apache.bookkeeper.util.collections

Class ConcurrentOpenHashMap<K,V>

java.lang.Object

org.apache.bookkeeper.util.collections.ConcurrentOpenHashMap<K,V>

Type Parameters:

V -

public class ConcurrentOpenHashMap<K,V>
extends java.lang.Object

Concurrent hash map.

Provides similar methods as a ConcurrentMap<K,V> but since it's an open hash map with linear probing, no node allocations are required to store the values
WARN: method forEach do not guarantee thread safety, nor do the keys and values method.
The forEach method is specifically designed for single-threaded usage. When iterating over a map with concurrent writes, it becomes possible for new values to be either observed or not observed. There is no guarantee that if we write value1 and value2, and are able to see value2, then we will also see value1. In some cases, it is even possible to encounter two mappings with the same key, leading the keys method to return a List containing two identical keys.
It is crucial to understand that the results obtained from aggregate status methods such as keys and values are typically reliable only when the map is not undergoing concurrent updates from other threads. When concurrent updates are involved, the results of these methods reflect transient states that may be suitable for monitoring or estimation purposes, but not for program control.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ConcurrentOpenHashMap.Builder<K,V>	Builder of ConcurrentOpenHashMap.

Constructor Summary

Constructors

Constructor	Description
ConcurrentOpenHashMap()	Deprecated.
ConcurrentOpenHashMap(int expectedItems)	Deprecated.
ConcurrentOpenHashMap(int expectedItems, int concurrencyLevel)	Deprecated.
ConcurrentOpenHashMap(int expectedItems, int concurrencyLevel, float mapFillFactor, float mapIdleFactor, boolean autoShrink, float expandFactor, float shrinkFactor)

Method Summary

Modifier and Type	Method	Description
long	capacity()
void	clear()
V	computeIfAbsent(K key, java.util.function.Function<K,V> provider)
boolean	containsKey(K key)
void	forEach(java.util.function.BiConsumer<? super K,? super V> processor)	Iterate over all the entries in the map and apply the processor function to each of them.
V	get(K key)
(package private) long	getUsedBucketCount()
(package private) static <K> long	hash(K key)
boolean	isEmpty()
java.util.List<K>	keys()
static <K,V> ConcurrentOpenHashMap.Builder<K,V>	newBuilder()
V	put(K key, V value)
V	putIfAbsent(K key, V value)
V	remove(K key)
boolean	remove(K key, java.lang.Object value)
int	removeIf(java.util.function.BiPredicate<K,V> filter)
(package private) static int	signSafeMod(long n, int max)
long	size()
java.util.List<V>	values()

Methods inherited from class java.lang.Object

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

Constructor Detail

ConcurrentOpenHashMap

@Deprecated
public ConcurrentOpenHashMap()

Deprecated.

ConcurrentOpenHashMap

@Deprecated
public ConcurrentOpenHashMap(int expectedItems)

Deprecated.

ConcurrentOpenHashMap

@Deprecated
public ConcurrentOpenHashMap(int expectedItems,
                             int concurrencyLevel)

Deprecated.

ConcurrentOpenHashMap

public ConcurrentOpenHashMap(int expectedItems,
                             int concurrencyLevel,
                             float mapFillFactor,
                             float mapIdleFactor,
                             boolean autoShrink,
                             float expandFactor,
                             float shrinkFactor)

Method Detail

newBuilder

public static <K,V> ConcurrentOpenHashMap.Builder<K,V> newBuilder()

getUsedBucketCount

long getUsedBucketCount()

size

public long size()

capacity

public long capacity()

isEmpty

public boolean isEmpty()

get

public V get(K key)

containsKey

public boolean containsKey(K key)

put

public V put(K key,
             V value)

putIfAbsent

public V putIfAbsent(K key,
                     V value)

computeIfAbsent

public V computeIfAbsent(K key,
                         java.util.function.Function<K,V> provider)

remove

public V remove(K key)

remove

public boolean remove(K key,
                      java.lang.Object value)

clear

public void clear()

forEach

public void forEach(java.util.function.BiConsumer<? super K,? super V> processor)

Iterate over all the entries in the map and apply the processor function to each of them.

Warning: Do Not Guarantee Thread-Safety.

Parameters:

processor - the function to apply to each entry

removeIf

public int removeIf(java.util.function.BiPredicate<K,V> filter)

keys

public java.util.List<K> keys()

Returns:

a new list of all keys (makes a copy)

values

public java.util.List<V> values()

hash

static final <K> long hash(K key)

signSafeMod

static final int signSafeMod(long n,
                             int max)