Package org.apache.bookkeeper.util.collections

Class ConcurrentLongHashMap<V>

java.lang.Object

org.apache.bookkeeper.util.collections.ConcurrentLongHashMap<V>

Type Parameters:

V -

public class ConcurrentLongHashMap<V>
extends java.lang.Object

Map from long to an Object.

Provides similar methods as a ConcurrentMap<long,Object> with 2 differences:

1. No boxing/unboxing from long -> Long
2. Open hash map with linear probing, no node allocations 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	ConcurrentLongHashMap.Builder<T>	Builder of ConcurrentLongHashMap.
static interface	ConcurrentLongHashMap.EntryProcessor<V>	An entry processor.
static interface	ConcurrentLongHashMap.LongObjectPredicate<V>	Predicate specialization for (long, V) types.

Constructor Summary

Constructors

Constructor	Description
ConcurrentLongHashMap()	Deprecated.
ConcurrentLongHashMap(int expectedItems)	Deprecated.
ConcurrentLongHashMap(int expectedItems, int concurrencyLevel)	Deprecated.
ConcurrentLongHashMap(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(long key, java.util.function.LongFunction<V> provider)
boolean	containsKey(long key)
void	forEach(ConcurrentLongHashMap.EntryProcessor<V> processor)	Iterate over all the entries in the map and apply the processor function to each of them.
V	get(long key)
(package private) long	getUsedBucketCount()
(package private) static long	hash(long key)
boolean	isEmpty()
java.util.List<java.lang.Long>	keys()
static <V> ConcurrentLongHashMap.Builder<V>	newBuilder()
V	put(long key, V value)
V	putIfAbsent(long key, V value)
V	remove(long key)
boolean	remove(long key, java.lang.Object value)
int	removeIf(ConcurrentLongHashMap.LongObjectPredicate<V> predicate)
(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

ConcurrentLongHashMap

@Deprecated
public ConcurrentLongHashMap()

Deprecated.

ConcurrentLongHashMap

@Deprecated
public ConcurrentLongHashMap(int expectedItems)

Deprecated.

ConcurrentLongHashMap

@Deprecated
public ConcurrentLongHashMap(int expectedItems,
                             int concurrencyLevel)

Deprecated.

ConcurrentLongHashMap

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

Method Detail

newBuilder

public static <V> ConcurrentLongHashMap.Builder<V> newBuilder()

size

public long size()

getUsedBucketCount

long getUsedBucketCount()

capacity

public long capacity()

isEmpty

public boolean isEmpty()

get

public V get(long key)

containsKey

public boolean containsKey(long key)

put

public V put(long key,
             V value)

putIfAbsent

public V putIfAbsent(long key,
                     V value)

computeIfAbsent

public V computeIfAbsent(long key,
                         java.util.function.LongFunction<V> provider)

remove

public V remove(long key)

remove

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

removeIf

public int removeIf(ConcurrentLongHashMap.LongObjectPredicate<V> predicate)

clear

public void clear()

forEach

public void forEach(ConcurrentLongHashMap.EntryProcessor<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 processor to apply to each entry

keys

public java.util.List<java.lang.Long> keys()

Returns:

a new list of all keys (makes a copy)

values

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

Returns:

a new list of all keys (makes a copy)

hash

static final long hash(long key)

signSafeMod

static final int signSafeMod(long n,
                             int max)