io.netty.util.concurrent

Class ConcurrentSkipListIntObjMultimap<V>

java.lang.Object

io.netty.util.concurrent.ConcurrentSkipListIntObjMultimap<V>

Type Parameters:

V - the type of mapped values

All Implemented Interfaces:

Iterable<ConcurrentSkipListIntObjMultimap.IntEntry<V>>

public class ConcurrentSkipListIntObjMultimap<V>
extends Object
implements Iterable<ConcurrentSkipListIntObjMultimap.IntEntry<V>>

A scalable concurrent multimap implementation. The map is sorted according to the natural ordering of its int keys.

This class implements a concurrent variant of SkipLists providing expected average log(n) time cost for the containsKey, get, put and remove operations and their variants. Insertion, removal, update, and access operations safely execute concurrently by multiple threads.

This class is a multimap, which means the same key can be associated with multiple values. Each such instance will be represented by a separate IntEntry. There is no defined ordering for the values mapped to the same key.

As a multimap, certain atomic operations like putIfPresent, compute, or computeIfPresent, cannot be supported. Likewise, some get-like operations cannot be supported.

Iterators and spliterators are weakly consistent.

All IntEntry pairs returned by methods in this class represent snapshots of mappings at the time they were produced. They do not support the Entry.setValue method. (Note however that it is possible to change mappings in the associated map using put, putIfAbsent, or replace, depending on exactly which effect you need.)

Beware that bulk operations putAll, equals, toArray, containsValue, and clear are not guaranteed to be performed atomically. For example, an iterator operating concurrently with a putAll operation might view only some of the added elements.

This class does not permit the use of null values because some null return values cannot be reliably distinguished from the absence of elements.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConcurrentSkipListIntObjMultimap.IntEntry<V> The multimap entry type with primitive int keys.

Constructor Summary

Constructors

Constructor and Description
ConcurrentSkipListIntObjMultimap(int noKey) Constructs a new, empty map, sorted according to the natural ordering of the keys.

Method Summary

Modifier and Type	Method and Description
ConcurrentSkipListIntObjMultimap.IntEntry<V>	ceilingEntry(int key) Returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such entry.
int	ceilingKey(int key)
void	clear() Removes all of the mappings from this map.
boolean	containsKey(int key) Returns true if this map contains a mapping for the specified key.
boolean	containsValue(Object value) Returns true if this map maps one or more keys to the specified value.
ConcurrentSkipListIntObjMultimap.IntEntry<V>	firstEntry() Returns a key-value mapping associated with the least key in this map, or null if the map is empty.
int	firstKey()
ConcurrentSkipListIntObjMultimap.IntEntry<V>	floorEntry(int key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key.
int	floorKey(int key)
V	get(int key) Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
V	getOrDefault(int key, V defaultValue) Returns the value to which the specified key is mapped, or the given defaultValue if this map contains no mapping for the key.
ConcurrentSkipListIntObjMultimap.IntEntry<V>	higherEntry(int key) Returns a key-value mapping associated with the least key strictly greater than the given key, or null if there is no such key.
int	higherKey(int key)
boolean	isEmpty() Check if the collection is empty.
Iterator<ConcurrentSkipListIntObjMultimap.IntEntry<V>>	iterator()
ConcurrentSkipListIntObjMultimap.IntEntry<V>	lastEntry() Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
int	lastKey()
ConcurrentSkipListIntObjMultimap.IntEntry<V>	lowerEntry(int key) Returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key.
int	lowerKey(int key)
ConcurrentSkipListIntObjMultimap.IntEntry<V>	pollCeilingEntry(int key)
ConcurrentSkipListIntObjMultimap.IntEntry<V>	pollFirstEntry() Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty.
ConcurrentSkipListIntObjMultimap.IntEntry<V>	pollLastEntry() Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
void	put(int key, V value) Associates the specified value with the specified key in this map.
V	remove(int key) Removes the mapping for the specified key from this map if present.
boolean	remove(int key, Object value) Remove the specific entry with the given key and value, if it exist.
boolean	replace(int key, V oldValue, V newValue) Replace the specific entry with the given key and value, with the given replacement value, if such an entry exist.
int	size() Get the approximate size of the collection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ConcurrentSkipListIntObjMultimap

public ConcurrentSkipListIntObjMultimap(int noKey)

Constructs a new, empty map, sorted according to the natural ordering of the keys.

Parameters:

noKey - The value to use as a sentinel for signaling the absence of a key.

Method Detail

containsKey

public boolean containsKey(int key)

Returns true if this map contains a mapping for the specified key.

Parameters:

key - key whose presence in this map is to be tested

Returns:

true if this map contains a mapping for the specified key

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if the specified key is null

get

public V get(int key)

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

More formally, if this map contains a mapping from a key k to a value v such that key compares equal to k according to the map's ordering, then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if the specified key is null

getOrDefault

public V getOrDefault(int key,
                      V defaultValue)

Returns the value to which the specified key is mapped, or the given defaultValue if this map contains no mapping for the key.

Parameters:

key - the key

defaultValue - the value to return if this map contains no mapping for the given key

Returns:

the mapping for the key, if present; else the defaultValue

Throws:

NullPointerException - if the specified key is null

Since:

1.8

put

public void put(int key,
                V value)

Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced.

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if the specified key or value is null

remove

public V remove(int key)

Removes the mapping for the specified key from this map if present.

Parameters:

key - key for which mapping should be removed

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if the specified key is null

containsValue

public boolean containsValue(Object value)

Returns true if this map maps one or more keys to the specified value. This operation requires time linear in the map size. Additionally, it is possible for the map to change during execution of this method, in which case the returned result may be inaccurate.

Parameters:

value - value whose presence in this map is to be tested

Returns:

true if a mapping to value exists; false otherwise

Throws:

NullPointerException - if the specified value is null

size

public int size()

Get the approximate size of the collection.

isEmpty

public boolean isEmpty()

Check if the collection is empty.

clear

public void clear()

Removes all of the mappings from this map.

remove

public boolean remove(int key,
                      Object value)

Remove the specific entry with the given key and value, if it exist.

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if the specified key is null

replace

public boolean replace(int key,
                       V oldValue,
                       V newValue)

Replace the specific entry with the given key and value, with the given replacement value, if such an entry exist.

Throws:

ClassCastException - if the specified key cannot be compared with the keys currently in the map

NullPointerException - if any of the arguments are null

firstKey

public int firstKey()

lastKey

public int lastKey()

lowerEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> lowerEntry(int key)

Returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key. The returned entry does not support the Entry.setValue method.

Throws:

NullPointerException - if the specified key is null

lowerKey

public int lowerKey(int key)

Throws:

NullPointerException - if the specified key is null

floorEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> floorEntry(int key)

Returns a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key. The returned entry does not support the Entry.setValue method.

Parameters:

key - the key

Throws:

NullPointerException - if the specified key is null

floorKey

public int floorKey(int key)

Parameters:

key - the key

Throws:

NullPointerException - if the specified key is null

ceilingEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> ceilingEntry(int key)

Returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such entry. The returned entry does not support the Entry.setValue method.

Throws:

NullPointerException - if the specified key is null

ceilingKey

public int ceilingKey(int key)

Throws:

NullPointerException - if the specified key is null

higherEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> higherEntry(int key)

Returns a key-value mapping associated with the least key strictly greater than the given key, or null if there is no such key. The returned entry does not support the Entry.setValue method.

Parameters:

key - the key

Throws:

NullPointerException - if the specified key is null

higherKey

public int higherKey(int key)

Parameters:

key - the key

Throws:

NullPointerException - if the specified key is null

firstEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> firstEntry()

Returns a key-value mapping associated with the least key in this map, or null if the map is empty. The returned entry does not support the Entry.setValue method.

lastEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> lastEntry()

Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty. The returned entry does not support the Entry.setValue method.

pollFirstEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> pollFirstEntry()

Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty. The returned entry does not support the Entry.setValue method.

pollLastEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> pollLastEntry()

Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty. The returned entry does not support the Entry.setValue method.

pollCeilingEntry

public ConcurrentSkipListIntObjMultimap.IntEntry<V> pollCeilingEntry(int key)

iterator

public Iterator<ConcurrentSkipListIntObjMultimap.IntEntry<V>> iterator()

Specified by:

iterator in interface Iterable<ConcurrentSkipListIntObjMultimap.IntEntry<V>>