backtype.storm.utils
Class RotatingMap<K,V>

java.lang.Object
  backtype.storm.utils.RotatingMap<K,V>

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

Expires keys that have not been updated in the configured number of seconds. The algorithm used will take between expirationSecs and expirationSecs * (1 + 1 / (numBuckets-1)) to actually expire the message. get, put, remove, containsKey, and size take O(numBuckets) time to run. The advantage of this design is that the expiration thread only locks the object for O(1) time, meaning the object is essentially always available for gets/puts.

Nested Class Summary

static interface

RotatingMap.ExpiredCallback<K,V>

Constructor Summary

RotatingMap(int numBuckets)

RotatingMap(int numBuckets, RotatingMap.ExpiredCallback<K,V> callback)

RotatingMap(RotatingMap.ExpiredCallback<K,V> callback)

Method Summary

boolean	containsKey(K key)
V	get(K key)
void	put(K key, V value)
java.lang.Object	remove(K key)
java.util.Map<K,V>	rotate()
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

RotatingMap

public RotatingMap(int numBuckets,
                   RotatingMap.ExpiredCallback<K,V> callback)

RotatingMap

public RotatingMap(RotatingMap.ExpiredCallback<K,V> callback)

RotatingMap

public RotatingMap(int numBuckets)

Method Detail

rotate

public java.util.Map<K,V> rotate()

containsKey

public boolean containsKey(K key)

get

public V get(K key)

put

public void put(K key,
                V value)

remove

public java.lang.Object remove(K key)

size

public int size()