org.apache.storm.windowing.persistence

Class SimpleWindowPartitionCache<K,V>

java.lang.Object

org.apache.storm.windowing.persistence.SimpleWindowPartitionCache<K,V>

All Implemented Interfaces:

WindowPartitionCache<K,V>

public class SimpleWindowPartitionCache<K,V>
extends Object
implements WindowPartitionCache<K,V>

A simple implementation that evicts the largest un-pinned entry from the cache. This works well for caching window partitions since the access pattern is mostly sequential scans.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SimpleWindowPartitionCache.SimpleWindowPartitionCacheBuilder<K,V>

Nested classes/interfaces inherited from interface org.apache.storm.windowing.persistence.WindowPartitionCache

WindowPartitionCache.Builder<K,V>, WindowPartitionCache.CacheLoader<K,V>, WindowPartitionCache.RemovalCause, WindowPartitionCache.RemovalListener<K,V>

Method Summary

Modifier and Type	Method and Description
ConcurrentMap<K,V>	asMap() Return a ConcurrentMap view of the current entries in the cache.
V	get(K key) Get value from the cache or load the value.
void	invalidate(K key) Invalidate an entry from the cache.
static <K,V> SimpleWindowPartitionCache.SimpleWindowPartitionCacheBuilder<K,V>	newBuilder()
V	pinAndGet(K key) Get value from the cache or load the value pinning it so that the entry will never get evicted.
boolean	unpin(K key) Unpin an entry from the cache so that it can be a candidate for eviction.

Methods inherited from class java.lang.Object

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

Method Detail

newBuilder

public static <K,V> SimpleWindowPartitionCache.SimpleWindowPartitionCacheBuilder<K,V> newBuilder()

get

public V get(K key)

Description copied from interface: WindowPartitionCache

Get value from the cache or load the value.

Specified by:

get in interface WindowPartitionCache<K,V>

Parameters:

key - the key

Returns:

the value

pinAndGet

public V pinAndGet(K key)

Description copied from interface: WindowPartitionCache

Get value from the cache or load the value pinning it so that the entry will never get evicted.

Specified by:

pinAndGet in interface WindowPartitionCache<K,V>

Parameters:

key - the key

Returns:

the value

unpin

public boolean unpin(K key)

Description copied from interface: WindowPartitionCache

Unpin an entry from the cache so that it can be a candidate for eviction.

Specified by:

unpin in interface WindowPartitionCache<K,V>

Parameters:

key - the key

Returns:

true if the entry was unpinned, false otherwise

asMap

public ConcurrentMap<K,V> asMap()

Description copied from interface: WindowPartitionCache

Return a ConcurrentMap view of the current entries in the cache.

Specified by:

asMap in interface WindowPartitionCache<K,V>

Returns:

the map of key-values currently cached.

invalidate

public void invalidate(K key)

Description copied from interface: WindowPartitionCache

Invalidate an entry from the cache.

Specified by:

invalidate in interface WindowPartitionCache<K,V>

Parameters:

key - the key