Package org.apache.storm.windowing.persistence

Interface WindowPartitionCache<K,V>

Type Parameters:

K - the key type

V - the value type

All Known Implementing Classes:

SimpleWindowPartitionCache

public interface WindowPartitionCache<K,V>

A loading cache abstraction for caching WindowState.WindowPartition.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	WindowPartitionCache.Builder<K,V>	Builder interface for WindowPartitionCache.
static interface	WindowPartitionCache.CacheLoader<K,V>	The interface for loading entires into the cache.
static enum	WindowPartitionCache.RemovalCause	The reason why an enrty got evicted from the cache.
static interface	WindowPartitionCache.RemovalListener<K,V>	A callback interface for handling removal of events from the cache.

Method Summary

Modifier and Type	Method	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.
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.

Method Details

get

V get(K key)

Get value from the cache or load the value.

Parameters:

key - the key

Returns:

the value

pinAndGet

V pinAndGet(K key)

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

Parameters:

key - the key

Returns:

the value

unpin

boolean unpin(K key)

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

Parameters:

key - the key

Returns:

true if the entry was unpinned, false otherwise

asMap

ConcurrentMap<K,V> asMap()

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

Returns:

the map of key-values currently cached.

invalidate

void invalidate(K key)

Invalidate an entry from the cache.

Parameters:

key - the key