org.glassfish.pfl.dynamic.copyobject.impl

Class FastCache<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.glassfish.pfl.dynamic.copyobject.impl.FastCache<K,V>

All Implemented Interfaces:

Map<K,V>

public class FastCache<K,V>
extends AbstractMap<K,V>

A cache intended to help speed up access to a Map. The idea is that some maps have a few values that are retrieved more frequently than others. So, we create a fixed size array that holds keys and values, and do a very fast hash on the key's identityHashCode. The cache is backed by a map, which can be an IdentityHashMap, or any other map (such as a WeakHashMap) where the keys satisfy k1.equals(k2) implies k1 == k2. Note that all put operations MUST go through this class, because calling put on the underlying map can result in the cache returning incorrect results for get.

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field and Description
static int	TABLE_SIZE

Constructor Summary

Constructors

Constructor and Description
FastCache(Map<K,V> map)

Method Summary

Modifier and Type	Method and Description
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
long	getCacheCount()
long	getTotalCount()
V	put(K key, V value) Put the key and value in the cache and the underlying map.

Methods inherited from class java.util.AbstractMap

clear, clone, containsKey, containsValue, equals, hashCode, isEmpty, keySet, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Detail

TABLE_SIZE

public static final int TABLE_SIZE

See Also:

Constant Field Values

Constructor Detail

FastCache

public FastCache(Map<K,V> map)

Method Detail

getCacheCount

public long getCacheCount()

getTotalCount

public long getTotalCount()

entrySet

public Set<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

put

public V put(K key,
             V value)

Put the key and value in the cache and the underlying map. This writes through to the map, rather than first storing a value in the cache which is only written as required, because that makes it easier to preserve the correct behavior of the map.

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>