voldemort.utils
Class WriteThroughCache<K,V>

java.lang.Object
  java.util.Dictionary<K,V>
      java.util.Hashtable<K,V>
          voldemort.utils.WriteThroughCache<K,V>

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<K,V>

public abstract class WriteThroughCache<K,V>
extends java.util.Hashtable<K,V>

Extends Java HashMap HashMap as a Write through cache
provide a hook to write custom write back strategies

See Also:

Serialized Form

Constructor Summary

WriteThroughCache()

Method Summary

V	get(java.lang.Object key) get() calls the readBack function if the value is not in HashMap otherwise serve copy from hash directly.
V	put(K key, V value) Updates the value in HashMap and writeBack as Atomic step
abstract V	readBack(K key)
abstract void	writeBack(K key, V value)

Methods inherited from class java.util.Hashtable

clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, hashCode, isEmpty, keys, keySet, putAll, rehash, remove, size, toString, values

Methods inherited from class java.lang.Object

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

Constructor Detail

WriteThroughCache

public WriteThroughCache()

Method Detail

readBack

public abstract V readBack(K key)

writeBack

public abstract void writeBack(K key,
                               V value)

get

public V get(java.lang.Object key)

get() calls the readBack function if the value is not in HashMap otherwise serve copy from hash directly.

Specified by:

get in interface java.util.Map<K,V>

Overrides:

get in class java.util.Hashtable<K,V>

put

public V put(K key,
             V value)

Updates the value in HashMap and writeBack as Atomic step

Specified by:

put in interface java.util.Map<K,V>

Overrides:

put in class java.util.Hashtable<K,V>