org.diirt.datasource

Class ForwardCache<T,R>

java.lang.Object

org.diirt.datasource.ForwardCache<T,R>

Type Parameters:

T - type to cache

R - type to forward when the cache changes

All Implemented Interfaces:

ReadFunction<T>, ValueCache<T>, WriteFunction<T>

public class ForwardCache<T,R>
extends Object
implements ValueCache<T>

A cache that, after a value is put in the given value cache, calculates the value of the forward function and stores it in the forward writer, while locking on the forward function.

This can be used to connect a function of multiple values to a single collector.

Author:

carcassi

Constructor Summary

Constructors

Constructor and Description
ForwardCache(ValueCache<T> valueCache, ReadFunction<R> forwardFunction, WriteFunction<R> forwardWriter) Creates a new ForwardCache.

Method Summary

Modifier and Type	Method and Description
Class<T>	getType() The type of objects that this cache can contain.
T	readValue() Calculates, if needed, and then returns the value for this function.
void	writeValue(T newValue) Takes the value and consumes it.

Methods inherited from class java.lang.Object

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

Constructor Detail

ForwardCache

public ForwardCache(ValueCache<T> valueCache,
                    ReadFunction<R> forwardFunction,
                    WriteFunction<R> forwardWriter)

Creates a new ForwardCache.

Parameters:

valueCache - the cache that will hold the value

forwardFunction - the function that calculates the value to forward

forwardWriter - the destination of the calculated value

Method Detail

readValue

public T readValue()

Description copied from interface: ReadFunction

Calculates, if needed, and then returns the value for this function.

Specified by:

readValue in interface ReadFunction<T>

Returns:

a value

writeValue

public void writeValue(T newValue)

Description copied from interface: WriteFunction

Takes the value and consumes it.

Specified by:

writeValue in interface WriteFunction<T>

Parameters:

newValue - a value

getType

public Class<T> getType()

Description copied from interface: ValueCache

The type of objects that this cache can contain.

Specified by:

getType in interface ValueCache<T>

Returns:

the class token