IDifferenceFromReferenceGenerator.java

package fr.openwide.core.jpa.more.business.difference.util;

import java.util.concurrent.Callable;

import fr.openwide.core.jpa.more.business.difference.model.Difference;

public interface IDifferenceFromReferenceGenerator<T> extends IDifferenceGenerator<T> {
	
	Difference<T> diffFromReference(T value);
	
	/**
	 * When we have to compute the differences for a lot of objects, this allows to get the references in only one
	 * transaction, instead of opening a transaction for each difference computation.
	 * <p>The returned reference, to be usable by the method {@link #diff(Object, Object)}, should be passed through
	 * the method {@link #initializeReference(Object)}
	 * @see #initializeReference(Object)
	 * @see #diff(Object, Object)
	 */
	Callable<T> getReferenceProvider(T value);

	/**
	 * Must be called on an object returned by {@link #retrieveReference(Object)} to make it usable by the method
	 * {@link #diff(Object, Object)}.
	 * @see #retrieveReference(Object)
	 * @see #diff(Object, Object)
	 */
	void initializeReference(T reference);

}