/*
 * Copyright 2006-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.batch.retry;

import org.springframework.core.AttributeAccessor;

/**
 * Low-level access to ongoing retry operation. Normally not needed by clients,
 * but can be used to alter the course of the retry, e.g. force an early
 * termination.
 * 
 * @author Dave Syer
 * 
 */
public interface RetryContext extends AttributeAccessor {

	/**
	 * Signal to the framework that no more attempts should be made to try or
	 * retry the current {@link RetryCallback}.
	 */
	void setExhaustedOnly();

	/**
	 * Public accessor for the exhausted flag {@link #setExhaustedOnly()}.
	 * 
	 * @return true if the flag has been set.
	 */
	boolean isExhaustedOnly();

	/**
	 * Accessor for the parent context if retry blocks are nested.
	 * 
	 * @return the parent or null if there is none.
	 */
	RetryContext getParent();

	/**
	 * Counts the number of retry attempts. Before the first attempt this
	 * counter is zero, and before the first and subsequent attempts it should
	 * increment accordingly.
	 * 
	 * @return the number of retries.
	 */
	int getRetryCount();

	/**
	 * Accessor for the exception object that caused the current retry.
	 * 
	 * @return the last exception that caused a retry, or possibly null. It will
	 * be null if this is the first attempt, but also if the enclosing policy
	 * decides not to provide it (e.g. because of concerns about memory usage).
	 */
	Exception getLastThrowable();

}
