flink-core/src/main/java/org/apache/flink/api/common/functions/IterationRuntimeContext.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.flink.api.common.functions;

import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.annotation.Public;
import org.apache.flink.api.common.aggregators.Aggregator;
import org.apache.flink.types.Value;

@Public
public interface IterationRuntimeContext extends RuntimeContext {
	
	/**
	 * Gets the number of the current superstep. Superstep numbers start at <i>1</i>.
	 * 
	 * @return The number of the current superstep.
	 */
	int getSuperstepNumber();

	@PublicEvolving
	<T extends Aggregator<?>> T getIterationAggregator(String name);
	
	<T extends Value> T getPreviousIterationAggregate(String name);
}