flink-runtime/src/main/java/org/apache/flink/runtime/operators/shipping/ShipStrategyType.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.runtime.operators.shipping;

/**
 * Enumeration defining the different shipping types of the output, such as local forward, re-partitioning by hash,
 * or re-partitioning by range.
 */
public enum ShipStrategyType {
	
	/**
	 * Constant used as an indicator for an unassigned ship strategy.
	 */
	NONE(false, false),
	
	/**
	 * Forwarding the data locally in memory.
	 */
	FORWARD(false, false),
	
	/**
	 * Repartitioning the data randomly, typically when the parallelism between two nodes changes.
	 */
	PARTITION_RANDOM(true, false),
	
	/**
	 * Repartitioning the data deterministically through a hash function.
	 */
	PARTITION_HASH(true, true),
	
	/**
	 * Partitioning the data in ranges according to a total order.
	 */
	PARTITION_RANGE(true, true),
	
	/**
	 * Partitioning the data evenly, forced at a specific location (cannot be pushed down by optimizer).
	 */
	PARTITION_FORCED_REBALANCE(true, false),
	
	/**
	 * Replicating the data set to all instances.
	 */
	BROADCAST(true, false),
	
	/**
	 * Partitioning using a custom partitioner.
	 */
	PARTITION_CUSTOM(true, true);
	
	// --------------------------------------------------------------------------------------------
	
	private final boolean isNetwork;
	
	private final boolean requiresComparator;
	
	
	private ShipStrategyType(boolean network, boolean requiresComparator) {
		this.isNetwork = network;
		this.requiresComparator = requiresComparator;
	}
	
	public boolean isNetworkStrategy() {
		return this.isNetwork;
	}
	
	public boolean requiresComparator() {
		return this.requiresComparator;
	}
}