flink-runtime/src/main/java/org/apache/flink/runtime/operators/DamBehavior.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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
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 */

package org.apache.flink.runtime.operators;

/**
 * Enumeration for the different dam behaviors of an algorithm or a driver strategy. The dam
 * behavior describes whether records pass through the algorithm (no dam), whether all records are
 * collected before the first is returned (full dam) or whether a certain large amount is collected
 * before the algorithm returns records.
 */
public enum DamBehavior {

    /**
     * Constant indicating that the algorithm does not come with any form of dam and records pass
     * through in a pipelined fashion.
     */
    PIPELINED,

    /**
     * Constant indicating that the algorithm materialized (some) records, but may return records
     * before all records are read.
     */
    MATERIALIZING,

    /** Constant indicating that the algorithm collects all records before returning any. */
    FULL_DAM;

    /**
     * Checks whether this enumeration represents some form of materialization, either with a full
     * dam or without.
     *
     * @return True, if this enumeration constant represents a materializing behavior, false
     *     otherwise.
     */
    public boolean isMaterializing() {
        return this != PIPELINED;
    }
}