org.apache.hoya.yarn.appmaster.state.RoleHistoryUtils.java Source code

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Here is the source code for org.apache.hoya.yarn.appmaster.state.RoleHistoryUtils.java

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/*
 * 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.hoya.yarn.appmaster.state;

import org.apache.hadoop.yarn.api.records.Container;
import org.apache.hadoop.yarn.api.records.NodeId;
import org.apache.hoya.exceptions.HoyaRuntimeException;
import org.apache.hoya.tools.HoyaUtils;

public class RoleHistoryUtils {

    public static String hostnameOf(Container container) {
        NodeId nodeId = container.getNodeId();
        if (nodeId == null) {
            throw new HoyaRuntimeException("Container has no node ID: %s", HoyaUtils.containerToString(container));
        }
        return nodeId.getHost();
    }

    /**
     * Decrement a value but hold it at zero. Usually a sanity check
     * on counters tracking outstanding operations
     * @param val value
     * @return decremented value
     */
    public static int decToFloor(int val) {
        int v = val - 1;
        if (v < 0) {
            v = 0;
        }
        return v;
    }

}