/*
 * 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.hyracks.api.job.profiling;

import java.io.Serializable;

import org.apache.hyracks.api.exceptions.HyracksDataException;
import org.apache.hyracks.api.io.IWritable;

public interface IStatsCollector extends IWritable, Serializable {

    /**
     * Adds {@link IOperatorStats} to the stats collections
     *
     * @param operatorStats
     * @throws HyracksDataException when an operator with the same was already added.
     */
    void add(IOperatorStats operatorStats) throws HyracksDataException;

    /**
     * @param operatorName
     * @return {@link IOperatorStats} for the operator with name <code>operatorName</code>
     * if one exists or else null.
     */
    IOperatorStats getOperatorStats(String operatorName);

    /**
     * @return A special {@link IOperatorStats} that has the aggregated stats
     * from all operators in the collection.
     */
    IOperatorStats getAggregatedStats();
}
