eagle-core/eagle-query/eagle-query-base/src/main/java/org/apache/eagle/query/aggregate/timeseries/HierarchicalAggregator.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.eagle.query.aggregate.timeseries;

import java.util.List;
import java.util.SortedMap;

import org.apache.eagle.log.base.taggedlog.TaggedLogAPIEntity;
import org.apache.eagle.query.aggregate.AggregateFunctionType;

public class HierarchicalAggregator extends AbstractAggregator {
    private HierarchicalAggregateEntity root = new HierarchicalAggregateEntity();

    public HierarchicalAggregator(List<String> groupbyFields, List<AggregateFunctionType> aggregateFuntionTypes, List<String> aggregatedFields) {
        super(groupbyFields, aggregateFuntionTypes, aggregatedFields);
    }

    public void accumulate(TaggedLogAPIEntity entity) throws Exception {
        List<Double> preAggregatedValues = createPreAggregatedValues(entity);
        // aggregate to root first
        addDatapoint(root, preAggregatedValues);
        // go through hierarchical tree
        HierarchicalAggregateEntity current = root;
        int i = 0;
        for (String groupbyField : groupbyFields) {
            // determine groupbyFieldValue from tag or fields
            String groupbyFieldValue = determineGroupbyFieldValue(entity, groupbyField, i);
            SortedMap<String, HierarchicalAggregateEntity> children = current.getChildren();
            if (children.get(groupbyFieldValue) == null) {
                HierarchicalAggregateEntity tmp = new HierarchicalAggregateEntity();
                children.put(groupbyFieldValue, tmp);
            }
            children.get(groupbyFieldValue).setKey(groupbyFieldValue);
            addDatapoint(children.get(groupbyFieldValue), preAggregatedValues);
            current = children.get(groupbyFieldValue);
        }
    }

    private void addDatapoint(HierarchicalAggregateEntity entity, List<Double> values) {
        List<GroupbyBucket.Function> functions = entity.getTmpValues();
        // initialize list of function
        if (functions.isEmpty()) {
            for (AggregateFunctionType type : aggregateFunctionTypes) {
                functions.add(GroupbyBucket.functionFactories.get(type.name()).createFunction());
            }
        }
        int functionIndex = 0;
        for (Double v : values) {
            functions.get(functionIndex).run(v);
            functionIndex++;
        }
    }

    private void finalizeHierarchicalAggregateEntity(HierarchicalAggregateEntity entity) {
        for (GroupbyBucket.Function f : entity.getTmpValues()) {
            entity.getValues().add(f.result());
        }
        for (HierarchicalAggregateEntity child : entity.getChildren().values()) {
            finalizeHierarchicalAggregateEntity(child);
        }
        entity.setTmpValues(null);
    }

    public HierarchicalAggregateEntity result() {
        finalizeHierarchicalAggregateEntity(root);
        return this.root;
    }
}