io.druid.query.Queries.java Source code

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Here is the source code for io.druid.query.Queries.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * Licensed 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 io.druid.query;

import com.google.common.base.Preconditions;
import com.google.common.collect.Sets;
import io.druid.query.aggregation.AggregatorFactory;
import io.druid.query.aggregation.PostAggregator;

import java.util.List;
import java.util.Set;

/**
 */
public class Queries {
    public static void verifyAggregations(List<AggregatorFactory> aggFactories, List<PostAggregator> postAggs) {
        Preconditions.checkNotNull(aggFactories, "aggregations cannot be null");
        Preconditions.checkArgument(aggFactories.size() > 0, "Must have at least one AggregatorFactory");

        final Set<String> aggNames = Sets.newHashSet();
        for (AggregatorFactory aggFactory : aggFactories) {
            Preconditions.checkArgument(aggNames.add(aggFactory.getName()), "[%s] already defined",
                    aggFactory.getName());
        }

        if (postAggs != null && !postAggs.isEmpty()) {
            final Set<String> combinedAggNames = Sets.newHashSet(aggNames);

            for (PostAggregator postAgg : postAggs) {
                final Set<String> dependencies = postAgg.getDependentFields();
                final Set<String> missing = Sets.difference(dependencies, combinedAggNames);

                Preconditions.checkArgument(missing.isEmpty(), "Missing fields [%s] for postAggregator [%s]",
                        missing, postAgg.getName());
                Preconditions.checkArgument(combinedAggNames.add(postAgg.getName()), "[%s] already defined");
            }
        }
    }
}