com.linkedin.pinot.core.query.aggregation.function.AggregationFunctionUtils.java Source code

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Here is the source code for com.linkedin.pinot.core.query.aggregation.function.AggregationFunctionUtils.java

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/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * 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 com.linkedin.pinot.core.query.aggregation.function;

import com.google.common.math.DoubleMath;
import com.linkedin.pinot.common.request.AggregationInfo;
import com.linkedin.pinot.common.segment.SegmentMetadata;
import com.linkedin.pinot.core.plan.AggregationFunctionInitializer;
import com.linkedin.pinot.core.query.aggregation.AggregationFunctionContext;
import java.util.List;
import java.util.Locale;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

/**
 * The <code>AggregationFunctionUtils</code> class provides utility methods for aggregation function.
 */
public class AggregationFunctionUtils {
    private AggregationFunctionUtils() {
    }

    @Nonnull
    public static AggregationFunctionContext[] getAggregationFunctionContexts(
            @Nonnull List<AggregationInfo> aggregationInfos, @Nullable SegmentMetadata segmentMetadata) {
        int numAggregationFunctions = aggregationInfos.size();
        AggregationFunctionContext[] aggregationFunctionContexts = new AggregationFunctionContext[numAggregationFunctions];
        for (int i = 0; i < numAggregationFunctions; i++) {
            AggregationInfo aggregationInfo = aggregationInfos.get(i);
            aggregationFunctionContexts[i] = AggregationFunctionContext.instantiate(aggregationInfo);
        }
        if (segmentMetadata != null) {
            AggregationFunctionInitializer aggregationFunctionInitializer = new AggregationFunctionInitializer(
                    segmentMetadata);
            for (AggregationFunctionContext aggregationFunctionContext : aggregationFunctionContexts) {
                aggregationFunctionContext.getAggregationFunction().accept(aggregationFunctionInitializer);
            }
        }
        return aggregationFunctionContexts;
    }

    @Nonnull
    public static AggregationFunction[] getAggregationFunctions(@Nonnull List<AggregationInfo> aggregationInfos) {
        int numAggregationFunctions = aggregationInfos.size();
        AggregationFunction[] aggregationFunctions = new AggregationFunction[numAggregationFunctions];
        for (int i = 0; i < numAggregationFunctions; i++) {
            aggregationFunctions[i] = AggregationFunctionFactory
                    .getAggregationFunction(aggregationInfos.get(i).getAggregationType());
        }
        return aggregationFunctions;
    }

    @Nonnull
    public static boolean[] getAggregationFunctionsSelectStatus(@Nonnull List<AggregationInfo> aggregationInfos) {
        int numAggregationFunctions = aggregationInfos.size();
        boolean[] aggregationFunctionsStatus = new boolean[numAggregationFunctions];
        for (int i = 0; i < numAggregationFunctions; i++) {
            aggregationFunctionsStatus[i] = aggregationInfos.get(i).isIsInSelectList();
        }
        return aggregationFunctionsStatus;
    }

    @Nonnull
    public static String formatValue(@Nonnull Object value) {
        if (value instanceof Double) {
            Double doubleValue = (Double) value;

            // String.format is very expensive, so avoid it for whole numbers that can fit in Long.
            // We simply append ".00000" to long, in order to keep the existing behavior.
            if (doubleValue <= Long.MAX_VALUE && DoubleMath.isMathematicalInteger(doubleValue)) {
                return Long.toString(doubleValue.longValue()) + ".00000";
            } else {
                return String.format(Locale.US, "%1.5f", doubleValue);
            }
        } else {
            return value.toString();
        }
    }
}