org.apache.druid.data.input.Rows.java Source code

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Here is the source code for org.apache.druid.data.input.Rows.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.druid.data.input;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSortedSet;
import com.google.common.collect.Maps;
import com.google.common.primitives.Longs;
import org.apache.druid.common.config.NullHandling;
import org.apache.druid.java.util.common.StringUtils;
import org.apache.druid.java.util.common.parsers.ParseException;

import javax.annotation.Nullable;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

/**
 */
public class Rows {

    /**
     * @param timeStamp rollup up timestamp to be used to create group key
     * @param inputRow  input row
     *
     * @return groupKey for the given input row
     */
    public static List<Object> toGroupKey(long timeStamp, InputRow inputRow) {
        final Map<String, Set<String>> dims = Maps.newTreeMap();
        for (final String dim : inputRow.getDimensions()) {
            final Set<String> dimValues = ImmutableSortedSet.copyOf(inputRow.getDimension(dim));
            if (dimValues.size() > 0) {
                dims.put(dim, dimValues);
            }
        }
        return ImmutableList.of(timeStamp, dims);
    }

    /**
     * Convert an object to a list of strings.
     */
    public static List<String> objectToStrings(final Object inputValue) {
        if (inputValue == null) {
            return Collections.emptyList();
        } else if (inputValue instanceof List) {
            // guava's toString function fails on null objects, so please do not use it
            return ((List<?>) inputValue).stream().map(String::valueOf).collect(Collectors.toList());
        } else {
            return Collections.singletonList(String.valueOf(inputValue));
        }
    }

    /**
     * Convert an object to a number. Nulls are treated as zeroes.
     *
     * @param name       field name of the object being converted (may be used for exception messages)
     * @param inputValue the actual object being converted
     *
     * @return a number
     *
     * @throws NullPointerException if the string is null
     * @throws ParseException       if the column cannot be converted to a number
     */
    @Nullable
    public static Number objectToNumber(final String name, final Object inputValue) {
        if (inputValue == null) {
            return NullHandling.defaultLongValue();
        }

        if (inputValue instanceof Number) {
            return (Number) inputValue;
        } else if (inputValue instanceof String) {
            try {
                String metricValueString = StringUtils.removeChar(((String) inputValue).trim(), ',');
                // Longs.tryParse() doesn't support leading '+', so we need to trim it ourselves
                metricValueString = trimLeadingPlusOfLongString(metricValueString);
                Long v = Longs.tryParse(metricValueString);
                // Do NOT use ternary operator here, because it makes Java to convert Long to Double
                if (v != null) {
                    return v;
                } else {
                    return Double.valueOf(metricValueString);
                }
            } catch (Exception e) {
                throw new ParseException(e, "Unable to parse value[%s] for field[%s]", inputValue, name);
            }
        } else {
            throw new ParseException("Unknown type[%s] for field", inputValue.getClass(), inputValue);
        }
    }

    private static String trimLeadingPlusOfLongString(String metricValueString) {
        if (metricValueString.length() > 1 && metricValueString.charAt(0) == '+') {
            char secondChar = metricValueString.charAt(1);
            if (secondChar >= '0' && secondChar <= '9') {
                metricValueString = metricValueString.substring(1);
            }
        }
        return metricValueString;
    }
}