io.druid.query.groupby.RowBasedValueMatcherFactory.java Source code

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Here is the source code for io.druid.query.groupby.RowBasedValueMatcherFactory.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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 io.druid.query.groupby;

import com.google.common.base.Predicate;
import com.google.common.base.Strings;
import io.druid.common.guava.GuavaUtils;
import io.druid.data.input.Row;
import io.druid.query.filter.DruidLongPredicate;
import io.druid.query.filter.DruidPredicateFactory;
import io.druid.query.filter.ValueMatcher;
import io.druid.query.filter.ValueMatcherFactory;
import io.druid.segment.column.Column;
import io.druid.segment.filter.BooleanValueMatcher;

import java.util.List;
import java.util.Objects;

public class RowBasedValueMatcherFactory implements ValueMatcherFactory {
    private Row row;

    public void setRow(Row row) {
        this.row = row;
    }

    @Override
    public ValueMatcher makeValueMatcher(final String dimension, final String value) {
        if (dimension.equals(Column.TIME_COLUMN_NAME)) {
            if (value == null) {
                return new BooleanValueMatcher(false);
            }

            final Long longValue = GuavaUtils.tryParseLong(value);
            if (longValue == null) {
                return new BooleanValueMatcher(false);
            }

            return new ValueMatcher() {
                // store the primitive, so we don't unbox for every comparison
                final long unboxedLong = longValue;

                @Override
                public boolean matches() {
                    return row.getTimestampFromEpoch() == unboxedLong;
                }
            };
        } else {
            final String valueOrNull = Strings.emptyToNull(value);
            return new ValueMatcher() {
                @Override
                public boolean matches() {
                    return doesMatch(row.getRaw(dimension), valueOrNull);
                }
            };
        }
    }

    // There is no easy way to determine column types from a Row, so this generates all possible predicates and then
    // uses instanceof checks to determine which one to apply to each row.
    @Override
    public ValueMatcher makeValueMatcher(final String dimension, final DruidPredicateFactory predicateFactory) {
        if (dimension.equals(Column.TIME_COLUMN_NAME)) {
            return new ValueMatcher() {
                final DruidLongPredicate predicate = predicateFactory.makeLongPredicate();

                @Override
                public boolean matches() {
                    return predicate.applyLong(row.getTimestampFromEpoch());
                }
            };
        } else {
            return new ValueMatcher() {
                final Predicate<String> stringPredicate = predicateFactory.makeStringPredicate();
                final DruidLongPredicate longPredicate = predicateFactory.makeLongPredicate();

                @Override
                public boolean matches() {
                    return doesMatch(row.getRaw(dimension), stringPredicate, longPredicate);
                }
            };
        }
    }

    // Precondition: value must be run through Strings.emptyToNull
    private boolean doesMatch(final Object raw, final String value) {
        if (raw == null) {
            return value == null;
        } else if (raw instanceof List) {
            final List theList = (List) raw;
            if (theList.isEmpty()) {
                // null should match empty rows in multi-value columns
                return value == null;
            } else {
                for (Object o : theList) {
                    if (doesMatch(o, value)) {
                        return true;
                    }
                }

                return false;
            }
        } else {
            return Objects.equals(Strings.emptyToNull(raw.toString()), value);
        }
    }

    private boolean doesMatch(final Object raw, final Predicate<String> stringPredicate,
            final DruidLongPredicate longPredicate) {
        if (raw == null) {
            return stringPredicate.apply(null);
        } else if (raw instanceof List) {
            final List theList = (List) raw;
            if (theList.isEmpty()) {
                return stringPredicate.apply(null);
            } else {
                for (Object o : theList) {
                    if (doesMatch(o, stringPredicate, longPredicate)) {
                        return true;
                    }
                }

                return false;
            }
        } else if (raw instanceof Long || raw instanceof Integer) {
            return longPredicate.applyLong(((Number) raw).longValue());
        } else {
            return stringPredicate.apply(Strings.emptyToNull(raw.toString()));
        }
    }
}