jon-wei commented on a change in pull request #6307: add PrefixFilteredDimensionSpec for multi-value dimensions URL: https://github.com/apache/incubator-druid/pull/6307#discussion_r224568087
########## File path: processing/src/main/java/org/apache/druid/query/dimension/PrefixFilteredDimensionSpec.java ########## @@ -0,0 +1,144 @@ +/* + * 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.query.dimension; + +import com.fasterxml.jackson.annotation.JsonProperty; +import com.google.common.base.Preconditions; +import com.google.common.base.Predicate; +import org.apache.druid.common.config.NullHandling; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.query.filter.DimFilterUtils; +import org.apache.druid.segment.DimensionSelector; +import it.unimi.dsi.fastutil.ints.Int2IntMap; +import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap; +import java.nio.ByteBuffer; +import javax.annotation.Nullable; + +/** + */ +public class PrefixFilteredDimensionSpec extends BaseFilteredDimensionSpec +{ + + private static final byte CACHE_TYPE_ID = 0x4; + + private final String prefix; + + public PrefixFilteredDimensionSpec( + @JsonProperty("delegate") DimensionSpec delegate, + @JsonProperty("prefix") String prefix //rows not starting with the prefix will be discarded + ) + { + super(delegate); + this.prefix = Preconditions.checkNotNull(prefix, "prefix must not be null"); + } + + @JsonProperty + public String getPrefix() + { + return prefix; + } + + @Override + public DimensionSelector decorate(final DimensionSelector selector) + { + if (selector == null) { + return null; + } + + final int selectorCardinality = selector.getValueCardinality(); + if (selectorCardinality < 0 || !selector.nameLookupPossibleInAdvance()) { + return new PredicateFilteredDimensionSelector( + selector, + new Predicate<String>() + { + @Override + public boolean apply(@Nullable String input) + { + return NullHandling.nullToEmptyIfNeeded(input).startsWith(prefix); Review comment: The result of `NullHandling.nullToEmptyIfNeeded(input)` needs a null check, since it can return null if `druid.generic.useDefaultValueForNull` is false ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
