andresgomezfrr commented on a change in pull request #5789: Add stringLast and stringFirst aggregators extension URL: https://github.com/apache/incubator-druid/pull/5789#discussion_r205684184
########## File path: processing/src/main/java/io/druid/query/aggregation/first/StringFirstAggregatorFactory.java ########## @@ -0,0 +1,224 @@ +/* + * 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.aggregation.first; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.fasterxml.jackson.annotation.JsonTypeName; +import com.google.common.base.Preconditions; +import com.google.common.primitives.Longs; +import io.druid.query.aggregation.AggregateCombiner; +import io.druid.query.aggregation.Aggregator; +import io.druid.query.aggregation.AggregatorFactory; +import io.druid.query.aggregation.AggregatorUtil; +import io.druid.query.aggregation.BufferAggregator; +import io.druid.query.aggregation.SerializablePairLongString; +import io.druid.query.cache.CacheKeyBuilder; +import io.druid.segment.ColumnSelectorFactory; +import io.druid.segment.column.Column; + +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.Objects; + +@JsonTypeName("stringFirst") +public class StringFirstAggregatorFactory extends AggregatorFactory +{ + public static final int DEFAULT_MAX_STRING_SIZE = 1024; + + public static final Comparator TIME_COMPARATOR = (o1, o2) -> Longs.compare( + ((SerializablePairLongString) o1).lhs, + ((SerializablePairLongString) o2).lhs + ); + + public static final Comparator VALUE_COMPARATOR = (o1, o2) -> { + String s1 = null; + String s2 = null; + + if (o1 != null) { + s1 = ((SerializablePairLongString) o1).rhs; + } + if (o2 != null) { + s2 = ((SerializablePairLongString) o2).rhs; + } + + return Objects.equals(s1, s2) ? 1 : 0; + }; + + private final String fieldName; + private final String name; + protected final int maxStringBytes; + + @JsonCreator + public StringFirstAggregatorFactory( + @JsonProperty("name") String name, + @JsonProperty("fieldName") final String fieldName, + @JsonProperty("maxStringBytes") Integer maxStringBytes + ) + { + Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); + this.name = name; + this.fieldName = fieldName; + this.maxStringBytes = maxStringBytes == null ? DEFAULT_MAX_STRING_SIZE : maxStringBytes; + } + + @Override + public Aggregator factorize(ColumnSelectorFactory metricFactory) + { + return new StringFirstAggregator( + metricFactory.makeColumnValueSelector(Column.TIME_COLUMN_NAME), + metricFactory.makeColumnValueSelector(fieldName), + maxStringBytes + ); + } + + @Override + public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) + { + return new StringFirstBufferAggregator( + metricFactory.makeColumnValueSelector(Column.TIME_COLUMN_NAME), + metricFactory.makeColumnValueSelector(fieldName), + maxStringBytes + ); + } + + @Override + public Comparator getComparator() + { + return VALUE_COMPARATOR; + } + + @Override + public Object combine(Object lhs, Object rhs) + { + return TIME_COMPARATOR.compare(lhs, rhs) > 0 ? lhs : rhs; + } + + @Override + public AggregateCombiner makeAggregateCombiner() + { + return new StringFirstAggregateCombiner(); + } + + @Override + public AggregatorFactory getCombiningFactory() + { + return new StringFirstFoldingAggregatorFactory(name, name, maxStringBytes); + } + + @Override + public List<AggregatorFactory> getRequiredColumns() + { + return Arrays.<AggregatorFactory>asList(new StringFirstAggregatorFactory(fieldName, fieldName, maxStringBytes)); Review comment: :+1: ---------------------------------------------------------------- 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
