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_r206687464
########## File path: processing/src/main/java/io/druid/query/aggregation/last/StringLastAggregatorFactory.java ########## @@ -0,0 +1,206 @@ +/* + * 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 io.druid.query.aggregation.last; + +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 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.aggregation.first.StringFirstAggregatorFactory; +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("stringLast") +public class StringLastAggregatorFactory extends AggregatorFactory +{ + private final String fieldName; + private final String name; + protected final int maxStringBytes; + + @JsonCreator + public StringLastAggregatorFactory( + @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 + ? StringFirstAggregatorFactory.DEFAULT_MAX_STRING_SIZE + : maxStringBytes; + } + + @Override + public Aggregator factorize(ColumnSelectorFactory metricFactory) + { + return new StringLastAggregator( + metricFactory.makeColumnValueSelector(Column.TIME_COLUMN_NAME), + metricFactory.makeColumnValueSelector(fieldName), + maxStringBytes + ); + } + + @Override + public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) + { + return new StringLastBufferAggregator( + metricFactory.makeColumnValueSelector(Column.TIME_COLUMN_NAME), + metricFactory.makeColumnValueSelector(fieldName), + maxStringBytes + ); + } + + @Override + public Comparator getComparator() + { + return StringFirstAggregatorFactory.VALUE_COMPARATOR; + } + + @Override + public Object combine(Object lhs, Object rhs) + { + return StringFirstAggregatorFactory.TIME_COMPARATOR.compare(lhs, rhs) > 0 ? lhs : rhs; + } + + @Override + public AggregateCombiner makeAggregateCombiner() + { + return new StringLastAggregateCombiner(); + } + + @Override + public AggregatorFactory getCombiningFactory() + { + return new StringLastFoldingAggregatorFactory(name, name, maxStringBytes); + } + + @Override + public List<AggregatorFactory> getRequiredColumns() + { + return Arrays.asList(new StringLastAggregatorFactory(fieldName, fieldName, maxStringBytes)); Review comment: 👍 ---------------------------------------------------------------- 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
