jihoonson commented on a change in pull request #6396: Implement MapVirtualColumn.makeDimensionSelector properly URL: https://github.com/apache/incubator-druid/pull/6396#discussion_r221338768
########## File path: extensions-contrib/virtual-columns/src/main/java/org/apache/druid/segment/StringTypeMapVirtualColumnDimensionSelector.java ########## @@ -0,0 +1,210 @@ +/* + * 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.segment; + +import com.google.common.base.Preconditions; +import com.google.common.base.Predicate; +import org.apache.druid.query.filter.ValueMatcher; +import org.apache.druid.query.monomorphicprocessing.RuntimeShapeInspector; +import org.apache.druid.segment.data.IndexedInts; +import org.apache.druid.segment.data.SingleIndexedInt; +import org.apache.druid.segment.data.ZeroIndexedInts; + +import javax.annotation.Nullable; +import java.util.Objects; +import java.util.stream.IntStream; + +/** + * {@link DimensionSelector} for String type {@link MapVirtualColumn}. The performance has not considered yet and so + * it may need to be improved later. + */ +final class StringTypeMapVirtualColumnDimensionSelector extends MapVirtualColumnDimensionSelector +{ + private final String subColumnName; + + StringTypeMapVirtualColumnDimensionSelector( + DimensionSelector keySelector, + DimensionSelector valueSelector, + String subColumnName + ) + { + super(keySelector, valueSelector); + this.subColumnName = Preconditions.checkNotNull(subColumnName, "subColumnName"); + } + + @Override + public IndexedInts getRow() + { + final DimensionSelector keySelector = getKeySelector(); + final DimensionSelector valueSelector = getValueSelector(); + + final IndexedInts keyIndices = keySelector.getRow(); + final IndexedInts valueIndices = valueSelector.getRow(); + + final int limit = Math.min(keyIndices.size(), valueIndices.size()); + final int valueIndex = IntStream + .range(0, limit) + .filter(i -> subColumnName.equals(keySelector.lookupName(keyIndices.get(i)))) // subColumnName is never null + .findAny() + .orElse(-1); + if (valueIndex < 0) { + return ZeroIndexedInts.instance(); + } else { + return new SingleIndexedInt(valueIndex); + } + } + + @Override + public ValueMatcher makeValueMatcher(@Nullable String value) + { + return new ValueMatcher() + { + @Override + public boolean matches() + { + return Objects.equals(value, getObject()); + } + + @Override + public void inspectRuntimeShape(RuntimeShapeInspector inspector) + { + inspector.visit("keySelector", getKeySelector()); + inspector.visit("valueSelector", getValueSelector()); + inspector.visit("subColumnName", subColumnName); + } + }; + } + + @Override + public ValueMatcher makeValueMatcher(Predicate<String> predicate) + { + return new ValueMatcher() + { + @Override + public boolean matches() + { + return predicate.apply((String) getObject()); + } + + @Override + public void inspectRuntimeShape(RuntimeShapeInspector inspector) + { + inspector.visit("keySelector", getKeySelector()); + inspector.visit("valueSelector", getValueSelector()); + inspector.visit("subColumnName", subColumnName); + } + }; + } + + @Override + public int getValueCardinality() + { + // To get the value cardinarlity, we need to first check all keys and values to find valid pairs, and then find the + // number of distinct values among them. + return CARDINALITY_UNKNOWN; + } + + @Nullable + @Override + public String lookupName(int id) + { + final DimensionSelector keySelector = getKeySelector(); + final DimensionSelector valueSelector = getValueSelector(); + + final IndexedInts keyIndices = keySelector.getRow(); + final IndexedInts valueIndices = valueSelector.getRow(); + + final int limit = Math.min(keyIndices.size(), valueIndices.size()); + final int valueIndex = IntStream + .range(0, limit) + .filter(i -> subColumnName.equals(keySelector.lookupName(keyIndices.get(i)))) // subColumnName is never null + .findAny() + .orElse(-1); + + if (valueIndex == id) { + return valueSelector.lookupName(id); + } else { + return null; + } + } + + @Override + public boolean nameLookupPossibleInAdvance() + { + return false; + } + + @Nullable + @Override + public IdLookup idLookup() + { + final DimensionSelector keySelector = getKeySelector(); + final DimensionSelector valueSelector = getValueSelector(); + + final IdLookup valueLookup = valueSelector.idLookup(); + + if (valueLookup != null) { + final IndexedInts keyIndices = keySelector.getRow(); + final IndexedInts valueIndices = valueSelector.getRow(); + + final int limit = Math.min(keyIndices.size(), valueIndices.size()); + final int valueIndex = IntStream + .range(0, limit) + .filter(i -> subColumnName.equals(keySelector.lookupName(keyIndices.get(i)))) // subColumnName is never null + .findAny() + .orElse(-1); Review comment: Done. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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