io.druid.segment.virtual.ExpressionObjectSelector Maven / Gradle / Ivy
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* Licensed to Metamarkets Group Inc. (Metamarkets) under one
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* 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
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package io.druid.segment.virtual;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.base.Supplier;
import com.google.common.collect.Maps;
import io.druid.math.expr.Expr;
import io.druid.math.expr.ExprEval;
import io.druid.math.expr.Parser;
import io.druid.query.dimension.DefaultDimensionSpec;
import io.druid.segment.ColumnSelectorFactory;
import io.druid.segment.DimensionSelector;
import io.druid.segment.ObjectColumnSelector;
import io.druid.segment.column.ColumnCapabilities;
import io.druid.segment.column.ValueType;
import io.druid.segment.data.IndexedInts;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Map;
public class ExpressionObjectSelector implements ObjectColumnSelector
{
private final Expr expression;
private final Expr.ObjectBinding bindings;
private ExpressionObjectSelector(Expr.ObjectBinding bindings, Expr expression)
{
this.bindings = Preconditions.checkNotNull(bindings, "bindings");
this.expression = Preconditions.checkNotNull(expression, "expression");
}
static ExpressionObjectSelector from(ColumnSelectorFactory columnSelectorFactory, Expr expression)
{
return new ExpressionObjectSelector(createBindings(columnSelectorFactory, expression), expression);
}
private static Expr.ObjectBinding createBindings(ColumnSelectorFactory columnSelectorFactory, Expr expression)
{
final Map> suppliers = Maps.newHashMap();
for (String columnName : Parser.findRequiredBindings(expression)) {
final ColumnCapabilities columnCapabilities = columnSelectorFactory.getColumnCapabilities(columnName);
final ValueType nativeType = columnCapabilities != null ? columnCapabilities.getType() : null;
final Supplier