org.apache.druid.query.expression.RegexpLikeExprMacro Maven / Gradle / Ivy
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A module that is everything required to understands Druid Segments
/*
* 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.expression;
import org.apache.druid.common.config.NullHandling;
import org.apache.druid.java.util.common.StringUtils;
import org.apache.druid.math.expr.Expr;
import org.apache.druid.math.expr.ExprEval;
import org.apache.druid.math.expr.ExprMacroTable;
import org.apache.druid.math.expr.ExpressionType;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexpLikeExprMacro implements ExprMacroTable.ExprMacro
{
private static final String FN_NAME = "regexp_like";
@Override
public String name()
{
return FN_NAME;
}
@Override
public Expr apply(final List args)
{
validationHelperCheckArgumentCount(args, 2);
final Expr arg = args.get(0);
final Expr patternExpr = args.get(1);
if (!ExprUtils.isStringLiteral(patternExpr)) {
throw validationFailed("pattern must be a STRING literal");
}
// Precompile the pattern.
final Pattern pattern = Pattern.compile(
StringUtils.nullToEmptyNonDruidDataString((String) patternExpr.getLiteralValue())
);
class RegexpLikeExpr extends ExprMacroTable.BaseScalarUnivariateMacroFunctionExpr
{
private RegexpLikeExpr(Expr arg)
{
super(FN_NAME, arg);
}
@Nonnull
@Override
public ExprEval eval(final ObjectBinding bindings)
{
final String s = NullHandling.nullToEmptyIfNeeded(arg.eval(bindings).asString());
if (s == null) {
// True nulls do not match anything. Note: this branch only executes in SQL-compatible null handling mode.
return ExprEval.ofLongBoolean(false);
} else {
final Matcher matcher = pattern.matcher(s);
return ExprEval.ofLongBoolean(matcher.find());
}
}
@Override
public Expr visit(Shuttle shuttle)
{
return shuttle.visit(apply(shuttle.visitAll(args)));
}
@Nullable
@Override
public ExpressionType getOutputType(InputBindingInspector inspector)
{
return ExpressionType.LONG;
}
@Override
public String stringify()
{
return StringUtils.format("%s(%s, %s)", FN_NAME, arg.stringify(), patternExpr.stringify());
}
}
return new RegexpLikeExpr(arg);
}
}