org.apache.hadoop.hive.ql.udf.UDFRegExp Maven / Gradle / Ivy
/**
* 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.hadoop.hive.ql.udf;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.FilterStringColRegExpStringScalar;
import org.apache.hadoop.io.BooleanWritable;
import org.apache.hadoop.io.Text;
/**
* UDFRegExp.
*
*/
@Description(name = "rlike,regexp",
value = "str _FUNC_ regexp - Returns true if str matches regexp and "
+ "false otherwise", extended = "Example:\n"
+ " > SELECT 'fb' _FUNC_ '.*' FROM src LIMIT 1;\n" + " true")
@VectorizedExpressions({FilterStringColRegExpStringScalar.class})
public class UDFRegExp extends UDF {
static final Log LOG = LogFactory.getLog(UDFRegExp.class.getName());
private final Text lastRegex = new Text();
private Pattern p = null;
private boolean warned = false;
private final BooleanWritable result = new BooleanWritable();
public UDFRegExp() {
}
public BooleanWritable evaluate(Text s, Text regex) {
if (s == null || regex == null) {
return null;
}
if (regex.getLength() == 0) {
if (!warned) {
warned = true;
LOG.warn(getClass().getSimpleName() + " regex is empty. Additional "
+ "warnings for an empty regex will be suppressed.");
}
result.set(false);
return result;
}
if (!regex.equals(lastRegex) || p == null) {
lastRegex.set(regex);
p = Pattern.compile(regex.toString());
}
Matcher m = p.matcher(s.toString());
result.set(m.find(0));
return result;
}
}