org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude Maven / Gradle / Ivy
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.search.aggregations.bucket.terms.support;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.CharsRef;
import org.apache.lucene.util.UnicodeUtil;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Defines the include/exclude regular expression filtering for string terms aggregation. In this filtering logic,
* exclusion has precedence, where the {@code include} is evaluated first and then the {@code exclude}.
*/
public class IncludeExclude {
private final Matcher include;
private final Matcher exclude;
private final CharsRef scratch = new CharsRef();
/**
* @param include The regular expression pattern for the terms to be included
* (may only be {@code null} if {@code exclude} is not {@code null}
* @param exclude The regular expression pattern for the terms to be excluded
* (may only be {@code null} if {@code include} is not {@code null}
*/
public IncludeExclude(Pattern include, Pattern exclude) {
assert include != null || exclude != null : "include & exclude cannot both be null"; // otherwise IncludeExclude object should be null
this.include = include != null ? include.matcher("") : null;
this.exclude = exclude != null ? exclude.matcher("") : null;
}
/**
* Returns whether the given value is accepted based on the {@code include} & {@code exclude} patterns.
*/
public boolean accept(BytesRef value) {
UnicodeUtil.UTF8toUTF16(value, scratch);
if (include == null) {
// exclude must not be null
return !exclude.reset(scratch).matches();
}
if (!include.reset(scratch).matches()) {
return false;
}
if (exclude == null) {
return true;
}
return !exclude.reset(scratch).matches();
}
}