/**
* Copyright 2013 Netflix, Inc.
*
* Licensed 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 com.netflix.servo.publish;
import com.netflix.servo.monitor.MonitorConfig;
import com.netflix.servo.tag.Tag;
import com.netflix.servo.tag.TagList;
import java.util.regex.Pattern;
/**
* Filter that checks if a tag value matches a regular expression.
*/
public final class RegexMetricFilter implements MetricFilter {
private final String tagKey;
private final Pattern pattern;
private final boolean matchIfMissingTag;
private final boolean invert;
/**
* Creates a new regex filter.
*
* @param tagKey tag to check against the pattern
* @param pattern pattern to check
* @param matchIfMissingTag should metrics without the specified tag match?
* @param invert should the match be inverted?
*/
public RegexMetricFilter(
String tagKey,
Pattern pattern,
boolean matchIfMissingTag,
boolean invert) {
this.tagKey = tagKey;
this.pattern = pattern;
this.matchIfMissingTag = matchIfMissingTag;
this.invert = invert;
}
/** {@inheritDoc} */
public boolean matches(MonitorConfig config) {
String name = config.getName();
TagList tags = config.getTags();
String value;
if (tagKey == null) {
value = name;
} else {
Tag t = tags.getTag(tagKey);
value = (t == null) ? null : t.getValue();
}
boolean match = matchIfMissingTag;
if (value != null) {
match = pattern.matcher(value).matches();
}
return match ^ invert;
}
}