RegexEtmFilter.java

/*
 *
 * Copyright (c) void.fm
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
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 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
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 * Neither the name void.fm nor the names of its contributors may be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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package etm.contrib.aggregation.filter;

import etm.core.aggregation.EtmFilter;
import etm.core.monitor.EtmPoint;

import java.util.HashSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 *
 * The RegexAggregationFilter filters etm point names based
 * on a list of JDK 1.4 regex.
 *
 * @version $Revision$
 * @author void.fm
 * @since 1.2.0
 * @see java.util.regex.Pattern
 */
public class RegexEtmFilter implements EtmFilter {
  protected final HashSet validNames;
  protected Pattern[] pattern;

  /**
   *
   * Create a RegexAggregationFilter instance based on a list
   * of regex pattern separated by semicolon.
   *
   * @param listOfPattern Java 1.4 Regex separated by semicolon.
   */
  public RegexEtmFilter(String listOfPattern) {
    this(listOfPattern.split(";"));
  }


  /**
   *
   * Create a RegexAggregationFilter
   *
   * @param regexPattern The Java 1.4 regex patterm/
   */
  public RegexEtmFilter(String[] regexPattern) {
    this.pattern = new Pattern[regexPattern.length];

    for (int i = 0; i < regexPattern.length; i++) {
      String string = regexPattern[i].trim();
      if (string.length() > 0) {
        this.pattern[i] = Pattern.compile(string);
      }
    }

    validNames = new HashSet();
  }

  public boolean matches(EtmPoint aPoint) {
    String name = aPoint.getName();
    if (validNames.contains(name)) {
      return true;
    }

    for (int i = 0; i < pattern.length; i++) {
      Matcher matcher = pattern[i].matcher(name);
      if (matcher.matches()) {
        synchronized (validNames) {
          validNames.add(name);
        }
        return true;
      }
    }
    return false;
  }
}