Benchmark.java

package org.arabidopsis.ahocorasick;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Benchmark {
  public static void main(String[] args) throws IOException, InterruptedException {
    String[] words = {
      "Christmas", "Cains", "Marley", "spectre", "Ebenezer", "double-ironed", "supernatural", "SPIRITS",
      "Ding", "Ali Baba"
    };

    long t0 = System.currentTimeMillis();

    BufferedReader fr = new BufferedReader(
        new InputStreamReader(Benchmark.class.getResourceAsStream("christmas.txt")));
    String text = "";
    String line = fr.readLine();
    while(line != null) {
      text += line + "\n";
      line = fr.readLine();
    }

    System.out.println("Starting benchmark");
    long t1 = System.currentTimeMillis();

    AhoCorasick finder = new AhoCorasick();
    for (String word: words)
      finder.add(word, word.toCharArray());
    finder.prepare();

    Iterator it = finder.search(text.toCharArray());
    while(it.hasNext())
      it.next();

    long t2 = System.currentTimeMillis();

    String pattern = "";
    for(String word: words) {
      if(!pattern.equals(""))
        pattern += "|";
      pattern += word;
    }
    Pattern p = Pattern.compile(pattern);
    Matcher m = p.matcher(text);
    while(m.find())
      continue;

    long t3 = System.currentTimeMillis();

    System.out.println("File reading: " + Long.toString(t1 - t0) + "ms");
    System.out.println("Aho-Corasick: " + Long.toString(t2 - t1) + "ms");
    System.out.println("Java-regexp: " + Long.toString(t3 - t2) + "ms");
  }
}