import org.drools.*;
import org.drools.io.RuleBaseLoader;
import org.xml.sax.SAXException;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
import java.io.IOException;

public class DroolsPerformanceExample {
    private RuleBase ruleBase;
    private List facts;

    private void initializeFacts(int n) {
        facts = new ArrayList(n);
        for(int i = 0; i < n; i++) {
            facts.add(new Integer(i));
        }
    }

    private void initializeRuleBase()
            throws IntegrationException, IOException, SAXException {
        ruleBase = RuleBaseLoader.loadFromUrl(DroolsPerformanceExample.class.getResource("odds.java.drl"));
    }

    private void run(int loopCount, int factCount, int printCount)
            throws IntegrationException, IOException, SAXException, FactException {
        initializeRuleBase();
        initializeFacts(factCount);
        int count = 0;
        long start = System.currentTimeMillis();
        long stop;
        for(int i = 0; i < loopCount; i++) {
            WorkingMemory workingMemory = ruleBase.newWorkingMemory();
            for (Iterator iter = facts.iterator(); iter.hasNext();) {
                Integer fact = (Integer) iter.next();
                workingMemory.assertObject(fact);
            }
            workingMemory.fireAllRules();
            count++;
            if (count == printCount) {
                stop = System.currentTimeMillis();
                System.out.println((i - count)+" - "+i+": "+(stop-start));
                count = 0;
                start = System.currentTimeMillis();
            }
        }
        if (count > 0) {
            stop = System.currentTimeMillis();
            System.out.println((loopCount - count)+" - "+loopCount+": "+(stop-start));
        }
    }

    public static void main(String[] args)
            throws IntegrationException, IOException, FactException, SAXException {
        DroolsPerformanceExample example = new DroolsPerformanceExample();
        example.run(1000000, 10, 1000);
    }

}