LargeRuleBase.java

package org.drools.integrationtests;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.StringReader;

import junit.framework.Assert;

import org.drools.RuleBase;
import org.drools.RuleBaseFactory;
import org.drools.common.DroolsObjectOutputStream;
import org.drools.compiler.DrlParser;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
import org.drools.lang.descr.PackageDescr;
import org.drools.rule.Package;

/**
 * This generates a large number of rules (complex ones) and then times
 * compiling, serializing etc.
 */
public class LargeRuleBase {

	private static final int RULE_COUNT = 20000;

	public static void main(String[] args) throws Exception {
		System.err.println(Runtime.getRuntime().freeMemory());

		// bigBlobCompile();
		realisticSmallBlobCompile();
		System.gc();
		Thread.sleep(5000);
		System.err.println(Runtime.getRuntime().freeMemory());

	}

	private static void bigBlobCompile() throws DroolsParserException,
			IOException, Exception {
		StringBuilder buf = new StringBuilder();
		buf.append(getHeader());

		for (int i = 0; i < RULE_COUNT; i++) {
			String name = "x" + i;
			int status = i;

			String r = getTemplate1(name, status);
			buf.append(r);
		}

		/* love you */long time = System.currentTimeMillis();

		DrlParser ps = new DrlParser();
		PackageDescr pkg = ps.parse(new StringReader(buf.toString()));

		System.err.println("Time taken for parsing: "
				+ (System.currentTimeMillis() - time));

		time = System.currentTimeMillis();
		PackageBuilder b = new PackageBuilder();
		b.addPackage(pkg);
		Assert.assertFalse(b.getErrors().toString(), b.hasErrors());

		System.err.println("Time taken for compiling: "
				+ (System.currentTimeMillis() - time));
		time = System.currentTimeMillis();

		Package p = b.getPackage();
		RuleBase rb = RuleBaseFactory.newRuleBase();

		rb.addPackage(p);

		System.err.println("Time taken rete building: "
				+ (System.currentTimeMillis() - time));

		File f = new File("foo.rulebase");
		if (f.exists())
			f.delete();

		time = System.currentTimeMillis();
		ObjectOutput out = new DroolsObjectOutputStream(new FileOutputStream(f));
		out.writeObject(rb);
		out.flush();
		out.close();
		System.err.println("Time taken serializing rulebase: "
				+ (System.currentTimeMillis() - time));

		time = System.currentTimeMillis();
		ObjectInputStream in = new ObjectInputStream(new FileInputStream(f));
		RuleBase rb_ = (RuleBase) in.readObject();
		System.err.println("Time taken de-serializing rulebase: "
				+ (System.currentTimeMillis() - time));

	}

	private static void smallBlobCompile() throws DroolsParserException,
			IOException, Exception {

		/* love you */long time = System.currentTimeMillis();
		PackageBuilder b = new PackageBuilder();
		b.addPackageFromDrl(new StringReader(getHeader()));
		for (int i = 0; i < RULE_COUNT; i++) {
			String name = "x" + i;
			int status = i;

			String r = getTemplate2(name, i, status);
			b.addPackageFromDrl(new StringReader(r));
			if (i % 1000 == 0)
				System.err.println("Rule #" + i);

		}

		Assert.assertFalse(b.getErrors().toString(), b.hasErrors());

		System.err.println("Time taken for compiling: "
				+ (System.currentTimeMillis() - time));
		time = System.currentTimeMillis();

		Package p = b.getPackage();
		RuleBase rb = RuleBaseFactory.newRuleBase();

		rb.addPackage(p);

		System.err.println("Time taken rete building: "
				+ (System.currentTimeMillis() - time));
	}

	private static void realisticSmallBlobCompile() throws DroolsParserException,
			IOException, Exception {

		/* love you */long time = System.currentTimeMillis();
		PackageBuilder b = new PackageBuilder();
		b.addPackageFromDrl(new StringReader(getHeader()));

		int count = 0;

		for (int i = 0; i < 2000; i++) {

			String name = "x" + i;
			for (int j = 0; j < 10; j++) {
				count++;
				int status = j;
				String r = getTemplate2(name, count, status);
				b.addPackageFromDrl(new StringReader(r));
				if (count % 1000 == 0)
					System.err.println("Rule #" + count);
			}

		}

		Assert.assertFalse(b.getErrors().toString(), b.hasErrors());

		System.err.println("Time taken for compiling: "
				+ (System.currentTimeMillis() - time));
		time = System.currentTimeMillis();

		Package p = b.getPackage();
		RuleBase rb = RuleBaseFactory.newRuleBase();

		rb.addPackage(p);

		System.err.println("Time taken rete building: "
				+ (System.currentTimeMillis() - time));
	}

	public static String getHeader() {
		return "package org.drools.test; \n " + "import org.drools.Person; \n "
				+ "import org.drools.Cheese; \n "
				+ "import org.drools.Cheesery; \n "
				+ " import java.util.List \n "
				+ " global List list \n dialect 'mvel'\n  ";
	}

	public static String getTemplate1(String name, int status) {
		return "rule 'match Person "
				+ name
				+ "' \n"
				+ " agenda-group \'xxx\' \n"
				+ " salience ($age2 - $age1) \n "
				+ " dialect 'mvel' \n"
				+ "	when \n "
				+ " 		$person : Person(name=='"
				+ name
				+ "', $age1 : age ) \n "
				+ "	    cheesery : Cheesery( cheeses contains $person, status == "
				+ status + " ) \n "
				+ " 		cheeses : List() from cheesery.getCheeses() \n "
				+ "		Person( age < ( $age1 ) ) \n "
				+ "		Person( $age2 : age -> ( $age1 == $age2 ) ) \n "
				+ "		eval( $age1 == $age2 ) \n " + "   then \n "
				+ "		list.add( $person ); \n "
				+ "		$person.setStatus(\"match Person ok\"); \n " + " end \n";
	}

	private static String getTemplate2(String name, int num,  int status) {
		return "rule 'match Person "
				+ num
				+ "' \n"
				+ " dialect 'mvel' \n"
				+ "	when \n "
				+ " 		$person : Person(name=='"
				+ name
				+ "', $age1 : age ) \n "
				+ "	    cheesery : Cheesery( cheeses contains $person, status == "
				+ status + " ) \n "
				+ " Person(age < " + num + ") \n"
				+ " then \n "
				+ "		list.add( $person ); \n "
				+ "		$person.setStatus(\"match Person ok\"); \n " + " end \n";
	}

}