[rules-users] stream mode and DroolsStreamUtils

[Jaroslaw Kijanowski]

Hi,
  I'm using sliding windows (hence stream mode).
Here's my rule:

declare Sensor
	@role (event)
end

rule 'r'
when
Number( dv:doubleValue > 1 ) from accumulate(
         Sensor( $v : value ) over window:length( 2 ),
         average( $v ) )
then
	System.out.println(dv);
end

Here's my class:

++++++++++++++++++++++++++++++++++++++++++++++
public class CEPTest {
   public static void main(String[] args) throws Exception {

     KnowledgeBuilder kbuilder = 
KnowledgeBuilderFactory.newKnowledgeBuilder();
     kbuilder.add(ResourceFactory.newClassPathResource("cep.drl"), 
ResourceType.DRL);
     if (kbuilder.getErrors().size() > 0) {
       throw new IllegalArgumentException("Could not parse knowledge.");
     }

     KnowledgeBaseConfiguration kbaseConfig = 
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
     kbaseConfig.setOption(EventProcessingOption.STREAM);
     KnowledgeBase kbase = 
KnowledgeBaseFactory.newKnowledgeBase(kbaseConfig);

     kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
     KnowledgeBase kbase2 = (KnowledgeBase) 
DroolsStreamUtils.streamIn(DroolsStreamUtils.streamOut(kbase), null);

     final StatefulKnowledgeSession ksession = 
kbase2.newStatefulKnowledgeSession();

     System.out.println("T1");
     ksession.insert(new Sensor(1.0));
     ksession.fireAllRules();

     System.out.println("T2");
     ksession.insert(new Sensor(2.0));
     ksession.fireAllRules();

     System.out.println("T3");
     ksession.insert(new Sensor(3.0));
     ksession.fireAllRules();

     ksession.dispose();
   }
}
++++++++++++++++++++++++++++++++++++++++++++++
The output is (as expected):
+++++++++++++++
T1
T2
1.5
T3
2.5
+++++++++++++++

I'm wondering why I have to use DroolsStreamUtils to get a knowledge 
base? When I use kbase (which didn't went through DroolsStreamUtils) 
instead of kbase2 to create a new session, the output will be:
+++++++++++++++
T1
T2
2.0
T3
3.0
+++++++++++++++

Thanks,
  Jarek