[rules-users] Updating an existing fact w/o using fact handle

[Fenderbosch, Eric]

Thanks.
 
What I've done is add an insertOrUpdate method on a util class we use.
How efficient is getFactHandle?  Is it a simple HashMap lookup?  Or
would we be better off keeping our own map of handles->facts?

public static FactHandle insertOrUpdate(Object fact, boolean dynamic) {
	FactHandle factHandle = workingMemory.getFactHandle(fact);
	if (factHandle == null) {
		return workingMemory.insert(fact, dynamic);
	}
	workingMemory.update(factHandle, fact);
	return factHandle;
}

________________________________

From: rules-users-bounces at lists.jboss.org
[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Edson Tirelli
Sent: Saturday, May 31, 2008 9:12 AM
To: Rules Users List
Subject: Re: [rules-users] Updating an existing fact w/o using fact
handle



   Nope. You must use the update method. You can get the previous fact
handle using the get method in working memory if you still have the
original non-modified object, or if behavior is equals based, using an
equals object.

   []
   Edson


2008/5/30 Fenderbosch, Eric <Eric.Fenderbosch at fedex.com>:


	Is it required to use WorkingMemory.update to update an existing
fact?
	I thought if assert behavior was set to equality and you
implemented the
	equals method properly, then you could simply use
WorkingMemory.insert
	to overwrite a fact in working memory with a new version.  If
this isn't
	the case, then are there other settings that will give this
behavior?
	
	I'm using 4.0.7.
	
	Thanks for any help.
	
	Eric
	
	Here's my RuleBaseConfiguration:
	AlphaNodeHashingThreshold : 3
	CompositeKeyDepth : 3
	ExecutorServiceorg.drools.concurrent.DefaultExecutorService
	RuleBaseUpdateHandler :
	org.drools.base.FireAllRulesRuleBaseUpdateListener
	AgendaGroupFactory :
	org.drools.common.PriorityQueueAgendaGroupFactory at 17653ae
	AssertBehaviour : equality
	ConflictResolver :
org.drools.conflict.DepthConflictResolver at 16fe0f4
	ConsequenceExceptionHandler :
	org.drools.base.DefaultConsequenceExceptionHandler at 19d0a1
	LogicalOverride : discard
	SequentialAgenda : sequential
	AlphaMemory : false
	IndexLeftBetaMemory : true
	IndexRightBetaMemory : true
	MaintainTms : true
	RemoveIdenities : true
	Sequential : false
	ShadowProxy : true
	ShareAlphaNodes : true
	ShareBetaNodes : true
	UseStaticObjensis : false
	
	
	My TestFact class:
	
	public class TestFact {
	
	       private String id;
	       private String value;
	
	       public String getId() {
	               return id;
	       }
	
	       public void setId(String id) {
	               this.id = id;
	       }
	
	       public String getValue() {
	               return value;
	       }
	
	       public void setValue(String value) {
	               this.value = value;
	       }
	
	       @Override
	       public int hashCode() {
	               return id.hashCode();
	       }
	
	       @Override
	       public boolean equals(Object obj) {
	               if (this == obj) return true;
	               if (!(obj instanceof TestFact)) return false;
	               TestFact other = (TestFact) obj;
	               // not null safe, i know
	               return this.id.equals(other.id);
	       }
	}
	
	And the JUnit Test Case that fails:
	       public void testFactUpdate() throws Exception {
	               TestFact testFact = new TestFact();
	               testFact.setId("1234");
	               testFact.setValue("old");
	
	               FactHandle testFactHandle =
	workingMemory.insert(testFact);
	
	               TestFact updatedFact = new TestFact();
	               updatedFact.setId("1234");
	               updatedFact.setValue("new");
	
	               FactHandle updatedFactHandle =
	workingMemory.insert(updatedFact);
	               // using workingMemory.update here works
	
	               // passes
	               assertTrue(testFactHandle == updatedFactHandle);
	
	               TestFact retrievedTestFact = (TestFact)
	workingMemory.getObject(testFactHandle);
	               // fails
	               assertEquals("new",
retrievedTestFact.getValue());
	       }
	
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-- 
Edson Tirelli
JBoss Drools Core Development
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