| Help requested for closure constraint. [message #1053529] |
Mon, 06 May 2013 12:10  |
 Daniel Di Nardo
Messages: 1
Registered: May 2013 |
Junior Member |
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Dear readers,
I'm trying to implement a constraint on the members of a linked list described by the following UML class diagrams:
In plain English, I want to ensure that for any given node, that the first predecessor node of the same channelId type has a frameCount that is one less than the current given node's frameCount. I introduced an index value to keep track of the order in which I created the nodes but I'm hoping that using this value won't be necessary.
My constraint is currently as follows:
class SampleNode inv:
let allNodes : Set(SampleNode) = self->closure(prev),
allNodesWithSameChannelId : Set(SampleNode) = allNodes->select(x : SampleNode | x.channelId = self.channelId),
orderedNodesWithSameChannelId : OrderedSet(SampleNode) = allNodesWithSameChannelId->sortedBy( index )
in
orderedNodesWithSameChannelId->size() > 0
implies
self.frameCount = orderedNodesWithSameChannelId->last().frameCount + 1
The issue I'm having is that while the above constraint works when we evaluate the OCL against a SampleNode instance that has 2500 predecessors, once I increase the number of predecessors to 5000 I get the following error:
Exception in thread "main" java.lang.StackOverflowError
at java.util.HashMap.getEntry(HashMap.java:344)
at java.util.HashMap.containsKey(HashMap.java:335)
at org.eclipse.ocl.AbstractEvaluationEnvironment.add(AbstractEvaluationEnvironment.java:122)
at org.eclipse.ocl.EvaluationVisitorImpl.visitVariable(EvaluationVisitorImpl.java:2368)
at org.eclipse.ocl.ecore.impl.VariableImpl.accept(VariableImpl.java:654)
at org.eclipse.ocl.internal.evaluation.IterationTemplate.initializeIterators(IterationTemplate.java:126)
at org.eclipse.ocl.internal.evaluation.IterationTemplate.evaluate(IterationTemplate.java:83)
at org.eclipse.ocl.internal.evaluation.IterationTemplateClosure.evaluateResult(IterationTemplateClosure.java:90)
at org.eclipse.ocl.internal.evaluation.IterationTemplate.evaluate(IterationTemplate.java:90)
at org.eclipse.ocl.internal.evaluation.IterationTemplateClosure.evaluateResult(IterationTemplateClosure.java:90)
at org.eclipse.ocl.internal.evaluation.IterationTemplate.evaluate(IterationTemplate.java:90)
at org.eclipse.ocl.internal.evaluation.IterationTemplateClosure.evaluateResult(IterationTemplateClosure.java:90)
at org.eclipse.ocl.internal.evaluation.IterationTemplate.evaluate(IterationTemplate.java:90)
Ideally I'd like to evaluate a linked list having up to one million nodes. Can anyone suggest a way of doing this without the memory issues?
Your help/tips would be appreciated.
Thanks.
[Updated on: Mon, 06 May 2013 13:32] Report message to a moderator |
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