[jira] [Commented] (TINKERPOP-2308) IncidentToAdjacentStrategy conflict with RepeatUnrollStrategy when traversal has pathStep

["Stephen Mallette (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TINKERPOP-2308?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16964224#comment-16964224 ] 

Stephen Mallette commented on TINKERPOP-2308:
---------------------------------------------

Do you have an example you could show that demonstrates the problem directly in Gremlin Console with one of the toy graphs? I can't seem to exactly recreate it....

> IncidentToAdjacentStrategy conflict with RepeatUnrollStrategy when traversal has pathStep
> -----------------------------------------------------------------------------------------
>
>                 Key: TINKERPOP-2308
>                 URL: https://issues.apache.org/jira/browse/TINKERPOP-2308
>             Project: TinkerPop
>          Issue Type: Improvement
>          Components: server
>    Affects Versions: 3.4.2
>            Reporter: Stark Arya
>            Priority: Critical
>
> My dsl like:
>  
> {code:java}
> g.V("gdb_sample_marko").repeat(__.bothE("gdb_sample_knows", "gdb_sample_created", "gdb_sample_create").otherV().hasLabel("gdb_sample_person", "gdb_sample_software").simplePath()).times(4).hasId("gdb_sample_lop").path().limit(3);{code}
> {code:java}
> // code placeholder
> I call RepeatUnrollStrategy, then EarlyLimitStrategy to optimize the traversal:
> protected  Traversal.Admin<?, ?> applyStrategy(GraphTraversal<?, ?> traversal) {
>    TraversalStrategies s = new DefaultTraversalStrategies();
>    s.addStrategies(RepeatUnrollStrategy.instance(), EarlyLimitStrategy.instance());
>    s.toList().forEach(traversalStrategy -> {
>        System.out.println("before " + traversalStrategy.toString() + " traversal - " + traversal);
>       traversalStrategy.apply(traversal.asAdmin());
>        });
>    //s.applyStrategies(traversal.asAdmin());
>    return traversal.asAdmin();
> }
> {code}
> And after RepeatUnrollStrategy finished, the traversal became:
> {code:java}
> before EarlyLimitStrategy traversal - [GraphStep(vertex,[gdb_sample_marko]), VertexStep(BOTH,[gdb_sample_knows, gdb_sample_created, gdb_sample_create],vertex), HasStep([~label.within([gdb_sample_person, gdb_sample_software])]), PathFilterStep(simple), NoOpBarrierStep(2500), VertexStep(BOTH,[gdb_sample_knows, gdb_sample_created, gdb_sample_create],vertex), HasStep([~label.within([gdb_sample_person, gdb_sample_software])]), PathFilterStep(simple), NoOpBarrierStep(2500), VertexStep(BOTH,[gdb_sample_knows, gdb_sample_created, gdb_sample_create],vertex), HasStep([~label.within([gdb_sample_person, gdb_sample_software])]), PathFilterStep(simple), NoOpBarrierStep(2500), VertexStep(BOTH,[gdb_sample_knows, gdb_sample_created, gdb_sample_create],vertex), HasStep([~label.within([gdb_sample_person, gdb_sample_software])]), PathFilterStep(simple), NoOpBarrierStep(2500), HasStep([~id.eq(gdb_sample_lop)]), PathStep, RangeGlobalStep(0,3)]
> before Gr{code}
> At this points , Bug occured: VertexStep and EdgeOtherVertexStep merge into VertexStep。 so the  path result will lost edge info。
>  
> Why ?
> {code:java}
> RepeatUnrollStrategy.apply has this line:
> TraversalHelper.applySingleLevelStrategies(traversal, repeatTraversal, RepeatUnrollStrategy.class);
> the code will use traversal.asAdmin().getStrategies() to optimize the following repeatTraversal:
>    [VertexStep(BOTH,[gdb_sample_knows, gdb_sample_created,gdb_sample_create],edge), 
>    EdgeOtherVertexStep,  
>    HasStep([~label.within([gdb_sample_person, gdb_sample_software])]),  
>    PathFilterStep(simple), 
>    RepeatEndStep]
> And traversal.asAdmin().getStrategies() list may be:
> [ConnectiveStrategy, IncidentToAdjacentStrategy, EarlyLimitStrategy, MatchPredicateStrategy, FilterRankingStrategy, InlineFilterStrategy, AdjacentToIncidentStrategy, RepeatUnrollStrategy, CountStrategy, PathRetractionStrategy, LazyBarrierStrategy]
> So IncidentToAdjacentStrategy will be appled before RepeatUnrollStrategy.
> so the error occured.
> {code}
>  How to fix?
> IncidentToAdjacentStrategy.apply add following slice and result just ok
> {code:java}
> @Override
> 123 public void apply(final Traversal.Admin<?, ?> traversal) {
> 124
> 125 if ( (!(traversal.getParent() instanceof EmptyStep)) && TraversalHelper.hasStepOfAssignableClassRecursively(INVALIDATING_ST EP_CLASSES, traversal.getParent().asStep().getTraversal())){
> 126 return;
> 127 }
> 128... origin logic code{code}



--
This message was sent by Atlassian Jira
(v8.3.4#803005)