[
https://issues.apache.org/jira/browse/TINKERPOP-1994?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17295601#comment-17295601
]
Stephen Mallette commented on TINKERPOP-1994:
---------------------------------------------
Came up with a way to fix this issue. It immediately resolved the problem
traversal in the description as well:
{code}
gremlin> g.V().repeat(out().barrier()).times(2).explain()
==>Traversal Explanation
===========================================================================================================================================================
Original Traversal [GraphStep(vertex,[]),
RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
RepeatEndStep],until(loops(2)),emit(false))]
ConnectiveStrategy [D] [GraphStep(vertex,[]),
RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
RepeatEndStep],until(loops(2)),emit(false))]
RepeatUnrollStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
IncidentToAdjacentStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
MatchPredicateStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
PathRetractionStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
FilterRankingStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
InlineFilterStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
AdjacentToIncidentStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
CountStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
EarlyLimitStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
LazyBarrierStrategy [O] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
TinkerGraphCountStrategy [P] [GraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
TinkerGraphStepStrategy [P] [TinkerGraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
ProfileStrategy [F] [TinkerGraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
StandardVerificationStrategy [V] [TinkerGraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
Final Traversal [TinkerGraphStep(vertex,[]),
VertexStep(OUT,vertex), NoOpBarrierStep, VertexStep(OUT,vertex),
NoOpBarrierStep]
{code}
The downside to my approach is that it further allows {{TraversalStrategy}}
implementations to know things about each other. I don't particularly like
that, but I think we've already allowed that to happen so I suppose there is
precedence and doing it the way I did offers a relatively low risk fix.
> LazyBarrierStrategy fully responsible for barrier() additions
> -------------------------------------------------------------
>
> Key: TINKERPOP-1994
> URL: https://issues.apache.org/jira/browse/TINKERPOP-1994
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.2.9
> Reporter: Stephen Mallette
> Priority: Minor
>
> As it stands, {{LazyBarrierStrategy}}, {{RepeatUnrollStrategy}} and
> {{PathRetractionStrategy}} (others??) add {{barrier()}} steps as needed - for
> example:
> {code}
> gremlin> g.V().repeat(out().barrier()).times(2).explain()
> ==>Traversal Explanation
> ===============================================================================================================================================================================================
> Original Traversal [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> ConnectiveStrategy [D] [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> MatchPredicateStrategy [O] [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> FilterRankingStrategy [O] [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> InlineFilterStrategy [O] [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> IncidentToAdjacentStrategy [O] [GraphStep(vertex,[]),
> RepeatStep([VertexStep(OUT,vertex), NoOpBarrierStep,
> RepeatEndStep],until(loops(2)),emit(false))]
> RepeatUnrollStrategy [O] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> PathRetractionStrategy [O] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> AdjacentToIncidentStrategy [O] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> CountStrategy [O] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> LazyBarrierStrategy [O] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> TinkerGraphCountStrategy [P] [GraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> TinkerGraphStepStrategy [P] [TinkerGraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> ProfileStrategy [F] [TinkerGraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> StandardVerificationStrategy [V] [TinkerGraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> Final Traversal [TinkerGraphStep(vertex,[]),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500),
> VertexStep(OUT,vertex), NoOpBarrierStep, NoOpBarrierStep(2500)]
> {code}
> We should centralize the logic for this in {{LazyBarrierStrategy}} and remove
> it from other strategies. By keeping the logic in a single place we can (1)
> ensure the best implementation - note in the above example, we're getting
> extra {{barrier()}} steps (2) users can be assured that removing the single
> {{LazyBarrierStrategy}} will remove all automated {{barrier()}} applications.
> This isn't a breaking change, but it could change traversal behavior I
> suppose - perhaps this goes just to 3.4.0.......
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
