AddNode GetLocalToGlobalTransform AppendNode ComputeConstraintsForNode
AddWorkItem DrainWorkQueue -> 循环 ComputeConstraintsForNode ComputeConstraint MaybeAddConstraint MaybeAddGlobalConstraint scan_matcher_task ComputeConstraint fast_correlative_scan_matcher->Match fast_correlative_scan_matcher->MatchFullSubmap ceres_scan_matcher_.Match NotifyEndOfNode finish_node_task_ WhenDone RunWhenDoneCallback HandleWorkQueue RunOptimization UpdateTrajectoryConnectivity DeleteTrajectoriesIfNeeded DrainWorkQueue