func newSchedulingDecisionsFromBindings()

in pkg/scheduler/framework/frameworkutils.go [279:357]
53 lines of code
13 McCabe index (conditional complexity)

func newSchedulingDecisionsFromBindings(
	maxUnselectedClusterDecisionCount int,
	notPicked ScoredClusters,
	filtered []*filteredClusterWithStatus,
	existing ...[]*placementv1beta1.ClusterResourceBinding,
) []placementv1beta1.ClusterDecision {
	// Pre-allocate with a reasonable capacity.
	newDecisions := make([]placementv1beta1.ClusterDecision, 0, maxUnselectedClusterDecisionCount)

	// Track clusters that have been added to the decision list.
	//
	// This is to avoid duplicate entries in the decision list, caused by a rare occurrence
	// where a cluster is picked before, but later loses its status as a matching (or most
	// preferable) cluster (e.g., a label/cluster property change) under the evaluation
	// of **the same** scheduling policy.
	//
	// Note that for such occurrences, we will honor the previously made decisions in an attempt
	// to reduce fluctations.
	seenClusters := make(map[string]bool)

	// Build new scheduling decisions.
	slotsLeft := clustersDecisionArrayLengthLimitInAPI
	for _, bindingSet := range existing {
		setLength := len(bindingSet)
		for i := 0; i < setLength && i < slotsLeft; i++ {
			newDecisions = append(newDecisions, bindingSet[i].Spec.ClusterDecision)
			seenClusters[bindingSet[i].Spec.TargetCluster] = true
		}

		slotsLeft -= setLength
		if slotsLeft <= 0 {
			klog.V(2).InfoS("Reached API limit of cluster decision count; decisions off the limit will be discarded")
			break
		}
	}

	// Add decisions for clusters that have been scored, but are not picked, if there are still
	// enough room.
	for _, sc := range notPicked {
		if slotsLeft == 0 || maxUnselectedClusterDecisionCount == 0 {
			break
		}

		if seenClusters[sc.Cluster.Name] {
			// Skip clusters that have been added to the decision list.
			continue
		}

		newDecisions = append(newDecisions, placementv1beta1.ClusterDecision{
			ClusterName: sc.Cluster.Name,
			Selected:    false,
			ClusterScore: &placementv1beta1.ClusterScore{
				AffinityScore:       ptr.To(sc.Score.AffinityScore),
				TopologySpreadScore: ptr.To(sc.Score.TopologySpreadScore),
			},
			Reason: fmt.Sprintf(notPickedByScoreReasonTemplate, sc.Cluster.Name, sc.Score.AffinityScore, sc.Score.TopologySpreadScore),
		})

		slotsLeft--
		maxUnselectedClusterDecisionCount--
	}

	// Move some decisions from unbound clusters, if there are still enough room.
	for i := 0; i < maxUnselectedClusterDecisionCount && i < len(filtered) && i < slotsLeft; i++ {
		clusterWithStatus := filtered[i]
		if _, ok := seenClusters[clusterWithStatus.cluster.Name]; ok {
			// Skip clusters that have been added to the decision list.
			continue
		}

		newDecisions = append(newDecisions, placementv1beta1.ClusterDecision{
			ClusterName: clusterWithStatus.cluster.Name,
			Selected:    false,
			Reason:      clusterWithStatus.status.String(),
		})
	}

	return newDecisions
}