kubernetes/pkg/scheduler/framework/plugins/podtopologyspread/scoring.go

const preScoreStateKey …

const invalidScore …

type preScoreState …

// Clone implements the mandatory Clone interface. We don't really copy the data since
// there is no need for that.
func (s *preScoreState) Clone() framework.StateData { … }

// initPreScoreState iterates "filteredNodes" to filter out the nodes which
// don't have required topologyKey(s), and initialize:
// 1) s.TopologyPairToPodCounts: keyed with both eligible topology pair and node names.
// 2) s.IgnoredNodes: the set of nodes that shouldn't be scored.
// 3) s.TopologyNormalizingWeight: The weight to be given to each constraint based on the number of values in a topology.
func (pl *PodTopologySpread) initPreScoreState(s *preScoreState, pod *v1.Pod, filteredNodes []*framework.NodeInfo, requireAllTopologies bool) error { … }

// PreScore builds and writes cycle state used by Score and NormalizeScore.
func (pl *PodTopologySpread) PreScore(
	ctx context.Context,
	cycleState *framework.CycleState,
	pod *v1.Pod,
	filteredNodes []*framework.NodeInfo,
) *framework.Status { … }

// Score invoked at the Score extension point.
// The "score" returned in this function is the matching number of pods on the `nodeName`,
// it is normalized later.
func (pl *PodTopologySpread) Score(ctx context.Context, cycleState *framework.CycleState, pod *v1.Pod, nodeName string) (int64, *framework.Status) { … }

// NormalizeScore invoked after scoring all nodes.
func (pl *PodTopologySpread) NormalizeScore(ctx context.Context, cycleState *framework.CycleState, pod *v1.Pod, scores framework.NodeScoreList) *framework.Status { … }

// ScoreExtensions of the Score plugin.
func (pl *PodTopologySpread) ScoreExtensions() framework.ScoreExtensions { … }

func getPreScoreState(cycleState *framework.CycleState) (*preScoreState, error) { … }

// topologyNormalizingWeight calculates the weight for the topology, based on
// the number of values that exist for a topology.
// Since <size> is at least 1 (all nodes that passed the Filters are in the
// same topology), and k8s supports 5k nodes, the result is in the interval
// <1.09, 8.52>.
//
// Note: <size> could also be zero when no nodes have the required topologies,
// however we don't care about topology weight in this case as we return a 0
// score for all nodes.
func topologyNormalizingWeight(size int) float64 { … }

// scoreForCount calculates the score based on number of matching pods in a
// topology domain, the constraint's maxSkew and the topology weight.
// `maxSkew-1` is added to the score so that differences between topology
// domains get watered down, controlling the tolerance of the score to skews.
func scoreForCount(cnt int64, maxSkew int32, tpWeight float64) float64 { … }