Method build

balancer/weightedtarget/weightedaggregator/aggregator.go:252–290

build combines sub-states into one. Caller must hold wbsa.mu.

()

//
// Caller must hold wbsa.mu.
func (wbsa *Aggregator) build() balancer.State {
	wbsa.logger.Infof("Child pickers with config: %+v", wbsa.idToPickerState)

	if len(wbsa.idToPickerState) == 0 {
		// This is the case when all sub-balancers are removed.
		return balancer.State{
			ConnectivityState: connectivity.TransientFailure,
			Picker:            base.NewErrPicker(errors.New("weighted-target: no targets to pick from")),
		}
	}

	// Make sure picker's return error is consistent with the aggregatedState.
	pickers := make([]weightedPickerState, 0, len(wbsa.idToPickerState))

	switch aggState := wbsa.csEvltr.CurrentState(); aggState {
	case connectivity.Connecting:
		return balancer.State{
			ConnectivityState: aggState,
			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable)}
	case connectivity.TransientFailure:
		// this means that all sub-balancers are now in TransientFailure.
		for _, ps := range wbsa.idToPickerState {
			pickers = append(pickers, *ps)
		}
		return balancer.State{
			ConnectivityState: aggState,
			Picker:            newWeightedPickerGroup(pickers, wbsa.newWRR)}
	default:
		for _, ps := range wbsa.idToPickerState {
			if ps.stateToAggregate == connectivity.Ready {
				pickers = append(pickers, *ps)
			}
		}
		return balancer.State{
			ConnectivityState: aggState,
			Picker:            newWeightedPickerGroup(pickers, wbsa.newWRR)}
	}

}

type weightedPickerGroup struct {
	w wrr.WRR