kubernetes/vendor/go.etcd.io/etcd/raft/v3/confchange/restore.go

// toConfChangeSingle translates a conf state into 1) a slice of operations creating
// first the config that will become the outgoing one, and then the incoming one, and
// b) another slice that, when applied to the config resulted from 1), represents the
// ConfState.
func toConfChangeSingle(cs pb.ConfState) (out []pb.ConfChangeSingle, in []pb.ConfChangeSingle) { … }

func chain(chg Changer, ops ...func(Changer) (tracker.Config, tracker.ProgressMap, error)) (tracker.Config, tracker.ProgressMap, error) { … }

// Restore takes a Changer (which must represent an empty configuration), and
// runs a sequence of changes enacting the configuration described in the
// ConfState.
//
// TODO(tbg) it's silly that this takes a Changer. Unravel this by making sure
// the Changer only needs a ProgressMap (not a whole Tracker) at which point
// this can just take LastIndex and MaxInflight directly instead and cook up
// the results from that alone.
func Restore(chg Changer, cs pb.ConfState) (tracker.Config, tracker.ProgressMap, error) { … }