// New instance set up for a fresh leader
func NewLeaderVolatileState(
clusterInfo *config.ClusterInfo,
indexOfLastEntry LogIndex,
) (*LeaderVolatileState, error) {
lvs := &LeaderVolatileState{
make(map[ServerId]LogIndex),
make(map[ServerId]LogIndex),
}
err := clusterInfo.ForEachPeer(
func(peerId ServerId) error {
// #5.3-p8s4: When a leader first comes to power, it initializes
// all nextIndex values to the index just after the last one in
// its log (11 in Figure 7).
lvs.NextIndex[peerId] = indexOfLastEntry + 1
//
lvs.MatchIndex[peerId] = 0
return nil
},
)
if err != nil {
return nil, err
}
return lvs, nil
}
// New instance set up for a fresh election
func NewCandidateVolatileState(
clusterInfo *config.ClusterInfo,
) (*CandidateVolatileState, error) {
cvs := &CandidateVolatileState{
1, // assumes we always vote for ourself
clusterInfo.QuorumSizeForCluster(),
make(map[ServerId]bool),
}
err := clusterInfo.ForEachPeer(
func(peerId ServerId) error {
cvs.VotedPeers[peerId] = false
return nil
},
)
if err != nil {
return nil, err
}
return cvs, nil
}