add abft.StartFrom

abft/bootstrap.go

@@ -54,6 +54,27 @@ func (p *Orderer) Bootstrap(callback OrdererCallbacks) error {
 	return err
 }
 
+// StartFrom initiates Orderer with specified parameters
+func (p *Orderer) StartFrom(callback OrdererCallbacks, epoch idx.Epoch, validators *pos.Validators) error {
+	if p.election != nil {
+		return errors.New("already bootstrapped")
+	}
+	// block handler must be set before p.handleElection
+	p.callback = callback
+
+	p.store.applyGenesis(epoch, validators)
+	// reset internal epoch DB
+	err := p.resetEpochStore(epoch)
+	if err != nil {
+		return err
+	}
+	if p.callback.EpochDBLoaded != nil {
+		p.callback.EpochDBLoaded(p.store.GetEpoch())
+	}
+	p.election = election.New(validators, FirstFrame, p.dagIndex.ForklessCause, p.store.GetFrameRoots)
+	return err
+}
+
 // Reset switches epoch state to a new empty epoch.
 func (p *Orderer) Reset(epoch idx.Epoch, validators *pos.Validators) error {
 	p.store.applyGenesis(epoch, validators)
@@ -62,6 +83,9 @@ func (p *Orderer) Reset(epoch idx.Epoch, validators *pos.Validators) error {
 	if err != nil {
 		return err
 	}
+	if p.callback.EpochDBLoaded != nil {
+		p.callback.EpochDBLoaded(p.store.GetEpoch())
+	}
 	p.election.Reset(validators, FirstFrame)
 	return nil
 }

abft/lachesis.go

@@ -97,6 +97,19 @@ func (p *Lachesis) BootstrapWithOrderer(callback lachesis.ConsensusCallbacks, or
 	return nil
 }
 
+func (p *Lachesis) StartFrom(callback lachesis.ConsensusCallbacks, epoch idx.Epoch, validators *pos.Validators) error {
+	return p.StartFromWithOrderer(callback, epoch, validators, p.OrdererCallbacks())
+}
+
+func (p *Lachesis) StartFromWithOrderer(callback lachesis.ConsensusCallbacks, epoch idx.Epoch, validators *pos.Validators, ordererCallbacks OrdererCallbacks) error {
+	err := p.Orderer.StartFrom(ordererCallbacks, epoch, validators)
+	if err != nil {
+		return err
+	}
+	p.callback = callback
+	return nil
+}
+
 func (p *Lachesis) OrdererCallbacks() OrdererCallbacks {
 	return OrdererCallbacks{
 		ApplyAtropos: p.applyAtropos,