2 files changed, 164 insertions, 4 deletions
diff --git a/pkg/state/single.go b/pkg/state/single.go
index 695f0e3..2e44fee 100644
--- a/pkg/state/single.go
+++ b/pkg/state/single.go
@@ -8,18 +8,21 @@ import (
 	"sync"
 	"time"
 
+	"git.sigsum.org/log-go/pkg/client"
 	"git.sigsum.org/log-go/pkg/db"
 	"git.sigsum.org/sigsum-go/pkg/log"
+	//"git.sigsum.org/sigsum-go/pkg/requests"
 	"git.sigsum.org/sigsum-go/pkg/types"
 )
 
-// StateManagerSingle implements a single-instance StateManager
+// StateManagerSingle implements a single-instance StateManager for primary nodes
 type StateManagerSingle struct {
 	client    db.Client
 	signer    crypto.Signer
 	namespace types.Hash
 	interval  time.Duration
 	deadline  time.Duration
+	secondary *client.Client
 
 	// Lock-protected access to pointers.  A write lock is only obtained once
 	// per interval when doing pointer rotation.  All endpoints are readers.
@@ -32,13 +35,14 @@ type StateManagerSingle struct {
 	cosignatures map[types.Hash]*types.Signature
 }
 
-func NewStateManagerSingle(client db.Client, signer crypto.Signer, interval, deadline time.Duration) (*StateManagerSingle, error) {
+func NewStateManagerSingle(dbcli db.Client, signer crypto.Signer, interval, deadline time.Duration, securl string, secpk types.PublicKey) (*StateManagerSingle, error) {
 	sm := &StateManagerSingle{
-		client:    client,
+		client:    dbcli,
 		signer:    signer,
 		namespace: *types.HashFn(signer.Public().(ed25519.PublicKey)),
 		interval:  interval,
 		deadline:  deadline,
+		secondary: client.NewClient(securl, secpk),
 	}
 	sth, err := sm.latestSTH(context.Background())
 	sm.setCosignedTreeHead()
@@ -157,9 +161,57 @@ func (sm *StateManagerSingle) latestSTH(ctx context.Context) (*types.SignedTreeH
 	if err != nil {
 		return nil, fmt.Errorf("failed fetching tree head: %v", err)
 	}
-	sth, err := th.Sign(sm.signer, &sm.namespace)
+
+	//pth, err := choseTree(ctx, sm.deadline, sm.secondary, th)
+	pth, err := th, nil	// DEBUG
+	if err != nil {
+		return nil, fmt.Errorf("failed chosing tree head: %v", err)
+	}
+
+	sth, err := pth.Sign(sm.signer, &sm.namespace)
 	if err != nil {
 		return nil, fmt.Errorf("failed signing tree head: %v", err)
 	}
+
 	return sth, nil
 }
+
+func choseTree(ctx context.Context, deadline time.Duration, secondary *client.Client, th *types.TreeHead) (*types.TreeHead, error) {
+	// TODO: handle multiple secondaries and not just one
+
+	if !secondary.Configured {
+		return th, nil
+	}
+
+	sctx, cancel := context.WithTimeout(ctx, deadline) // FIXME: use a separate timeout value for secondaries?
+	defer cancel()
+	secsth, err := secondary.GetCurrentTreeHead(sctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed getting the latest tree head from all secondaries: %v", err)
+	}
+
+	if secsth.TreeSize < th.TreeSize {
+		// We're stuck at secsth.size so let's verify
+		// consistency since secsth and sign that
+
+		// TODO: get and verify consinstency proof
+
+		// req := &requests.ConsistencyProof{
+		// 	OldSize: secsth.TreeSize,
+		// 	NewSize: th.TreeSize,
+		// }
+
+		// proof, err := sm.client.GetConsistencyProof(ctx, req)
+		// if err != nil {
+		// 	return nil, fmt.Errorf("unable to get consistency proof from %d to %d: %v", req.OldSize, req.NewSize, err)
+		// }
+
+		// if !proof.Verify() {
+		// 	return nil, fmt.Errorf("invalid consistency proof from %d to %d", req.OldSize, req.NewSize)
+		// }
+
+		th = &secsth.TreeHead // FIXME: need to copy?
+	}
+
+	return th, nil
+}
diff --git a/pkg/state/single_sec.go b/pkg/state/single_sec.go
new file mode 100644
index 0000000..9c69fa8
--- /dev/null
+++ b/pkg/state/single_sec.go
@@ -0,0 +1,108 @@
+package state
+
+import (
+	"context"
+	"crypto"
+	"crypto/ed25519"
+	"fmt"
+	"sync"
+	"time"
+
+	"git.sigsum.org/log-go/pkg/client"
+	"git.sigsum.org/log-go/pkg/db"
+	"git.sigsum.org/sigsum-go/pkg/log"
+	//"git.sigsum.org/sigsum-go/pkg/requests"
+	"git.sigsum.org/sigsum-go/pkg/types"
+)
+
+// StateManagerSingleSecondary implements a single-instance StateManager for secondary nodes
+type StateManagerSingleSecondary struct {
+	client    db.Client
+	signer    crypto.Signer
+	namespace types.Hash
+	interval  time.Duration
+	deadline  time.Duration
+	primary   *client.Client
+
+	// Lock-protected access to pointers.  A write lock is only obtained once
+	// per interval when doing pointer rotation.  All endpoints are readers.
+	sync.RWMutex
+	signedTreeHead *types.SignedTreeHead
+}
+
+func NewStateManagerSingleSecondary(dbcli db.Client, signer crypto.Signer, interval, deadline time.Duration, primurl string, primpk types.PublicKey) (*StateManagerSingleSecondary, error) {
+	sm := &StateManagerSingleSecondary{
+		client:    dbcli,
+		signer:    signer,
+		namespace: *types.HashFn(signer.Public().(ed25519.PublicKey)),
+		interval:  interval,
+		deadline:  deadline,
+		primary:   client.NewClient(primurl, primpk),
+	}
+	sth, err := sm.latestSTH(context.Background())
+	sm.setSignedTreeHead(sth)
+	return sm, err
+}
+
+func (sm *StateManagerSingleSecondary) Run(ctx context.Context) {
+	rotation := func() {
+		nextSTH, err := sm.latestSTH(ctx)
+		if err != nil {
+			log.Warning("cannot rotate without tree head: %v", err)
+			return
+		}
+		sm.rotate(nextSTH)
+	}
+
+	ticker := time.NewTicker(sm.interval)
+	defer ticker.Stop()
+
+	// TODO: fetch leaves from primary
+
+	rotation()
+	for {
+		select {
+		case <-ticker.C:
+			rotation()
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func (sm *StateManagerSingleSecondary) AddCosignature(ctx context.Context, pub *types.PublicKey, sig *types.Signature) error {
+	return fmt.Errorf("internal error: AddCosignature() called in secondary node")
+}
+func (sm *StateManagerSingleSecondary) CosignedTreeHead(_ context.Context) (*types.CosignedTreeHead, error) {
+	return nil, fmt.Errorf("internal error: AddCosignature() called in secondary node")
+}
+func (sm *StateManagerSingleSecondary) ToCosignTreeHead(_ context.Context) (*types.SignedTreeHead, error) {
+	return nil, fmt.Errorf("internal error: AddCosignature() called in secondary node")
+}
+
+func (sm *StateManagerSingleSecondary) setSignedTreeHead(nextSTH *types.SignedTreeHead) {
+	sm.signedTreeHead = nextSTH
+}
+
+func (sm *StateManagerSingleSecondary) latestSTH(ctx context.Context) (*types.SignedTreeHead, error) {
+	ictx, cancel := context.WithTimeout(ctx, sm.deadline)
+	defer cancel()
+
+	th, err := sm.client.GetTreeHead(ictx)
+	if err != nil {
+		return nil, fmt.Errorf("failed fetching tree head: %v", err)
+	}
+	sth, err := th.Sign(sm.signer, &sm.namespace)
+	if err != nil {
+		return nil, fmt.Errorf("failed signing tree head: %v", err)
+	}
+	return sth, nil
+}
+
+func (sm *StateManagerSingleSecondary) rotate(nextSTH *types.SignedTreeHead) {
+	sm.Lock()
+	defer sm.Unlock()
+
+	log.Debug("rotating tree heads")
+	sm.setSignedTreeHead(nextSTH)
+}