state: Refactor with new tree head endpoints

For details see doc/proposals/2022-01-no-quick-tree-head-endpoint.

1 files changed, 17 insertions, 4 deletions

diff --git a/pkg/state/state_manager.go b/pkg/state/state_manager.go
index 5aa7609..ab0293c 100644
--- a/pkg/state/state_manager.go
+++ b/pkg/state/state_manager.go
@@ -6,11 +6,24 @@ import (
 	"git.sigsum.org/sigsum-lib-go/pkg/types"
 )
 
-// StateManager coordinates access to a log's tree heads and (co)signatures
+// StateManager coordinates access to a log's tree heads and (co)signatures.
 type StateManager interface {
-	Latest(context.Context) (*types.SignedTreeHead, error)
-	ToSign(context.Context) (*types.SignedTreeHead, error)
-	Cosigned(context.Context) (*types.CosignedTreeHead, error)
+	// ToCosignTreeHead returns the log's to-cosign tree head
+	ToCosignTreeHead(context.Context) (*types.SignedTreeHead, error)
+
+	// CosignedTreeHead returns the log's cosigned tree head
+	CosignedTreeHead(context.Context) (*types.CosignedTreeHead, error)
+
+	// AddCosignature verifies that a cosignature is valid for the to-cosign
+	// tree head before adding it
 	AddCosignature(context.Context, *types.PublicKey, *types.Signature) error
+
+	// Run peridically rotates the log's to-cosign and cosigned tree heads
 	Run(context.Context)
 }
+
+// event is a verified cosignature request
+type event struct {
+	keyHash     *types.Hash
+	cosignature *types.Signature
+}