Start adding versioned queries support

app/store.go

@@ -60,7 +60,7 @@ func NewStore(dbName string, cacheSize int, logger log.Logger) (*Store, error) {
 			dbm.NewMemDB(),
 		)
 		store := &Store{
-			State:  state.NewState(tree, false),
+			State:  state.NewState(tree, true),
 			height: initialHeight,
 			logger: logger,
 		}
@@ -148,7 +148,7 @@ func (s *Store) Commit() abci.Result {
 		Height: s.height,
 	}))
 
-	hash, err := s.State.Commit()
+	hash, err := s.State.Commit(s.height)
 	if err != nil {
 		return abci.NewError(abci.CodeType_InternalError, err.Error())
 	}
@@ -164,25 +164,25 @@ func (s *Store) Commit() abci.Result {
 
 // Query implements abci.Application
 func (s *Store) Query(reqQuery abci.RequestQuery) (resQuery abci.ResponseQuery) {
-
-	if reqQuery.Height != 0 {
-		// TODO: support older commits
-		resQuery.Code = abci.CodeType_InternalError
-		resQuery.Log = "merkleeyes only supports queries on latest commit"
-		return
-	}
-
 	// set the query response height to current
-	resQuery.Height = s.height
-
 	tree := s.State.Committed()
 
+	height := reqQuery.Height
+	if height == 0 {
+		if tree.Tree.VersionExists(s.height - 1) {
+			height = s.height - 1
+		} else {
+			height = s.height
+		}
+	}
+	resQuery.Height = height
+
 	switch reqQuery.Path {
 	case "/store", "/key": // Get by key
 		key := reqQuery.Data // Data holds the key bytes
 		resQuery.Key = key
 		if reqQuery.Prove {
-			value, proof, err := tree.GetWithProof(key)
+			value, proof, err := tree.GetVersionedWithProof(key, height)
 			if err != nil {
 				resQuery.Log = err.Error()
 				break

state/bonsai.go

@@ -54,6 +54,10 @@ func (b *Bonsai) GetWithProof(key []byte) ([]byte, iavl.KeyProof, error) {
 	return b.Tree.GetWithProof(key)
 }
 
+func (b *Bonsai) GetVersionedWithProof(key []byte, version uint64) ([]byte, iavl.KeyProof, error) {
+	return b.Tree.GetVersionedWithProof(key, version)
+}
+
 func (b *Bonsai) List(start, end []byte, limit int) []Model {
 	res := []Model{}
 	stopAtCount := func(key []byte, value []byte) (stop bool) {

state/merkle.go

@@ -61,7 +61,7 @@ func (s *State) BatchSet(key, value []byte) {
 }
 
 // Commit save persistent nodes to the database and re-copies the trees
-func (s *State) Commit() ([]byte, error) {
+func (s *State) Commit(version uint64) ([]byte, error) {
 	// commit (if we didn't do hash earlier)
 	err := s.committed.Commit(s.deliverTx)
 	if err != nil {
@@ -70,10 +70,11 @@ func (s *State) Commit() ([]byte, error) {
 
 	var hash []byte
 	if s.persistent {
-		nextVersion := s.committed.Tree.LatestVersion() + 1
-		hash, err = s.committed.Tree.SaveVersion(nextVersion)
-		if err != nil {
-			return nil, err
+		if s.committed.Tree.Size() > 0 || s.committed.Tree.LatestVersion() > 0 {
+			hash, err = s.committed.Tree.SaveVersion(version)
+			if err != nil {
+				return nil, err
+			}
 		}
 	} else {
 		hash = s.committed.Tree.Hash()