feat: state migration from IAVL to SMT (ADR-040)

store/v2/multi/migration.go

@@ -1,7 +1,7 @@
 package root
 
 import (
-	prefixdb "github.com/cosmos/cosmos-sdk/db/prefix"
+	dbm "github.com/cosmos/cosmos-sdk/db"
 	"github.com/cosmos/cosmos-sdk/store/iavl"
 	"github.com/cosmos/cosmos-sdk/store/mem"
 	v1Store "github.com/cosmos/cosmos-sdk/store/rootmulti"
@@ -11,44 +11,50 @@ import (
 )
 
 // MigrateV2 will migrate the state from iavl to smt
-func MigrateV2(rs *v1Store.Store, rootStore *Store) error {
-	if len(rootStore.schema) != 0 {
-		// schema already exists
-		return sdkerrors.Wrapf(sdkerrors.ErrLogic, "smt store already have schema")
+func MigrateV2(rs *v1Store.Store, db dbm.DBConnection, storeConfig StoreConfig) (*Store, error) {
+	type namedStore struct {
+		*iavl.Store
+		name string
 	}
-
-	// set the schema to smt store
-	schemaWriter := prefixdb.NewPrefixWriter(rootStore.stateTxn, schemaPrefix)
-
+	var stores []namedStore
 	for key := range rs.GetStores() {
 		switch store := rs.GetCommitKVStore(key).(type) {
 		case *iavl.Store:
-			rootStore.schema[key.Name()] = types.StoreTypePersistent
-			err := schemaWriter.Set([]byte(key.Name()), []byte{byte(types.StoreTypePersistent)})
-			if err != nil {
-				return sdkerrors.Wrap(err, "error at set the store schema key values")
-			}
-
-			subStore, err := rootStore.getSubstore(key.Name())
-			if err != nil {
-				return err
-			}
-			// iterate all iavl tree node key/values
-			iterator := store.Iterator(nil, nil)
-			for ; iterator.Valid(); iterator.Next() {
-				// set the iavl key,values into smt node
-				subStore.Set(iterator.Key(), iterator.Value())
-			}
-
+			storeConfig.prefixRegistry.StoreSchema[key.Name()] = types.StoreTypePersistent
+			stores = append(stores, namedStore{name: key.Name(), Store: store})
 		case *transient.Store, *mem.Store:
+			// Non-persisted stores shouldn't be snapshotted
 			continue
 		default:
-			continue
+			return nil, sdkerrors.Wrapf(sdkerrors.ErrLogic, "don't know how to snapshot store %q of type %T", key.Name(), store)
+		}
+	}
+
+	// creating the new store of smt tree
+	rootStore, err := NewStore(db, storeConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	// iterate through the rootmulti stores and save the key/values into smt tree
+	for _, store := range stores {
+		subStore, err := rootStore.getSubstore(store.name)
+		if err != nil {
+			return nil, err
+		}
+		// iterate all iavl tree node key/values
+		iterator := store.Iterator(nil, nil)
+		for ; iterator.Valid(); iterator.Next() {
+			// set the iavl key,values into smt node
+			subStore.Set(iterator.Key(), iterator.Value())
 		}
 	}
 
 	// commit the all key/values from iavl to smt tree (SMT Store)
-	rootStore.Commit()
+	_, err = rootStore.commit(uint64(rs.LastCommitID().Version))
+	if err != nil {
+		return nil, err
+	}
 
-	return nil
+	return rootStore, nil
 }

store/v2/multi/migration_test.go

@@ -23,16 +23,15 @@ func TestMigrationV2(t *testing.T) {
 	// setup a temporary test data
 	v1StoreKVStore := v1Store.GetKVStore(kvStoreKey)
 	v1StoreKVStore.Set([]byte("temp_data"), []byte("one"))
+	v1Store.Commit()
 
 	// setup a new root store of smt
 	db2 := memdb.NewDB()
-	v2Store, err := NewStore(db2, DefaultStoreConfig())
-	require.Nil(t, err)
-
 	// migrating the iavl store (v1) to smt store (v2)
-	err = MigrateV2(v1Store, v2Store)
+	v2Store, err := MigrateV2(v1Store, db2, DefaultStoreConfig())
 	require.NoError(t, err)
 
 	v2StoreKVStore := v2Store.GetKVStore(kvStoreKey)
 	require.Equal(t, v2StoreKVStore.Get([]byte("temp_data")), []byte("one"))
+	require.Equal(t, v2Store.LastCommitID().Version,v1Store.LastCommitID().Version)
 }