implement postgres for the state store

internal/storage/storageservice.go

@@ -53,40 +53,58 @@ func NewMenuStorageService(dbDir string, resourceDir string) *MenuStorageService
 	}
 }
 
-func (ms *MenuStorageService) GetPersister(ctx context.Context) (*persist.Persister, error) {
+func (ms *MenuStorageService) getOrCreateDb(ctx context.Context, existingDb db.Db, fileName string) (db.Db, error) {
-	ms.stateStore = NewThreadGdbmDb()
-	storeFile := path.Join(ms.dbDir, "state.gdbm")
-	err := ms.stateStore.Connect(ctx, storeFile)
-	if err != nil {
-		return nil, err
-	}
-	pr := persist.NewPersister(ms.stateStore)
-	logg.TraceCtxf(ctx, "menu storage service", "persist", pr, "store", ms.stateStore)
-	return pr, nil
-}
-
-func (ms *MenuStorageService) GetUserdataDb(ctx context.Context) (db.Db, error) {
 	database, ok := ctx.Value("Database").(string)
 	if !ok {
 		return nil, fmt.Errorf("failed to select the database")
 	}
 
-	if database == "postgres" {
+	if existingDb != nil {
-		ms.userDataStore = NewPostgresDb()
+		return existingDb, nil
-		connStr := buildConnStr()
-		err := ms.userDataStore.Connect(ctx, connStr)
-		if err != nil {
-			return nil, err
-		}
-	} else {
-		ms.userDataStore = NewThreadGdbmDb()
-		storeFile := path.Join(ms.dbDir, "userdata.gdbm")
-		err := ms.userDataStore.Connect(ctx, storeFile)
-		if err != nil {
-			return nil, err
-		}
 	}
 
+	var newDb db.Db
+	var err error
+
+	if database == "postgres" {
+		newDb = NewPostgresDb()
+		connStr := buildConnStr()
+		err = newDb.Connect(ctx, connStr)
+	} else {
+		newDb = NewThreadGdbmDb()
+		storeFile := path.Join(ms.dbDir, fileName)
+		err = newDb.Connect(ctx, storeFile)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return newDb, nil
+}
+
+func (ms *MenuStorageService) GetPersister(ctx context.Context) (*persist.Persister, error) {
+	stateStore, err := ms.GetStateStore(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	pr := persist.NewPersister(stateStore)
+	logg.TraceCtxf(ctx, "menu storage service", "persist", pr, "store", stateStore)
+	return pr, nil
+}
+
+func (ms *MenuStorageService) GetUserdataDb(ctx context.Context) (db.Db, error) {
+	if ms.userDataStore != nil {
+		return ms.userDataStore, nil
+	}
+
+	userDataStore, err := ms.getOrCreateDb(ctx, ms.userDataStore, "userdata.gdbm")
+	if err != nil {
+		return nil, err
+	}
+
+	ms.userDataStore = userDataStore
 	return ms.userDataStore, nil
 }
 
@@ -102,14 +120,15 @@ func (ms *MenuStorageService) GetResource(ctx context.Context) (resource.Resourc
 
 func (ms *MenuStorageService) GetStateStore(ctx context.Context) (db.Db, error) {
 	if ms.stateStore != nil {
-		panic("set up store when already exists")
+		return ms.stateStore, nil
 	}
-	ms.stateStore = NewThreadGdbmDb()
+
-	storeFile := path.Join(ms.dbDir, "state.gdbm")
+	stateStore, err := ms.getOrCreateDb(ctx, ms.stateStore, "state.gdbm")
-	err := ms.stateStore.Connect(ctx, storeFile)
 	if err != nil {
 		return nil, err
 	}
+
+	ms.stateStore = stateStore
 	return ms.stateStore, nil
 }