feat: add a state db for account manager

core/manager/account/db.go

@@ -0,0 +1,49 @@
+package account
+
+import (
+	"encoding/json"
+
+	"github.com/jinzhu/gorm"
+)
+
+type StateDB struct {
+	gorm *gorm.DB `gorm:"-"`
+	gorm.Model
+
+	StartCounter int
+}
+
+func OpenStateDB(path string) (*StateDB, error) {
+	// open db
+	db, err := gorm.Open("sqlite3", path)
+	if err != nil {
+		return nil, err
+	}
+
+	// create tables and columns
+	if err := db.AutoMigrate(&StateDB{}).Error; err != nil {
+		return nil, err
+	}
+
+	// preload last state
+	var state StateDB
+	if err := db.FirstOrInit(&state).Error; err != nil {
+		return nil, err
+	}
+	state.gorm = db
+
+	return &state, nil
+}
+
+func (state StateDB) String() string {
+	out, _ := json.Marshal(state)
+	return string(out)
+}
+
+func (state *StateDB) Save() error {
+	return state.gorm.Save(state).Error
+}
+
+func (state *StateDB) Close() {
+	state.gorm.Close()
+}

core/manager/account/db_test.go

@@ -0,0 +1,33 @@
+package account
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestStateDB(t *testing.T) {
+	Convey("Testing StateDB", t, func() {
+		tmpFile, err := ioutil.TempFile("", "sqlite")
+		So(err, ShouldBeNil)
+		defer os.Remove(tmpFile.Name())
+
+		state, err := OpenStateDB(tmpFile.Name())
+		So(err, ShouldBeNil)
+		defer state.Close()
+		So(state.StartCounter, ShouldEqual, 0)
+
+		state.StartCounter++
+		So(state.Save(), ShouldBeNil)
+		So(state.StartCounter, ShouldEqual, 1)
+
+		state.Close()
+
+		state, err = OpenStateDB(tmpFile.Name())
+		So(err, ShouldBeNil)
+		defer state.Close()
+		So(state.StartCounter, ShouldEqual, 1)
+	})
+}