Add register plugin API

errors.go

@@ -27,4 +27,6 @@ var (
 	ErrorModelValueRequired = errors.New("model value required")
 	// ErrUnsupportedDriver unsupported driver
 	ErrUnsupportedDriver = errors.New("unsupported driver")
+	// ErrRegistered registered
+	ErrRegistered = errors.New("registered")
 )

gorm.go

@@ -39,6 +39,8 @@ type Config struct {
 	ConnPool ConnPool
 	// Dialector database dialector
 	Dialector
+	// Plugins registered plugins
+	Plugins map[string]Plugin
 
 	callbacks  *callbacks
 	cacheStore *sync.Map
@@ -309,3 +311,16 @@ func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interfac
 
 	return nil
 }
+
+func (db *DB) Use(plugin Plugin) (err error) {
+	name := plugin.Name()
+	if _, ok := db.Plugins[name]; !ok {
+		if err = plugin.Initialize(db); err == nil {
+			db.Plugins[name] = plugin
+		}
+	} else {
+		return ErrRegistered
+	}
+
+	return err
+}

interfaces.go

@@ -20,6 +20,12 @@ type Dialector interface {
 	Explain(sql string, vars ...interface{}) string
 }
 
+// Plugin GORM plugin interface
+type Plugin interface {
+	Name() string
+	Initialize(*DB) error
+}
+
 // ConnPool db conns pool interface
 type ConnPool interface {
 	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
@@ -28,6 +34,7 @@ type ConnPool interface {
 	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
 }
 
+// SavePointerDialectorInterface save pointer interface
 type SavePointerDialectorInterface interface {
 	SavePoint(tx *DB, name string) error
 	RollbackTo(tx *DB, name string) error