Session refactoring

grade/internal/infrastructure/seedwork/session/deferred_result.go

@@ -0,0 +1,50 @@
+package session
+
+import (
+	"errors"
+)
+
+type DeferredResultImp struct {
+	lastInsertId int64
+	rowsAffected int64
+	callbacks    []DeferredResultCallback
+	isResolved   bool
+}
+
+func (r *DeferredResultImp) Resolve(lastInsertId, rowsAffected int64) error {
+	r.lastInsertId = lastInsertId
+	r.rowsAffected = rowsAffected
+	r.isResolved = true
+	for i := range r.callbacks {
+		err := r.callbacks[i](r)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *DeferredResultImp) AddCallback(callback DeferredResultCallback) error {
+	if r.isResolved {
+		return callback(r)
+	} else {
+		r.callbacks = append(r.callbacks, callback)
+	}
+	return nil
+}
+
+func (r DeferredResultImp) LastInsertId() (int64, error) {
+	if r.rowsAffected == 0 {
+		return r.lastInsertId, nil
+	} else {
+		return 0, errors.New("LastInsertId is not supported by this driver")
+	}
+}
+
+func (r DeferredResultImp) RowsAffected() (int64, error) {
+	if r.lastInsertId == 0 {
+		return r.rowsAffected, nil
+	} else {
+		return 0, errors.New("RowsAffected is not supported by INSERT command")
+	}
+}