New donut driver with local file encoding

pkg/storage/donut/objectwriter.go

@@ -0,0 +1,39 @@
+package donut
+
+import (
+	"errors"
+)
+
+type objectWriter struct {
+	metadata map[string]string
+}
+
+func (self objectWriter) Write(data []byte) (length int, err error) {
+	return 11, nil
+}
+
+func (self objectWriter) Close() error {
+	return nil
+}
+
+func (self objectWriter) CloseWithError(err error) error {
+	return errors.New("Not Implemented")
+}
+
+func (self objectWriter) SetMetadata(metadata map[string]string) error {
+	for k := range self.metadata {
+		delete(self.metadata, k)
+	}
+	for k, v := range metadata {
+		self.metadata[k] = v
+	}
+	return nil
+}
+
+func (self objectWriter) GetMetadata() (map[string]string, error) {
+	ret := make(map[string]string)
+	for k, v := range self.metadata {
+		ret[k] = v
+	}
+	return ret, nil
+}