Add Inner Ring code

pkg/core/object/headers/user.go

@@ -0,0 +1,45 @@
+package headers
+
+// UserHeader is a value of object extended header
+// that carries user string key-value pairs.
+//
+// All user headers must be type of TypeUser.
+// All user header must have UserHeader pointer value.
+type UserHeader struct {
+	key, val string
+}
+
+// NewUserHeader creates, initialized and returns
+// the user extended header.
+func NewUserHeader(key, val string) *Header {
+	res := new(Header)
+
+	res.SetType(TypeUser)
+
+	res.SetValue(&UserHeader{
+		key: key,
+		val: val,
+	})
+
+	return res
+}
+
+// Key returns the user header key.
+func (u UserHeader) Key() string {
+	return u.key
+}
+
+// SetKey sets the user header key.
+func (u *UserHeader) SetKey(key string) {
+	u.key = key
+}
+
+// Value returns the user header value.
+func (u UserHeader) Value() string {
+	return u.val
+}
+
+// SetValue sets the user header value.
+func (u *UserHeader) SetValue(val string) {
+	u.val = val
+}