Change Option<T> serialization format to include length

[rust-lightning] / lightning / src / util / ser.rs

diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
index 38133d59670dd5c717a3d1dc850fe3296fc316c6..60d5329d781c8ed247a36eef791470e224878d48 100644 (file)
--- a/lightning/src/util/ser.rs
+++ b/lightning/src/util/ser.rs
@@ -172,6 +172,10 @@ pub trait Writeable {
        }
 }
 
+impl<'a, T: Writeable> Writeable for &'a T {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> { (*self).write(writer) }
+}
+
 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 pub trait Readable
        where Self: Sized
@@ -592,7 +596,9 @@ impl<T: Writeable> Writeable for Option<T> {
                match *self {
                        None => 0u8.write(w)?,
                        Some(ref data) => {
-                               1u8.write(w)?;
+                               let mut len_calc = LengthCalculatingWriter(0);
+                               data.write(&mut len_calc).expect("No in-memory data may fail to serialize");
+                               BigSize(len_calc.0 as u64 + 1).write(w)?;
                                data.write(w)?;
                        }
                }
@@ -603,10 +609,12 @@ impl<T: Writeable> Writeable for Option<T> {
 impl<T: Readable> Readable for Option<T>
 {
        fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
-               match <u8 as Readable>::read(r)? {
+               match BigSize::read(r)?.0 {
                        0 => Ok(None),
-                       1 => Ok(Some(Readable::read(r)?)),
-                       _ => return Err(DecodeError::InvalidValue),
+                       len => {
+                               let mut reader = FixedLengthReader::new(r, len - 1);
+                               Ok(Some(Readable::read(&mut reader)?))
+                       }
                }
        }
 }