X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fser.rs;h=9682c09d95c9aa4e096c6213513b980f9a5ed98b;hb=fb670c8faae8c1e990496b869e62dfbde10a64f8;hp=85b991c61d43674970f588c93add1228722b219c;hpb=be8797e17ab5c56582340d1f5e57f92477ede69d;p=rust-lightning

diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
index 85b991c6..9682c09d 100644
--- a/lightning/src/util/ser.rs
+++ b/lightning/src/util/ser.rs
@@ -199,8 +199,14 @@ pub trait Writeable {
 
 	/// Writes `self` out to a `Vec<u8>`.
 	fn encode(&self) -> Vec<u8> {
-		let mut msg = VecWriter(Vec::new());
+		let len = self.serialized_length();
+		let mut msg = VecWriter(Vec::with_capacity(len));
 		self.write(&mut msg).unwrap();
+		// Note that objects with interior mutability may change size between when we called
+		// serialized_length and when we called write. That's okay, but shouldn't happen during
+		// testing as most of our tests are not threaded.
+		#[cfg(test)]
+		debug_assert_eq!(len, msg.0.len());
 		msg.0
 	}
 
@@ -211,6 +217,7 @@ pub trait Writeable {
 		0u16.write(&mut msg).unwrap();
 		self.write(&mut msg).unwrap();
 		let len = msg.0.len();
+		debug_assert_eq!(len - 2, self.serialized_length());
 		msg.0[..2].copy_from_slice(&(len as u16 - 2).to_be_bytes());
 		msg.0
 	}
@@ -1289,7 +1296,7 @@ impl Readable for String {
 /// This serialization is used by [`BOLT 7`] hostnames.
 ///
 /// [`BOLT 7`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct Hostname(String);
 impl Hostname {
 	/// Returns the length of the hostname.
@@ -1382,7 +1389,7 @@ impl Readable for Duration {
 /// if the `Transaction`'s consensus-serialized length is <= u16::MAX.
 ///
 /// Use [`TransactionU16LenLimited::into_transaction`] to convert into the contained `Transaction`.
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct TransactionU16LenLimited(Transaction);
 
 impl TransactionU16LenLimited {