Extend and expose TlvRecord and TlvStream

To avoid implementing another TLV struct needed for custom TLV logic, we
slightly modify and expose these existing types.

Author: alecchendev

lightning/src/offers/merkle.rs

@@ -144,7 +144,7 @@ fn tagged_branch_hash_from_engine(
 /// [`Iterator`] over a sequence of bytes yielding [`TlvRecord`]s. The input is assumed to be a
 /// well-formed TLV stream.
 #[derive(Clone)]
-pub(super) struct TlvStream<'a> {
+pub(crate) struct TlvStream<'a> {
 	data: io::Cursor<&'a [u8]>,
 }
 
@@ -170,13 +170,26 @@ impl<'a> TlvStream<'a> {
 }
 
 /// A slice into a [`TlvStream`] for a record.
-pub(super) struct TlvRecord<'a> {
+#[derive(PartialEq)]
+pub(crate) struct TlvRecord<'a> {
 	pub(super) r#type: u64,
 	type_bytes: &'a [u8],
 	// The entire TLV record.
 	pub(super) record_bytes: &'a [u8],
 }
 
+impl TlvRecord<'_> {
+	pub(crate) fn get_type(&self) -> u64 {
+		self.r#type
+	}
+}
+
+impl Writeable for TlvRecord<'_> {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		writer.write_all(self.record_bytes)
+	}
+}
+
 impl<'a> Iterator for TlvStream<'a> {
 	type Item = TlvRecord<'a>;
 

lightning/src/offers/mod.rs

@@ -15,6 +15,7 @@
 pub mod invoice;
 pub mod invoice_request;
 mod merkle;
+pub(crate) use merkle::{TlvRecord, TlvStream};
 pub mod offer;
 pub mod parse;
 mod payer;