From a16cc51c52ab8dd68f96d705c66cd662522203ac Mon Sep 17 00:00:00 2001
From: Jeffrey Czyz <jkczyz@gmail.com>
Date: Fri, 7 Oct 2022 15:08:27 -0500
Subject: [PATCH] f - define try_from_tlv_stream_bytes

---
 lightning/src/offers/invoice_request.rs | 17 ++++++-----------
 lightning/src/offers/offer.rs           | 19 +++++++------------
 lightning/src/util/ser_macros.rs        | 20 ++++++++++++++++++++
 3 files changed, 33 insertions(+), 23 deletions(-)

diff --git a/lightning/src/offers/invoice_request.rs b/lightning/src/offers/invoice_request.rs
index 758005cd52b..02ada0bedd9 100644
--- a/lightning/src/offers/invoice_request.rs
+++ b/lightning/src/offers/invoice_request.rs
@@ -340,15 +340,8 @@ impl TryFrom<Vec<u8>> for InvoiceRequest {
 	type Error = ParseError;
 
 	fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
-		let mut cursor = io::Cursor::new(bytes);
-		let tlv_stream: FullInvoiceRequestTlvStream = SeekReadable::read(&mut cursor)?;
-
-		if cursor.position() < cursor.get_ref().len() as u64 {
-			return Err(ParseError::Decode(DecodeError::InvalidValue));
-		}
-
-		let bytes = cursor.into_inner();
-		InvoiceRequest::try_from((bytes, tlv_stream))
+		let parsed_invoice_request = ParsedInvoiceRequest::try_from(bytes)?;
+		InvoiceRequest::try_from(parsed_invoice_request)
 	}
 }
 
@@ -361,7 +354,9 @@ tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, 80..160, {
 	(89, payer_note: (String, WithoutLength)),
 });
 
-type ParsedInvoiceRequest = (Vec<u8>, FullInvoiceRequestTlvStream);
+try_from_tlv_stream_bytes!(FullInvoiceRequestTlvStream, ParsedInvoiceRequest);
+
+struct ParsedInvoiceRequest(Vec<u8>, FullInvoiceRequestTlvStream);
 
 type FullInvoiceRequestTlvStream =
 	(PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
@@ -389,7 +384,7 @@ impl TryFrom<ParsedInvoiceRequest> for InvoiceRequest {
 	type Error = ParseError;
 
 	fn try_from(invoice_request: ParsedInvoiceRequest) -> Result<Self, Self::Error> {
-		let (bytes, tlv_stream) = invoice_request;
+		let ParsedInvoiceRequest(bytes, tlv_stream) = invoice_request;
 		let (
 			payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 			SignatureTlvStream { signature },
diff --git a/lightning/src/offers/offer.rs b/lightning/src/offers/offer.rs
index 6f0133ffa7c..12d20061548 100644
--- a/lightning/src/offers/offer.rs
+++ b/lightning/src/offers/offer.rs
@@ -75,7 +75,7 @@ use core::str::FromStr;
 use core::time::Duration;
 use io;
 use ln::features::OfferFeatures;
-use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
+use ln::msgs::MAX_VALUE_MSAT;
 use offers::invoice_request::InvoiceRequestBuilder;
 use offers::parse::{Bech32Encode, ParseError, SemanticError};
 use onion_message::BlindedPath;
@@ -447,15 +447,8 @@ impl TryFrom<Vec<u8>> for Offer {
 	type Error = ParseError;
 
 	fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
-		let mut cursor = io::Cursor::new(bytes);
-		let tlv_stream: OfferTlvStream = SeekReadable::read(&mut cursor)?;
-
-		if cursor.position() < cursor.get_ref().len() as u64 {
-			return Err(ParseError::Decode(DecodeError::InvalidValue));
-		}
-
-		let bytes = cursor.into_inner();
-		Offer::try_from((bytes, tlv_stream))
+		let parsed_offer = ParsedOffer::try_from(bytes)?;
+		Offer::try_from(parsed_offer)
 	}
 }
 
@@ -533,11 +526,13 @@ tlv_stream!(OfferTlvStream, OfferTlvStreamRef, 1..80, {
 	(22, node_id: PublicKey),
 });
 
+try_from_tlv_stream_bytes!(OfferTlvStream, ParsedOffer);
+
 impl Bech32Encode for Offer {
 	const BECH32_HRP: &'static str = "lno";
 }
 
-type ParsedOffer = (Vec<u8>, OfferTlvStream);
+struct ParsedOffer(Vec<u8>, OfferTlvStream);
 
 impl FromStr for Offer {
 	type Err = ParseError;
@@ -551,7 +546,7 @@ impl TryFrom<ParsedOffer> for Offer {
 	type Error = ParseError;
 
 	fn try_from(offer: ParsedOffer) -> Result<Self, Self::Error> {
-		let (bytes, tlv_stream) = offer;
+		let ParsedOffer(bytes, tlv_stream) = offer;
 		let contents = OfferContents::try_from(tlv_stream)?;
 		Ok(Offer { bytes, contents })
 	}
diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs
index ef2673e8fec..709cb4008c8 100644
--- a/lightning/src/util/ser_macros.rs
+++ b/lightning/src/util/ser_macros.rs
@@ -551,6 +551,26 @@ macro_rules! tlv_record_ref_type {
 	($type:ty) => { &'a $type };
 }
 
+macro_rules! try_from_tlv_stream_bytes {
+	($tlv_stream:ty, $parsed_message:ident) => {
+		impl TryFrom<Vec<u8>> for $parsed_message {
+			type Error = ::ln::msgs::DecodeError;
+
+			fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
+				let mut cursor = io::Cursor::new(bytes);
+				let tlv_stream: $tlv_stream = SeekReadable::read(&mut cursor)?;
+
+				if cursor.position() < cursor.get_ref().len() as u64 {
+					return Err(::ln::msgs::DecodeError::InvalidValue);
+				}
+
+				let bytes = cursor.into_inner();
+				Ok(Self(bytes, tlv_stream))
+			}
+		}
+	};
+}
+
 macro_rules! _impl_writeable_tlv_based_enum_common {
 	($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 		{$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}