f - refactor tlv_stream-related macros

Author: jkczyz

lightning/src/util/ser_macros.rs

@@ -26,13 +26,11 @@ macro_rules! encode_tlv {
 			field.write($stream)?;
 		}
 	};
-	($stream: expr, $type: expr, $field: expr, (tlv_record, $fieldty:tt)) => {
-		if let Some(field) = $field {
-			let field: encoded_tlv_record_ref_type!($fieldty) = From::from(field);
-			BigSize($type).write($stream)?;
-			BigSize(field.serialized_length() as u64).write($stream)?;
-			field.write($stream)?;
-		}
+	($stream: expr, $type: expr, $field: expr, (tlv_record, ($fieldty:ty, $wrapper:ident))) => {
+		encode_tlv!($stream, $type, $field.map(|f| $wrapper(f)), option);
+	};
+	($stream: expr, $type: expr, $field: expr, (tlv_record, $fieldty:ty)) => {
+		encode_tlv!($stream, $type, $field, option);
 	};
 }
 
@@ -186,12 +184,15 @@ macro_rules! decode_tlv {
 	($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 		$field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 	}};
-	($reader: expr, $field: ident, (tlv_record, $fieldty:tt)) => {{
+	($reader: expr, $field: ident, (tlv_record, ($fieldty:ty, $wrapper:ident))) => {{
 		$field = {
-			let field: encoded_tlv_record_type!($fieldty) = ser::Readable::read(&mut $reader)?;
+			let field: $wrapper<$fieldty> = ser::Readable::read(&mut $reader)?;
 			Some(field.into())
 		};
 	}};
+	($reader: expr, $field: ident, (tlv_record, $fieldty:ty)) => {{
+		decode_tlv!($reader, $field, option);
+	}};
 }
 
 macro_rules! decode_tlv_stream {
@@ -453,7 +454,9 @@ macro_rules! impl_writeable_tlv_based {
 /// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
 /// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
 /// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
-/// representing a TLV record has its type wrapped with an [`Option`].
+/// representing a TLV record has its type wrapped with an [`Option`]. A tuple consisting of a type
+/// and a serialization wrapper may be given in place of a type when custom serialization is
+/// required.
 ///
 /// [`Readable`]: crate::util::ser::Readable
 /// [`Writeable`]: crate::util::ser::Writeable
@@ -503,57 +506,18 @@ macro_rules! tlv_stream {
 }
 
 macro_rules! tlv_record_type {
-	(($type:ty, $wrapper:ident)) => {
-		$type
-	};
-	($type:ty) => {
-		$type
-	};
+	(($type:ty, $wrapper:ident)) => { $type };
+	($type:ty) => { $type };
 }
 
 macro_rules! tlv_record_ref_type {
-	(u8) => {
-		u8
-	};
-	(char) => {
-		char
-	};
-	(($type:ty, HighZeroBytesDroppedBigSize)) => {
-		$type
-	};
-	(($type:ty, $wrapper:ident)) => {
-		&'a $type
-	};
-	($type:ty) => {
-		&'a $type
-	};
-}
-
-macro_rules! encoded_tlv_record_type {
-	(($type:ty, $wrapper:ident)) => {
-		$wrapper<$type>
-	};
-	($type:ty) => {
-		$type
-	};
-}
-
-macro_rules! encoded_tlv_record_ref_type {
-	(u8) => {
-		u8
-	};
-	(char) => {
-		char
-	};
-	(($type:ty, HighZeroBytesDroppedBigSize)) => {
-		HighZeroBytesDroppedBigSize<$type>
-	};
-	(($type:ty, $wrapper:ident)) => {
-		$wrapper<&$type>
-	};
-	($type:ty) => {
-		&$type
-	};
+	(char) => { char };
+	(u8) => { u8 };
+	((u16, $wrapper: ident)) => { u16 };
+	((u32, $wrapper: ident)) => { u32 };
+	((u64, $wrapper: ident)) => { u64 };
+	(($type:ty, $wrapper:ident)) => { &'a $type };
+	($type:ty) => { &'a $type };
 }
 
 macro_rules! _impl_writeable_tlv_based_enum_common {