From: Matt Corallo <649246+TheBlueMatt@users.noreply.github.com>
Date: Thu, 27 May 2021 23:05:47 +0000 (+0000)
Subject: Merge pull request #928 from TheBlueMatt/2021-05-really-tlv-ser
X-Git-Tag: v0.0.98~14
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=df829a85263e0bc675ca696c0f6ff0a49d89e623;p=rust-lightning

Merge pull request #928 from TheBlueMatt/2021-05-really-tlv-ser

Migrate some inner structs to TLVs
---

df829a85263e0bc675ca696c0f6ff0a49d89e623
diff --cc lightning/src/util/ser_macros.rs
index 872901893,db970df5f..b8119ddd5
--- a/lightning/src/util/ser_macros.rs
+++ b/lightning/src/util/ser_macros.rs
@@@ -275,9 -283,103 +283,104 @@@ macro_rules! read_tlv_fields 
  	} }
  }
  
+ // If we naively create a struct in impl_writeable_tlv_based below, we may end up returning
+ // `Self { ,,vecfield: vecfield }` which is obviously incorrect. Instead, we have to match here to
+ // detect at least one empty field set and skip the potentially-extra comma.
+ macro_rules! _init_tlv_based_struct {
+ 	({}, {$($field: ident),*}, {$($vecfield: ident),*}) => {
+ 		Ok(Self {
+ 			$($field),*,
+ 			$($vecfield: $vecfield.unwrap().0),*
+ 		})
+ 	};
+ 	({$($reqfield: ident),*}, {}, {$($vecfield: ident),*}) => {
+ 		Ok(Self {
+ 			$($reqfield: $reqfield.0.unwrap()),*,
+ 			$($vecfield: $vecfield.unwrap().0),*
+ 		})
+ 	};
+ 	({$($reqfield: ident),*}, {$($field: ident),*}, {}) => {
+ 		Ok(Self {
+ 			$($reqfield: $reqfield.0.unwrap()),*,
+ 			$($field),*
+ 		})
+ 	};
+ 	({$($reqfield: ident),*}, {$($field: ident),*}, {$($vecfield: ident),*}) => {
+ 		Ok(Self {
+ 			$($reqfield: $reqfield.0.unwrap()),*,
+ 			$($field),*,
+ 			$($vecfield: $vecfield.unwrap().0),*
+ 		})
+ 	}
+ }
+ 
+ // If we don't have any optional types below, but do have some vec types, we end up calling
+ // `write_tlv_field!($stream, {..}, {, (vec_ty, vec_val)})`, which is obviously broken.
+ // Instead, for write and read we match the missing values and skip the extra comma.
+ macro_rules! _write_tlv_fields {
+ 	($stream: expr, {$(($type: expr, $field: expr)),* $(,)*}, {}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}) => {
+ 		write_tlv_fields!($stream, {$(($type, $field)),*} , {$(($optional_type, $optional_field)),*});
+ 	};
+ 	($stream: expr, {$(($type: expr, $field: expr)),* $(,)*}, {$(($optional_type: expr, $optional_field: expr)),* $(,)*}, {$(($optional_type_2: expr, $optional_field_2: expr)),* $(,)*}) => {
+ 		write_tlv_fields!($stream, {$(($type, $field)),*} , {$(($optional_type, $optional_field)),*, $(($optional_type_2, $optional_field_2)),*});
+ 	}
+ }
+ macro_rules! _read_tlv_fields {
+ 	($stream: expr, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {}, {$(($type: expr, $field: ident)),* $(,)*}) => {
+ 		read_tlv_fields!($stream, {$(($reqtype, $reqfield)),*}, {$(($type, $field)),*});
+ 	};
+ 	($stream: expr, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {$(($type: expr, $field: ident)),* $(,)*}, {$(($type_2: expr, $field_2: ident)),* $(,)*}) => {
+ 		read_tlv_fields!($stream, {$(($reqtype, $reqfield)),*}, {$(($type, $field)),*, $(($type_2, $field_2)),*});
+ 	}
+ }
+ 
+ /// Implements Readable/Writeable for a struct storing it as a set of TLVs
+ /// First block includes all the required fields including a dummy value which is used during
+ /// deserialization but which will never be exposed to other code.
+ /// The second block includes optional fields.
+ /// The third block includes any Vecs which need to have their individual elements serialized.
+ macro_rules! impl_writeable_tlv_based {
+ 	($st: ident, {$(($reqtype: expr, $reqfield: ident)),* $(,)*}, {$(($type: expr, $field: ident)),* $(,)*}, {$(($vectype: expr, $vecfield: ident)),* $(,)*}) => {
+ 		impl ::util::ser::Writeable for $st {
+ 			fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ 				_write_tlv_fields!(writer, {
+ 					$(($reqtype, self.$reqfield)),*
+ 				}, {
+ 					$(($type, self.$field)),*
+ 				}, {
+ 					$(($vectype, Some(::util::ser::VecWriteWrapper(&self.$vecfield)))),*
+ 				});
+ 				Ok(())
+ 			}
+ 		}
+ 
+ 		impl ::util::ser::Readable for $st {
+ 			fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
+ 				$(
+ 					let mut $reqfield = ::util::ser::OptionDeserWrapper(None);
+ 				)*
+ 				$(
+ 					let mut $field = None;
+ 				)*
+ 				$(
+ 					let mut $vecfield = Some(::util::ser::VecReadWrapper(Vec::new()));
+ 				)*
+ 				_read_tlv_fields!(reader, {
+ 					$(($reqtype, $reqfield)),*
+ 				}, {
+ 					$(($type, $field)),*
+ 				}, {
+ 					$(($vectype, $vecfield)),*
+ 				});
+ 				_init_tlv_based_struct!({$($reqfield),*}, {$($field),*}, {$($vecfield),*})
+ 			}
+ 		}
+ 	}
+ }
+ 
  #[cfg(test)]
  mod tests {
 +	use prelude::*;
  	use std::io::{Cursor, Read};
  	use ln::msgs::DecodeError;
  	use util::ser::{Readable, Writeable, HighZeroBytesDroppedVarInt, VecWriter};