Add semantics to logger::Records

Include optional peer and channel ids to logger::Record. This will be
used by wrappers around Logger in order to provide more context (e.g.,
the peer that sent a message, the channel an operation is pertaining to,
etc.). Implementations of Logger can include this as metadata to aid in
searching logs.

Author: jkczyz

lightning/src/util/logger.rs

@@ -19,6 +19,7 @@ use bitcoin::secp256k1::PublicKey;
 use core::cmp;
 use core::fmt;
 
+use crate::ln::ChannelId;
 #[cfg(c_bindings)]
 use crate::prelude::*; // Needed for String
 
@@ -95,6 +96,11 @@ impl Level {
 pub struct Record<'a> {
 	/// The verbosity level of the message.
 	pub level: Level,
+	/// The node id of the peer pertaining to the logged record.
+	pub peer_id: Option<PublicKey>,
+	/// The channel id of the channel pertaining to the logged record. May be a temporary id before
+	/// the channel has been funded.
+	pub channel_id: Option<ChannelId>,
 	#[cfg(not(c_bindings))]
 	/// The message body.
 	pub args: fmt::Arguments<'a>,
@@ -119,9 +125,14 @@ impl<'a> Record<'a> {
 	///
 	/// This is not exported to bindings users as fmt can't be used in C
 	#[inline]
-	pub fn new(level: Level, args: fmt::Arguments<'a>, module_path: &'static str, file: &'static str, line: u32) -> Record<'a> {
+	pub fn new(
+		level: Level, peer_id: Option<PublicKey>, channel_id: Option<ChannelId>,
+		args: fmt::Arguments<'a>, module_path: &'static str, file: &'static str, line: u32
+	) -> Record<'a> {
 		Record {
 			level,
+			peer_id,
+			channel_id,
 			#[cfg(not(c_bindings))]
 			args,
 			#[cfg(c_bindings)]

lightning/src/util/macro_logger.rs

@@ -159,7 +159,7 @@ macro_rules! log_spendable {
 #[macro_export]
 macro_rules! log_internal {
 	($logger: expr, $lvl:expr, $($arg:tt)+) => (
-		$logger.log($crate::util::logger::Record::new($lvl, format_args!($($arg)+), module_path!(), file!(), line!()))
+		$logger.log($crate::util::logger::Record::new($lvl, None, None, format_args!($($arg)+), module_path!(), file!(), line!()))
 	);
 }