Swap read_event read type for a slice isntead of a Vec

It looks like we don't currently use the Vec as a Vec, and can
happily take a slice, which makes things easier on the calling
side.

Author: TheBlueMatt

fuzz/src/full_stack.rs

@@ -384,7 +384,7 @@ pub fn do_test(data: &[u8], logger: &Arc<dyn Logger>) {
 			3 => {
 				let peer_id = get_slice!(1)[0];
 				if !peers.borrow()[peer_id as usize] { return; }
-				match loss_detector.handler.read_event(&mut Peer{id: peer_id, peers_connected: &peers}, get_slice!(get_slice!(1)[0]).to_vec()) {
+				match loss_detector.handler.read_event(&mut Peer{id: peer_id, peers_connected: &peers}, get_slice!(get_slice!(1)[0])) {
 					Ok(res) => assert!(!res),
 					Err(_) => { peers.borrow_mut()[peer_id as usize] = false; }
 				}

lightning-net-tokio/src/lib.rs

@@ -62,7 +62,7 @@ impl Connection {
 			//TODO: There's a race where we don't meet the requirements of socket_disconnected if its
 			//called right here, after we release the us_ref lock in the scope above, but before we
 			//call read_event!
-			match peer_manager.read_event(&mut SocketDescriptor::new(us_ref.clone(), peer_manager.clone()), pending_read) {
+			match peer_manager.read_event(&mut SocketDescriptor::new(us_ref.clone(), peer_manager.clone()), &pending_read) {
 				Ok(pause_read) => {
 					if pause_read {
 						let mut lock = us_ref.lock().unwrap();
@@ -181,7 +181,7 @@ impl<CMH: ChannelMessageHandler> peer_handler::SocketDescriptor for SocketDescri
 					}
 					if !read_data.is_empty() {
 						let mut us_clone = $us_ref.clone();
-						match $us_ref.peer_manager.read_event(&mut us_clone, read_data) {
+						match $us_ref.peer_manager.read_event(&mut us_clone, &read_data) {
 							Ok(pause_read) => {
 								if pause_read { return Ok(()); }
 							},

lightning/src/ln/peer_handler.rs

@@ -435,7 +435,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
 	/// on this file descriptor has resume_read set (preventing DoS issues in the send buffer).
 	///
 	/// Panics if the descriptor was not previously registered in a new_*_connection event.
-	pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: Vec<u8>) -> Result<bool, PeerHandleError> {
+	pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
 		match self.do_read_event(peer_descriptor, data) {
 			Ok(res) => Ok(res),
 			Err(e) => {
@@ -445,7 +445,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
 		}
 	}
 
-	fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: Vec<u8>) -> Result<bool, PeerHandleError> {
+	fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
 		let pause_read = {
 			let mut peers_lock = self.peers.lock().unwrap();
 			let peers = &mut *peers_lock;
@@ -1199,9 +1199,9 @@ mod tests {
 		let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
 		let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone()).unwrap();
 		peer_a.new_inbound_connection(fd_a.clone()).unwrap();
-		assert_eq!(peer_a.read_event(&mut fd_a, initial_data).unwrap(), false);
-		assert_eq!(peer_b.read_event(&mut fd_b, fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
-		assert_eq!(peer_a.read_event(&mut fd_a, fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
+		assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
+		assert_eq!(peer_b.read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
+		assert_eq!(peer_a.read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
 	}
 
 	#[test]