f - Drop unnecessary std gates and restore unrelated whitespace

`Notifier`, `Future`, and `.await` are all available in no-std; only
`Future::wait_timeout` requires std. Stop gating the notifier field and
callers on `std`, and also revert the incidental blank-line removals
that crept into the async-receive-offer refresh changes.

Co-Authored-By: HAL 9000

Author: tnull

lightning/src/ln/channelmanager.rs

@@ -5893,7 +5893,6 @@ impl<
 	///
 	/// [`Future`]: crate::util::wakers::Future
 	/// [`Future::wait_timeout`]: crate::util::wakers::Future::wait_timeout
-	#[cfg(feature = "std")]
 	pub async fn await_async_receive_offer(&self) -> Result<Offer, ()> {
 		if let Ok(offer) = self.get_async_receive_offer() {
 			return Ok(offer);
@@ -5909,7 +5908,6 @@ impl<
 	///
 	/// [`Future`]: crate::util::wakers::Future
 	/// [`OffersMessageFlow::get_async_receive_offer_ready_future`]: crate::offers::flow::OffersMessageFlow::get_async_receive_offer_ready_future
-	#[cfg(feature = "std")]
 	pub fn get_async_receive_offer_ready_future(&self) -> crate::util::wakers::Future {
 		self.flow.get_async_receive_offer_ready_future()
 	}

lightning/src/offers/flow.rs

@@ -61,10 +61,7 @@ use crate::sync::{Mutex, RwLock};
 use crate::types::payment::{PaymentHash, PaymentSecret};
 use crate::util::logger::Logger;
 use crate::util::ser::Writeable;
-#[cfg(feature = "std")]
-use crate::util::wakers::Future;
-#[cfg(feature = "std")]
-use crate::util::wakers::Notifier;
+use crate::util::wakers::{Future, Notifier};
 
 /// A BOLT12 offers code and flow utility provider, which facilitates
 /// BOLT12 builder generation and onion message handling.
@@ -91,7 +88,6 @@ pub struct OffersMessageFlow<MR: MessageRouter, L: Logger> {
 
 	pending_async_payments_messages: Mutex<Vec<(AsyncPaymentsMessage, MessageSendInstructions)>>,
 	async_receive_offer_cache: Mutex<AsyncReceiveOfferCache>,
-	#[cfg(feature = "std")]
 	async_receive_offer_ready_notifier: Notifier,
 
 	logger: L,
@@ -122,7 +118,6 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 			pending_async_payments_messages: Mutex::new(Vec::new()),
 
 			async_receive_offer_cache: Mutex::new(AsyncReceiveOfferCache::new()),
-			#[cfg(feature = "std")]
 			async_receive_offer_ready_notifier: Notifier::new(),
 
 			logger,
@@ -1369,6 +1364,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 				Some(idx) => idx,
 				None => return Ok(()),
 			};
+
 		// If we need new offers, send out offer paths request messages to the static invoice server.
 		let context = MessageContext::AsyncPayments(AsyncPaymentsContext::OfferPaths {
 			path_absolute_expiry: duration_since_epoch
@@ -1482,6 +1478,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 			},
 			_ => return None,
 		};
+
 		// Create the blinded paths that will be included in the async recipient's offer.
 		let (offer_paths, paths_expiry) = {
 			let path_absolute_expiry =
@@ -1543,6 +1540,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 			},
 			_ => return None,
 		};
+
 		{
 			// Only respond with `ServeStaticInvoice` if we actually need a new offer built.
 			let mut cache = self.async_receive_offer_cache.lock().unwrap();
@@ -1574,6 +1572,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 				return None;
 			},
 		};
+
 		let (invoice, forward_invoice_request_path) = match self.create_static_invoice_for_server(
 			&offer,
 			offer_nonce,
@@ -1587,6 +1586,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 				return None;
 			},
 		};
+
 		if let Err(()) = self.async_receive_offer_cache.lock().unwrap().cache_pending_offer(
 			offer,
 			message.paths_absolute_expiry,
@@ -1598,6 +1598,7 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 			log_error!(self.logger, "Failed to cache pending offer");
 			return None;
 		}
+
 		let reply_path_context = {
 			MessageContext::AsyncPayments(AsyncPaymentsContext::StaticInvoicePersisted {
 				offer_id,
@@ -1714,7 +1715,6 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 	pub fn handle_static_invoice_persisted(&self, context: AsyncPaymentsContext) -> bool {
 		let mut cache = self.async_receive_offer_cache.lock().unwrap();
 		let updated = cache.static_invoice_persisted(context);
-		#[cfg(feature = "std")]
 		if updated {
 			self.async_receive_offer_ready_notifier.notify();
 		}
@@ -1727,7 +1727,6 @@ impl<MR: MessageRouter, L: Logger> OffersMessageFlow<MR, L> {
 	/// Callers can either `.await` the returned [`Future`] in an async context or call
 	/// [`Future::wait_timeout`] from a synchronous context. After it completes, use
 	/// [`Self::get_async_receive_offer`] to retrieve the offer.
-	#[cfg(feature = "std")]
 	pub fn get_async_receive_offer_ready_future(&self) -> Future {
 		self.async_receive_offer_ready_notifier.get_future()
 	}