Add methods to set features in Features objects.

Author: valentinewallace

lightning/src/ln/features.rs

@@ -32,6 +32,7 @@ use ln::msgs::DecodeError;
 use util::ser::{Readable, Writeable, Writer};
 
 mod sealed {
+	use ln::features::Features;
 	/// The context in which [`Features`] are applicable. Defines which features are required and
 	/// which are optional for the context.
 	///
@@ -157,7 +158,8 @@ mod sealed {
 	///
 	/// [`Context`]: trait.Context.html
 	macro_rules! define_feature {
-		($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr) => {
+		($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $supports_setter: ident,
+		 $requires_setter: ident) => {
 			#[doc = $doc]
 			///
 			/// See [BOLT #9] for details.
@@ -242,6 +244,18 @@ mod sealed {
 				}
 			}
 
+			impl <T: $feature> Features<T> {
+				/// Set this feature as supported.
+				pub fn $supports_setter(&mut self) {
+					<T as $feature>::set_optional_bit(&mut self.flags);
+				}
+
+				/// Set this feature as required.
+				pub fn $requires_setter(&mut self) {
+					<T as $feature>::set_required_bit(&mut self.flags);
+				}
+			}
+
 			$(
 				impl $feature for $context {
 					// EVEN_BIT % 2 == 0
@@ -251,28 +265,34 @@ mod sealed {
 					const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
 				}
 			)*
+
 		}
 	}
 
 	define_feature!(1, DataLossProtect, [InitContext, NodeContext],
-		"Feature flags for `option_data_loss_protect`.");
+		"Feature flags for `option_data_loss_protect`.", set_supports_data_loss_protect,
+		set_requires_data_loss_protect);
 	// NOTE: Per Bolt #9, initial_routing_sync has no even bit.
-	define_feature!(3, InitialRoutingSync, [InitContext],
-		"Feature flags for `initial_routing_sync`.");
+	define_feature!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
+		set_supports_initial_routing_sync, set_requires_initial_routing_sync);
 	define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
-		"Feature flags for `option_upfront_shutdown_script`.");
+		"Feature flags for `option_upfront_shutdown_script`.", set_supports_upfront_shutdown_script,
+		set_requires_upfront_shutdown_script);
 	define_feature!(7, GossipQueries, [InitContext, NodeContext],
-		"Feature flags for `gossip_queries`.");
+		"Feature flags for `gossip_queries`.", set_supports_gossip_queries, set_requires_gossip_queries);
 	define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
-		"Feature flags for `var_onion_optin`.");
+		"Feature flags for `var_onion_optin`.", set_supports_variable_length_onion,
+		set_requires_variable_length_onion);
 	define_feature!(13, StaticRemoteKey, [InitContext, NodeContext],
-		"Feature flags for `option_static_remotekey`.");
+		"Feature flags for `option_static_remotekey`.", set_supports_static_remote_key,
+		set_requires_static_remote_key);
 	define_feature!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
-		"Feature flags for `payment_secret`.");
+		"Feature flags for `payment_secret`.", set_supports_payment_secret, set_requires_payment_secret);
 	define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
-		"Feature flags for `basic_mpp`.");
+		"Feature flags for `basic_mpp`.", set_supports_basic_mpp, set_requires_basic_mpp);
 	define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
-		"Feature flags for `opt_shutdown_anysegwit`.");
+		"Feature flags for `opt_shutdown_anysegwit`.", set_supports_shutdown_any_segwit,
+		set_requires_shutdown_any_segwit);
 
 	#[cfg(test)]
 	define_context!(TestingContext {
@@ -296,7 +316,8 @@ mod sealed {
 
 	#[cfg(test)]
 	define_feature!(23, UnknownFeature, [TestingContext],
-		"Feature flags for an unknown feature used in testing.");
+		"Feature flags for an unknown feature used in testing.", set_supports_unknown_feature,
+		set_requires_unknown_feature);
 }
 
 /// Tracks the set of features which a node implements, templated by the context in which it