NIH the delegate macro

devrandom · devrandom · commit 01af6ed85377 · 2025-02-20T19:34:31.000+01:00
diff --git a/lightning/Cargo.toml b/lightning/Cargo.toml
@@ -17,7 +17,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
 # Internal test utilities exposed to other repo crates
-_test_utils = ["regex", "bitcoin/bitcoinconsensus", "lightning-types/_test_utils", "delegate"]
+_test_utils = ["regex", "bitcoin/bitcoinconsensus", "lightning-types/_test_utils"]
 _externalize_tests = ["inventory", "_test_utils"]
 # Allow signing of local transactions that may have been revoked or will be revoked, for functional testing (e.g. justice tx handling).
 # This is unsafe to use in production because it may result in the counterparty publishing taking our funds.
@@ -48,14 +48,12 @@ regex = { version = "1.5.6", optional = true }
 backtrace = { version = "0.3", optional = true }
 
 libm = { version = "0.2", default-features = false }
-delegate = { version = "0.13.1", optional = true }
 inventory = { version = "0.3", optional = true  }
 
 [dev-dependencies]
 regex = "1.5.6"
 lightning-types = { version = "0.3.0", path = "../lightning-types", features = ["_test_utils"] }
 lightning-macros = { path = "../lightning-macros" }
-delegate = { version = "0.13.1" }
 
 [dev-dependencies.bitcoin]
 version = "0.32.2"
diff --git a/lightning/src/util/dyn_signer.rs b/lightning/src/util/dyn_signer.rs
@@ -3,9 +3,9 @@
 use crate::prelude::*;
 
 use core::any::Any;
-use delegate::delegate;
 
 use crate::chain::transaction::OutPoint;
+use crate::delegate;
 use crate::io::Read;
 use crate::ln::chan_utils::{
 	ChannelPublicKeys, ChannelTransactionParameters, ClosingTransaction, CommitmentTransaction,
@@ -256,44 +256,30 @@ impl EcdsaChannelSigner for DynSigner {
 	}
 }
 
-impl ChannelSignerExt for DynSigner {
-	delegate! {
-		to self.inner {
-			fn commitment_seed(&self) -> [u8; 32];
-			fn channel_type_features(&self) -> Option<&ChannelTypeFeatures>;
-			fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys>;
-			fn funding_outpoint(&self) -> Option<&OutPoint>;
-			fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters>;
-		}
-	}
-}
-
-impl ChannelSigner for DynSigner {
-	delegate! {
-		to self.inner {
-			fn get_per_commitment_point(
-				&self,
-				idx: u64,
-				secp_ctx: &Secp256k1<secp256k1::All>,
-			) -> Result<PublicKey, ()>;
-			fn release_commitment_secret(&self, idx: u64) -> Result<[u8; 32], ()>;
-
-			fn validate_holder_commitment(
-				&self,
-				holder_tx: &HolderCommitmentTransaction,
-				preimages: Vec<PaymentPreimage>,
-			) -> Result<(), ()>;
-
-			fn pubkeys(&self) -> &ChannelPublicKeys;
-
-			fn channel_keys_id(&self) -> [u8; 32];
-
-			fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
-
-			fn validate_counterparty_revocation(&self, idx: u64, secret: &SecretKey) -> Result<(), ()>;
-		}
-	}
-}
+delegate!(DynSigner, ChannelSignerExt,
+	inner,
+	fn commitment_seed(,) -> [u8; 32],
+	fn channel_type_features(,) -> Option<&ChannelTypeFeatures>,
+	fn counterparty_pubkeys(,) -> Option<&ChannelPublicKeys>,
+	fn funding_outpoint(,) -> Option<&OutPoint>,
+	fn get_channel_parameters(,) -> Option<&ChannelTransactionParameters>);
+
+delegate!(DynSigner, ChannelSigner,
+	inner,
+	fn get_per_commitment_point(,
+		idx: u64,
+		secp_ctx: &Secp256k1<secp256k1::All>
+	) -> Result<PublicKey, ()>,
+	fn release_commitment_secret(, idx: u64) -> Result<[u8; 32], ()>,
+	fn validate_holder_commitment(,
+		holder_tx: &HolderCommitmentTransaction,
+		preimages: Vec<PaymentPreimage>
+	) -> Result<(), ()>,
+	fn pubkeys(,) -> &ChannelPublicKeys,
+	fn channel_keys_id(,) -> [u8; 32],
+	fn validate_counterparty_revocation(, idx: u64, secret: &SecretKey) -> Result<(), ()>,
+	fn provide_channel_parameters(mut, channel_parameters: &ChannelTransactionParameters) -> ()
+);
 
 impl DynSignerTrait for InMemorySigner {}
 
@@ -320,64 +306,41 @@ impl DynKeysInterface {
 	}
 }
 
-impl NodeSigner for DynKeysInterface {
-	delegate! {
-		to self.inner {
-			fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
-			fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
-			fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
-
-			fn sign_invoice(&self, invoice: &RawBolt11Invoice, recipient: Recipient) -> Result<RecoverableSignature, ()>;
-
-			fn sign_bolt12_invoice(
-				&self, invoice: &crate::offers::invoice::UnsignedBolt12Invoice
-			) -> Result<secp256k1::schnorr::Signature, ()>;
-
-			fn get_inbound_payment_key(&self) -> ExpandedKey;
-		}
-	}
-}
-
-impl SignerProvider for DynKeysInterface {
-	type EcdsaSigner = DynSigner;
+delegate!(DynKeysInterface, NodeSigner,
+inner,
+		fn get_node_id(, recipient: Recipient) -> Result<PublicKey, ()>,
+		fn sign_gossip_message(, msg: UnsignedGossipMessage) -> Result<Signature, ()>,
+		fn ecdh(, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>,
+		fn sign_invoice(, invoice: &RawBolt11Invoice, recipient: Recipient) -> Result<RecoverableSignature, ()>,
+		fn sign_bolt12_invoice(,
+			invoice: &crate::offers::invoice::UnsignedBolt12Invoice
+		) -> Result<secp256k1::schnorr::Signature, ()>,
+		fn get_inbound_payment_key(,) -> ExpandedKey
+);
+
+delegate!(DynKeysInterface, SignerProvider,
+	inner,
+	fn get_destination_script(, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()>,
+	fn get_shutdown_scriptpubkey(,) -> Result<ShutdownScript, ()>,
+	fn generate_channel_keys_id(, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32],
+	fn derive_channel_signer(, _channel_value_satoshis: u64, _channel_keys_id: [u8; 32]) -> Self::EcdsaSigner,
+	fn read_chan_signer(, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError>;
+	type EcdsaSigner = DynSigner,
 	#[cfg(taproot)]
-	type TaprootSigner = DynSigner;
-
-	delegate! {
-		to self.inner {
-			fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()>;
-
-			fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
-
-			fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32];
-
-			fn derive_channel_signer(&self, _channel_value_satoshis: u64, _channel_keys_id: [u8; 32]) -> Self::EcdsaSigner;
-
-			fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError>;
-		}
-	}
-}
-
-impl EntropySource for DynKeysInterface {
-	delegate! {
-		to self.inner {
-			fn get_secure_random_bytes(&self) -> [u8; 32];
-		}
-	}
-}
-
-impl OutputSpender for DynKeysInterface {
-	delegate! {
-		to self.inner {
-			fn spend_spendable_outputs(
-				&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
-				change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
-				locktime: Option<LockTime>, secp_ctx: &Secp256k1<All>,
-			) -> Result<Transaction, ()>;
-		}
-	}
-}
-
+	type TaprootSigner = DynSigner
+);
+
+delegate!(DynKeysInterface, EntropySource, inner,
+	fn get_secure_random_bytes(,) -> [u8; 32]
+);
+
+delegate!(DynKeysInterface, OutputSpender, inner,
+	fn spend_spendable_outputs(,
+		descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+		change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
+		locktime: Option<LockTime>, secp_ctx: &Secp256k1<All>
+	) -> Result<Transaction, ()>
+);
 #[cfg(not(taproot))]
 /// A supertrait for all the traits that a keys interface implements
 pub trait DynKeysInterfaceTrait:
@@ -413,36 +376,34 @@ impl DynPhantomKeysInterface {
 	}
 }
 
-impl NodeSigner for DynPhantomKeysInterface {
-	delegate! {
-		to self.inner {
-			fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()>;
-			fn sign_gossip_message(&self, msg: UnsignedGossipMessage) -> Result<Signature, ()>;
-			fn ecdh(&self, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>;
-
-			fn sign_invoice(&self, invoice: &RawBolt11Invoice, recipient: Recipient) -> Result<RecoverableSignature, ()>;
-
-			fn sign_bolt12_invoice(
-				&self, invoice: &crate::offers::invoice::UnsignedBolt12Invoice
-			) -> Result<secp256k1::schnorr::Signature, ()>;
-			fn get_inbound_payment_key(&self) -> ExpandedKey;
-		}
-	}
-}
+delegate!(DynPhantomKeysInterface, NodeSigner,
+	inner,
+	fn get_node_id(, recipient: Recipient) -> Result<PublicKey, ()>,
+	fn sign_gossip_message(, msg: UnsignedGossipMessage) -> Result<Signature, ()>,
+	fn ecdh(, recipient: Recipient, other_key: &PublicKey, tweak: Option<&Scalar>) -> Result<SharedSecret, ()>,
+	fn sign_invoice(, invoice: &RawBolt11Invoice, recipient: Recipient) -> Result<RecoverableSignature, ()>,
+	fn sign_bolt12_invoice(, invoice: &crate::offers::invoice::UnsignedBolt12Invoice
+	) -> Result<secp256k1::schnorr::Signature, ()>,
+	fn get_inbound_payment_key(,) -> ExpandedKey
+);
 
 impl SignerProvider for DynPhantomKeysInterface {
 	type EcdsaSigner = DynSigner;
 	#[cfg(taproot)]
 	type TaprootSigner = DynSigner;
 
-	delegate! {
-		to self.inner {
-			fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()>;
+	fn get_destination_script(&self, channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
+		self.inner.get_destination_script(channel_keys_id)
+	}
 
-			fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()>;
+	fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
+		self.inner.get_shutdown_scriptpubkey()
+	}
 
-			fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32];
-		}
+	fn generate_channel_keys_id(
+		&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128,
+	) -> [u8; 32] {
+		self.inner.generate_channel_keys_id(_inbound, _channel_value_satoshis, _user_channel_id)
 	}
 
 	fn derive_channel_signer(
@@ -452,30 +413,23 @@ impl SignerProvider for DynPhantomKeysInterface {
 		DynSigner::new(inner)
 	}
 
-	fn read_chan_signer(&self, _reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError> {
-		todo!()
+	fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::EcdsaSigner, DecodeError> {
+		let inner = self.inner.read_chan_signer(reader)?;
+		Ok(DynSigner::new(inner))
 	}
 }
 
-impl EntropySource for DynPhantomKeysInterface {
-	delegate! {
-		to self.inner {
-			fn get_secure_random_bytes(&self) -> [u8; 32];
-		}
-	}
-}
-
-impl OutputSpender for DynPhantomKeysInterface {
-	delegate! {
-		to self.inner {
-			fn spend_spendable_outputs(
-				&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
-				change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
-				locktime: Option<LockTime>, secp_ctx: &Secp256k1<All>,
-			) -> Result<Transaction, ()>;
-		}
-	}
-}
+delegate!(DynPhantomKeysInterface, EntropySource, inner,
+	fn get_secure_random_bytes(,) -> [u8; 32]
+);
+
+delegate!(DynPhantomKeysInterface, OutputSpender, inner,
+	fn spend_spendable_outputs(,
+		descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>,
+		change_destination_script: ScriptBuf, feerate_sat_per_1000_weight: u32,
+		locktime: Option<LockTime>, secp_ctx: &Secp256k1<All>
+	) -> Result<Transaction, ()>
+);
 
 impl DynKeysInterfaceTrait for DynPhantomKeysInterface {
 	#[cfg(test)]
diff --git a/lightning/src/util/mod.rs b/lightning/src/util/mod.rs
@@ -68,3 +68,40 @@ pub mod string {
 	//! [`lightning::types::string`]: crate::types::string
 	pub use lightning_types::string::{PrintableString, UntrustedString};
 }
+
+
+/// A macro to delegate trait implementations to a field of a struct.
+///
+/// For example:
+/// ```no_run
+/// delegate!(A, T, inner,
+//     fn b(, c: u64) -> u64,
+//     fn m(mut, d: u64) -> (),
+//     fn o(, ) -> u64,
+//     #[cfg(debug_assertions)]
+//     fn t(,) -> (),
+//     ;
+//     type O = u64,
+//     #[cfg(debug_assertions)]
+//     type T = (),
+// );
+#[macro_export]
+macro_rules! delegate {
+    ($N: ident, $T: ident, $ref: ident,
+        $($(#[$fpat: meta])? fn $f: ident($($mu: ident)?, $($n: ident: $t: ty),*) -> $r: ty),* $(,)?
+        $(;$($(#[$tpat: meta])? type $TN: ident = $TT: ty),*)? $(,)?
+    ) => {
+        impl $T for $N {
+            $(
+                $(#[$fpat])?
+                fn $f(&$($mu)? self, $($n: $t),*) ->  $r {
+                   self.$ref.$f($($n),*)
+               }
+            )*
+            $($(
+                $(#[$tpat])?
+                type $TN = $TT;
+            )*)?
+        }
+    };
+}
