Add BIP 157 compact block filter chain source

Author: febyeji

Cargo.toml

@@ -54,6 +54,7 @@ lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning",
 bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
 bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
 bdk_electrum = { version = "0.23.0", default-features = false, features = ["use-rustls-ring"]}
+bip157 = { version = "0.4.2", default-features = false }
 bdk_wallet = { version = "2.3.0", default-features = false, features = ["std", "keys-bip39"]}
 
 bitreq = { version = "0.3", default-features = false, features = ["async-https", "json-using-serde"] }

bindings/ldk_node.udl

@@ -9,6 +9,8 @@ typedef dictionary EsploraSyncConfig;
 
 typedef dictionary ElectrumSyncConfig;
 
+typedef dictionary CbfSyncConfig;
+
 typedef dictionary TorConfig;
 
 typedef interface NodeEntropy;
@@ -38,6 +40,7 @@ interface Builder {
 	constructor(Config config);
 	void set_chain_source_esplora(string server_url, EsploraSyncConfig? config);
 	void set_chain_source_electrum(string server_url, ElectrumSyncConfig? config);
+	void set_chain_source_cbf(sequence<string> peers, CbfSyncConfig? sync_config);
 	void set_chain_source_bitcoind_rpc(string rpc_host, u16 rpc_port, string rpc_user, string rpc_password);
 	void set_chain_source_bitcoind_rest(string rest_host, u16 rest_port, string rpc_host, u16 rpc_port, string rpc_user, string rpc_password);
 	void set_gossip_source_p2p();

src/builder.rs

@@ -45,8 +45,8 @@ use vss_client::headers::VssHeaderProvider;
 use crate::chain::ChainSource;
 use crate::config::{
 	default_user_config, may_announce_channel, AnnounceError, AsyncPaymentsRole,
-	BitcoindRestClientConfig, Config, ElectrumSyncConfig, EsploraSyncConfig, TorConfig,
-	DEFAULT_ESPLORA_SERVER_URL, DEFAULT_LOG_FILENAME, DEFAULT_LOG_LEVEL,
+	BitcoindRestClientConfig, CbfSyncConfig, Config, ElectrumSyncConfig, EsploraSyncConfig,
+	TorConfig, DEFAULT_ESPLORA_SERVER_URL, DEFAULT_LOG_FILENAME, DEFAULT_LOG_LEVEL,
 };
 use crate::connection::ConnectionManager;
 use crate::entropy::NodeEntropy;
@@ -105,6 +105,10 @@ enum ChainDataSourceConfig {
 		rpc_password: String,
 		rest_client_config: Option<BitcoindRestClientConfig>,
 	},
+	Cbf {
+		peers: Vec<String>,
+		sync_config: Option<CbfSyncConfig>,
+	},
 }
 
 #[derive(Debug, Clone)]
@@ -365,6 +369,26 @@ impl NodeBuilder {
 		self
 	}
 
+	/// Configures the [`Node`] instance to source its chain data via BIP 157 compact block
+	/// filters.
+	///
+	/// `peers` is an optional list of peer addresses to connect to for sourcing compact block
+	/// filters. If empty, the node will discover peers via DNS seeds.
+	///
+	/// If no `sync_config` is given, default values are used. See [`CbfSyncConfig`] for more
+	/// information.
+	///
+	/// Note: fee rate estimation with this chain source uses block-level averages (total fees
+	/// divided by block weight) rather than per-transaction fee rates. This can underestimate
+	/// next-block inclusion rates during periods of high mempool congestion. Percentile-based
+	/// target selection partially mitigates this.
+	pub fn set_chain_source_cbf(
+		&mut self, peers: Vec<String>, sync_config: Option<CbfSyncConfig>,
+	) -> &mut Self {
+		self.chain_data_source_config = Some(ChainDataSourceConfig::Cbf { peers, sync_config });
+		self
+	}
+
 	/// Configures the [`Node`] instance to connect to a Bitcoin Core node via RPC.
 	///
 	/// This method establishes an RPC connection that enables all essential chain operations including
@@ -892,6 +916,23 @@ impl ArcedNodeBuilder {
 		self.inner.write().unwrap().set_chain_source_electrum(server_url, sync_config);
 	}
 
+	/// Configures the [`Node`] instance to source its chain data via BIP 157 compact block
+	/// filters.
+	///
+	/// `peers` is an optional list of peer addresses to connect to for sourcing compact block
+	/// filters. If empty, the node will discover peers via DNS seeds.
+	///
+	/// If no `sync_config` is given, default values are used. See [`CbfSyncConfig`] for more
+	/// information.
+	///
+	/// Note: fee rate estimation with this chain source uses block-level averages (total fees
+	/// divided by block weight) rather than per-transaction fee rates. This can underestimate
+	/// next-block inclusion rates during periods of high mempool congestion. Percentile-based
+	/// target selection partially mitigates this.
+	pub fn set_chain_source_cbf(&self, peers: Vec<String>, sync_config: Option<CbfSyncConfig>) {
+		self.inner.write().unwrap().set_chain_source_cbf(peers, sync_config);
+	}
+
 	/// Configures the [`Node`] instance to connect to a Bitcoin Core node via RPC.
 	///
 	/// This method establishes an RPC connection that enables all essential chain operations including
@@ -1364,6 +1405,20 @@ fn build_with_store_internal(
 			}),
 		},
 
+		Some(ChainDataSourceConfig::Cbf { peers, sync_config }) => {
+			let sync_config = sync_config.clone().unwrap_or(CbfSyncConfig::default());
+			ChainSource::new_cbf(
+				peers.clone(),
+				sync_config,
+				Arc::clone(&fee_estimator),
+				Arc::clone(&tx_broadcaster),
+				Arc::clone(&kv_store),
+				Arc::clone(&config),
+				Arc::clone(&logger),
+				Arc::clone(&node_metrics),
+			)
+		},
+
 		None => {
 			// Default to Esplora client.
 			let server_url = DEFAULT_ESPLORA_SERVER_URL.to_string();
@@ -2079,6 +2134,9 @@ pub(crate) fn sanitize_alias(alias_str: &str) -> Result<NodeAlias, BuildError> {
 
 #[cfg(test)]
 mod tests {
+	#[cfg(feature = "uniffi")]
+	use crate::config::CbfSyncConfig;
+
 	use super::{sanitize_alias, BuildError, NodeAlias};
 
 	#[test]
@@ -2116,4 +2174,23 @@ mod tests {
 		let node = sanitize_alias(alias);
 		assert_eq!(node.err().unwrap(), BuildError::InvalidNodeAlias);
 	}
+
+	#[cfg(feature = "uniffi")]
+	#[test]
+	fn arced_builder_can_set_cbf_chain_source() {
+		let builder = super::ArcedNodeBuilder::new();
+		let sync_config = CbfSyncConfig::default();
+
+		let peers = vec!["127.0.0.1:8333".to_string()];
+		builder.set_chain_source_cbf(peers.clone(), Some(sync_config.clone()));
+
+		let guard = builder.inner.read().unwrap();
+		assert!(matches!(
+			guard.chain_data_source_config.as_ref(),
+			Some(super::ChainDataSourceConfig::Cbf {
+				peers: p,
+				sync_config: Some(config),
+			}) if config == &sync_config && p == &peers
+		));
+	}
 }