feat(wip): configure node builder with tier storage

Author: enigbe

bindings/ldk_node.udl

@@ -46,6 +46,12 @@ dictionary LSPS2ServiceConfig {
 	u64 max_payment_size_msat;
 };
 
+dictionary RetryConfig {
+	u16 initial_retry_delay_ms;
+	u16 maximum_delay_secs;
+	f32 backoff_multiplier;
+};
+
 enum LogLevel {
 	"Gossip",
 	"Trace",
@@ -67,6 +73,45 @@ interface LogWriter {
 	void log(LogRecord record);
 };
 
+interface DynStore {
+    [Name=from_store]
+    constructor(KVStore store);
+};
+
+[Trait, WithForeign]
+interface KVStore {
+	[Throws=IOError]
+	sequence<u8> read(string primary_namespace, string secondary_namespace, string key);
+	[Throws=IOError]
+	void write(string primary_namespace, string secondary_namespace, string key, sequence<u8> buf);
+	[Throws=IOError]
+	void remove(string primary_namespace, string secondary_namespace, string key, boolean lazy);
+	[Throws=IOError]
+	sequence<string> list(string primary_namespace, string secondary_namespace);
+};
+
+[Error]
+enum IOError {
+  	"NotFound",
+    "PermissionDenied",
+    "ConnectionRefused",
+    "ConnectionReset",
+    "ConnectionAborted",
+    "NotConnected",
+    "AddrInUse",
+    "AddrNotAvailable",
+    "BrokenPipe",
+    "AlreadyExists",
+    "WouldBlock",
+    "InvalidInput",
+    "InvalidData",
+    "TimedOut",
+    "WriteZero",
+    "Interrupted",
+    "UnexpectedEof",
+    "Other",
+};
+
 interface Builder {
 	constructor();
 	[Name=from_config]
@@ -94,6 +139,9 @@ interface Builder {
 	void set_announcement_addresses(sequence<SocketAddress> announcement_addresses);
 	[Throws=BuildError]
 	void set_node_alias(string node_alias);
+	void set_tier_store_retry_config(RetryConfig retry_config);
+	void set_tier_store_backup(KVStore backup_store);
+	void set_tier_store_ephemeral(KVStore ephemeral_store);
 	[Throws=BuildError]
 	Node build();
 	[Throws=BuildError]

src/builder.rs

@@ -15,8 +15,10 @@ use crate::config::{
 use crate::connection::ConnectionManager;
 use crate::event::EventQueue;
 use crate::fee_estimator::OnchainFeeEstimator;
+use crate::ffi::maybe_extract_inner;
 use crate::gossip::GossipSource;
 use crate::io::sqlite_store::SqliteStore;
+use crate::io::tier_store::{RetryConfig, TierStore};
 use crate::io::utils::{read_node_metrics, write_node_metrics};
 use crate::io::vss_store::VssStore;
 use crate::io::{
@@ -30,14 +32,20 @@ use crate::message_handler::NodeCustomMessageHandler;
 use crate::peer_store::PeerStore;
 use crate::runtime::Runtime;
 use crate::tx_broadcaster::TransactionBroadcaster;
+
 use crate::types::{
-	ChainMonitor, ChannelManager, DynStore, GossipSync, Graph, KeysManager, MessageRouter,
-	OnionMessenger, PaymentStore, PeerManager,
+	ChainMonitor, ChannelManager, GossipSync, Graph, KeysManager, MessageRouter, OnionMessenger,
+	PaymentStore, PeerManager,
 };
 use crate::wallet::persist::KVStoreWalletPersister;
 use crate::wallet::Wallet;
 use crate::{Node, NodeMetrics};
 
+#[cfg(feature = "uniffi")]
+use crate::ffi::DynStore;
+#[cfg(not(feature = "uniffi"))]
+use crate::types::DynStore;
+
 use lightning::chain::{chainmonitor, BestBlock, Watch};
 use lightning::io::Cursor;
 use lightning::ln::channelmanager::{self, ChainParameters, ChannelManagerReadArgs};
@@ -150,6 +158,23 @@ impl std::fmt::Debug for LogWriterConfig {
 	}
 }
 
+#[derive(Default)]
+struct TierStoreConfig {
+	ephemeral: Option<Arc<DynStore>>,
+	backup: Option<Arc<DynStore>>,
+	retry: Option<RetryConfig>,
+}
+
+impl std::fmt::Debug for TierStoreConfig {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		f.debug_struct("TierStoreConfig")
+			.field("ephemeral", &self.ephemeral.as_ref().map(|_| "Arc<DynStore>"))
+			.field("backup", &self.backup.as_ref().map(|_| "Arc<DynStore>"))
+			.field("retry", &self.retry)
+			.finish()
+	}
+}
+
 /// An error encountered during building a [`Node`].
 ///
 /// [`Node`]: crate::Node
@@ -240,6 +265,7 @@ pub struct NodeBuilder {
 	gossip_source_config: Option<GossipSourceConfig>,
 	liquidity_source_config: Option<LiquiditySourceConfig>,
 	log_writer_config: Option<LogWriterConfig>,
+	tier_store_config: Option<TierStoreConfig>,
 	runtime_handle: Option<tokio::runtime::Handle>,
 }
 
@@ -257,6 +283,7 @@ impl NodeBuilder {
 		let gossip_source_config = None;
 		let liquidity_source_config = None;
 		let log_writer_config = None;
+		let tier_store_config = None;
 		let runtime_handle = None;
 		Self {
 			config,
@@ -265,6 +292,7 @@ impl NodeBuilder {
 			gossip_source_config,
 			liquidity_source_config,
 			log_writer_config,
+			tier_store_config,
 			runtime_handle,
 		}
 	}
@@ -544,6 +572,53 @@ impl NodeBuilder {
 		Ok(self)
 	}
 
+	/// Configures retry behavior for transient errors when accessing the primary store.
+	///
+	/// When building with [`build_with_tier_store`], controls the exponential backoff parameters
+	/// used when retrying failed operations on the primary store due to transient errors
+	/// (network issues, timeouts, etc.).
+	///
+	/// If not set, default retry parameters are used. See [`RetryConfig`] for details.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_retry_config(&mut self, config: RetryConfig) -> &mut Self {
+		let tier_store_config = self.tier_store_config.get_or_insert(TierStoreConfig::default());
+		tier_store_config.retry = Some(config);
+		self
+	}
+
+	/// Configures the backup store for local disaster recovery.
+	///
+	/// When building with [`build_with_tier_store`], this store receives asynchronous copies
+	/// of all critical data written to the primary store. If the primary store becomes
+	/// unavailable, reads will fall back to this backup store.
+	///
+	/// Backup writes are non-blocking and do not affect primary store operation performance.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_backup(&mut self, backup_store: Arc<DynStore>) -> &mut Self {
+		let tier_store_config = self.tier_store_config.get_or_insert(TierStoreConfig::default());
+		let store = maybe_extract_inner(backup_store);
+		tier_store_config.backup = Some(store);
+		self
+	}
+
+	/// Configures the ephemeral store for non-critical, frequently-accessed data.
+	///
+	/// When building with [`build_with_tier_store`], this store is used for data like
+	/// the network graph and scorer data to reduce latency for reads. Data stored here
+	/// can be rebuilt if lost.
+	///
+	/// If not set, non-critical data will be stored in the primary store.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_ephemeral(&mut self, ephemeral_store: Arc<DynStore>) -> &mut Self {
+		let tier_store_config = self.tier_store_config.get_or_insert(TierStoreConfig::default());
+		let store = maybe_extract_inner(ephemeral_store);
+		tier_store_config.ephemeral = Some(store);
+		self
+	}
+
 	/// Builds a [`Node`] instance with a [`SqliteStore`] backend and according to the options
 	/// previously configured.
 	pub fn build(&self) -> Result<Node, BuildError> {
@@ -707,6 +782,98 @@ impl NodeBuilder {
 		)
 	}
 
+	/// Builds a [`Node`] instance with tiered storage for managing data across multiple storage layers.
+	///
+	/// This build method enables a three-tier storage architecture optimized for different data types
+	/// and access patterns:
+	///
+	/// ### Storage Tiers
+	///
+	/// - **Primary Store** (required): The authoritative store for critical channel state and payment data.
+	///   Typically a remote/cloud storage service for durability and accessibility across devices.
+	///
+	/// - **Ephemeral Store** (optional): Local storage for non-critical, frequently-accessed data like
+	///   the network graph and scorer. Improves performance by reducing latency for data that can be
+	///   rebuilt if lost. Configure with [`set_tier_store_ephemeral`].
+	///
+	/// - **Backup Store** (optional): Local backup of critical data for disaster recovery scenarios.
+	///   Provides a safety net if the primary store becomes temporarily unavailable. Writes are
+	///   asynchronous to avoid blocking primary operations. Configure with [`set_tier_store_backup`].
+	///
+	/// ## Configuration
+	///
+	/// Use the setter methods to configure optional stores and retry behavior:
+	/// - [`set_tier_store_ephemeral`] - Set local store for network graph and scorer
+	/// - [`set_tier_store_backup`] - Set local backup store for disaster recovery
+	/// - [`set_tier_store_retry_config`] - Configure retry delays and backoff for transient errors
+	///
+	/// ## Example
+	///
+	/// ```ignore
+	/// # use ldk_node::{Builder, Config};
+	/// # use ldk_node::io::tier_store::RetryConfig;
+	/// # use std::sync::Arc;
+	/// let config = Config::default();
+	/// let mut builder = NodeBuilder::from_config(config);
+	///
+	/// let primary = Arc::new(VssStore::new(...));
+	/// let ephemeral = Arc::new(FilesystemStore::new(...));
+	/// let backup = Arc::new(SqliteStore::new(...));
+	///	let retry_config = RetryConfig::default();
+	///
+	/// builder
+	///     .set_tier_store_ephemeral(ephemeral)
+	///     .set_tier_store_backup(backup)
+	/// 	.set_tier_store_retry_config(retry_config);
+	///
+	/// let node = builder.build_with_tier_store(primary)?;
+	/// # Ok::<(), ldk_node::BuildError>(())
+	/// ```
+	///
+	/// [`set_tier_store_ephemeral`]: Self::set_tier_store_ephemeral
+	/// [`set_tier_store_backup`]: Self::set_tier_store_backup
+	/// [`set_tier_store_retry_config`]: Self::set_tier_store_retry_config
+	pub fn build_with_tier_store(&self, primary_store: Arc<DynStore>) -> Result<Node, BuildError> {
+		let logger = setup_logger(&self.log_writer_config, &self.config)?;
+		let runtime = if let Some(handle) = self.runtime_handle.as_ref() {
+			Arc::new(Runtime::with_handle(handle.clone(), Arc::clone(&logger)))
+		} else {
+			Arc::new(Runtime::new(Arc::clone(&logger)).map_err(|e| {
+				log_error!(logger, "Failed to setup tokio runtime: {}", e);
+				BuildError::RuntimeSetupFailed
+			})?)
+		};
+		let seed_bytes = seed_bytes_from_config(
+			&self.config,
+			self.entropy_source_config.as_ref(),
+			Arc::clone(&logger),
+		)?;
+		let config = Arc::new(self.config.clone());
+
+		let ts_config = self.tier_store_config.as_ref();
+		let retry_config = ts_config.and_then(|c| c.retry).unwrap_or_default();
+
+		let primary = maybe_extract_inner(primary_store);
+		let mut tier_store =
+			TierStore::new(primary, Arc::clone(&runtime), Arc::clone(&logger), retry_config);
+
+		if let Some(config) = ts_config {
+			config.ephemeral.as_ref().map(|s| tier_store.set_ephemeral_store(Arc::clone(s)));
+			config.backup.as_ref().map(|s| tier_store.set_backup_store(Arc::clone(s)));
+		}
+
+		build_with_store_internal(
+			config,
+			self.chain_data_source_config.as_ref(),
+			self.gossip_source_config.as_ref(),
+			self.liquidity_source_config.as_ref(),
+			seed_bytes,
+			runtime,
+			logger,
+			Arc::new(tier_store),
+		)
+	}
+
 	/// Builds a [`Node`] instance according to the options previously configured.
 	pub fn build_with_store(&self, kv_store: Arc<DynStore>) -> Result<Node, BuildError> {
 		let logger = setup_logger(&self.log_writer_config, &self.config)?;
@@ -989,6 +1156,45 @@ impl ArcedNodeBuilder {
 		self.inner.write().unwrap().set_node_alias(node_alias).map(|_| ())
 	}
 
+	/// Configures retry behavior for transient errors when accessing the primary store.
+	///
+	/// When building with [`build_with_tier_store`], controls the exponential backoff parameters
+	/// used when retrying failed operations on the primary store due to transient errors
+	/// (network issues, timeouts, etc.).
+	///
+	/// If not set, default retry parameters are used. See [`RetryConfig`] for details.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_retry_config(&self, config: RetryConfig) {
+		self.inner.write().unwrap().set_tier_store_retry_config(config);
+	}
+
+	/// Configures the backup store for local disaster recovery.
+	///
+	/// When building with [`build_with_tier_store`], this store receives asynchronous copies
+	/// of all critical data written to the primary store. If the primary store becomes
+	/// unavailable, reads will fall back to this backup store.
+	///
+	/// Backup writes are non-blocking and do not affect primary store operation performance.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_backup(&mut self, backup_store: Arc<DynStore>) {
+		self.inner.write().unwrap().set_tier_store_backup(backup_store);
+	}
+
+	/// Configures the ephemeral store for non-critical, frequently-accessed data.
+	///
+	/// When building with [`build_with_tier_store`], this store is used for data like
+	/// the network graph and scorer data to reduce latency for reads. Data stored here
+	/// can be rebuilt if lost.
+	///
+	/// If not set, non-critical data will be stored in the primary store.
+	///
+	/// [`build_with_tier_store`]: Self::build_with_tier_store
+	pub fn set_tier_store_ephemeral(&mut self, ephemeral_store: Arc<DynStore>) {
+		self.inner.write().unwrap().set_tier_store_ephemeral(ephemeral_store);
+	}
+
 	/// Builds a [`Node`] instance with a [`SqliteStore`] backend and according to the options
 	/// previously configured.
 	pub fn build(&self) -> Result<Arc<Node>, BuildError> {

src/ffi/mod.rs

@@ -31,6 +31,15 @@ pub fn maybe_wrap<T>(ldk_type: impl Into<T>) -> std::sync::Arc<T> {
 	std::sync::Arc::new(ldk_type.into())
 }
 
+#[cfg(feature = "uniffi")]
+pub fn maybe_extract_inner<T, R>(wrapped: std::sync::Arc<T>) -> std::sync::Arc<R>
+where
+	T: AsRef<std::sync::Arc<R>>,
+	R: ?Sized,
+{
+	std::sync::Arc::clone(wrapped.as_ref().as_ref())
+}
+
 #[cfg(not(feature = "uniffi"))]
 pub fn maybe_deref<T>(value: &T) -> &T {
 	value
@@ -45,3 +54,11 @@ pub fn maybe_try_convert_enum<T>(value: &T) -> Result<&T, crate::error::Error> {
 pub fn maybe_wrap<T>(value: T) -> T {
 	value
 }
+
+#[cfg(not(feature = "uniffi"))]
+pub fn maybe_extract_inner<R>(value: std::sync::Arc<R>) -> std::sync::Arc<R>
+where
+	R: ?Sized,
+{
+	value
+}