Break builder pattern and expose setters via bindings

tnull · tnull · commit c6340949c20c · 2023-05-25T12:15:33.000+02:00
Unfortunately there is no good way of exposing the builder pattern via
Uniffi bindings currenlty. We therefore resort to internal mutability
and using setters on the `Builder` object.
diff --git a/README.md b/README.md
@@ -11,14 +11,15 @@ The primary abstraction of the library is the `Node`, which can be retrieved by
 use ldk_node::{Builder, NetAddress};
 use ldk_node::lightning_invoice::Invoice;
 use ldk_node::bitcoin::secp256k1::PublicKey;
+use ldk_node::bitcoin::Network;
 use std::str::FromStr;
 
 fn main() {
-	let node = Builder::new()
-		.set_network("testnet")
-		.set_esplora_server_url("https://blockstream.info/testnet/api".to_string())
-		.build();
+	let mut builder = Builder::new();
+	builder.set_network(Network::Testnet);
+	builder.set_esplora_server_url("https://blockstream.info/testnet/api".to_string());
 
+	let node = builder.build();
 	node.start().unwrap();
 
 	let _funding_address = node.new_funding_address();
diff --git a/bindings/ldk_node.udl b/bindings/ldk_node.udl
@@ -13,6 +13,15 @@ interface Builder {
 	constructor();
 	[Name=from_config]
 	constructor(Config config);
+	void set_entropy_seed_path(string seed_path);
+	void set_entropy_seed_bytes(sequence<u8> seed_bytes);
+	void set_entropy_bip39_mnemonic(Mnemonic mnemonic, string? passphrase);
+	void set_gossip_source_p2p();
+	void set_gossip_source_rgs(string rgs_server_url);
+	void set_storage_dir_path(string storage_dir_path);
+	void set_esplora_server_url(string esplora_server_url);
+	void set_network(Network network);
+	void set_listening_address(NetAddress listening_address);
 	LDKNode build();
 };
 
@@ -85,6 +94,7 @@ enum NodeError {
 	"InvalidAddress",
 	"InvalidNetAddress",
 	"InvalidPublicKey",
+	"InvalidSecretKey",
 	"InvalidPaymentHash",
 	"InvalidPaymentPreimage",
 	"InvalidPaymentSecret",
@@ -188,3 +198,6 @@ typedef string UserChannelId;
 
 [Custom]
 typedef string Network;
+
+[Custom]
+typedef string Mnemonic;
diff --git a/src/error.rs b/src/error.rs
@@ -37,6 +37,8 @@ pub enum Error {
 	InvalidNetAddress,
 	/// The given public key is invalid.
 	InvalidPublicKey,
+	/// The given secret key is invalid.
+	InvalidSecretKey,
 	/// The given payment hash is invalid.
 	InvalidPaymentHash,
 	/// The given payment preimage is invalid.
@@ -79,6 +81,7 @@ impl fmt::Display for Error {
 			Self::InvalidAddress => write!(f, "The given address is invalid."),
 			Self::InvalidNetAddress => write!(f, "The given network address is invalid."),
 			Self::InvalidPublicKey => write!(f, "The given public key is invalid."),
+			Self::InvalidSecretKey => write!(f, "The given secret key is invalid."),
 			Self::InvalidPaymentHash => write!(f, "The given payment hash is invalid."),
 			Self::InvalidPaymentPreimage => write!(f, "The given payment preimage is invalid."),
 			Self::InvalidPaymentSecret => write!(f, "The given payment secret is invalid."),
diff --git a/src/lib.rs b/src/lib.rs
@@ -29,14 +29,15 @@
 //! use ldk_node::{Builder, NetAddress};
 //! use ldk_node::lightning_invoice::Invoice;
 //! use ldk_node::bitcoin::secp256k1::PublicKey;
+//! use ldk_node::bitcoin::Network;
 //! use std::str::FromStr;
 //!
 //! fn main() {
-//! 	let node = Builder::new()
-//! 		.set_network("testnet")
-//! 		.set_esplora_server_url("https://blockstream.info/testnet/api".to_string())
-//! 		.build();
+//! 	let mut builder = Builder::new();
+//! 	builder.set_network(Network::Testnet);
+//! 	builder.set_esplora_server_url("https://blockstream.info/testnet/api".to_string());
 //!
+//! 	let node = builder.build();
 //! 	node.start().unwrap();
 //!
 //! 	let _funding_address = node.new_funding_address();
@@ -144,6 +145,8 @@ use bitcoin::hashes::Hash;
 use bitcoin::secp256k1::PublicKey;
 use bitcoin::Network;
 
+use bip39::Mnemonic;
+
 use bitcoin::{Address, BlockHash, OutPoint, Txid};
 
 use rand::Rng;
@@ -152,7 +155,6 @@ use std::convert::TryInto;
 use std::default::Default;
 use std::fs;
 use std::net::ToSocketAddrs;
-use std::str::FromStr;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex, RwLock};
 use std::time::{Duration, Instant, SystemTime};
@@ -212,7 +214,7 @@ impl Default for Config {
 enum EntropySourceConfig {
 	SeedFile(String),
 	SeedBytes([u8; WALLET_KEYS_SEED_LEN]),
-	Bip39Mnemonic { mnemonic: bip39::Mnemonic, passphrase: Option<String> },
+	Bip39Mnemonic { mnemonic: Mnemonic, passphrase: Option<String> },
 }
 
 #[derive(Debug, Clone)]
@@ -223,107 +225,107 @@ enum GossipSourceConfig {
 
 /// A builder for an [`Node`] instance, allowing to set some configuration and module choices from
 /// the getgo.
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub struct Builder {
-	config: Config,
-	entropy_source_config: Option<EntropySourceConfig>,
-	gossip_source_config: Option<GossipSourceConfig>,
+	config: Mutex<Config>,
+	entropy_source_config: Mutex<Option<EntropySourceConfig>>,
+	gossip_source_config: Mutex<Option<GossipSourceConfig>>,
 }
 
 impl Builder {
 	/// Creates a new builder instance with the default configuration.
 	pub fn new() -> Self {
-		let config = Config::default();
-		let entropy_source_config = None;
-		let gossip_source_config = None;
+		let config = Mutex::new(Config::default());
+		let entropy_source_config = Mutex::new(None);
+		let gossip_source_config = Mutex::new(None);
 		Self { config, entropy_source_config, gossip_source_config }
 	}
 
 	/// Creates a new builder instance from an [`Config`].
 	pub fn from_config(config: Config) -> Self {
-		let entropy_source_config = None;
-		let gossip_source_config = None;
+		let config = Mutex::new(config);
+		let entropy_source_config = Mutex::new(None);
+		let gossip_source_config = Mutex::new(None);
 		Self { config, entropy_source_config, gossip_source_config }
 	}
 
 	/// Configures the [`Node`] instance to source its wallet entropy from a seed file on disk.
 	///
 	/// If the given file does not exist a new random seed file will be generated and
 	/// stored at the given location.
-	pub fn set_entropy_seed_path(&mut self, seed_path: String) -> &mut Self {
-		self.entropy_source_config = Some(EntropySourceConfig::SeedFile(seed_path));
-		self
+	pub fn set_entropy_seed_path(&self, seed_path: String) {
+		*self.entropy_source_config.lock().unwrap() =
+			Some(EntropySourceConfig::SeedFile(seed_path));
+	}
+
+	/// Configures the [`Node`] instance to source its wallet entropy from the given 64 seed bytes.
+	///
+	/// **Note:** Panics if the length of the given `seed_bytes` differs from 64.
+	pub fn set_entropy_seed_bytes(&self, seed_bytes: Vec<u8>) {
+		if seed_bytes.len() != WALLET_KEYS_SEED_LEN {
+			panic!("Failed to set seed due to invalid length.");
+		}
+		let mut bytes = [0u8; WALLET_KEYS_SEED_LEN];
+		bytes.copy_from_slice(&seed_bytes);
+		*self.entropy_source_config.lock().unwrap() = Some(EntropySourceConfig::SeedBytes(bytes));
 	}
 
-	/// Configures the [`Node`] instance to source its wallet entropy from the given seed bytes.
-	pub fn set_entropy_seed_bytes(&mut self, seed_bytes: [u8; WALLET_KEYS_SEED_LEN]) -> &mut Self {
-		self.entropy_source_config = Some(EntropySourceConfig::SeedBytes(seed_bytes));
-		self
+	/// Configures the [`Node`] instance to source its wallet entropy from a [BIP 39] mnemonic.
+	///
+	/// [BIP 39]: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
+	pub fn set_entropy_bip39_mnemonic(&self, mnemonic: Mnemonic, passphrase: Option<String>) {
+		*self.entropy_source_config.lock().unwrap() =
+			Some(EntropySourceConfig::Bip39Mnemonic { mnemonic, passphrase });
 	}
 
 	/// Configures the [`Node`] instance to source its gossip data from the Lightning peer-to-peer
 	/// network.
-	pub fn set_gossip_source_p2p(&mut self) -> &mut Self {
-		self.gossip_source_config = Some(GossipSourceConfig::P2PNetwork);
-		self
+	pub fn set_gossip_source_p2p(&self) {
+		*self.gossip_source_config.lock().unwrap() = Some(GossipSourceConfig::P2PNetwork);
 	}
 
 	/// Configures the [`Node`] instance to source its gossip data from the given RapidGossipSync
 	/// server.
-	pub fn set_gossip_source_rgs(&mut self, rgs_server_url: String) -> &mut Self {
-		self.gossip_source_config = Some(GossipSourceConfig::RapidGossipSync(rgs_server_url));
-		self
-	}
-
-	/// Configures the [`Node`] instance to source its wallet entropy from a [BIP 39] mnemonic.
-	///
-	/// [BIP 39]: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
-	pub fn set_entropy_bip39_mnemonic(
-		&mut self, mnemonic: bip39::Mnemonic, passphrase: Option<String>,
-	) -> &mut Self {
-		self.entropy_source_config =
-			Some(EntropySourceConfig::Bip39Mnemonic { mnemonic, passphrase });
-		self
+	pub fn set_gossip_source_rgs(&self, rgs_server_url: String) {
+		*self.gossip_source_config.lock().unwrap() =
+			Some(GossipSourceConfig::RapidGossipSync(rgs_server_url));
 	}
 
 	/// Sets the used storage directory path.
 	///
 	/// Default: `/tmp/ldk_node/`
-	pub fn set_storage_dir_path(&mut self, storage_dir_path: String) -> &mut Self {
-		self.config.storage_dir_path = storage_dir_path;
-		self
+	pub fn set_storage_dir_path(&self, storage_dir_path: String) {
+		let mut config = self.config.lock().unwrap();
+		config.storage_dir_path = storage_dir_path;
 	}
 
 	/// Sets the Esplora server URL.
 	///
 	/// Default: `https://blockstream.info/api`
-	pub fn set_esplora_server_url(&mut self, esplora_server_url: String) -> &mut Self {
-		self.config.esplora_server_url = esplora_server_url;
-		self
+	pub fn set_esplora_server_url(&self, esplora_server_url: String) {
+		let mut config = self.config.lock().unwrap();
+		config.esplora_server_url = esplora_server_url;
 	}
 
 	/// Sets the Bitcoin network used.
-	///
-	/// Options: `mainnet`/`bitcoin`, `testnet`, `regtest`, `signet`
-	///
-	/// Default: `regtest`
-	pub fn set_network(&mut self, network: &str) -> &mut Self {
-		self.config.network = Network::from_str(network).unwrap_or(Network::Regtest);
-		self
+	pub fn set_network(&self, network: Network) {
+		let mut config = self.config.lock().unwrap();
+		config.network = network;
 	}
 
 	/// Sets the IP address and TCP port on which [`Node`] will listen for incoming network connections.
 	///
 	/// Default: `0.0.0.0:9735`
-	pub fn set_listening_address(&mut self, listening_address: NetAddress) -> &mut Self {
-		self.config.listening_address = Some(listening_address);
-		self
+	pub fn set_listening_address(&self, listening_address: NetAddress) {
+		let mut config = self.config.lock().unwrap();
+		config.listening_address = Some(listening_address);
 	}
 
 	/// Builds a [`Node`] instance with a [`FilesystemStore`] backend and according to the options
 	/// previously configured.
 	pub fn build(&self) -> Arc<Node<FilesystemStore>> {
-		let ldk_data_dir = format!("{}/ldk", self.config.storage_dir_path);
+		let config = self.config.lock().unwrap();
+		let ldk_data_dir = format!("{}/ldk", config.storage_dir_path);
 		let kv_store = Arc::new(FilesystemStore::new(ldk_data_dir.clone().into()));
 		self.build_with_store(kv_store)
 	}
@@ -332,7 +334,7 @@ impl Builder {
 	pub fn build_with_store<K: KVStore + Sync + Send + 'static>(
 		&self, kv_store: Arc<K>,
 	) -> Arc<Node<K>> {
-		let config = Arc::new(self.config.clone());
+		let config = Arc::new(self.config.lock().unwrap().clone());
 
 		let ldk_data_dir = format!("{}/ldk", config.storage_dir_path);
 		fs::create_dir_all(ldk_data_dir.clone()).expect("Failed to create LDK data directory");
@@ -345,7 +347,9 @@ impl Builder {
 		let logger = Arc::new(FilesystemLogger::new(log_file_path));
 
 		// Initialize the on-chain wallet and chain access
-		let seed_bytes = if let Some(entropy_source_config) = &self.entropy_source_config {
+		let seed_bytes = if let Some(entropy_source_config) =
+			&*self.entropy_source_config.lock().unwrap()
+		{
 			// Use the configured entropy source, if the user set one.
 			match entropy_source_config {
 				EntropySourceConfig::SeedBytes(bytes) => bytes.clone(),
@@ -550,8 +554,9 @@ impl Builder {
 
 		// Initialize the GossipSource
 		// Use the configured gossip source, if the user set one, otherwise default to P2PNetwork.
+		let gossip_source_config_lock = self.gossip_source_config.lock().unwrap();
 		let gossip_source_config =
-			self.gossip_source_config.as_ref().unwrap_or(&GossipSourceConfig::P2PNetwork);
+			gossip_source_config_lock.as_ref().unwrap_or(&GossipSourceConfig::P2PNetwork);
 
 		let gossip_source = match gossip_source_config {
 			GossipSourceConfig::P2PNetwork => {
diff --git a/src/types.rs b/src/types.rs
@@ -24,8 +24,9 @@ use bitcoin::hashes::Hash;
 use bitcoin::secp256k1::PublicKey;
 use bitcoin::{Address, Network, OutPoint, Txid};
 
-use core::convert::TryFrom;
-use std::convert::TryInto;
+use bip39::Mnemonic;
+
+use std::convert::{TryFrom, TryInto};
 use std::fmt::Display;
 use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs};
 use std::str::FromStr;
@@ -436,6 +437,17 @@ impl Display for NetAddress {
 	}
 }
 
+impl UniffiCustomTypeConverter for Mnemonic {
+	type Builtin = String;
+	fn into_custom(val: Self::Builtin) -> uniffi::Result<Self> {
+		Ok(Mnemonic::from_str(&val).map_err(|_| Error::InvalidSecretKey)?)
+	}
+
+	fn from_custom(obj: Self) -> Self::Builtin {
+		obj.to_string()
+	}
+}
+
 impl UniffiCustomTypeConverter for NetAddress {
 	type Builtin = String;
 	fn into_custom(val: Self::Builtin) -> uniffi::Result<Self> {
