X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning-block-sync%2Fsrc%2Finit.rs;h=83e356919b8e231a8d4a3bda41b0d65645e146fc;hb=2cb5b1af992263e219f47c1f09763ffd17fcda15;hp=287f75904f667fc492734c6a8ff5e429b0585536;hpb=ee995a3a5542dee16b7fbdc5e55c6311b3c78442;p=rust-lightning

diff --git a/lightning-block-sync/src/init.rs b/lightning-block-sync/src/init.rs
index 287f7590..83e35691 100644
--- a/lightning-block-sync/src/init.rs
+++ b/lightning-block-sync/src/init.rs
@@ -7,6 +7,18 @@ use bitcoin::network::constants::Network;
 
 use lightning::chain;
 
+/// Returns a validated block header of the source's best chain tip.
+///
+/// Upon success, the returned header can be used to initialize [`SpvClient`]. Useful during a fresh
+/// start when there are no chain listeners to sync yet.
+pub async fn validate_best_block_header<B: BlockSource>(block_source: &mut B) ->
+BlockSourceResult<ValidatedBlockHeader> {
+	let (best_block_hash, best_block_height) = block_source.get_best_block().await?;
+	block_source
+		.get_header(&best_block_hash, best_block_height).await?
+		.validate(best_block_hash)
+}
+
 /// Performs a one-time sync of chain listeners using a single *trusted* block source, bringing each
 /// listener's view of the chain from its paired block hash to `block_source`'s best chain tip.
 ///
@@ -66,7 +78,7 @@ use lightning::chain;
 ///
 /// 	// Read the channel manager paired with the block hash when it was persisted.
 /// 	let serialized_manager = "...";
-/// 	let (manager_block_hash_option, mut manager) = {
+/// 	let (manager_block_hash, mut manager) = {
 /// 		let read_args = ChannelManagerReadArgs::new(
 /// 			keys_manager,
 /// 			fee_estimator,
@@ -76,19 +88,17 @@ use lightning::chain;
 /// 			config,
 /// 			vec![&mut monitor],
 /// 		);
-/// 		<(Option<BlockHash>, ChannelManager<S, &ChainMonitor<S, &C, &T, &F, &L, &P>, &T, &K, &F, &L>)>::read(
+/// 		<(BlockHash, ChannelManager<S, &ChainMonitor<S, &C, &T, &F, &L, &P>, &T, &K, &F, &L>)>::read(
 /// 			&mut Cursor::new(&serialized_manager), read_args).unwrap()
 /// 	};
 ///
 /// 	// Synchronize any channel monitors and the channel manager to be on the best block.
 /// 	let mut cache = UnboundedCache::new();
 /// 	let mut monitor_listener = (monitor, &*tx_broadcaster, &*fee_estimator, &*logger);
-/// 	let mut listeners = vec![
+/// 	let listeners = vec![
 /// 		(monitor_block_hash, &mut monitor_listener as &mut dyn chain::Listen),
+/// 		(manager_block_hash, &mut manager as &mut dyn chain::Listen),
 /// 	];
-/// 	if let Some(manager_block_hash) = manager_block_hash_option {
-/// 		listeners.push((manager_block_hash, &mut manager as &mut dyn chain::Listen))
-/// 	}
 /// 	let chain_tip = init::synchronize_listeners(
 /// 		block_source, Network::Bitcoin, &mut cache, listeners).await.unwrap();
 ///
@@ -112,10 +122,7 @@ pub async fn synchronize_listeners<B: BlockSource, C: Cache>(
 	header_cache: &mut C,
 	mut chain_listeners: Vec<(BlockHash, &mut dyn chain::Listen)>,
 ) -> BlockSourceResult<ValidatedBlockHeader> {
-	let (best_block_hash, best_block_height) = block_source.get_best_block().await?;
-	let best_header = block_source
-		.get_header(&best_block_hash, best_block_height).await?
-		.validate(best_block_hash)?;
+	let best_header = validate_best_block_header(block_source).await?;
 
 	// Fetch the header for the block hash paired with each listener.
 	let mut chain_listeners_with_old_headers = Vec::new();