PREVIEW

Author: tnull

lightning-background-processor/src/lib.rs

@@ -6,21 +6,21 @@ use crate::{AsyncBlockSourceResult, BlockData, BlockSource, BlockSourceError};
 
 use bitcoin::blockdata::block::Block;
 use bitcoin::blockdata::constants::ChainHash;
-use bitcoin::blockdata::transaction::{TxOut, OutPoint};
+use bitcoin::blockdata::transaction::{OutPoint, TxOut};
 use bitcoin::hash_types::BlockHash;
 
 use lightning::ln::peer_handler::APeerManager;
 
 use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
-use lightning::routing::utxo::{UtxoFuture, UtxoLookup, UtxoResult, UtxoLookupError};
+use lightning::routing::utxo::{UtxoFuture, UtxoLookup, UtxoLookupError, UtxoResult};
 
 use lightning::util::logger::Logger;
 
-use std::sync::{Arc, Mutex};
 use std::collections::VecDeque;
 use std::future::Future;
 use std::ops::Deref;
 use std::pin::Pin;
+use std::sync::{Arc, Mutex};
 use std::task::Poll;
 
 /// A trait which extends [`BlockSource`] and can be queried to fetch the block at a given height
@@ -29,12 +29,14 @@ use std::task::Poll;
 /// Note that while this is implementable for a [`BlockSource`] which returns filtered block data
 /// (i.e. [`BlockData::HeaderOnly`] for [`BlockSource::get_block`] requests), such an
 /// implementation will reject all gossip as it is not fully able to verify the UTXOs referenced.
-pub trait UtxoSource : BlockSource + 'static {
+pub trait UtxoSource: BlockSource + 'static {
 	/// Fetches the block hash of the block at the given height.
 	///
 	/// This will, in turn, be passed to to [`BlockSource::get_block`] to fetch the block needed
 	/// for gossip validation.
-	fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash>;
+	fn get_block_hash_by_height<'a>(
+		&'a self, block_height: u32,
+	) -> AsyncBlockSourceResult<'a, BlockHash>;
 
 	/// Returns true if the given output has *not* been spent, i.e. is a member of the current UTXO
 	/// set.
@@ -45,7 +47,7 @@ pub trait UtxoSource : BlockSource + 'static {
 ///
 /// If the `tokio` feature is enabled, this is implemented on `TokioSpawner` struct which
 /// delegates to `tokio::spawn()`.
-pub trait FutureSpawner : Send + Sync + 'static {
+pub trait FutureSpawner: Send + Sync + 'static {
 	/// Spawns the given future as a background task.
 	///
 	/// This method MUST NOT block on the given future immediately.
@@ -65,8 +67,8 @@ impl FutureSpawner for TokioSpawner {
 /// A trivial future which joins two other futures and polls them at the same time, returning only
 /// once both complete.
 pub(crate) struct Joiner<
-	A: Future<Output=Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
-	B: Future<Output=Result<BlockHash, BlockSourceError>> + Unpin,
+	A: Future<Output = Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
+	B: Future<Output = Result<BlockHash, BlockSourceError>> + Unpin,
 > {
 	pub a: A,
 	pub b: B,
@@ -75,16 +77,20 @@ pub(crate) struct Joiner<
 }
 
 impl<
-	A: Future<Output=Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
-	B: Future<Output=Result<BlockHash, BlockSourceError>> + Unpin,
-> Joiner<A, B> {
-	fn new(a: A, b: B) -> Self { Self { a, b, a_res: None, b_res: None } }
+		A: Future<Output = Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
+		B: Future<Output = Result<BlockHash, BlockSourceError>> + Unpin,
+	> Joiner<A, B>
+{
+	fn new(a: A, b: B) -> Self {
+		Self { a, b, a_res: None, b_res: None }
+	}
 }
 
 impl<
-	A: Future<Output=Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
-	B: Future<Output=Result<BlockHash, BlockSourceError>> + Unpin,
-> Future for Joiner<A, B> {
+		A: Future<Output = Result<(BlockHash, Option<u32>), BlockSourceError>> + Unpin,
+		B: Future<Output = Result<BlockHash, BlockSourceError>> + Unpin,
+	> Future for Joiner<A, B>
+{
 	type Output = Result<((BlockHash, Option<u32>), BlockHash), BlockSourceError>;
 	fn poll(mut self: Pin<&mut Self>, ctx: &mut core::task::Context<'_>) -> Poll<Self::Output> {
 		if self.a_res.is_none() {
@@ -107,14 +113,13 @@ impl<
 					} else {
 						return Poll::Ready(Err(res.unwrap_err()));
 					}
-
 				},
 				Poll::Pending => {},
 			}
 		}
 		if let Some(b_res) = self.b_res {
 			if let Some(a_res) = self.a_res {
-				return Poll::Ready(Ok((a_res, b_res)))
+				return Poll::Ready(Ok((a_res, b_res)));
 			}
 		}
 		Poll::Pending
@@ -129,7 +134,8 @@ impl<
 /// value of 1024 should more than suffice), and ensure you have sufficient file descriptors
 /// available on both Bitcoin Core and your LDK application for each request to hold its own
 /// connection.
-pub struct GossipVerifier<S: FutureSpawner,
+pub struct GossipVerifier<
+	S: FutureSpawner,
 	Blocks: Deref + Send + Sync + 'static + Clone,
 	L: Deref + Send + Sync + 'static,
 > where
@@ -145,10 +151,9 @@ pub struct GossipVerifier<S: FutureSpawner,
 
 const BLOCK_CACHE_SIZE: usize = 5;
 
-impl<S: FutureSpawner,
-	Blocks: Deref + Send + Sync + Clone,
-	L: Deref + Send + Sync,
-> GossipVerifier<S, Blocks, L> where
+impl<S: FutureSpawner, Blocks: Deref + Send + Sync + Clone, L: Deref + Send + Sync>
+	GossipVerifier<S, Blocks, L>
+where
 	Blocks::Target: UtxoSource,
 	L::Target: Logger,
 {
@@ -157,27 +162,35 @@ impl<S: FutureSpawner,
 	/// This is expected to be given to a [`P2PGossipSync`] (initially constructed with `None` for
 	/// the UTXO lookup) via [`P2PGossipSync::add_utxo_lookup`].
 	pub fn new<APM: Deref + Send + Sync + Clone + 'static>(
-		source: Blocks, spawn: S, gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, peer_manager: APM
-	) -> Self where APM::Target: APeerManager {
+		source: Blocks, spawn: S, gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>,
+		peer_manager: APM,
+	) -> Self
+	where
+		APM::Target: APeerManager,
+	{
 		let peer_manager_wake = Arc::new(move || peer_manager.as_ref().process_events());
 		Self {
-			source, spawn, gossiper, peer_manager_wake,
+			source,
+			spawn,
+			gossiper,
+			peer_manager_wake,
 			block_cache: Arc::new(Mutex::new(VecDeque::with_capacity(BLOCK_CACHE_SIZE))),
 		}
 	}
 
 	async fn retrieve_utxo(
-		source: Blocks, block_cache: Arc<Mutex<VecDeque<(u32, Block)>>>, short_channel_id: u64
+		source: Blocks, block_cache: Arc<Mutex<VecDeque<(u32, Block)>>>, short_channel_id: u64,
 	) -> Result<TxOut, UtxoLookupError> {
 		let block_height = (short_channel_id >> 5 * 8) as u32; // block height is most significant three bytes
 		let transaction_index = ((short_channel_id >> 2 * 8) & 0xffffff) as u32;
 		let output_index = (short_channel_id & 0xffff) as u16;
 
 		let (outpoint, output);
 
-		'tx_found: loop { // Used as a simple goto
+		'tx_found: loop {
+			// Used as a simple goto
 			macro_rules! process_block {
-				($block: expr) => { {
+				($block: expr) => {{
 					if transaction_index as usize >= $block.txdata.len() {
 						return Err(UtxoLookupError::UnknownTx);
 					}
@@ -188,7 +201,7 @@ impl<S: FutureSpawner,
 
 					outpoint = OutPoint::new(transaction.txid(), output_index.into());
 					output = transaction.output[output_index as usize].clone();
-				} }
+				}};
 			}
 			{
 				let recent_blocks = block_cache.lock().unwrap();
@@ -202,8 +215,8 @@ impl<S: FutureSpawner,
 
 			let ((_, tip_height_opt), block_hash) =
 				Joiner::new(source.get_best_block(), source.get_block_hash_by_height(block_height))
-				.await
-				.map_err(|_| UtxoLookupError::UnknownTx)?;
+					.await
+					.map_err(|_| UtxoLookupError::UnknownTx)?;
 			if let Some(tip_height) = tip_height_opt {
 				// If the block doesn't yet have five confirmations, error out.
 				//
@@ -214,8 +227,8 @@ impl<S: FutureSpawner,
 					return Err(UtxoLookupError::UnknownTx);
 				}
 			}
-			let block_data = source.get_block(&block_hash).await
-				.map_err(|_| UtxoLookupError::UnknownTx)?;
+			let block_data =
+				source.get_block(&block_hash).await.map_err(|_| UtxoLookupError::UnknownTx)?;
 			let block = match block_data {
 				BlockData::HeaderOnly(_) => return Err(UtxoLookupError::UnknownTx),
 				BlockData::FullBlock(block) => block,
@@ -237,7 +250,7 @@ impl<S: FutureSpawner,
 				}
 			}
 			break 'tx_found;
-		};
+		}
 		let outpoint_unspent =
 			source.is_output_unspent(outpoint).await.map_err(|_| UtxoLookupError::UnknownTx)?;
 		if outpoint_unspent {
@@ -248,22 +261,21 @@ impl<S: FutureSpawner,
 	}
 }
 
-impl<S: FutureSpawner,
-	Blocks: Deref + Send + Sync + Clone,
-	L: Deref + Send + Sync,
-> Deref for GossipVerifier<S, Blocks, L> where
+impl<S: FutureSpawner, Blocks: Deref + Send + Sync + Clone, L: Deref + Send + Sync> Deref
+	for GossipVerifier<S, Blocks, L>
+where
 	Blocks::Target: UtxoSource,
 	L::Target: Logger,
 {
 	type Target = Self;
-	fn deref(&self) -> &Self { self }
+	fn deref(&self) -> &Self {
+		self
+	}
 }
 
-
-impl<S: FutureSpawner,
-	Blocks: Deref + Send + Sync + Clone,
-	L: Deref + Send + Sync,
-> UtxoLookup for GossipVerifier<S, Blocks, L> where
+impl<S: FutureSpawner, Blocks: Deref + Send + Sync + Clone, L: Deref + Send + Sync> UtxoLookup
+	for GossipVerifier<S, Blocks, L>
+where
 	Blocks::Target: UtxoSource,
 	L::Target: Logger,
 {