//! current UTXO set. This module defines an implementation of the LDK API required to do so
//! against a [`BlockSource`] which implements a few additional methods for accessing the UTXO set.
-use crate::{AsyncBlockSourceResult, BlockData, BlockSource};
+use crate::{AsyncBlockSourceResult, BlockData, BlockSource, BlockSourceError};
+use bitcoin::blockdata::block::Block;
+use bitcoin::blockdata::constants::ChainHash;
use bitcoin::blockdata::transaction::{TxOut, OutPoint};
use bitcoin::hash_types::BlockHash;
-use lightning::sign::NodeSigner;
-
-use lightning::ln::peer_handler::{CustomMessageHandler, PeerManager, SocketDescriptor};
-use lightning::ln::msgs::{ChannelMessageHandler, OnionMessageHandler};
+use lightning::ln::peer_handler::APeerManager;
use lightning::routing::gossip::{NetworkGraph, P2PGossipSync};
use lightning::routing::utxo::{UtxoFuture, UtxoLookup, UtxoResult, UtxoLookupError};
use lightning::util::logger::Logger;
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
+use std::collections::VecDeque;
use std::future::Future;
use std::ops::Deref;
+use std::pin::Pin;
+use std::task::Poll;
/// A trait which extends [`BlockSource`] and can be queried to fetch the block at a given height
/// as well as whether a given output is unspent (i.e. a member of the current UTXO set).
/// 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.
-///
-/// For efficiency, an implementation may consider caching some set of blocks, as many redundant
-/// calls may be made.
pub trait UtxoSource : BlockSource + 'static {
/// Fetches the block hash of the block at the given height.
///
}
}
+/// 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,
+> {
+ pub a: A,
+ pub b: B,
+ a_res: Option<(BlockHash, Option<u32>)>,
+ b_res: Option<BlockHash>,
+}
+
+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 } }
+}
+
+impl<
+ 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() {
+ match Pin::new(&mut self.a).poll(ctx) {
+ Poll::Ready(res) => {
+ if let Ok(ok) = res {
+ self.a_res = Some(ok);
+ } else {
+ return Poll::Ready(Err(res.unwrap_err()));
+ }
+ },
+ Poll::Pending => {},
+ }
+ }
+ if self.b_res.is_none() {
+ match Pin::new(&mut self.b).poll(ctx) {
+ Poll::Ready(res) => {
+ if let Ok(ok) = res {
+ self.b_res = Some(ok);
+ } 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)))
+ }
+ }
+ Poll::Pending
+ }
+}
+
/// A struct which wraps a [`UtxoSource`] and a few LDK objects and implements the LDK
/// [`UtxoLookup`] trait.
///
pub struct GossipVerifier<S: FutureSpawner,
Blocks: Deref + Send + Sync + 'static + Clone,
L: Deref + Send + Sync + 'static,
- Descriptor: SocketDescriptor + Send + Sync + 'static,
- CM: Deref + Send + Sync + 'static,
- OM: Deref + Send + Sync + 'static,
- CMH: Deref + Send + Sync + 'static,
- NS: Deref + Send + Sync + 'static,
+ APM: Deref + Send + Sync + 'static + Clone,
> where
Blocks::Target: UtxoSource,
L::Target: Logger,
- CM::Target: ChannelMessageHandler,
- OM::Target: OnionMessageHandler,
- CMH::Target: CustomMessageHandler,
- NS::Target: NodeSigner,
+ APM::Target: APeerManager,
{
source: Blocks,
- peer_manager: Arc<PeerManager<Descriptor, CM, Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, OM, L, CMH, NS>>,
+ peer_manager: APM,
gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>,
spawn: S,
+ block_cache: Arc<Mutex<VecDeque<(u32, Block)>>>,
}
+const BLOCK_CACHE_SIZE: usize = 5;
+
impl<S: FutureSpawner,
Blocks: Deref + Send + Sync + Clone,
L: Deref + Send + Sync,
- Descriptor: SocketDescriptor + Send + Sync,
- CM: Deref + Send + Sync,
- OM: Deref + Send + Sync,
- CMH: Deref + Send + Sync,
- NS: Deref + Send + Sync,
-> GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ APM: Deref + Send + Sync + Clone,
+> GossipVerifier<S, Blocks, L, APM> where
Blocks::Target: UtxoSource,
L::Target: Logger,
- CM::Target: ChannelMessageHandler,
- OM::Target: OnionMessageHandler,
- CMH::Target: CustomMessageHandler,
- NS::Target: NodeSigner,
+ APM::Target: APeerManager,
{
/// Constructs a new [`GossipVerifier`].
///
/// 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(source: Blocks, spawn: S, gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, peer_manager: Arc<PeerManager<Descriptor, CM, Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, OM, L, CMH, NS>>) -> Self {
- Self { source, spawn, gossiper, peer_manager }
+ pub fn new(source: Blocks, spawn: S, gossiper: Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, peer_manager: APM) -> Self {
+ Self {
+ source, spawn, gossiper, peer_manager,
+ block_cache: Arc::new(Mutex::new(VecDeque::with_capacity(BLOCK_CACHE_SIZE))),
+ }
}
- async fn retrieve_utxo(source: Blocks, short_channel_id: u64) -> Result<TxOut, UtxoLookupError> {
+ async fn retrieve_utxo(
+ 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 block_hash = source.get_block_hash_by_height(block_height).await
- .map_err(|_| UtxoLookupError::UnknownTx)?;
- let block_data = source.get_block(&block_hash).await
- .map_err(|_| UtxoLookupError::UnknownTx)?;
- let mut block = match block_data {
- BlockData::HeaderOnly(_) => return Err(UtxoLookupError::UnknownTx),
- BlockData::FullBlock(block) => block,
+ let (outpoint, output);
+
+ 'tx_found: loop { // Used as a simple goto
+ macro_rules! process_block {
+ ($block: expr) => { {
+ if transaction_index as usize >= $block.txdata.len() {
+ return Err(UtxoLookupError::UnknownTx);
+ }
+ let transaction = &$block.txdata[transaction_index as usize];
+ if output_index as usize >= transaction.output.len() {
+ return Err(UtxoLookupError::UnknownTx);
+ }
+
+ outpoint = OutPoint::new(transaction.txid(), output_index.into());
+ output = transaction.output[output_index as usize].clone();
+ } }
+ }
+ {
+ let recent_blocks = block_cache.lock().unwrap();
+ for (height, block) in recent_blocks.iter() {
+ if *height == block_height {
+ process_block!(block);
+ break 'tx_found;
+ }
+ }
+ }
+
+ 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)?;
+ if let Some(tip_height) = tip_height_opt {
+ // If the block doesn't yet have five confirmations, error out.
+ //
+ // The BOLT spec requires nodes wait for six confirmations before announcing a
+ // channel, and we give them one block of headroom in case we're delayed seeing a
+ // block.
+ if block_height + 5 > tip_height {
+ return 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,
+ };
+ process_block!(block);
+ {
+ let mut recent_blocks = block_cache.lock().unwrap();
+ let mut insert = true;
+ for (height, _) in recent_blocks.iter() {
+ if *height == block_height {
+ insert = false;
+ }
+ }
+ if insert {
+ if recent_blocks.len() >= BLOCK_CACHE_SIZE {
+ recent_blocks.pop_front();
+ }
+ recent_blocks.push_back((block_height, block));
+ }
+ }
+ break 'tx_found;
};
- if transaction_index as usize >= block.txdata.len() {
- return Err(UtxoLookupError::UnknownTx);
- }
- let mut transaction = block.txdata.swap_remove(transaction_index as usize);
- if output_index as usize >= transaction.output.len() {
- return Err(UtxoLookupError::UnknownTx);
- }
let outpoint_unspent =
- source.is_output_unspent(OutPoint::new(transaction.txid(), output_index.into())).await
- .map_err(|_| UtxoLookupError::UnknownTx)?;
+ source.is_output_unspent(outpoint).await.map_err(|_| UtxoLookupError::UnknownTx)?;
if outpoint_unspent {
- Ok(transaction.output.swap_remove(output_index as usize))
+ Ok(output)
} else {
Err(UtxoLookupError::UnknownTx)
}
impl<S: FutureSpawner,
Blocks: Deref + Send + Sync + Clone,
L: Deref + Send + Sync,
- Descriptor: SocketDescriptor + Send + Sync,
- CM: Deref + Send + Sync,
- OM: Deref + Send + Sync,
- CMH: Deref + Send + Sync,
- NS: Deref + Send + Sync,
-> Deref for GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ APM: Deref + Send + Sync + Clone,
+> Deref for GossipVerifier<S, Blocks, L, APM> where
Blocks::Target: UtxoSource,
L::Target: Logger,
- CM::Target: ChannelMessageHandler,
- OM::Target: OnionMessageHandler,
- CMH::Target: CustomMessageHandler,
- NS::Target: NodeSigner,
+ APM::Target: APeerManager,
{
type Target = Self;
fn deref(&self) -> &Self { self }
impl<S: FutureSpawner,
Blocks: Deref + Send + Sync + Clone,
L: Deref + Send + Sync,
- Descriptor: SocketDescriptor + Send + Sync,
- CM: Deref + Send + Sync,
- OM: Deref + Send + Sync,
- CMH: Deref + Send + Sync,
- NS: Deref + Send + Sync,
-> UtxoLookup for GossipVerifier<S, Blocks, L, Descriptor, CM, OM, CMH, NS> where
+ APM: Deref + Send + Sync + Clone,
+> UtxoLookup for GossipVerifier<S, Blocks, L, APM> where
Blocks::Target: UtxoSource,
L::Target: Logger,
- CM::Target: ChannelMessageHandler,
- OM::Target: OnionMessageHandler,
- CMH::Target: CustomMessageHandler,
- NS::Target: NodeSigner,
+ APM::Target: APeerManager,
{
- fn get_utxo(&self, _genesis_hash: &BlockHash, short_channel_id: u64) -> UtxoResult {
+ fn get_utxo(&self, _chain_hash: &ChainHash, short_channel_id: u64) -> UtxoResult {
let res = UtxoFuture::new();
let fut = res.clone();
let source = self.source.clone();
let gossiper = Arc::clone(&self.gossiper);
- let pm = Arc::clone(&self.peer_manager);
+ let block_cache = Arc::clone(&self.block_cache);
+ let pm = self.peer_manager.clone();
self.spawn.spawn(async move {
- let res = Self::retrieve_utxo(source, short_channel_id).await;
+ let res = Self::retrieve_utxo(source, block_cache, short_channel_id).await;
fut.resolve(gossiper.network_graph(), &*gossiper, res);
- pm.process_events();
+ pm.as_ref().process_events();
});
UtxoResult::Async(res)
}