Add a simple naive block cache in gossip sync lookups

This commit is contained in:
Matt Corallo 2023-04-30 02:06:19 +00:00
parent b315856e68
commit 3482fceeab

View file

@ -4,6 +4,7 @@
use crate::{AsyncBlockSourceResult, BlockData, BlockSource};
use bitcoin::blockdata::block::Block;
use bitcoin::blockdata::transaction::{TxOut, OutPoint};
use bitcoin::hash_types::BlockHash;
@ -17,7 +18,8 @@ use lightning::routing::utxo::{UtxoFuture, UtxoLookup, UtxoResult, UtxoLookupErr
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;
@ -27,9 +29,6 @@ use std::ops::Deref;
/// 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.
///
@ -91,8 +90,11 @@ pub struct GossipVerifier<S: FutureSpawner,
peer_manager: Arc<PeerManager<Descriptor, CM, Arc<P2PGossipSync<Arc<NetworkGraph<L>>, Self, L>>, OM, L, CMH, NS>>,
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,
@ -114,34 +116,76 @@ 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(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 }
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,
};
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
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 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 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;
};
let outpoint_unspent =
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)
}
@ -190,9 +234,10 @@ impl<S: FutureSpawner,
let fut = res.clone();
let source = self.source.clone();
let gossiper = Arc::clone(&self.gossiper);
let block_cache = Arc::clone(&self.block_cache);
let pm = Arc::clone(&self.peer_manager);
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();
});