X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning-block-sync%2Fsrc%2Flib.rs;h=4a01d4673b31e91d56c3cb350d995c1b7a3d7403;hb=10480f009e6e57cd409916ea08ac679b0953e4d5;hp=5ed8689fb965e00ee1d7305e790207d339d2c9c0;hpb=8505382b197ee9469028b2ea6062fe2489aee6c1;p=rust-lightning diff --git a/lightning-block-sync/src/lib.rs b/lightning-block-sync/src/lib.rs index 5ed8689f..4a01d467 100644 --- a/lightning-block-sync/src/lib.rs +++ b/lightning-block-sync/src/lib.rs @@ -12,15 +12,23 @@ //! //! Both features support either blocking I/O using `std::net::TcpStream` or, with feature `tokio`, //! non-blocking I/O using `tokio::net::TcpStream` from inside a Tokio runtime. -//! -//! [`SpvClient`]: struct.SpvClient.html -//! [`BlockSource`]: trait.BlockSource.html + +#![deny(rustdoc::broken_intra_doc_links)] +#![deny(rustdoc::private_intra_doc_links)] + +#![deny(missing_docs)] +#![deny(unsafe_code)] + +#![cfg_attr(docsrs, feature(doc_auto_cfg))] #[cfg(any(feature = "rest-client", feature = "rpc-client"))] pub mod http; +pub mod init; pub mod poll; +pub mod gossip; + #[cfg(feature = "rest-client")] pub mod rest; @@ -38,11 +46,15 @@ mod utils; use crate::poll::{ChainTip, Poll, ValidatedBlockHeader}; -use bitcoin::blockdata::block::{Block, BlockHeader}; +use bitcoin::blockdata::block::{Block, Header}; use bitcoin::hash_types::BlockHash; -use bitcoin::util::uint::Uint256; +use bitcoin::pow::Work; + +use lightning::chain; +use lightning::chain::Listen; use std::future::Future; +use std::ops::Deref; use std::pin::Pin; /// Abstract type for retrieving block headers and data. @@ -53,29 +65,28 @@ pub trait BlockSource : Sync + Send { /// /// Implementations that cannot find headers based on the hash should return a `Transient` error /// when `height_hint` is `None`. - fn get_header<'a>(&'a mut self, header_hash: &'a BlockHash, height_hint: Option) -> AsyncBlockSourceResult<'a, BlockHeaderData>; + fn get_header<'a>(&'a self, header_hash: &'a BlockHash, height_hint: Option) -> AsyncBlockSourceResult<'a, BlockHeaderData>; /// Returns the block for a given hash. A headers-only block source should return a `Transient` /// error. - fn get_block<'a>(&'a mut self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, Block>; + fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, BlockData>; /// Returns the hash of the best block and, optionally, its height. /// /// When polling a block source, [`Poll`] implementations may pass the height to [`get_header`] /// to allow for a more efficient lookup. /// - /// [`Poll`]: poll/trait.Poll.html - /// [`get_header`]: #tymethod.get_header - fn get_best_block<'a>(&'a mut self) -> AsyncBlockSourceResult<(BlockHash, Option)>; + /// [`get_header`]: Self::get_header + fn get_best_block<'a>(&'a self) -> AsyncBlockSourceResult<(BlockHash, Option)>; } /// Result type for `BlockSource` requests. -type BlockSourceResult = Result; +pub type BlockSourceResult = Result; // TODO: Replace with BlockSourceResult once `async` trait functions are supported. For details, // see: https://areweasyncyet.rs. /// Result type for asynchronous `BlockSource` requests. -type AsyncBlockSourceResult<'a, T> = Pin> + 'a + Send>>; +pub type AsyncBlockSourceResult<'a, T> = Pin> + 'a + Send>>; /// Error type for `BlockSource` requests. /// @@ -88,7 +99,7 @@ pub struct BlockSourceError { } /// The kind of `BlockSourceError`, either persistent or transient. -#[derive(Clone, Copy, Debug, PartialEq)] +#[derive(Clone, Copy, Debug, PartialEq, Eq)] pub enum BlockSourceErrorKind { /// Indicates an error that won't resolve when retrying a request (e.g., invalid data). Persistent, @@ -122,6 +133,9 @@ impl BlockSourceError { } /// Converts the error into the underlying error. + /// + /// May contain an [`std::io::Error`] from the [`BlockSource`]. See implementations for further + /// details, if any. pub fn into_inner(self) -> Box { self.error } @@ -129,17 +143,28 @@ impl BlockSourceError { /// A block header and some associated data. This information should be available from most block /// sources (and, notably, is available in Bitcoin Core's RPC and REST interfaces). -#[derive(Clone, Copy, Debug, PartialEq)] +#[derive(Clone, Copy, Debug, PartialEq, Eq)] pub struct BlockHeaderData { /// The block header itself. - pub header: BlockHeader, + pub header: Header, /// The block height where the genesis block has height 0. pub height: u32, - /// The total chain work in expected number of double-SHA256 hashes required to build a chain - /// of equivalent weight. - pub chainwork: Uint256, + /// The total chain work required to build a chain of equivalent weight. + pub chainwork: Work, +} + +/// A block including either all its transactions or only the block header. +/// +/// [`BlockSource`] may be implemented to either always return full blocks or, in the case of +/// compact block filters (BIP 157/158), return header-only blocks when no pertinent transactions +/// match. See [`chain::Filter`] for details on how to notify a source of such transactions. +pub enum BlockData { + /// A block containing all its transactions. + FullBlock(Block), + /// A block header for when the block does not contain any pertinent transactions. + HeaderOnly(Header), } /// A lightweight client for keeping a listener in sync with the chain, allowing for Simplified @@ -154,22 +179,11 @@ pub struct BlockHeaderData { /// custom cache eviction policy. This offers flexibility to those sensitive to resource usage. /// Hence, there is a trade-off between a lower memory footprint and potentially increased network /// I/O as headers are re-fetched during fork detection. -pub struct SpvClient { +pub struct SpvClient<'a, P: Poll, C: Cache, L: Deref> +where L::Target: chain::Listen { chain_tip: ValidatedBlockHeader, chain_poller: P, - chain_notifier: ChainNotifier, - chain_listener: L, -} - -/// Adaptor used for notifying when blocks have been connected or disconnected from the chain. -/// -/// Used when needing to replay chain data upon startup or as new chain events occur. -pub trait ChainListener { - /// Notifies the listener that a block was added at the given height. - fn block_connected(&mut self, block: &Block, height: u32); - - /// Notifies the listener that a block was removed at the given height. - fn block_disconnected(&mut self, header: &BlockHeader, height: u32); + chain_notifier: ChainNotifier<'a, C, L>, } /// The `Cache` trait defines behavior for managing a block header cache, where block headers are @@ -182,8 +196,6 @@ pub trait ChainListener { /// Implementations may define how long to retain headers such that it's unlikely they will ever be /// needed to disconnect a block. In cases where block sources provide access to headers on stale /// forks reliably, caches may be entirely unnecessary. -/// -/// [`ChainNotifier`]: struct.ChainNotifier.html pub trait Cache { /// Retrieves the block header keyed by the given block hash. fn look_up(&self, block_hash: &BlockHash) -> Option<&ValidatedBlockHeader>; @@ -214,7 +226,7 @@ impl Cache for UnboundedCache { } } -impl SpvClient { +impl<'a, P: Poll, C: Cache, L: Deref> SpvClient<'a, P, C, L> where L::Target: chain::Listen { /// Creates a new SPV client using `chain_tip` as the best known chain tip. /// /// Subsequent calls to [`poll_best_tip`] will poll for the best chain tip using the given chain @@ -224,15 +236,15 @@ impl SpvClient { /// * `header_cache` is used to look up and store headers on the best chain /// * `chain_listener` is notified of any blocks connected or disconnected /// - /// [`poll_best_tip`]: struct.SpvClient.html#method.poll_best_tip + /// [`poll_best_tip`]: SpvClient::poll_best_tip pub fn new( chain_tip: ValidatedBlockHeader, chain_poller: P, - header_cache: C, + header_cache: &'a mut C, chain_listener: L, ) -> Self { - let chain_notifier = ChainNotifier { header_cache }; - Self { chain_tip, chain_poller, chain_notifier, chain_listener } + let chain_notifier = ChainNotifier { header_cache, chain_listener }; + Self { chain_tip, chain_poller, chain_notifier } } /// Polls for the best tip and updates the chain listener with any connected or disconnected @@ -262,7 +274,7 @@ impl SpvClient { /// blocks. Returns whether there were any such blocks. async fn update_chain_tip(&mut self, best_chain_tip: ValidatedBlockHeader) -> bool { match self.chain_notifier.synchronize_listener( - best_chain_tip, &self.chain_tip, &mut self.chain_poller, &mut self.chain_listener).await + best_chain_tip, &self.chain_tip, &mut self.chain_poller).await { Ok(_) => { self.chain_tip = best_chain_tip; @@ -279,10 +291,13 @@ impl SpvClient { /// Notifies [listeners] of blocks that have been connected or disconnected from the chain. /// -/// [listeners]: trait.ChainListener.html -struct ChainNotifier { +/// [listeners]: lightning::chain::Listen +pub struct ChainNotifier<'a, C: Cache, L: Deref> where L::Target: chain::Listen { /// Cache for looking up headers before fetching from a block source. - header_cache: C, + header_cache: &'a mut C, + + /// Listener that will be notified of connected or disconnected blocks. + chain_listener: L, } /// Changes made to the chain between subsequent polls that transformed it from having one chain tip @@ -291,6 +306,11 @@ struct ChainNotifier { /// Blocks are given in height-descending order. Therefore, blocks are first disconnected in order /// before new blocks are connected in reverse order. struct ChainDifference { + /// The most recent ancestor common between the chain tips. + /// + /// If there are any disconnected blocks, this is where the chain forked. + common_ancestor: ValidatedBlockHeader, + /// Blocks that were disconnected from the chain since the last poll. disconnected_blocks: Vec, @@ -298,45 +318,28 @@ struct ChainDifference { connected_blocks: Vec, } -impl ChainNotifier { - /// Finds the fork point between `new_header` and `old_header`, disconnecting blocks from - /// `old_header` to get to that point and then connecting blocks until `new_header`. +impl<'a, C: Cache, L: Deref> ChainNotifier<'a, C, L> where L::Target: chain::Listen { + /// Finds the first common ancestor between `new_header` and `old_header`, disconnecting blocks + /// from `old_header` to get to that point and then connecting blocks until `new_header`. /// /// Validates headers along the transition path, but doesn't fetch blocks until the chain is /// disconnected to the fork point. Thus, this may return an `Err` that includes where the tip /// ended up which may not be `new_header`. Note that the returned `Err` contains `Some` header /// if and only if the transition from `old_header` to `new_header` is valid. - async fn synchronize_listener( + async fn synchronize_listener( &mut self, new_header: ValidatedBlockHeader, old_header: &ValidatedBlockHeader, chain_poller: &mut P, - chain_listener: &mut L, ) -> Result<(), (BlockSourceError, Option)> { - let mut difference = self.find_difference(new_header, old_header, chain_poller).await + let difference = self.find_difference(new_header, old_header, chain_poller).await .map_err(|e| (e, None))?; - - let mut new_tip = *old_header; - for header in difference.disconnected_blocks.drain(..) { - if let Some(cached_header) = self.header_cache.block_disconnected(&header.block_hash) { - assert_eq!(cached_header, header); - } - chain_listener.block_disconnected(&header.header, header.height); - new_tip = header; - } - - for header in difference.connected_blocks.drain(..).rev() { - let block = chain_poller - .fetch_block(&header).await - .or_else(|e| Err((e, Some(new_tip))))?; - debug_assert_eq!(block.block_hash, header.block_hash); - - self.header_cache.block_connected(header.block_hash, header); - chain_listener.block_connected(&block, header.height); - new_tip = header; - } - - Ok(()) + self.disconnect_blocks(difference.disconnected_blocks); + self.connect_blocks( + difference.common_ancestor, + difference.connected_blocks, + chain_poller, + ).await } /// Returns the changes needed to produce the chain with `current_header` as its tip from the @@ -373,7 +376,8 @@ impl ChainNotifier { } } - Ok(ChainDifference { disconnected_blocks, connected_blocks }) + let common_ancestor = current; + Ok(ChainDifference { common_ancestor, disconnected_blocks, connected_blocks }) } /// Returns the previous header for the given header, either by looking it up in the cache or @@ -388,6 +392,46 @@ impl ChainNotifier { None => chain_poller.look_up_previous_header(header).await, } } + + /// Notifies the chain listeners of disconnected blocks. + fn disconnect_blocks(&mut self, mut disconnected_blocks: Vec) { + for header in disconnected_blocks.drain(..) { + if let Some(cached_header) = self.header_cache.block_disconnected(&header.block_hash) { + assert_eq!(cached_header, header); + } + self.chain_listener.block_disconnected(&header.header, header.height); + } + } + + /// Notifies the chain listeners of connected blocks. + async fn connect_blocks( + &mut self, + mut new_tip: ValidatedBlockHeader, + mut connected_blocks: Vec, + chain_poller: &mut P, + ) -> Result<(), (BlockSourceError, Option)> { + for header in connected_blocks.drain(..).rev() { + let height = header.height; + let block_data = chain_poller + .fetch_block(&header).await + .map_err(|e| (e, Some(new_tip)))?; + debug_assert_eq!(block_data.block_hash, header.block_hash); + + match block_data.deref() { + BlockData::FullBlock(block) => { + self.chain_listener.block_connected(block, height); + }, + BlockData::HeaderOnly(header) => { + self.chain_listener.filtered_block_connected(header, &[], height); + }, + } + + self.header_cache.block_connected(header.block_hash, header); + new_tip = header; + } + + Ok(()) + } } #[cfg(test)] @@ -403,8 +447,9 @@ mod spv_client_tests { let best_tip = chain.at_height(1); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(best_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(best_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => { assert_eq!(e.kind(), BlockSourceErrorKind::Persistent); @@ -421,8 +466,9 @@ mod spv_client_tests { let common_tip = chain.tip(); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(common_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(common_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => panic!("Unexpected error: {:?}", e), Ok((chain_tip, blocks_connected)) => { @@ -440,8 +486,9 @@ mod spv_client_tests { let old_tip = chain.at_height(1); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(old_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => panic!("Unexpected error: {:?}", e), Ok((chain_tip, blocks_connected)) => { @@ -459,8 +506,9 @@ mod spv_client_tests { let old_tip = chain.at_height(1); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(old_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => panic!("Unexpected error: {:?}", e), Ok((chain_tip, blocks_connected)) => { @@ -478,8 +526,9 @@ mod spv_client_tests { let old_tip = chain.at_height(1); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(old_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => panic!("Unexpected error: {:?}", e), Ok((chain_tip, blocks_connected)) => { @@ -498,8 +547,9 @@ mod spv_client_tests { let worse_tip = chain.tip(); let poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - let cache = UnboundedCache::new(); - let mut client = SpvClient::new(best_tip, poller, cache, NullChainListener {}); + let mut cache = UnboundedCache::new(); + let mut listener = NullChainListener {}; + let mut client = SpvClient::new(best_tip, poller, &mut cache, &mut listener); match client.poll_best_tip().await { Err(e) => panic!("Unexpected error: {:?}", e), Ok((chain_tip, blocks_connected)) => { @@ -524,12 +574,15 @@ mod chain_notifier_tests { let new_tip = chain.tip(); let old_tip = chain.at_height(1); - let mut listener = MockChainListener::new() + let chain_listener = &MockChainListener::new() .expect_block_connected(*chain.at_height(2)) .expect_block_connected(*new_tip); - let mut notifier = ChainNotifier { header_cache: chain.header_cache(0..=1) }; + let mut notifier = ChainNotifier { + header_cache: &mut chain.header_cache(0..=1), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((e, _)) => panic!("Unexpected error: {:?}", e), Ok(_) => {}, } @@ -542,10 +595,13 @@ mod chain_notifier_tests { let new_tip = test_chain.tip(); let old_tip = main_chain.tip(); - let mut listener = MockChainListener::new(); - let mut notifier = ChainNotifier { header_cache: main_chain.header_cache(0..=1) }; + let chain_listener = &MockChainListener::new(); + let mut notifier = ChainNotifier { + header_cache: &mut main_chain.header_cache(0..=1), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut test_chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((e, _)) => { assert_eq!(e.kind(), BlockSourceErrorKind::Persistent); assert_eq!(e.into_inner().as_ref().to_string(), "genesis block reached"); @@ -561,12 +617,15 @@ mod chain_notifier_tests { let new_tip = fork_chain.tip(); let old_tip = main_chain.tip(); - let mut listener = MockChainListener::new() + let chain_listener = &MockChainListener::new() .expect_block_disconnected(*old_tip) .expect_block_connected(*new_tip); - let mut notifier = ChainNotifier { header_cache: main_chain.header_cache(0..=2) }; + let mut notifier = ChainNotifier { + header_cache: &mut main_chain.header_cache(0..=2), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut fork_chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((e, _)) => panic!("Unexpected error: {:?}", e), Ok(_) => {}, } @@ -580,13 +639,16 @@ mod chain_notifier_tests { let new_tip = fork_chain.tip(); let old_tip = main_chain.tip(); - let mut listener = MockChainListener::new() + let chain_listener = &MockChainListener::new() .expect_block_disconnected(*old_tip) .expect_block_disconnected(*main_chain.at_height(2)) .expect_block_connected(*new_tip); - let mut notifier = ChainNotifier { header_cache: main_chain.header_cache(0..=3) }; + let mut notifier = ChainNotifier { + header_cache: &mut main_chain.header_cache(0..=3), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut fork_chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((e, _)) => panic!("Unexpected error: {:?}", e), Ok(_) => {}, } @@ -600,13 +662,16 @@ mod chain_notifier_tests { let new_tip = fork_chain.tip(); let old_tip = main_chain.tip(); - let mut listener = MockChainListener::new() + let chain_listener = &MockChainListener::new() .expect_block_disconnected(*old_tip) .expect_block_connected(*fork_chain.at_height(2)) .expect_block_connected(*new_tip); - let mut notifier = ChainNotifier { header_cache: main_chain.header_cache(0..=2) }; + let mut notifier = ChainNotifier { + header_cache: &mut main_chain.header_cache(0..=2), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut fork_chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((e, _)) => panic!("Unexpected error: {:?}", e), Ok(_) => {}, } @@ -618,10 +683,13 @@ mod chain_notifier_tests { let new_tip = chain.tip(); let old_tip = chain.at_height(1); - let mut listener = MockChainListener::new(); - let mut notifier = ChainNotifier { header_cache: chain.header_cache(0..=1) }; + let chain_listener = &MockChainListener::new(); + let mut notifier = ChainNotifier { + header_cache: &mut chain.header_cache(0..=1), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((_, tip)) => assert_eq!(tip, None), Ok(_) => panic!("Expected error"), } @@ -633,10 +701,13 @@ mod chain_notifier_tests { let new_tip = chain.tip(); let old_tip = chain.at_height(1); - let mut listener = MockChainListener::new(); - let mut notifier = ChainNotifier { header_cache: chain.header_cache(0..=3) }; + let chain_listener = &MockChainListener::new(); + let mut notifier = ChainNotifier { + header_cache: &mut chain.header_cache(0..=3), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((_, tip)) => assert_eq!(tip, Some(old_tip)), Ok(_) => panic!("Expected error"), } @@ -648,13 +719,37 @@ mod chain_notifier_tests { let new_tip = chain.tip(); let old_tip = chain.at_height(1); - let mut listener = MockChainListener::new() + let chain_listener = &MockChainListener::new() .expect_block_connected(*chain.at_height(2)); - let mut notifier = ChainNotifier { header_cache: chain.header_cache(0..=3) }; + let mut notifier = ChainNotifier { + header_cache: &mut chain.header_cache(0..=3), + chain_listener, + }; let mut poller = poll::ChainPoller::new(&mut chain, Network::Testnet); - match notifier.synchronize_listener(new_tip, &old_tip, &mut poller, &mut listener).await { + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { Err((_, tip)) => assert_eq!(tip, Some(chain.at_height(2))), Ok(_) => panic!("Expected error"), } } + + #[tokio::test] + async fn sync_from_chain_with_filtered_blocks() { + let mut chain = Blockchain::default().with_height(3).filtered_blocks(); + + let new_tip = chain.tip(); + let old_tip = chain.at_height(1); + let chain_listener = &MockChainListener::new() + .expect_filtered_block_connected(*chain.at_height(2)) + .expect_filtered_block_connected(*new_tip); + let mut notifier = ChainNotifier { + header_cache: &mut chain.header_cache(0..=1), + chain_listener, + }; + let mut poller = poll::ChainPoller::new(&mut chain, Network::Testnet); + match notifier.synchronize_listener(new_tip, &old_tip, &mut poller).await { + Err((e, _)) => panic!("Unexpected error: {:?}", e), + Ok(_) => {}, + } + } + }