-
-/// BlockNotifierArc is useful when you need a BlockNotifier that points to ChainListeners with
-/// static lifetimes, e.g. when you're using lightning-net-tokio (since tokio::spawn requires
-/// parameters with static lifetimes). Other times you can afford a reference, which is more
-/// efficient, in which case BlockNotifierRef is a more appropriate type. Defining these type
-/// aliases prevents issues such as overly long function definitions.
-pub type BlockNotifierArc = Arc<BlockNotifier<'static, Arc<ChainListener>>>;
-
-/// BlockNotifierRef is useful when you want a BlockNotifier that points to ChainListeners
-/// with nonstatic lifetimes. This is useful for when static lifetimes are not needed. Nonstatic
-/// lifetimes are more efficient but less flexible, and should be used by default unless static
-/// lifetimes are required, e.g. when you're using lightning-net-tokio (since tokio::spawn
-/// requires parameters with static lifetimes), in which case BlockNotifierArc is a more
-/// appropriate type. Defining these type aliases for common usages prevents issues such as
-/// overly long function definitions.
-pub type BlockNotifierRef<'a> = BlockNotifier<'a, &'a ChainListener>;
-
-/// Utility for notifying listeners about new blocks, and handling block rescans if new watch
-/// data is registered.
-///
-/// Rather than using a plain BlockNotifier, it is preferable to use either a BlockNotifierArc
-/// or a BlockNotifierRef for conciseness. See their documentation for more details, but essentially
-/// you should default to using a BlockNotifierRef, and use a BlockNotifierArc instead when you
-/// require ChainListeners with static lifetimes, such as when you're using lightning-net-tokio.
-pub struct BlockNotifier<'a, CL: Deref<Target = ChainListener + 'a> + 'a> {
- listeners: Mutex<Vec<CL>>,
- chain_monitor: Arc<ChainWatchInterface>,
- phantom: PhantomData<&'a ()>,
-}
-
-impl<'a, CL: Deref<Target = ChainListener + 'a> + 'a> BlockNotifier<'a, CL> {
- /// Constructs a new BlockNotifier without any listeners.
- pub fn new(chain_monitor: Arc<ChainWatchInterface>) -> BlockNotifier<'a, CL> {
- BlockNotifier {
- listeners: Mutex::new(Vec::new()),
- chain_monitor,
- phantom: PhantomData,
- }
- }
-
- /// Register the given listener to receive events.
- pub fn register_listener(&self, listener: CL) {
- let mut vec = self.listeners.lock().unwrap();
- vec.push(listener);
- }
- /// Unregister the given listener to no longer
- /// receive events.
- ///
- /// If the same listener is registered multiple times, unregistering
- /// will remove ALL occurrences of that listener. Comparison is done using
- /// the pointer returned by the Deref trait implementation.
- pub fn unregister_listener(&self, listener: CL) {
- let mut vec = self.listeners.lock().unwrap();
- // item is a ref to an abstract thing that dereferences to a ChainListener,
- // so dereference it twice to get the ChainListener itself
- vec.retain(|item | !ptr::eq(&(**item), &(*listener)));
- }
-
- /// Notify listeners that a block was connected given a full, unfiltered block.
- ///
- /// Handles re-scanning the block and calling block_connected again if listeners register new
- /// watch data during the callbacks for you (see ChainListener::block_connected for more info).
- pub fn block_connected<'b>(&self, block: &'b Block, height: u32) {
- let mut reentered = true;
- while reentered {
- let (matched, matched_index) = self.chain_monitor.filter_block(block);
- reentered = self.block_connected_checked(&block.header, height, matched.as_slice(), matched_index.as_slice());
- }
- }
-
- /// Notify listeners that a block was connected, given pre-filtered list of transactions in the
- /// block which matched the filter (probably using does_match_tx).
- ///
- /// Returns true if notified listeners registered additional watch data (implying that the
- /// block must be re-scanned and this function called again prior to further block_connected
- /// calls, see ChainListener::block_connected for more info).
- pub fn block_connected_checked(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) -> bool {
- let last_seen = self.chain_monitor.reentered();
-
- let listeners = self.listeners.lock().unwrap();
- for listener in listeners.iter() {
- listener.block_connected(header, height, txn_matched, indexes_of_txn_matched);
- }
- return last_seen != self.chain_monitor.reentered();
- }
-
- /// Notify listeners that a block was disconnected.
- pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
- let listeners = self.listeners.lock().unwrap();
- for listener in listeners.iter() {
- listener.block_disconnected(&header, disconnected_height);
- }
- }
-}
-
-/// Utility to capture some common parts of ChainWatchInterface implementors.
-///
-/// Keeping a local copy of this in a ChainWatchInterface implementor is likely useful.
-pub struct ChainWatchInterfaceUtil {
- network: Network,
- watched: Mutex<ChainWatchedUtil>,
- reentered: AtomicUsize,
- logger: Arc<Logger>,
-}
-
-// We only expose PartialEq in test since its somewhat unclear exactly what it should do and we're
-// only comparing a subset of fields (essentially just checking that the set of things we're
-// watching is the same).
-#[cfg(test)]
-impl PartialEq for ChainWatchInterfaceUtil {
- fn eq(&self, o: &Self) -> bool {
- self.network == o.network &&
- *self.watched.lock().unwrap() == *o.watched.lock().unwrap()
- }
-}
-
-/// Register listener
-impl ChainWatchInterface for ChainWatchInterfaceUtil {
- fn install_watch_tx(&self, txid: &Sha256dHash, script_pub_key: &Script) {
- let mut watched = self.watched.lock().unwrap();
- if watched.register_tx(txid, script_pub_key) {
- self.reentered.fetch_add(1, Ordering::Relaxed);
- }
- }
-
- fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32), out_script: &Script) {
- let mut watched = self.watched.lock().unwrap();
- if watched.register_outpoint(outpoint, out_script) {
- self.reentered.fetch_add(1, Ordering::Relaxed);
- }
- }
-
- fn watch_all_txn(&self) {
- let mut watched = self.watched.lock().unwrap();
- if watched.watch_all() {
- self.reentered.fetch_add(1, Ordering::Relaxed);
- }
- }
-
- fn get_chain_utxo(&self, genesis_hash: Sha256dHash, _unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError> {
- if genesis_hash != genesis_block(self.network).header.bitcoin_hash() {
- return Err(ChainError::NotWatched);
- }
- Err(ChainError::NotSupported)
- }
-
- fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec<u32>) {
- let mut matched = Vec::new();
- let mut matched_index = Vec::new();
- {
- let watched = self.watched.lock().unwrap();
- for (index, transaction) in block.txdata.iter().enumerate() {
- if self.does_match_tx_unguarded(transaction, &watched) {
- matched.push(transaction);
- matched_index.push(index as u32);
- }
- }
- }
- (matched, matched_index)
- }
-
- fn reentered(&self) -> usize {
- self.reentered.load(Ordering::Relaxed)
- }
-}
-
-impl ChainWatchInterfaceUtil {
- /// Creates a new ChainWatchInterfaceUtil for the given network
- pub fn new(network: Network, logger: Arc<Logger>) -> ChainWatchInterfaceUtil {
- ChainWatchInterfaceUtil {
- network: network,
- watched: Mutex::new(ChainWatchedUtil::new()),
- reentered: AtomicUsize::new(1),
- logger: logger,
- }
- }
-
- /// Checks if a given transaction matches the current filter.
- pub fn does_match_tx(&self, tx: &Transaction) -> bool {
- let watched = self.watched.lock().unwrap();
- self.does_match_tx_unguarded (tx, &watched)
- }
-
- fn does_match_tx_unguarded(&self, tx: &Transaction, watched: &MutexGuard<ChainWatchedUtil>) -> bool {
- watched.does_match_tx(tx)
- }
-}
-
-#[cfg(test)]
-mod tests {
- use ln::functional_test_utils::{create_chanmon_cfgs, create_node_cfgs};
- use super::{BlockNotifier, ChainListener};
- use std::ptr;
-
- #[test]
- fn register_listener_test() {
- let chanmon_cfgs = create_chanmon_cfgs(1);
- let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
- let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor.clone());
- assert_eq!(block_notifier.listeners.lock().unwrap().len(), 0);
- let listener = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
- block_notifier.register_listener(listener);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 1);
- let item = vec.first().clone().unwrap();
- assert!(ptr::eq(&(**item), &(*listener)));
- }
-
- #[test]
- fn unregister_single_listener_test() {
- let chanmon_cfgs = create_chanmon_cfgs(2);
- let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
- let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor.clone());
- let listener1 = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
- let listener2 = &node_cfgs[1].chan_monitor.simple_monitor as &ChainListener;
- block_notifier.register_listener(listener1);
- block_notifier.register_listener(listener2);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 2);
- drop(vec);
- block_notifier.unregister_listener(listener1);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 1);
- let item = vec.first().clone().unwrap();
- assert!(ptr::eq(&(**item), &(*listener2)));
- }
-
- #[test]
- fn unregister_single_listener_ref_test() {
- let chanmon_cfgs = create_chanmon_cfgs(2);
- let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
- let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor.clone());
- block_notifier.register_listener(&node_cfgs[0].chan_monitor.simple_monitor as &ChainListener);
- block_notifier.register_listener(&node_cfgs[1].chan_monitor.simple_monitor as &ChainListener);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 2);
- drop(vec);
- block_notifier.unregister_listener(&node_cfgs[0].chan_monitor.simple_monitor);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 1);
- let item = vec.first().clone().unwrap();
- assert!(ptr::eq(&(**item), &(*&node_cfgs[1].chan_monitor.simple_monitor)));
- }
-
- #[test]
- fn unregister_multiple_of_the_same_listeners_test() {
- let chanmon_cfgs = create_chanmon_cfgs(2);
- let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
- let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor.clone());
- let listener1 = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
- let listener2 = &node_cfgs[1].chan_monitor.simple_monitor as &ChainListener;
- block_notifier.register_listener(listener1);
- block_notifier.register_listener(listener1);
- block_notifier.register_listener(listener2);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 3);
- drop(vec);
- block_notifier.unregister_listener(listener1);
- let vec = block_notifier.listeners.lock().unwrap();
- assert_eq!(vec.len(), 1);
- let item = vec.first().clone().unwrap();
- assert!(ptr::eq(&(**item), &(*listener2)));
- }
-}