X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=f497236552844c65d2039a6847d52a4bc6571364;hb=4909d3cd6a05dfcba39fe08e6d8f539944c8ef66;hp=32fef48eb44a54acaa7a576502ad1e0f1e56311d;hpb=969f8630133d8f53050d7ad48ca7a1450ebae08b;p=rust-lightning diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs index 32fef48e..f4972365 100644 --- a/lightning/src/chain/chaininterface.rs +++ b/lightning/src/chain/chaininterface.rs @@ -9,16 +9,20 @@ use bitcoin::blockdata::transaction::Transaction; use bitcoin::blockdata::script::Script; use bitcoin::blockdata::constants::genesis_block; use bitcoin::util::hash::BitcoinHash; -use bitcoin_hashes::sha256d::Hash as Sha256dHash; +use bitcoin::hashes::sha256d::Hash as Sha256dHash; use bitcoin::network::constants::Network; use util::logger::Logger; -use std::sync::{Mutex,Weak,MutexGuard,Arc}; +use std::sync::{Mutex, MutexGuard, Arc}; use std::sync::atomic::{AtomicUsize, Ordering}; use std::collections::HashSet; +use std::ops::Deref; +use std::marker::PhantomData; +use std::ptr; /// Used to give chain error details upstream +#[derive(Clone)] pub enum ChainError { /// Client doesn't support UTXO lookup (but the chain hash matches our genesis block hash) NotSupported, @@ -50,6 +54,15 @@ pub trait ChainWatchInterface: Sync + Send { /// bytes are the block height, the next 3 the transaction index within the block, and the /// final two the output within the transaction. fn get_chain_utxo(&self, genesis_hash: Sha256dHash, unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError>; + + /// Gets the list of transactions and transaction indices that the ChainWatchInterface is + /// watching for. + fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec); + + /// Returns a usize that changes when the ChainWatchInterface's watched data is modified. + /// Users of `filter_block` should pre-save a copy of `reentered`'s return value and use it to + /// determine whether they need to re-filter a given block. + fn reentered(&self) -> usize; } /// An interface to send a transaction to the Bitcoin network. @@ -61,11 +74,16 @@ pub trait BroadcasterInterface: Sync + Send { /// A trait indicating a desire to listen for events from the chain pub trait ChainListener: Sync + Send { /// Notifies a listener that a block was connected. - /// Note that if a new transaction/outpoint is watched during a block_connected call, the block - /// *must* be re-scanned with the new transaction/outpoints and block_connected should be - /// called again with the same header and (at least) the new transactions. /// - /// Note that if non-new transaction/outpoints may be registered during a call, a second call + /// The txn_matched array should be set to references to transactions which matched the + /// relevant installed watch outpoints/txn, or the full set of transactions in the block. + /// + /// Note that if txn_matched includes only matched transactions, and a new + /// transaction/outpoint is watched during a block_connected call, the block *must* be + /// re-scanned with the new transaction/outpoints and block_connected should be called + /// again with the same header and (at least) the new transactions. + /// + /// Note that if non-new transaction/outpoints are be registered during a call, a second call /// *must not* happen. /// /// This also means those counting confirmations using block_connected callbacks should watch @@ -106,7 +124,11 @@ pub trait FeeEstimator: Sync + Send { fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u64; } +/// Minimum relay fee as required by bitcoin network mempool policy. +pub const MIN_RELAY_FEE_SAT_PER_1000_WEIGHT: u64 = 4000; + /// Utility for tracking registered txn/outpoints and checking for matches +#[cfg_attr(test, derive(PartialEq))] pub struct ChainWatchedUtil { watch_all: bool, @@ -193,29 +215,62 @@ impl ChainWatchedUtil { } } +/// 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>>; + +/// 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. -pub struct BlockNotifier<'a> { - listeners: Mutex>>, //TODO(vmw): try removing Weak +/// +/// 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 + 'a> { + listeners: Mutex>, chain_monitor: Arc, + phantom: PhantomData<&'a ()>, } -impl<'a> BlockNotifier<'a> { +impl<'a, CL: Deref + 'a> BlockNotifier<'a, CL> { /// Constructs a new BlockNotifier without any listeners. - pub fn new(chain_monitor: Arc) -> BlockNotifier<'a> { + pub fn new(chain_monitor: Arc) -> BlockNotifier<'a, CL> { BlockNotifier { listeners: Mutex::new(Vec::new()), chain_monitor, + phantom: PhantomData, } } - /// Register the given listener to receive events. Only a weak pointer is provided and - /// the registration should be freed once that pointer expires. - // TODO: unregister - pub fn register_listener(&self, listener: Weak) { + /// 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. /// @@ -238,28 +293,20 @@ impl<'a> BlockNotifier<'a> { 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().clone(); + let listeners = self.listeners.lock().unwrap(); for listener in listeners.iter() { - match listener.upgrade() { - Some(arc) => arc.block_connected(header, height, txn_matched, indexes_of_txn_matched), - None => () - } + 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().clone(); + let listeners = self.listeners.lock().unwrap(); for listener in listeners.iter() { - match listener.upgrade() { - Some(arc) => arc.block_disconnected(&header, disconnected_height), - None => () - } + listener.block_disconnected(&header, disconnected_height); } } - } /// Utility to capture some common parts of ChainWatchInterface implementors. @@ -272,6 +319,17 @@ pub struct ChainWatchInterfaceUtil { logger: Arc, } +// 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) { @@ -301,6 +359,25 @@ impl ChainWatchInterface for ChainWatchInterfaceUtil { } Err(ChainError::NotSupported) } + + fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec) { + 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 { @@ -314,7 +391,6 @@ impl ChainWatchInterfaceUtil { } } - /// Checks if a given transaction matches the current filter. pub fn does_match_tx(&self, tx: &Transaction) -> bool { let watched = self.watched.lock().unwrap(); @@ -325,3 +401,80 @@ impl ChainWatchInterfaceUtil { 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))); + } +}