X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=c187d2f8b055d3c0962276e6a50845a161b0a672;hb=87126b391b895098484a86dc484a381b825e9a31;hp=c0330fb2963ea868d753c16dd633d5cbbd8890c9;hpb=53052234959a3c0a7323a194c351c4ba9b46339b;p=rust-lightning

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index c0330fb2..c187d2f8 100644
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -9,16 +9,18 @@ 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::network::constants::Network;
+use bitcoin::hash_types::{Txid, BlockHash};
 
-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,
@@ -36,25 +38,29 @@ pub enum ChainError {
 /// events).
 pub trait ChainWatchInterface: Sync + Send {
 	/// Provides a txid/random-scriptPubKey-in-the-tx which much be watched for.
-	fn install_watch_tx(&self, txid: &Sha256dHash, script_pub_key: &Script);
+	fn install_watch_tx(&self, txid: &Txid, script_pub_key: &Script);
 
 	/// Provides an outpoint which must be watched for, providing any transactions which spend the
 	/// given outpoint.
-	fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32), out_script: &Script);
+	fn install_watch_outpoint(&self, outpoint: (Txid, u32), out_script: &Script);
 
 	/// Indicates that a listener needs to see all transactions.
 	fn watch_all_txn(&self);
 
-	/// Register the given listener to receive events. Only a weak pointer is provided and the
-	/// registration should be freed once that pointer expires.
-	fn register_listener(&self, listener: Weak<ChainListener>);
-	//TODO: unregister
-
 	/// Gets the script and value in satoshis for a given unspent transaction output given a
 	/// short_channel_id (aka unspent_tx_output_identier). For BTC/tBTC channels the top three
 	/// 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>;
+	fn get_chain_utxo(&self, genesis_hash: BlockHash, 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<u32>);
+
+	/// 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.
@@ -66,11 +72,16 @@ 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
@@ -111,18 +122,22 @@ 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,
 
 	// We are more conservative in matching during testing to ensure everything matches *exactly*,
 	// even though during normal runtime we take more optimized match approaches...
 	#[cfg(test)]
-	watched_txn: HashSet<(Sha256dHash, Script)>,
+	watched_txn: HashSet<(Txid, Script)>,
 	#[cfg(not(test))]
 	watched_txn: HashSet<Script>,
 
-	watched_outpoints: HashSet<(Sha256dHash, u32)>,
+	watched_outpoints: HashSet<(Txid, u32)>,
 }
 
 impl ChainWatchedUtil {
@@ -137,7 +152,7 @@ impl ChainWatchedUtil {
 
 	/// Registers a tx for monitoring, returning true if it was a new tx and false if we'd already
 	/// been watching for it.
-	pub fn register_tx(&mut self, txid: &Sha256dHash, script_pub_key: &Script) -> bool {
+	pub fn register_tx(&mut self, txid: &Txid, script_pub_key: &Script) -> bool {
 		if self.watch_all { return false; }
 		#[cfg(test)]
 		{
@@ -152,7 +167,7 @@ impl ChainWatchedUtil {
 
 	/// Registers an outpoint for monitoring, returning true if it was a new outpoint and false if
 	/// we'd already been watching for it
-	pub fn register_outpoint(&mut self, outpoint: (Sha256dHash, u32), _script_pub_key: &Script) -> bool {
+	pub fn register_outpoint(&mut self, outpoint: (Txid, u32), _script_pub_key: &Script) -> bool {
 		if self.watch_all { return false; }
 		self.watched_outpoints.insert(outpoint)
 	}
@@ -198,27 +213,130 @@ 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<C> = Arc<BlockNotifier<'static, Arc<ChainListener>, C>>;
+
+/// 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, C> = BlockNotifier<'a, &'a ChainListener, C>;
+
+/// 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, C: Deref> where C::Target: ChainWatchInterface {
+	listeners: Mutex<Vec<CL>>,
+	chain_monitor: C,
+	phantom: PhantomData<&'a ()>,
+}
+
+impl<'a, CL: Deref<Target = ChainListener + 'a> + 'a, C: Deref> BlockNotifier<'a, CL, C> where C::Target: ChainWatchInterface {
+	/// Constructs a new BlockNotifier without any listeners.
+	pub fn new(chain_monitor: C) -> BlockNotifier<'a, CL, C> {
+		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>,
-	listeners: Mutex<Vec<Weak<ChainListener>>>,
 	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) {
+	fn install_watch_tx(&self, txid: &Txid, 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) {
+	fn install_watch_outpoint(&self, outpoint: (Txid, 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);
@@ -232,81 +350,41 @@ impl ChainWatchInterface for ChainWatchInterfaceUtil {
 		}
 	}
 
-	fn register_listener(&self, listener: Weak<ChainListener>) {
-		let mut vec = self.listeners.lock().unwrap();
-		vec.push(listener);
-	}
-
-	fn get_chain_utxo(&self, genesis_hash: Sha256dHash, _unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError> {
+	fn get_chain_utxo(&self, genesis_hash: BlockHash, _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)
 	}
-}
-
-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()),
-			listeners: Mutex::new(Vec::new()),
-			reentered: AtomicUsize::new(1),
-			logger: logger,
-		}
-	}
 
-	/// 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_with_filtering(&self, block: &Block, height: u32) {
-		let mut reentered = true;
-		while reentered {
-			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);
-					}
+	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);
 				}
 			}
-			reentered = self.block_connected_checked(&block.header, height, matched.as_slice(), matched_index.as_slice());
 		}
+		(matched, matched_index)
 	}
 
-	/// Notify listeners that a block was disconnected.
-	pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
-		let listeners = self.listeners.lock().unwrap().clone();
-		for listener in listeners.iter() {
-			match listener.upgrade() {
-				Some(arc) => arc.block_disconnected(&header, disconnected_height),
-				None => ()
-			}
-		}
+	fn reentered(&self) -> usize {
+		self.reentered.load(Ordering::Relaxed)
 	}
+}
 
-	/// 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.reentered.load(Ordering::Relaxed);
-
-		let listeners = self.listeners.lock().unwrap().clone();
-		for listener in listeners.iter() {
-			match listener.upgrade() {
-				Some(arc) => arc.block_connected(header, height, txn_matched, indexes_of_txn_matched),
-				None => ()
-			}
+impl ChainWatchInterfaceUtil {
+	/// Creates a new ChainWatchInterfaceUtil for the given network
+	pub fn new(network: Network) -> ChainWatchInterfaceUtil {
+		ChainWatchInterfaceUtil {
+			network,
+			watched: Mutex::new(ChainWatchedUtil::new()),
+			reentered: AtomicUsize::new(1),
 		}
-		return last_seen != self.reentered.load(Ordering::Relaxed);
 	}
 
 	/// Checks if a given transaction matches the current filter.
@@ -319,3 +397,80 @@ 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);
+		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);
+		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);
+		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);
+		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)));
+	}
+}