+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
//! Traits and utility impls which allow other parts of rust-lightning to interact with the
//! blockchain.
//!
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,
/// 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);
/// 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
+ /// Gets the list of transaction indices within a given block that the ChainWatchInterface is
/// watching for.
- fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec<u32>);
+ fn filter_block(&self, block: &Block) -> Vec<usize>;
/// 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
/// 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
/// for duplicate headers and not count them towards confirmations!
- fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]);
+ fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[usize]);
/// Notifies a listener that a block was disconnected.
/// Unlike block_connected, this *must* never be called twice for the same disconnect event.
/// Height must be the one of the block which was disconnected (not new height of the best chain)
/// This translates to:
/// * satoshis-per-byte * 250
/// * ceil(satoshis-per-kbyte / 4)
- fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u64;
+ fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32;
}
/// 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 {
/// 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)]
{
/// 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)
}
}
}
+/// 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.
-pub struct BlockNotifier<'a> {
- listeners: Mutex<Vec<Weak<ChainListener + 'a>>>, //TODO(vmw): try removing Weak
- chain_monitor: Arc<ChainWatchInterface>,
+///
+/// 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, C: Deref>
+ where CL::Target: ChainListener + 'a, C::Target: ChainWatchInterface {
+ listeners: Mutex<Vec<CL>>,
+ chain_monitor: C,
+ phantom: PhantomData<&'a ()>,
}
-impl<'a> BlockNotifier<'a> {
+impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a, CL, C>
+ where CL::Target: ChainListener + 'a, C::Target: ChainWatchInterface {
/// Constructs a new BlockNotifier without any listeners.
- pub fn new(chain_monitor: Arc<ChainWatchInterface>) -> BlockNotifier<'a> {
+ 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. 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<ChainListener + 'a>) {
+ /// 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) {
+ pub fn block_connected(&self, block: &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());
+ let matched_indexes = self.chain_monitor.filter_block(block);
+ let mut matched_txn = Vec::new();
+ for index in matched_indexes.iter() {
+ matched_txn.push(&block.txdata[*index]);
+ }
+ reentered = self.block_connected_checked(&block.header, height, matched_txn.as_slice(), matched_indexes.as_slice());
}
}
/// 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 {
+ pub fn block_connected_checked(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[usize]) -> 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.
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) {
+ 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);
}
}
- 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() {
+ 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.block_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();
+ fn filter_block(&self, block: &Block) -> Vec<usize> {
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_index.push(index);
}
}
}
- (matched, matched_index)
+ matched_index
}
fn reentered(&self) -> usize {
impl ChainWatchInterfaceUtil {
/// Creates a new ChainWatchInterfaceUtil for the given network
- pub fn new(network: Network, logger: Arc<Logger>) -> ChainWatchInterfaceUtil {
+ pub fn new(network: Network) -> ChainWatchInterfaceUtil {
ChainWatchInterfaceUtil {
- network: 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();
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)));
+ }
+}
projects / rust-lightning / blobdiff