X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=aa69d8596f63efd15c09011fc50c5af8795c74a2;hb=bc4f4631ccda9045a0f3ec884109de49f3a0db12;hp=644c3214aca9f464d4a99a628ea6cba072c2f0ba;hpb=22a0dd5f339058fd6733920ffca0f5eb64db4e32;p=rust-lightning diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs index 644c3214..aa69d859 100644 --- a/lightning/src/chain/chaininterface.rs +++ b/lightning/src/chain/chaininterface.rs @@ -16,62 +16,14 @@ use bitcoin::blockdata::block::{Block, BlockHeader}; use bitcoin::blockdata::transaction::Transaction; use bitcoin::blockdata::script::Script; -use bitcoin::blockdata::constants::genesis_block; -use bitcoin::util::hash::BitcoinHash; -use bitcoin::network::constants::Network; -use bitcoin::hash_types::{Txid, BlockHash}; +use bitcoin::hash_types::Txid; -use std::sync::{Mutex, MutexGuard, Arc}; -use std::sync::atomic::{AtomicUsize, Ordering}; +use std::sync::{Mutex, Arc}; 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, - /// Chain isn't the one watched - NotWatched, - /// Tx doesn't exist or is unconfirmed - UnknownTx, -} - -/// An interface to request notification of certain scripts as they appear the -/// chain. -/// -/// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're -/// called from inside the library in response to ChainListener events, P2P events, or timer -/// 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: &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: (Txid, u32), out_script: &Script); - - /// Indicates that a listener needs to see all transactions. - fn watch_all_txn(&self); - - /// 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: BlockHash, unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError>; - - /// Gets the list of transaction indices within a given block that the ChainWatchInterface is - /// watching for. - fn filter_block(&self, block: &Block) -> 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. pub trait BroadcasterInterface: Sync + Send { /// Sends a transaction out to (hopefully) be mined. @@ -80,22 +32,10 @@ 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. - /// - /// 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: &[usize]); + /// Notifies a listener that a block was connected. Transactions may be filtered and are given + /// paired with their position within the block. + fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32); + /// 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) @@ -227,7 +167,9 @@ impl ChainWatchedUtil { /// 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, C>>; +/// +/// (C-not exported) as we let clients handle any reference counting they need to do +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 @@ -236,27 +178,26 @@ pub type BlockNotifierArc = Arc, C> /// 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>; +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. +/// Utility for notifying listeners when blocks are connected or disconnected. /// /// 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 C::Target: ChainWatchInterface { +pub struct BlockNotifier<'a, CL: Deref + 'a> + where CL::Target: ChainListener + 'a { listeners: Mutex>, - chain_monitor: C, phantom: PhantomData<&'a ()>, } -impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a, CL, C> where C::Target: ChainWatchInterface { +impl<'a, CL: Deref + 'a> BlockNotifier<'a, CL> + where CL::Target: ChainListener + 'a { /// Constructs a new BlockNotifier without any listeners. - pub fn new(chain_monitor: C) -> BlockNotifier<'a, CL, C> { + pub fn new() -> BlockNotifier<'a, CL> { BlockNotifier { listeners: Mutex::new(Vec::new()), - chain_monitor, phantom: PhantomData, } } @@ -272,6 +213,8 @@ impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a /// 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. + /// + /// (C-not exported) because the equality check would always fail 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, @@ -279,36 +222,13 @@ impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a 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). + /// Notify listeners that a block was connected. pub fn block_connected(&self, block: &Block, height: u32) { - let mut reentered = true; - while reentered { - 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()); - } - } - - /// 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: &[usize]) -> bool { - let last_seen = self.chain_monitor.reentered(); - + let txdata: Vec<_> = block.txdata.iter().enumerate().collect(); let listeners = self.listeners.lock().unwrap(); for listener in listeners.iter() { - listener.block_connected(header, height, txn_matched, indexes_of_txn_matched); + listener.block_connected(&block.header, &txdata, height); } - return last_seen != self.chain_monitor.reentered(); } /// Notify listeners that a block was disconnected. @@ -320,168 +240,64 @@ impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a } } -/// 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, - reentered: AtomicUsize, -} - -// 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: &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: (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 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: 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) - } - - fn filter_block(&self, block: &Block) -> Vec { - 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_index.push(index); - } - } - } - 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) -> ChainWatchInterfaceUtil { - ChainWatchInterfaceUtil { - network, - watched: Mutex::new(ChainWatchedUtil::new()), - reentered: AtomicUsize::new(1), - } - } - - /// 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) -> bool { - watched.does_match_tx(tx) - } -} - #[cfg(test)] mod tests { - use ln::functional_test_utils::{create_chanmon_cfgs, create_node_cfgs}; + use bitcoin::blockdata::block::BlockHeader; + use bitcoin::blockdata::transaction::Transaction; use super::{BlockNotifier, ChainListener}; use std::ptr; + struct TestChainListener(u8); + + impl ChainListener for TestChainListener { + fn block_connected(&self, _header: &BlockHeader, _txdata: &[(usize, &Transaction)], _height: u32) {} + fn block_disconnected(&self, _header: &BlockHeader, _disconnected_height: u32) {} + } + #[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); + let block_notifier = BlockNotifier::new(); 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 listener = &TestChainListener(0); + block_notifier.register_listener(listener as &ChainListener); let vec = block_notifier.listeners.lock().unwrap(); assert_eq!(vec.len(), 1); - let item = vec.first().clone().unwrap(); - assert!(ptr::eq(&(**item), &(*listener))); + let item = vec.first().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 block_notifier = BlockNotifier::new(); + let listener1 = &TestChainListener(1); + let listener2 = &TestChainListener(2); + block_notifier.register_listener(listener1 as &ChainListener); + block_notifier.register_listener(listener2 as &ChainListener); 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))); + let item = vec.first().unwrap(); + assert!(ptr::eq(&(**item), listener2)); } #[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 block_notifier = BlockNotifier::new(); + let listener1 = &TestChainListener(1); + let listener2 = &TestChainListener(2); + block_notifier.register_listener(listener1 as &ChainListener); + block_notifier.register_listener(listener1 as &ChainListener); + block_notifier.register_listener(listener2 as &ChainListener); 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))); + let item = vec.first().unwrap(); + assert!(ptr::eq(&(**item), listener2)); } }