Split out BroadcastInterface, ChainWatchInterface monitors re-enter from called listeners

Author: tamasblummer

Cargo.toml

@@ -15,7 +15,6 @@ non_bitcoin_chain_hash_routing = []
 
 [dependencies]
 bitcoin = "0.11"
-bitcoin-chain = { git = "https://github.com/rust-bitcoin/rust-bitcoin-chain", branch = "master" }
 rust-crypto = "0.2"
 rand = "0.4"
 secp256k1 = "0.8"

src/chain/bitcoincorerpcchain.rs

@@ -1,8 +1,8 @@
-use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::script::Script;
+use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::util::hash::Sha256dHash;
 
-use chain::chaininterface::{ChainWatchInterface,ChainWatchInterfaceUtil,ChainListener};
+use chain::chaininterface::{ChainWatchInterface,ChainWatchInterfaceUtil,ChainListener, BroadcasterInterface};
 
 use std::sync::Weak;
 
@@ -23,19 +23,29 @@ impl ChainWatchInterface for BitcoinCoreRPCClientChain {
 		self.util.watch_all_txn()
 	}
 
-	fn broadcast_transaction(&self, _tx: &Transaction) {
-		unimplemented!()
-	}
-
 	fn register_listener(&self, listener: Weak<ChainListener>) {
 		self.util.register_listener(listener)
 	}
 }
 
+impl BroadcasterInterface for BitcoinCoreRPCClientChain {
+	fn broadcast_transaction(&self, tx: &Transaction) -> Result<(), Box<Error>> {
+		unimplemented!()
+	}
+}
+
 impl BitcoinCoreRPCClientChain {
 	pub fn new() -> BitcoinCoreRPCClientChain {
 		BitcoinCoreRPCClientChain {
 			util: ChainWatchInterfaceUtil::new(),
 		}
 	}
+
+	pub fn block_connected(&self, block: &Block, height: u32) {
+		self.util.block_connected(block, height)
+	}
+
+	pub fn block_disconnected(&self, header: &BlockHeader) {
+		self.util.block_disconnected(header)
+	}
 }

src/chain/chaininterface.rs

@@ -1,9 +1,10 @@
-use bitcoin::blockdata::block::BlockHeader;
+use std::error::Error;
+use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::script::Script;
 use bitcoin::util::hash::Sha256dHash;
-
-use std::sync::{Weak,Mutex};
+use std::sync::{Mutex,Weak};
+use std::sync::atomic::{AtomicUsize, Ordering};
 
 /// An interface to request notification of certain scripts as they appear the
 /// chain.
@@ -21,13 +22,18 @@ pub trait ChainWatchInterface: Sync + Send {
 	/// Indicates that a listener needs to see all transactions.
 	fn watch_all_txn(&self);
 
-	/// Sends a transaction out to (hopefully) be mined
-	fn broadcast_transaction(&self, tx: &Transaction);
-
 	fn register_listener(&self, listener: Weak<ChainListener>);
 	//TODO: unregister
 }
 
+/// An interface to send a transaction to connected Bitcoin peers.
+/// This is for final settlement. An error might indicate that no peers can be reached or
+/// that peers rejected the transaction.
+pub trait BroadcasterInterface: Sync + Send {
+	/// Sends a transaction out to (hopefully) be mined
+	fn broadcast_transaction(&self, tx: &Transaction) -> Result<(), Box<Error>>;
+}
+
 /// 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.
@@ -54,45 +60,80 @@ pub enum ConfirmationTarget {
 /// called from inside the library in response to ChainListener events, P2P events, or timer
 /// events).
 pub trait FeeEstimator: Sync + Send {
-	fn get_est_sat_per_vbyte(&self, ConfirmationTarget) -> u64;
+	fn get_est_sat_per_vbyte(&self, confirmation_target: ConfirmationTarget) -> u64;
 }
 
 /// 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 {
 	watched: Mutex<(Vec<Script>, Vec<(Sha256dHash, u32)>, bool)>, //TODO: Something clever to optimize this
 	listeners: Mutex<Vec<Weak<ChainListener>>>,
+	reentered: AtomicUsize
 }
 
-impl ChainWatchInterfaceUtil {
-	pub fn new() -> ChainWatchInterfaceUtil {
-		ChainWatchInterfaceUtil {
-			watched: Mutex::new((Vec::new(), Vec::new(), false)),
-			listeners: Mutex::new(Vec::new()),
-		}
-	}
-
-	pub fn install_watch_script(&self, spk: Script) {
+/// Register listener
+impl ChainWatchInterface for ChainWatchInterfaceUtil {
+	fn install_watch_script(&self, script_pub_key: Script) {
 		let mut watched = self.watched.lock().unwrap();
-		watched.0.push(Script::from(spk));
+		watched.0.push(Script::from(script_pub_key));
+		self.reentered.fetch_add(1, Ordering::Relaxed);
 	}
 
-	pub fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32)) {
+	fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32)) {
 		let mut watched = self.watched.lock().unwrap();
 		watched.1.push(outpoint);
+		self.reentered.fetch_add(1, Ordering::Relaxed);
 	}
 
-	pub fn watch_all_txn(&self) { //TODO: refcnt this?
+	fn watch_all_txn(&self) {
 		let mut watched = self.watched.lock().unwrap();
 		watched.2 = true;
+		self.reentered.fetch_add(1, Ordering::Relaxed);
 	}
 
-	pub fn register_listener(&self, listener: Weak<ChainListener>) {
+	fn register_listener(&self, listener: Weak<ChainListener>) {
 		let mut vec = self.listeners.lock().unwrap();
 		vec.push(listener);
 	}
+}
+
+impl ChainWatchInterfaceUtil {
+	pub fn new() -> ChainWatchInterfaceUtil {
+		ChainWatchInterfaceUtil {
+			watched: Mutex::new((Vec::new(), Vec::new(), false)),
+			listeners: Mutex::new(Vec::new()),
+			reentered: AtomicUsize::new(1)
+		}
+	}
+
+	/// notify listener that a block was connected
+	/// notification will repeat if notified listener register new listeners
+	pub fn block_connected(&self, block: &Block, height: u32) {
+		let mut watch = self.reentered.load(Ordering::Relaxed);
+		let mut last_seen = 0;
+		// re-scan if new watch added during previous scan
+		while last_seen != watch {
+			let mut matched = Vec::new();
+			let mut matched_index = Vec::new();
+			for (index, transaction) in block.txdata.iter().enumerate() {
+				if self.does_match_tx(transaction) {
+					matched.push(transaction);
+					matched_index.push(index as u32);
+				}
+			}
+			last_seen = watch;
+			self.do_call_block_connected(&block.header, height, matched.as_slice(), matched_index.as_slice());
+			watch = self.reentered.load(Ordering::Relaxed);
+		}
+	}
+
+	/// notify listener that a block was disconnected
+	pub fn block_disconnected(&self, header: &BlockHeader) {
+		self.do_call_block_disconnected(header);
+	}
 
-	pub fn do_call_block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) {
+	/// call listeners for connected blocks if they are still around
+	fn do_call_block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) {
 		let listeners = self.listeners.lock().unwrap().clone();
 		for listener in listeners.iter() {
 			match listener.upgrade() {
@@ -102,7 +143,8 @@ impl ChainWatchInterfaceUtil {
 		}
 	}
 
-	pub fn do_call_block_disconnected(&self, header: &BlockHeader) {
+	/// call listeners for disconnected blocks if they are still around
+	fn do_call_block_disconnected(&self, header: &BlockHeader) {
 		let listeners = self.listeners.lock().unwrap().clone();
 		for listener in listeners.iter() {
 			match listener.upgrade() {
@@ -113,7 +155,7 @@ impl ChainWatchInterfaceUtil {
 	}
 
 	/// Checks if a given transaction matches the current filter
-	pub fn does_match_tx(&self, tx: &Transaction) -> bool {
+	fn does_match_tx(&self, tx: &Transaction) -> bool {
 		let watched = self.watched.lock().unwrap();
 		if watched.2 {
 			return true;

src/chain/mod.rs

@@ -1,3 +1,2 @@
 pub mod chaininterface;
 pub mod bitcoincorerpcchain;
-pub mod rustbitcoinchain;

src/chain/rustbitcoinchain.rs

@@ -1,7 +1,6 @@
 #![crate_name = "lightning"]
 
 extern crate bitcoin;
-extern crate bitcoin_chain;
 extern crate secp256k1;
 extern crate rand;
 extern crate crypto;

src/lib.rs

@@ -13,7 +13,7 @@ use secp256k1::key::{SecretKey,PublicKey};
 use ln::msgs::HandleError;
 use ln::chan_utils;
 use ln::chan_utils::HTLCOutputInCommitment;
-use chain::chaininterface::{ChainListener,ChainWatchInterface};
+use chain::chaininterface::{ChainListener, ChainWatchInterface, BroadcasterInterface};
 
 use std::collections::HashMap;
 use std::sync::{Arc,Mutex};
@@ -39,24 +39,26 @@ pub trait ManyChannelMonitor: Send + Sync {
 pub struct SimpleManyChannelMonitor<Key> {
 	monitors: Mutex<HashMap<Key, ChannelMonitor>>,
 	chain_monitor: Arc<ChainWatchInterface>,
+	broadcaster: Arc<BroadcasterInterface>
 }
 
 impl<Key : Send + cmp::Eq + hash::Hash> ChainListener for SimpleManyChannelMonitor<Key> {
 	fn block_connected(&self, _header: &BlockHeader, height: u32, txn_matched: &[&Transaction], _indexes_of_txn_matched: &[u32]) {
 		let monitors = self.monitors.lock().unwrap();
 		for monitor in monitors.values() {
-			monitor.block_connected(txn_matched, height, &*self.chain_monitor);
+			monitor.block_connected(txn_matched, height, &*self.broadcaster);
 		}
 	}
 
 	fn block_disconnected(&self, _: &BlockHeader) { }
 }
 
 impl<Key : Send + cmp::Eq + hash::Hash + 'static> SimpleManyChannelMonitor<Key> {
-	pub fn new(chain_monitor: Arc<ChainWatchInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
+	pub fn new(chain_monitor: Arc<ChainWatchInterface>, broadcaster: Arc<BroadcasterInterface>) -> Arc<SimpleManyChannelMonitor<Key>> {
 		let res = Arc::new(SimpleManyChannelMonitor {
 			monitors: Mutex::new(HashMap::new()),
-			chain_monitor: chain_monitor,
+			chain_monitor,
+			broadcaster
 		});
 		let weak_res = Arc::downgrade(&res);
 		res.chain_monitor.register_listener(weak_res);
@@ -443,7 +445,7 @@ impl ChannelMonitor {
 		txn_to_broadcast
 	}
 
-	fn block_connected(&self, txn_matched: &[&Transaction], height: u32, chain_monitor: &ChainWatchInterface) {
+	fn block_connected(&self, txn_matched: &[&Transaction], height: u32, broadcaster: &BroadcasterInterface) {
 		for tx in txn_matched {
 			if tx.input.len() != 1 {
 				// We currently only ever sign something spending a commitment or HTLC
@@ -454,7 +456,7 @@ impl ChannelMonitor {
 			for txin in tx.input.iter() {
 				if self.funding_txo.is_none() || (txin.prev_hash == self.funding_txo.unwrap().0 && txin.prev_index == self.funding_txo.unwrap().1 as u32) {
 					for tx in self.check_spend_transaction(tx, height).iter() {
-						chain_monitor.broadcast_transaction(tx);
+						broadcaster.broadcast_transaction(tx); // TODO: use result
 					}
 				}
 			}