X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fchain%2Fchaininterface.rs;h=7b5e0d0749832a7cf2ffcfcd560156d085fd53f7;hb=4d77e9d75216d84795bfbaf6a9b41f94637fac1c;hp=78a40099c35d69687962d33c88b058c06399e6ba;hpb=07ac327f8be0401235ca85baaef5486b629bfd6a;p=rust-lightning

diff --git a/src/chain/chaininterface.rs b/src/chain/chaininterface.rs
index 78a40099..7b5e0d07 100644
--- a/src/chain/chaininterface.rs
+++ b/src/chain/chaininterface.rs
@@ -1,13 +1,21 @@
+//! Traits and utility impls which allow other parts of rust-lightning to interact with the
+//! blockchain.
+//!
+//! Includes traits for monitoring and receiving notifications of new blocks and block
+//! disconnections, transactio broadcasting, and feerate information requests.
+
 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::Sha256dHash;
+use bitcoin::util::hash::{BitcoinHash, Sha256dHash};
 use bitcoin::network::constants::Network;
-use bitcoin::network::serialize::BitcoinHash;
+
 use util::logger::Logger;
+
 use std::sync::{Mutex,Weak,MutexGuard,Arc};
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::collections::HashSet;
 
 /// Used to give chain error details upstream
 pub enum ChainError {
@@ -21,12 +29,13 @@ pub enum ChainError {
 
 /// 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 scriptPubKey which much be watched for.
-	fn install_watch_script(&self, script_pub_key: &Script);
+	/// Provides a txid/random-scriptPubKey-in-the-tx which much be watched for.
+	fn install_watch_tx(&self, txid: &Sha256dHash, script_pub_key: &Script);
 
 	/// Provides an outpoint which must be watched for, providing any transactions which spend the
 	/// given outpoint.
@@ -35,6 +44,8 @@ pub trait ChainWatchInterface: Sync + Send {
 	/// 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
 
@@ -54,9 +65,13 @@ 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 script/transaction is watched during a block_connected call, the block
-	/// *must* be re-scanned with the new script/transaction and block_connected should be called
-	/// again with the same header and (at least) the new transactions.
+	/// 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
+	/// *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]);
@@ -65,31 +80,128 @@ pub trait ChainListener: Sync + Send {
 	fn block_disconnected(&self, header: &BlockHeader);
 }
 
+/// An enum that represents the speed at which we want a transaction to confirm used for feerate
+/// estimation.
 pub enum ConfirmationTarget {
+	/// We are happy with this transaction confirming slowly when feerate drops some.
 	Background,
+	/// We'd like this transaction to confirm without major delay, but 12-18 blocks is fine.
 	Normal,
+	/// We'd like this transaction to confirm in the next few blocks.
 	HighPriority,
 }
 
 /// A trait which should be implemented to provide feerate information on a number of time
 /// horizons.
+///
 /// 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 FeeEstimator: Sync + Send {
-	/// Gets estimated satoshis of fee required per 1000 Weight-Units. This translates to:
-	///  * satoshis-per-byte * 250
-	///  * ceil(satoshis-per-kbyte / 4)
+	/// Gets estimated satoshis of fee required per 1000 Weight-Units.
+	///
 	/// Must be no smaller than 253 (ie 1 satoshi-per-byte rounded up to ensure later round-downs
 	/// don't put us below 1 satoshi-per-byte).
+	///
+	/// This translates to:
+	///  * satoshis-per-byte * 250
+	///  * ceil(satoshis-per-kbyte / 4)
 	fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u64;
 }
 
+/// Utility for tracking registered txn/outpoints and checking for matches
+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)>,
+	#[cfg(not(test))]
+	watched_txn: HashSet<Script>,
+
+	watched_outpoints: HashSet<(Sha256dHash, u32)>,
+}
+
+impl ChainWatchedUtil {
+	/// Constructs an empty (watches nothing) ChainWatchedUtil
+	pub fn new() -> Self {
+		Self {
+			watch_all: false,
+			watched_txn: HashSet::new(),
+			watched_outpoints: HashSet::new(),
+		}
+	}
+
+	/// 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 {
+		if self.watch_all { return false; }
+		#[cfg(test)]
+		{
+			self.watched_txn.insert((txid.clone(), script_pub_key.clone()))
+		}
+		#[cfg(not(test))]
+		{
+			let _tx_unused = txid; // Its used in cfg(test), though
+			self.watched_txn.insert(script_pub_key.clone())
+		}
+	}
+
+	/// 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 {
+		if self.watch_all { return false; }
+		self.watched_outpoints.insert(outpoint)
+	}
+
+	/// Sets us to match all transactions, returning true if this is a new setting anf false if
+	/// we'd already been set to match everything.
+	pub fn watch_all(&mut self) -> bool {
+		if self.watch_all { return false; }
+		self.watch_all = true;
+		true
+	}
+
+	/// Checks if a given transaction matches the current filter.
+	pub fn does_match_tx(&self, tx: &Transaction) -> bool {
+		if self.watch_all {
+			return true;
+		}
+		for out in tx.output.iter() {
+			#[cfg(test)]
+			for &(ref txid, ref script) in self.watched_txn.iter() {
+				if *script == out.script_pubkey {
+					if tx.txid() == *txid {
+						return true;
+					}
+				}
+			}
+			#[cfg(not(test))]
+			for script in self.watched_txn.iter() {
+				if *script == out.script_pubkey {
+					return true;
+				}
+			}
+		}
+		for input in tx.input.iter() {
+			for outpoint in self.watched_outpoints.iter() {
+				let &(outpoint_hash, outpoint_index) = outpoint;
+				if outpoint_hash == input.previous_output.txid && outpoint_index == input.previous_output.vout {
+					return true;
+				}
+			}
+		}
+		false
+	}
+}
+
 /// 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<(Vec<Script>, Vec<(Sha256dHash, u32)>, bool)>, //TODO: Something clever to optimize this
+	watched: Mutex<ChainWatchedUtil>,
 	listeners: Mutex<Vec<Weak<ChainListener>>>,
 	reentered: AtomicUsize,
 	logger: Arc<Logger>,
@@ -97,22 +209,25 @@ pub struct ChainWatchInterfaceUtil {
 
 /// Register listener
 impl ChainWatchInterface for ChainWatchInterfaceUtil {
-	fn install_watch_script(&self, script_pub_key: &Script) {
+	fn install_watch_tx(&self, txid: &Sha256dHash, script_pub_key: &Script) {
 		let mut watched = self.watched.lock().unwrap();
-		watched.0.push(script_pub_key.clone());
-		self.reentered.fetch_add(1, Ordering::Relaxed);
+		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: (Sha256dHash, u32), out_script: &Script) {
 		let mut watched = self.watched.lock().unwrap();
-		watched.1.push(outpoint);
-		self.reentered.fetch_add(1, Ordering::Relaxed);
+		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();
-		watched.2 = true;
-		self.reentered.fetch_add(1, Ordering::Relaxed);
+		if watched.watch_all() {
+			self.reentered.fetch_add(1, Ordering::Relaxed);
+		}
 	}
 
 	fn register_listener(&self, listener: Weak<ChainListener>) {
@@ -129,10 +244,11 @@ impl ChainWatchInterface for ChainWatchInterfaceUtil {
 }
 
 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((Vec::new(), Vec::new(), false)),
+			watched: Mutex::new(ChainWatchedUtil::new()),
 			listeners: Mutex::new(Vec::new()),
 			reentered: AtomicUsize::new(1),
 			logger: logger,
@@ -140,6 +256,7 @@ impl ChainWatchInterfaceUtil {
 	}
 
 	/// 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) {
@@ -173,6 +290,7 @@ impl ChainWatchInterfaceUtil {
 
 	/// 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).
@@ -195,25 +313,7 @@ impl ChainWatchInterfaceUtil {
 		self.does_match_tx_unguarded (tx, &watched)
 	}
 
-	fn does_match_tx_unguarded(&self, tx: &Transaction, watched: &MutexGuard<(Vec<Script>, Vec<(Sha256dHash, u32)>, bool)>) -> bool {
-		if watched.2 {
-			return true;
-		}
-		for out in tx.output.iter() {
-			for script in watched.0.iter() {
-				if script[..] == out.script_pubkey[..] {
-					return true;
-				}
-			}
-		}
-		for input in tx.input.iter() {
-			for outpoint in watched.1.iter() {
-				let &(outpoint_hash, outpoint_index) = outpoint;
-				if outpoint_hash == input.previous_output.txid && outpoint_index == input.previous_output.vout {
-					return true;
-				}
-			}
-		}
-		false
+	fn does_match_tx_unguarded(&self, tx: &Transaction, watched: &MutexGuard<ChainWatchedUtil>) -> bool {
+		watched.does_match_tx(tx)
 	}
 }