X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fchain%2Fchaininterface.rs;h=ef09cbbaaa0f79eb89942860608a315772ef88f3;hb=ab10b050754e4e51b57cd87da8ff588d36565dd0;hp=ad298ce94db35eb4a29bec7c11fc884e6a8cf8af;hpb=4e05b107a3a42a770efb422b15f6cc4e49de2eac;p=rust-lightning

diff --git a/src/chain/chaininterface.rs b/src/chain/chaininterface.rs
index ad298ce9..ef09cbba 100644
--- a/src/chain/chaininterface.rs
+++ b/src/chain/chaininterface.rs
@@ -1,39 +1,77 @@
-use bitcoin::blockdata::block::BlockHeader;
+//! 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, transaction broadcasting, and feerate information requests.
+
+use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::script::Script;
-use bitcoin::util::hash::Sha256dHash;
+use bitcoin::blockdata::constants::genesis_block;
+use bitcoin::util::hash::{BitcoinHash, Sha256dHash};
+use bitcoin::network::constants::Network;
+
+use util::logger::Logger;
+
+use std::sync::{Mutex,Weak,MutexGuard,Arc};
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::collections::HashSet;
 
-use std::sync::{Weak,Mutex};
+/// Used to give chain error details upstream
+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 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.
-	fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32));
+	fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32), out_script: &Script);
 
 	/// 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);
-
+	/// 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>;
+}
+
+/// An interface to send a transaction to the Bitcoin network.
+pub trait BroadcasterInterface: Sync + Send {
+	/// Sends a transaction out to (hopefully) be mined.
+	fn broadcast_transaction(&self, tx: &Transaction);
 }
 
 /// 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]);
@@ -42,97 +80,240 @@ 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 {
-	fn get_est_sat_per_vbyte(&self, ConfirmationTarget) -> u64;
+	/// 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; // It's 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 and 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 {
-	watched: Mutex<(Vec<Script>, Vec<(Sha256dHash, u32)>, bool)>, //TODO: Something clever to optimize this
+	network: Network,
+	watched: Mutex<ChainWatchedUtil>,
 	listeners: Mutex<Vec<Weak<ChainListener>>>,
+	reentered: AtomicUsize,
+	logger: Arc<Logger>,
 }
 
-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_tx(&self, txid: &Sha256dHash, script_pub_key: &Script) {
 		let mut watched = self.watched.lock().unwrap();
-		watched.0.push(Script::from(spk));
+		if watched.register_tx(txid, 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), out_script: &Script) {
 		let mut watched = self.watched.lock().unwrap();
-		watched.1.push(outpoint);
+		if watched.register_outpoint(outpoint, out_script) {
+			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;
+		if watched.watch_all() {
+			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);
 	}
 
-	pub fn do_call_block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) {
+	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() {
+			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);
+					}
+				}
+			}
+			reentered = self.block_connected_checked(&block.header, height, matched.as_slice(), matched_index.as_slice());
+		}
+	}
+
+	/// Notify listeners that a block was disconnected.
+	pub fn block_disconnected(&self, header: &BlockHeader) {
 		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),
+				Some(arc) => arc.block_disconnected(header),
 				None => ()
 			}
 		}
 	}
 
-	pub fn do_call_block_disconnected(&self, header: &BlockHeader) {
+	/// 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_disconnected(header),
+				Some(arc) => arc.block_connected(header, height, txn_matched, indexes_of_txn_matched),
 				None => ()
 			}
 		}
+		return last_seen != self.reentered.load(Ordering::Relaxed);
 	}
 
-	/// Checks if a given transaction matches the current filter
+	/// Checks if a given transaction matches the current filter.
 	pub fn does_match_tx(&self, tx: &Transaction) -> bool {
 		let watched = self.watched.lock().unwrap();
-		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.prev_hash && outpoint_index == input.prev_index {
-					return true;
-				}
-			}
-		}
-		false
+		self.does_match_tx_unguarded (tx, &watched)
+	}
+
+	fn does_match_tx_unguarded(&self, tx: &Transaction, watched: &MutexGuard<ChainWatchedUtil>) -> bool {
+		watched.does_match_tx(tx)
 	}
 }