X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=cbf609485ce1984800fa991e22d952e33ab5db56;hb=28c9b56113ff1ebb1b505a2c979c55c1626aa06b;hp=92c9c102597b8546e6ca42f3272d5f0cb9e2289f;hpb=65f7c9f54268401949ebbfecf33892f399e33202;p=rust-lightning

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index 92c9c102..cbf60948 100644
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -1,93 +1,31 @@
+// 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.
 //!
 //! 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::blockdata::constants::genesis_block;
-use bitcoin::util::hash::BitcoinHash;
-use bitcoin_hashes::sha256d::Hash as 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;
-
-/// 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 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), out_script: &Script);
+use core::{cmp, ops::Deref};
 
-	/// 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: Sha256dHash, unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError>;
-
-	/// Gets the list of transactions and transaction indices that the ChainWatchInterface is
-	/// watching for.
-	fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec<u32>);
-
-	/// 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;
-}
+use bitcoin::blockdata::transaction::Transaction;
 
 /// An interface to send a transaction to the Bitcoin network.
-pub trait BroadcasterInterface: Sync + Send {
+pub trait BroadcasterInterface {
 	/// 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 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]);
-	/// 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)
-	fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32);
-}
-
 /// An enum that represents the speed at which we want a transaction to confirm used for feerate
 /// estimation.
+#[derive(Clone, Copy, PartialEq, Eq)]
 pub enum ConfirmationTarget {
 	/// We are happy with this transaction confirming slowly when feerate drops some.
 	Background,
@@ -101,255 +39,76 @@ pub enum ConfirmationTarget {
 /// 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 {
+/// called from inside the library in response to chain events, P2P events, or timer events).
+pub trait FeeEstimator {
 	/// 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).
+	/// LDK will wrap this method and ensure that the value returned is 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:
+	/// The following unit conversions can be used to convert to sats/KW:
 	///  * satoshis-per-byte * 250
-	///  * ceil(satoshis-per-kbyte / 4)
-	fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u64;
+	///  * satoshis-per-kbyte / 4
+	fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32;
 }
 
-/// Utility for tracking registered txn/outpoints and checking for matches
-pub struct ChainWatchedUtil {
-	watch_all: bool,
+/// Minimum relay fee as required by bitcoin network mempool policy.
+pub const MIN_RELAY_FEE_SAT_PER_1000_WEIGHT: u64 = 4000;
+/// Minimum feerate that takes a sane approach to bitcoind weight-to-vbytes rounding.
+/// See the following Core Lightning commit for an explanation:
+/// <https://github.com/ElementsProject/lightning/commit/2e687b9b352c9092b5e8bd4a688916ac50b44af0>
+pub const FEERATE_FLOOR_SATS_PER_KW: u32 = 253;
 
-	// 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 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>,
-}
-
-impl<'a> BlockNotifier<'a> {
-	/// Constructs a new BlockNotifier without any listeners.
-	pub fn new(chain_monitor: Arc<ChainWatchInterface>) -> BlockNotifier<'a> {
-		BlockNotifier {
-			listeners: Mutex::new(Vec::new()),
-			chain_monitor,
-		}
-	}
-
-	/// 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>) {
-		let mut vec = self.listeners.lock().unwrap();
-		vec.push(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) {
-		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());
-		}
-	}
-
-	/// 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.chain_monitor.reentered();
-
-		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),
-				None => ()
-			}
-		}
-		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();
-		for listener in listeners.iter() {
-			match listener.upgrade() {
-				Some(arc) => arc.block_disconnected(&header, disconnected_height),
-				None => ()
-			}
-		}
-	}
-
-}
-
-/// Utility to capture some common parts of ChainWatchInterface implementors.
+/// Wraps a `Deref` to a `FeeEstimator` so that any fee estimations provided by it
+/// are bounded below by `FEERATE_FLOOR_SATS_PER_KW` (253 sats/KW).
 ///
-/// Keeping a local copy of this in a ChainWatchInterface implementor is likely useful.
-pub struct ChainWatchInterfaceUtil {
-	network: Network,
-	watched: Mutex<ChainWatchedUtil>,
-	reentered: AtomicUsize,
-	logger: Arc<Logger>,
-}
+/// Note that this does *not* implement [`FeeEstimator`] to make it harder to accidentally mix the
+/// two.
+pub(crate) struct LowerBoundedFeeEstimator<F: Deref>(pub F) where F::Target: FeeEstimator;
 
-/// Register listener
-impl ChainWatchInterface for ChainWatchInterfaceUtil {
-	fn install_watch_tx(&self, txid: &Sha256dHash, 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);
-		}
+impl<F: Deref> LowerBoundedFeeEstimator<F> where F::Target: FeeEstimator {
+	/// Creates a new `LowerBoundedFeeEstimator` which wraps the provided fee_estimator
+	pub fn new(fee_estimator: F) -> Self {
+		LowerBoundedFeeEstimator(fee_estimator)
 	}
 
-	fn install_watch_outpoint(&self, outpoint: (Sha256dHash, 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);
-		}
+	pub fn bounded_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32 {
+		cmp::max(
+			self.0.get_est_sat_per_1000_weight(confirmation_target),
+			FEERATE_FLOOR_SATS_PER_KW,
+		)
 	}
+}
 
-	fn watch_all_txn(&self) {
-		let mut watched = self.watched.lock().unwrap();
-		if watched.watch_all() {
-			self.reentered.fetch_add(1, Ordering::Relaxed);
-		}
-	}
+#[cfg(test)]
+mod tests {
+	use super::{FEERATE_FLOOR_SATS_PER_KW, LowerBoundedFeeEstimator, ConfirmationTarget, FeeEstimator};
 
-	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)
+	struct TestFeeEstimator {
+		sat_per_kw: u32,
 	}
 
-	fn filter_block<'a>(&self, block: &'a Block) -> (Vec<&'a Transaction>, Vec<u32>) {
-		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);
-				}
-			}
+	impl FeeEstimator for TestFeeEstimator {
+		fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
+			self.sat_per_kw
 		}
-		(matched, matched_index)
 	}
 
-	fn reentered(&self) -> usize {
-		self.reentered.load(Ordering::Relaxed)
-	}
-}
+	#[test]
+	fn test_fee_estimator_less_than_floor() {
+		let sat_per_kw = FEERATE_FLOOR_SATS_PER_KW - 1;
+		let test_fee_estimator = &TestFeeEstimator { sat_per_kw };
+		let fee_estimator = LowerBoundedFeeEstimator::new(test_fee_estimator);
 
-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()),
-			reentered: AtomicUsize::new(1),
-			logger: logger,
-		}
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), FEERATE_FLOOR_SATS_PER_KW);
 	}
 
+	#[test]
+	fn test_fee_estimator_greater_than_floor() {
+		let sat_per_kw = FEERATE_FLOOR_SATS_PER_KW + 1;
+		let test_fee_estimator = &TestFeeEstimator { sat_per_kw };
+		let fee_estimator = LowerBoundedFeeEstimator::new(test_fee_estimator);
 
-	/// 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<ChainWatchedUtil>) -> bool {
-		watched.does_match_tx(tx)
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), sat_per_kw);
 	}
 }