Drop return value from `Filter::register_output`

[rust-lightning] / lightning / src / chain / mod.rs

diff --git a/lightning/src/chain/mod.rs b/lightning/src/chain/mod.rs
index 25e5a97d288df42d4a2baf2263aae9e9d493f28e..170f543e1dcdaabf58dc05b251cb033af21120ad 100644 (file)
--- a/lightning/src/chain/mod.rs
+++ b/lightning/src/chain/mod.rs
@@ -12,9 +12,10 @@
 use bitcoin::blockdata::block::{Block, BlockHeader};
 use bitcoin::blockdata::constants::genesis_block;
 use bitcoin::blockdata::script::Script;
-use bitcoin::blockdata::transaction::{Transaction, TxOut};
+use bitcoin::blockdata::transaction::TxOut;
 use bitcoin::hash_types::{BlockHash, Txid};
 use bitcoin::network::constants::Network;
+use bitcoin::secp256k1::PublicKey;
 
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, MonitorEvent};
 use chain::keysinterface::Sign;
@@ -76,7 +77,7 @@ pub trait Access {
        /// Returns an error if `genesis_hash` is for a different chain or if such a transaction output
        /// is unknown.
        ///
-       /// [`short_channel_id`]: https://github.com/lightningnetwork/lightning-rfc/blob/master/07-routing-gossip.md#definition-of-short_channel_id
+       /// [`short_channel_id`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#definition-of-short_channel_id
        fn get_utxo(&self, genesis_hash: &BlockHash, short_channel_id: u64) -> Result<TxOut, AccessError>;
 }
 
@@ -87,9 +88,20 @@ pub trait Access {
 /// sourcing chain data using a block-oriented API should prefer this interface over [`Confirm`].
 /// Such clients fetch the entire header chain whereas clients using [`Confirm`] only fetch headers
 /// when needed.
+///
+/// By using [`Listen::filtered_block_connected`] this interface supports clients fetching the
+/// entire header chain and only blocks with matching transaction data using BIP 157 filters or
+/// other similar filtering.
 pub trait Listen {
+       /// Notifies the listener that a block was added at the given height, with the transaction data
+       /// possibly filtered.
+       fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32);
+
        /// Notifies the listener that a block was added at the given height.
-       fn block_connected(&self, block: &Block, height: u32);
+       fn block_connected(&self, block: &Block, height: u32) {
+               let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
+               self.filtered_block_connected(&block.header, &txdata, height);
+       }
 
        /// Notifies the listener that a block was removed at the given height.
        fn block_disconnected(&self, header: &BlockHeader, height: u32);
@@ -291,7 +303,7 @@ pub trait Watch<ChannelSigner: Sign> {
        ///
        /// For details on asynchronous [`ChannelMonitor`] updating and returning
        /// [`MonitorEvent::UpdateCompleted`] here, see [`ChannelMonitorUpdateErr::TemporaryFailure`].
-       fn release_pending_monitor_events(&self) -> Vec<MonitorEvent>;
+       fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>;
 }
 
 /// The `Filter` trait defines behavior for indicating chain activity of interest pertaining to
@@ -321,21 +333,18 @@ pub trait Filter {
 
        /// Registers interest in spends of a transaction output.
        ///
-       /// Optionally, when `output.block_hash` is set, should return any transaction spending the
-       /// output that is found in the corresponding block along with its index.
-       ///
-       /// This return value is useful for Electrum clients in order to supply in-block descendant
-       /// transactions which otherwise were not included. This is not necessary for other clients if
-       /// such descendant transactions were already included (e.g., when a BIP 157 client provides the
-       /// full block).
-       fn register_output(&self, output: WatchedOutput) -> Option<(usize, Transaction)>;
+       /// Note that this method might be called during processing of a new block. You therefore need
+       /// to ensure that also dependent output spents within an already connected block are correctly
+       /// handled, e.g., by re-scanning the block in question whenever new outputs have been
+       /// registered mid-processing.
+       fn register_output(&self, output: WatchedOutput);
 }
 
 /// A transaction output watched by a [`ChannelMonitor`] for spends on-chain.
 ///
 /// Used to convey to a [`Filter`] such an output with a given spending condition. Any transaction
 /// spending the output must be given to [`ChannelMonitor::block_connected`] either directly or via
-/// the return value of [`Filter::register_output`].
+/// [`Confirm::transactions_confirmed`].
 ///
 /// If `block_hash` is `Some`, this indicates the output was created in the corresponding block and
 /// may have been spent there. See [`Filter::register_output`] for details.
@@ -355,8 +364,8 @@ pub struct WatchedOutput {
 }
 
 impl<T: Listen> Listen for core::ops::Deref<Target = T> {
-       fn block_connected(&self, block: &Block, height: u32) {
-               (**self).block_connected(block, height);
+       fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+               (**self).filtered_block_connected(header, txdata, height);
        }
 
        fn block_disconnected(&self, header: &BlockHeader, height: u32) {
@@ -369,9 +378,9 @@ where
        T::Target: Listen,
        U::Target: Listen,
 {
-       fn block_connected(&self, block: &Block, height: u32) {
-               self.0.block_connected(block, height);
-               self.1.block_connected(block, height);
+       fn filtered_block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+               self.0.filtered_block_connected(header, txdata, height);
+               self.1.filtered_block_connected(header, txdata, height);
        }
 
        fn block_disconnected(&self, header: &BlockHeader, height: u32) {