use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent};
use chain::keysinterface::Sign;
-use chain::transaction::OutPoint;
+use chain::transaction::{OutPoint, TransactionData};
pub mod chaininterface;
pub mod chainmonitor;
fn get_utxo(&self, genesis_hash: &BlockHash, short_channel_id: u64) -> Result<TxOut, AccessError>;
}
-/// The `Listen` trait is used to be notified of when blocks have been connected or disconnected
-/// from the chain.
+/// The `Listen` trait is used to notify when blocks have been connected or disconnected from the
+/// chain.
///
-/// Useful when needing to replay chain data upon startup or as new chain events occur.
+/// Useful when needing to replay chain data upon startup or as new chain events occur. Clients
+/// 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.
pub trait Listen {
/// Notifies the listener that a block was added at the given height.
fn block_connected(&self, block: &Block, height: u32);
fn block_disconnected(&self, header: &BlockHeader, height: u32);
}
+/// The `Confirm` trait is used to notify when transactions have been confirmed on chain or
+/// unconfirmed during a chain reorganization.
+///
+/// Clients sourcing chain data using a transaction-oriented API should prefer this interface over
+/// [`Listen`]. For instance, an Electrum client may implement [`Filter`] by subscribing to activity
+/// related to registered transactions and outputs. Upon notification, it would pass along the
+/// matching transactions using this interface.
+///
+/// # Use
+///
+/// The intended use is as follows:
+/// - Call [`transactions_confirmed`] to process any on-chain activity of interest.
+/// - Call [`transaction_unconfirmed`] to process any transaction returned by [`get_relevant_txids`]
+/// that has been reorganized out of the chain.
+/// - Call [`best_block_updated`] whenever a new chain tip becomes available.
+///
+/// # Order
+///
+/// Clients must call these methods in chain order. Specifically:
+/// - Transactions confirmed in a block must be given before transactions confirmed in a later
+/// block.
+/// - Dependent transactions within the same block must be given in topological order, possibly in
+/// separate calls.
+/// - Unconfirmed transactions must be given after the original confirmations and before any
+/// reconfirmation.
+///
+/// See individual method documentation for further details.
+///
+/// [`transactions_confirmed`]: Self::transactions_confirmed
+/// [`transaction_unconfirmed`]: Self::transaction_unconfirmed
+/// [`best_block_updated`]: Self::best_block_updated
+/// [`get_relevant_txids`]: Self::get_relevant_txids
+pub trait Confirm {
+ /// Processes transactions confirmed in a block with a given header and height.
+ ///
+ /// Should be called for any transactions registered by [`Filter::register_tx`] or any
+ /// transactions spending an output registered by [`Filter::register_output`]. Such transactions
+ /// appearing in the same block do not need to be included in the same call; instead, multiple
+ /// calls with additional transactions may be made so long as they are made in [chain order].
+ ///
+ /// May be called before or after [`best_block_updated`] for the corresponding block. However,
+ /// in the event of a chain reorganization, it must not be called with a `header` that is no
+ /// longer in the chain as of the last call to [`best_block_updated`].
+ ///
+ /// [chain order]: Self#order
+ /// [`best_block_updated`]: Self::best_block_updated
+ fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32);
+
+ /// Processes a transaction that is no longer confirmed as result of a chain reorganization.
+ ///
+ /// Should be called for any transaction returned by [`get_relevant_txids`] if it has been
+ /// reorganized out of the best chain. Once called, the given transaction should not be returned
+ /// by [`get_relevant_txids`] unless it has been reconfirmed via [`transactions_confirmed`].
+ ///
+ /// [`get_relevant_txids`]: Self::get_relevant_txids
+ /// [`transactions_confirmed`]: Self::transactions_confirmed
+ fn transaction_unconfirmed(&self, txid: &Txid);
+
+ /// Processes an update to the best header connected at the given height.
+ ///
+ /// Should be called when a new header is available but may be skipped for intermediary blocks
+ /// if they become available at the same time.
+ fn best_block_updated(&self, header: &BlockHeader, height: u32);
+
+ /// Returns transactions that should be monitored for reorganization out of the chain.
+ ///
+ /// Should include any transactions passed to [`transactions_confirmed`] that have insufficient
+ /// confirmations to be safe from a chain reorganization. Should not include any transactions
+ /// passed to [`transaction_unconfirmed`] unless later reconfirmed.
+ ///
+ /// May be called to determine the subset of transactions that must still be monitored for
+ /// reorganization. Will be idempotent between calls but may change as a result of calls to the
+ /// other interface methods. Thus, this is useful to determine which transactions may need to be
+ /// given to [`transaction_unconfirmed`].
+ ///
+ /// [`transactions_confirmed`]: Self::transactions_confirmed
+ /// [`transaction_unconfirmed`]: Self::transaction_unconfirmed
+ fn get_relevant_txids(&self) -> Vec<Txid>;
+}
+
/// The `Watch` trait defines behavior for watching on-chain activity pertaining to channels as
/// blocks are connected and disconnected.
///
projects / rust-lightning / commitdiff