X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fmod.rs;h=856a9e8af62287b76f3e174f2543091361eca300;hb=c40ebf18e5b5c65944907cc5ef94a271edadf604;hp=67ae5b347f9d94b029f93333fbb68dc6e23f9518;hpb=d70fdd3a5c7bb2f240ef9de0fa075494b3923fe5;p=rust-lightning diff --git a/lightning/src/chain/mod.rs b/lightning/src/chain/mod.rs index 67ae5b34..856a9e8a 100644 --- a/lightning/src/chain/mod.rs +++ b/lightning/src/chain/mod.rs @@ -16,13 +16,15 @@ use bitcoin::hash_types::{BlockHash, Txid}; 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; pub mod channelmonitor; pub mod transaction; pub mod keysinterface; +pub(crate) mod onchaintx; +pub(crate) mod package; /// An error when accessing the chain via [`Access`]. #[derive(Clone)] @@ -36,7 +38,7 @@ pub enum AccessError { /// The `Access` trait defines behavior for accessing chain data and state, such as blocks and /// UTXOs. -pub trait Access: Send + Sync { +pub trait Access { /// Returns the transaction output of a funding transaction encoded by [`short_channel_id`]. /// Returns an error if `genesis_hash` is for a different chain or if such a transaction output /// is unknown. @@ -45,10 +47,13 @@ pub trait Access: Send + Sync { fn get_utxo(&self, genesis_hash: &BlockHash, short_channel_id: u64) -> Result; } -/// 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); @@ -57,6 +62,86 @@ pub trait Listen { 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]: Confirm#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; +} + /// The `Watch` trait defines behavior for watching on-chain activity pertaining to channels as /// blocks are connected and disconnected. /// @@ -78,7 +163,7 @@ pub trait Listen { /// [`ChannelMonitor`]: channelmonitor::ChannelMonitor /// [`ChannelMonitorUpdateErr`]: channelmonitor::ChannelMonitorUpdateErr /// [`PermanentFailure`]: channelmonitor::ChannelMonitorUpdateErr::PermanentFailure -pub trait Watch: Send + Sync { +pub trait Watch { /// Watches a channel identified by `funding_txo` using `monitor`. /// /// Implementations are responsible for watching the chain for the funding transaction along @@ -124,20 +209,46 @@ pub trait Watch: Send + Sync { /// [`TemporaryFailure`]: channelmonitor::ChannelMonitorUpdateErr::TemporaryFailure /// [BIP 157]: https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki /// [BIP 158]: https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki -pub trait Filter: Send + Sync { +pub trait Filter { /// Registers interest in a transaction with `txid` and having an output with `script_pubkey` as /// a spending condition. fn register_tx(&self, txid: &Txid, script_pubkey: &Script); - /// Registers interest in spends of a transaction output identified by `outpoint` having - /// `script_pubkey` as the spending condition. + /// Registers interest in spends of a transaction output. /// - /// Optionally, returns any transaction dependent on the output. This is useful for Electrum - /// clients to facilitate registering in-block descendants. - fn register_output(&self, outpoint: &OutPoint, script_pubkey: &Script) -> Option<(usize, Transaction)>; + /// 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)>; +} + +/// 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`]. +/// +/// 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. +/// +/// [`ChannelMonitor`]: channelmonitor::ChannelMonitor +/// [`ChannelMonitor::block_connected`]: channelmonitor::ChannelMonitor::block_connected +pub struct WatchedOutput { + /// First block where the transaction output may have been spent. + pub block_hash: Option, + + /// Outpoint identifying the transaction output. + pub outpoint: OutPoint, + + /// Spending condition of the transaction output. + pub script_pubkey: Script, } -impl Listen for std::ops::Deref { +impl Listen for core::ops::Deref { fn block_connected(&self, block: &Block, height: u32) { (**self).block_connected(block, height); } @@ -147,7 +258,7 @@ impl Listen for std::ops::Deref { } } -impl Listen for (T, U) +impl Listen for (T, U) where T::Target: Listen, U::Target: Listen,