-/// 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.
-///
-/// 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>,
-}
-
-/// 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);
- }
- }
-
- 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);
- }
- }
-
- fn watch_all_txn(&self) {
- let mut watched = self.watched.lock().unwrap();
- if watched.watch_all() {
- self.reentered.fetch_add(1, Ordering::Relaxed);
- }
- }
-
- 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)
- }
-
- 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);
- }
- }
- }
- (matched, matched_index)
- }
-
- fn reentered(&self) -> usize {
- self.reentered.load(Ordering::Relaxed)
- }
-}
-
-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,
- }
- }
-
-
- /// 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)
- }
-}