chaininterface+multi: add filter_block and reentered to ChainWatchInterface

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

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index 32fef48eb44a54acaa7a576502ad1e0f1e56311d..92c9c102597b8546e6ca42f3272d5f0cb9e2289f 100644 (file)
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -50,6 +50,15 @@ pub trait ChainWatchInterface: Sync + Send {
        /// 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;
 }
 
 /// An interface to send a transaction to the Bitcoin network.
@@ -301,6 +310,25 @@ impl ChainWatchInterface for ChainWatchInterfaceUtil {
                }
                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 {