_ Git - rust-lightning/blob - src/chain/chaininterface.rs

   1 use bitcoin::blockdata::block::BlockHeader;
   2 use bitcoin::blockdata::transaction::Transaction;
   3 use bitcoin::blockdata::script::Script;
   4 use bitcoin::util::hash::Sha256dHash;
   5
   6 use std::sync::{Weak,Mutex};
   7
   8 /// An interface to request notification of certain scripts as they appear the
   9 /// chain.
  10 /// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
  11 /// called from inside the library in response to ChainListener events, P2P events, or timer
  12 /// events).
  13 pub trait ChainWatchInterface: Sync + Send {
  14         /// Provides a scriptPubKey which much be watched for.
  15         fn install_watch_script(&self, script_pub_key: Script);
  16
  17         /// Provides an outpoint which must be watched for, providing any transactions which spend the
  18         /// given outpoint.
  19         fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32));
  20
  21         /// Indicates that a listener needs to see all transactions.
  22         fn watch_all_txn(&self);
  23
  24         /// Sends a transaction out to (hopefully) be mined
  25         fn broadcast_transaction(&self, tx: &Transaction);
  26
  27         fn register_listener(&self, listener: Weak<ChainListener>);
  28         //TODO: unregister
  29 }
  30
  31 /// A trait indicating a desire to listen for events from the chain
  32 pub trait ChainListener: Sync + Send {
  33         /// Notifies a listener that a block was connected.
  34         /// Note that if a new script/transaction is watched during a block_connected call, the block
  35         /// *must* be re-scanned with the new script/transaction and block_connected should be called
  36         /// again with the same header and (at least) the new transactions.
  37         /// This also means those counting confirmations using block_connected callbacks should watch
  38         /// for duplicate headers and not count them towards confirmations!
  39         fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]);
  40         /// Notifies a listener that a block was disconnected.
  41         /// Unlike block_connected, this *must* never be called twice for the same disconnect event.
  42         fn block_disconnected(&self, header: &BlockHeader);
  43 }
  44
  45 pub enum ConfirmationTarget {
  46         Background,
  47         Normal,
  48         HighPriority,
  49 }
  50
  51 /// A trait which should be implemented to provide feerate information on a number of time
  52 /// horizons.
  53 /// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
  54 /// called from inside the library in response to ChainListener events, P2P events, or timer
  55 /// events).
  56 pub trait FeeEstimator: Sync + Send {
  57         fn get_est_sat_per_vbyte(&self, ConfirmationTarget) -> u64;
  58 }
  59
  60 /// Utility to capture some common parts of ChainWatchInterface implementors.
  61 /// Keeping a local copy of this in a ChainWatchInterface implementor is likely useful.
  62 pub struct ChainWatchInterfaceUtil {
  63         watched: Mutex<(Vec<Script>, Vec<(Sha256dHash, u32)>, bool)>, //TODO: Something clever to optimize this
  64         listeners: Mutex<Vec<Weak<ChainListener>>>,
  65 }
  66
  67 impl ChainWatchInterfaceUtil {
  68         pub fn new() -> ChainWatchInterfaceUtil {
  69                 ChainWatchInterfaceUtil {
  70                         watched: Mutex::new((Vec::new(), Vec::new(), false)),
  71                         listeners: Mutex::new(Vec::new()),
  72                 }
  73         }
  74
  75         pub fn install_watch_script(&self, spk: Script) {
  76                 let mut watched = self.watched.lock().unwrap();
  77                 watched.0.push(Script::from(spk));
  78         }
  79
  80         pub fn install_watch_outpoint(&self, outpoint: (Sha256dHash, u32)) {
  81                 let mut watched = self.watched.lock().unwrap();
  82                 watched.1.push(outpoint);
  83         }
  84
  85         pub fn watch_all_txn(&self) { //TODO: refcnt this?
  86                 let mut watched = self.watched.lock().unwrap();
  87                 watched.2 = true;
  88         }
  89
  90         pub fn register_listener(&self, listener: Weak<ChainListener>) {
  91                 let mut vec = self.listeners.lock().unwrap();
  92                 vec.push(listener);
  93         }
  94
  95         pub fn do_call_block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[u32]) {
  96                 let listeners = self.listeners.lock().unwrap().clone();
  97                 for listener in listeners.iter() {
  98                         match listener.upgrade() {
  99                                 Some(arc) => arc.block_connected(header, height, txn_matched, indexes_of_txn_matched),
 100                                 None => ()
 101                         }
 102                 }
 103         }
 104
 105         pub fn do_call_block_disconnected(&self, header: &BlockHeader) {
 106                 let listeners = self.listeners.lock().unwrap().clone();
 107                 for listener in listeners.iter() {
 108                         match listener.upgrade() {
 109                                 Some(arc) => arc.block_disconnected(header),
 110                                 None => ()
 111                         }
 112                 }
 113         }
 114
 115         /// Checks if a given transaction matches the current filter
 116         pub fn does_match_tx(&self, tx: &Transaction) -> bool {
 117                 let watched = self.watched.lock().unwrap();
 118                 if watched.2 {
 119                         return true;
 120                 }
 121                 for out in tx.output.iter() {
 122                         for script in watched.0.iter() {
 123                                 if script[..] == out.script_pubkey[..] {
 124                                         return true;
 125                                 }
 126                         }
 127                 }
 128                 for input in tx.input.iter() {
 129                         for outpoint in watched.1.iter() {
 130                                 let &(outpoint_hash, outpoint_index) = outpoint;
 131                                 if outpoint_hash == input.prev_hash && outpoint_index == input.prev_index {
 132                                         return true;
 133                                 }
 134                         }
 135                 }
 136                 false
 137         }
 138 }