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