_ Git - rust-lightning/blob - lightning-transaction-sync/src/common.rs

   1 use bitcoin::block::Header;
   2 use bitcoin::{BlockHash, OutPoint, Transaction, Txid};
   3 use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
   4 use lightning::chain::{Confirm, WatchedOutput};
   5
   6 use std::collections::{HashMap, HashSet};
   7 use std::ops::Deref;
   8
   9 // Represents the current state.
  10 pub(crate) struct SyncState {
  11         // Transactions that were previously processed, but must not be forgotten
  12         // yet since they still need to be monitored for confirmation on-chain.
  13         pub watched_transactions: HashSet<Txid>,
  14         // Outputs that were previously processed, but must not be forgotten yet as
  15         // as we still need to monitor any spends on-chain.
  16         pub watched_outputs: HashMap<OutPoint, WatchedOutput>,
  17         // Outputs for which we previously saw a spend on-chain but kept around until the spends reach
  18         // sufficient depth.
  19         pub outputs_spends_pending_threshold_conf: Vec<(Txid, u32, OutPoint, WatchedOutput)>,
  20         // The tip hash observed during our last sync.
  21         pub last_sync_hash: Option<BlockHash>,
  22         // Indicates whether we need to resync, e.g., after encountering an error.
  23         pub pending_sync: bool,
  24 }
  25
  26 impl SyncState {
  27         pub fn new() -> Self {
  28                 Self {
  29                         watched_transactions: HashSet::new(),
  30                         watched_outputs: HashMap::new(),
  31                         outputs_spends_pending_threshold_conf: Vec::new(),
  32                         last_sync_hash: None,
  33                         pending_sync: false,
  34                 }
  35         }
  36         pub fn sync_unconfirmed_transactions<C: Deref>(
  37                 &mut self, confirmables: &Vec<C>, unconfirmed_txs: Vec<Txid>,
  38         ) where
  39                 C::Target: Confirm,
  40         {
  41                 for txid in unconfirmed_txs {
  42                         for c in confirmables {
  43                                 c.transaction_unconfirmed(&txid);
  44                         }
  45
  46                         self.watched_transactions.insert(txid);
  47
  48                         // If a previously-confirmed output spend is unconfirmed, re-add the watched output to
  49                         // the tracking map.
  50                         self.outputs_spends_pending_threshold_conf.retain(
  51                                 |(conf_txid, _, prev_outpoint, output)| {
  52                                         if txid == *conf_txid {
  53                                                 self.watched_outputs.insert(*prev_outpoint, output.clone());
  54                                                 false
  55                                         } else {
  56                                                 true
  57                                         }
  58                                 },
  59                         )
  60                 }
  61         }
  62
  63         pub fn sync_confirmed_transactions<C: Deref>(
  64                 &mut self, confirmables: &Vec<C>, confirmed_txs: Vec<ConfirmedTx>,
  65         ) where
  66                 C::Target: Confirm,
  67         {
  68                 for ctx in confirmed_txs {
  69                         for c in confirmables {
  70                                 c.transactions_confirmed(
  71                                         &ctx.block_header,
  72                                         &[(ctx.pos, &ctx.tx)],
  73                                         ctx.block_height,
  74                                 );
  75                         }
  76
  77                         self.watched_transactions.remove(&ctx.tx.txid());
  78
  79                         for input in &ctx.tx.input {
  80                                 if let Some(output) = self.watched_outputs.remove(&input.previous_output) {
  81                                         let spent = (ctx.tx.txid(), ctx.block_height, input.previous_output, output);
  82                                         self.outputs_spends_pending_threshold_conf.push(spent);
  83                                 }
  84                         }
  85                 }
  86         }
  87
  88         pub fn prune_output_spends(&mut self, cur_height: u32) {
  89                 self.outputs_spends_pending_threshold_conf
  90                         .retain(|(_, conf_height, _, _)| cur_height < conf_height + ANTI_REORG_DELAY - 1);
  91         }
  92 }
  93
  94 // A queue that is to be filled by `Filter` and drained during the next syncing round.
  95 pub(crate) struct FilterQueue {
  96         // Transactions that were registered via the `Filter` interface and have to be processed.
  97         pub transactions: HashSet<Txid>,
  98         // Outputs that were registered via the `Filter` interface and have to be processed.
  99         pub outputs: HashMap<OutPoint, WatchedOutput>,
 100 }
 101
 102 impl FilterQueue {
 103         pub fn new() -> Self {
 104                 Self { transactions: HashSet::new(), outputs: HashMap::new() }
 105         }
 106
 107         // Processes the transaction and output queues and adds them to the given [`SyncState`].
 108         //
 109         // Returns `true` if new items had been registered.
 110         pub fn process_queues(&mut self, sync_state: &mut SyncState) -> bool {
 111                 let mut pending_registrations = false;
 112
 113                 if !self.transactions.is_empty() {
 114                         pending_registrations = true;
 115
 116                         sync_state.watched_transactions.extend(self.transactions.drain());
 117                 }
 118
 119                 if !self.outputs.is_empty() {
 120                         pending_registrations = true;
 121
 122                         sync_state.watched_outputs.extend(self.outputs.drain());
 123                 }
 124                 pending_registrations
 125         }
 126 }
 127
 128 #[derive(Debug)]
 129 pub(crate) struct ConfirmedTx {
 130         pub tx: Transaction,
 131         pub txid: Txid,
 132         pub block_header: Header,
 133         pub block_height: u32,
 134         pub pos: usize,
 135 }