_ Git - rust-lightning/blob - lightning/src/util/persist.rs

   1 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   2 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   3 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   4 // You may not use this file except in accordance with one or both of these
   5 // licenses.
   6
   7 //! This module contains a simple key-value store trait KVStorePersister that
   8 //! allows one to implement the persistence for [`ChannelManager`], [`NetworkGraph`],
   9 //! and [`ChannelMonitor`] all in one place.
  10
  11 use core::ops::Deref;
  12 use bitcoin::hashes::hex::ToHex;
  13 use io::{self};
  14
  15 use crate::{chain::{keysinterface::{Sign, KeysInterface}, self, transaction::{OutPoint}, chaininterface::{BroadcasterInterface, FeeEstimator}, chainmonitor::{Persist, MonitorUpdateId}, channelmonitor::{ChannelMonitor, ChannelMonitorUpdate}}, ln::channelmanager::ChannelManager, routing::network_graph::NetworkGraph};
  16 use super::{logger::Logger, ser::Writeable};
  17
  18 /// Trait for a key-value store for persisting some writeable object at some key
  19 /// Implementing `KVStorePersister` provides auto-implementations for [`Persister`]
  20 /// and [`Persist`] traits.  It uses "manager", "network_graph",
  21 /// and "monitors/{funding_txo_id}_{funding_txo_index}" for keys.
  22 pub trait KVStorePersister {
  23         /// Persist the given writeable using the provided key
  24         fn persist<W: Writeable>(&self, key: &str, object: &W) -> io::Result<()>;
  25 }
  26
  27 /// Trait that handles persisting a [`ChannelManager`] and [`NetworkGraph`] to disk.
  28 pub trait Persister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
  29         where M::Target: 'static + chain::Watch<Signer>,
  30                 T::Target: 'static + BroadcasterInterface,
  31                 K::Target: 'static + KeysInterface<Signer = Signer>,
  32                 F::Target: 'static + FeeEstimator,
  33                 L::Target: 'static + Logger,
  34 {
  35         /// Persist the given ['ChannelManager'] to disk, returning an error if persistence failed.
  36         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), io::Error>;
  37
  38         /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
  39         fn persist_graph(&self, network_graph: &NetworkGraph) -> Result<(), io::Error>;
  40 }
  41
  42 impl<A: KVStorePersister, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Persister<Signer, M, T, K, F, L> for A
  43         where M::Target: 'static + chain::Watch<Signer>,
  44                 T::Target: 'static + BroadcasterInterface,
  45                 K::Target: 'static + KeysInterface<Signer = Signer>,
  46                 F::Target: 'static + FeeEstimator,
  47                 L::Target: 'static + Logger,
  48 {
  49         /// Persist the given ['ChannelManager'] to disk, returning an error if persistence failed.
  50         fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), io::Error> {
  51                 self.persist("manager", channel_manager)
  52         }
  53
  54         /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
  55         fn persist_graph(&self, network_graph: &NetworkGraph) -> Result<(), io::Error> {
  56                 self.persist("network_graph", network_graph)
  57         }
  58 }
  59
  60 impl<ChannelSigner: Sign, K: KVStorePersister> Persist<ChannelSigner> for K {
  61         // TODO: We really need a way for the persister to inform the user that its time to crash/shut
  62         // down once these start returning failure.
  63         // A PermanentFailure implies we need to shut down since we're force-closing channels without
  64         // even broadcasting!
  65
  66         fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> Result<(), chain::ChannelMonitorUpdateErr> {
  67                 let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
  68                 self.persist(&key, monitor)
  69                         .map_err(|_| chain::ChannelMonitorUpdateErr::PermanentFailure)
  70         }
  71
  72         fn update_persisted_channel(&self, funding_txo: OutPoint, _update: &Option<ChannelMonitorUpdate>, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> Result<(), chain::ChannelMonitorUpdateErr> {
  73                 let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
  74                 self.persist(&key, monitor)
  75                         .map_err(|_| chain::ChannelMonitorUpdateErr::PermanentFailure)
  76         }
  77 }