// You may not use this file except in accordance with one or both of these
// licenses.
-//! This module contains a simple key-value store trait KVStorePersister that
+//! This module contains a simple key-value store trait [`KVStore`] that
//! allows one to implement the persistence for [`ChannelManager`], [`NetworkGraph`],
//! and [`ChannelMonitor`] all in one place.
use core::ops::Deref;
-use bitcoin::hashes::hex::ToHex;
+use bitcoin::hashes::hex::{FromHex, ToHex};
+use bitcoin::{BlockHash, Txid};
+
use crate::io;
+use crate::prelude::{Vec, String};
use crate::routing::scoring::WriteableScore;
use crate::chain;
use crate::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
use crate::chain::chainmonitor::{Persist, MonitorUpdateId};
-use crate::chain::keysinterface::{EntropySource, NodeSigner, WriteableEcdsaChannelSigner, SignerProvider};
+use crate::sign::{EntropySource, NodeSigner, WriteableEcdsaChannelSigner, SignerProvider};
use crate::chain::transaction::OutPoint;
use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate};
use crate::ln::channelmanager::ChannelManager;
use crate::routing::router::Router;
use crate::routing::gossip::NetworkGraph;
-use super::{logger::Logger, ser::Writeable};
-
-/// Trait for a key-value store for persisting some writeable object at some key
-/// Implementing `KVStorePersister` provides auto-implementations for [`Persister`]
-/// and [`Persist`] traits. It uses "manager", "network_graph",
-/// and "monitors/{funding_txo_id}_{funding_txo_index}" for keys.
-pub trait KVStorePersister {
- /// Persist the given writeable using the provided key
- fn persist<W: Writeable>(&self, key: &str, object: &W) -> io::Result<()>;
+use crate::util::logger::Logger;
+use crate::util::ser::{ReadableArgs, Writeable};
+
+/// The alphabet of characters allowed for namespaces and keys.
+pub const KVSTORE_NAMESPACE_KEY_ALPHABET: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
+
+/// The maximum number of characters namespaces and keys may have.
+pub const KVSTORE_NAMESPACE_KEY_MAX_LEN: usize = 120;
+
+/// The namespace under which the [`ChannelManager`] will be persisted.
+pub const CHANNEL_MANAGER_PERSISTENCE_NAMESPACE: &str = "";
+/// The sub-namespace under which the [`ChannelManager`] will be persisted.
+pub const CHANNEL_MANAGER_PERSISTENCE_SUB_NAMESPACE: &str = "";
+/// The key under which the [`ChannelManager`] will be persisted.
+pub const CHANNEL_MANAGER_PERSISTENCE_KEY: &str = "manager";
+
+/// The namespace under which [`ChannelMonitor`]s will be persisted.
+pub const CHANNEL_MONITOR_PERSISTENCE_NAMESPACE: &str = "monitors";
+/// The sub-namespace under which [`ChannelMonitor`]s will be persisted.
+pub const CHANNEL_MONITOR_PERSISTENCE_SUB_NAMESPACE: &str = "";
+
+/// The namespace under which the [`NetworkGraph`] will be persisted.
+pub const NETWORK_GRAPH_PERSISTENCE_NAMESPACE: &str = "";
+/// The sub-namespace under which the [`NetworkGraph`] will be persisted.
+pub const NETWORK_GRAPH_PERSISTENCE_SUB_NAMESPACE: &str = "";
+/// The key under which the [`NetworkGraph`] will be persisted.
+pub const NETWORK_GRAPH_PERSISTENCE_KEY: &str = "network_graph";
+
+/// The namespace under which the [`WriteableScore`] will be persisted.
+pub const SCORER_PERSISTENCE_NAMESPACE: &str = "";
+/// The sub-namespace under which the [`WriteableScore`] will be persisted.
+pub const SCORER_PERSISTENCE_SUB_NAMESPACE: &str = "";
+/// The key under which the [`WriteableScore`] will be persisted.
+pub const SCORER_PERSISTENCE_KEY: &str = "scorer";
+
+/// Provides an interface that allows storage and retrieval of persisted values that are associated
+/// with given keys.
+///
+/// In order to avoid collisions the key space is segmented based on the given `namespace`s and
+/// `sub_namespace`s. Implementations of this trait are free to handle them in different ways, as
+/// long as per-namespace key uniqueness is asserted.
+///
+/// Keys and namespaces are required to be valid ASCII strings in the range of
+/// [`KVSTORE_NAMESPACE_KEY_ALPHABET`] and no longer than [`KVSTORE_NAMESPACE_KEY_MAX_LEN`]. Empty
+/// namespaces and sub-namespaces (`""`) are assumed to be a valid, however, if `namespace` is
+/// empty, `sub_namespace` is required to be empty, too. This means that concerns should always be
+/// separated by namespace first, before sub-namespaces are used. While the number of namespaces
+/// will be relatively small and is determined at compile time, there may be many sub-namespaces
+/// per namespace. Note that per-namespace uniqueness needs to also hold for keys *and*
+/// namespaces/sub-namespaces in any given namespace/sub-namespace, i.e., conflicts between keys
+/// and equally named namespaces/sub-namespaces must be avoided.
+///
+/// **Note:** Users migrating custom persistence backends from the pre-v0.0.117 `KVStorePersister`
+/// interface can use a concatenation of `[{namespace}/[{sub_namespace}/]]{key}` to recover a `key` compatible with the
+/// data model previously assumed by `KVStorePersister::persist`.
+pub trait KVStore {
+ /// Returns the data stored for the given `namespace`, `sub_namespace`, and `key`.
+ ///
+ /// Returns an [`ErrorKind::NotFound`] if the given `key` could not be found in the given
+ /// `namespace` and `sub_namespace`.
+ ///
+ /// [`ErrorKind::NotFound`]: io::ErrorKind::NotFound
+ fn read(&self, namespace: &str, sub_namespace: &str, key: &str) -> io::Result<Vec<u8>>;
+ /// Persists the given data under the given `key`.
+ ///
+ /// Will create the given `namespace` and `sub_namespace` if not already present in the store.
+ fn write(&self, namespace: &str, sub_namespace: &str, key: &str, buf: &[u8]) -> io::Result<()>;
+ /// Removes any data that had previously been persisted under the given `key`.
+ ///
+ /// If the `lazy` flag is set to `true`, the backend implementation might choose to lazily
+ /// remove the given `key` at some point in time after the method returns, e.g., as part of an
+ /// eventual batch deletion of multiple keys. As a consequence, subsequent calls to
+ /// [`KVStore::list`] might include the removed key until the changes are actually persisted.
+ ///
+ /// Note that while setting the `lazy` flag reduces the I/O burden of multiple subsequent
+ /// `remove` calls, it also influences the atomicity guarantees as lazy `remove`s could
+ /// potentially get lost on crash after the method returns. Therefore, this flag should only be
+ /// set for `remove` operations that can be safely replayed at a later time.
+ ///
+ /// Returns successfully if no data will be stored for the given `namespace`, `sub_namespace`, and
+ /// `key`, independently of whether it was present before its invokation or not.
+ fn remove(&self, namespace: &str, sub_namespace: &str, key: &str, lazy: bool) -> io::Result<()>;
+ /// Returns a list of keys that are stored under the given `sub_namespace` in `namespace`.
+ ///
+ /// Returns the keys in arbitrary order, so users requiring a particular order need to sort the
+ /// returned keys. Returns an empty list if `namespace` or `sub_namespace` is unknown.
+ fn list(&self, namespace: &str, sub_namespace: &str) -> io::Result<Vec<String>>;
}
/// Trait that handles persisting a [`ChannelManager`], [`NetworkGraph`], and [`WriteableScore`] to disk.
fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error>;
}
-impl<'a, A: KVStorePersister, M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, M, T, ES, NS, SP, F, R, L, S> for A
+
+impl<'a, A: KVStore, M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, M, T, ES, NS, SP, F, R, L, S> for A
where M::Target: 'static + chain::Watch<<SP::Target as SignerProvider>::Signer>,
T::Target: 'static + BroadcasterInterface,
ES::Target: 'static + EntropySource,
R::Target: 'static + Router,
L::Target: 'static + Logger,
{
- /// Persist the given ['ChannelManager'] to disk with the name "manager", returning an error if persistence failed.
+ /// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed.
fn persist_manager(&self, channel_manager: &ChannelManager<M, T, ES, NS, SP, F, R, L>) -> Result<(), io::Error> {
- self.persist("manager", channel_manager)
+ self.write(CHANNEL_MANAGER_PERSISTENCE_NAMESPACE,
+ CHANNEL_MANAGER_PERSISTENCE_SUB_NAMESPACE,
+ CHANNEL_MANAGER_PERSISTENCE_KEY,
+ &channel_manager.encode())
}
- /// Persist the given [`NetworkGraph`] to disk with the name "network_graph", returning an error if persistence failed.
+ /// Persist the given [`NetworkGraph`] to disk, returning an error if persistence failed.
fn persist_graph(&self, network_graph: &NetworkGraph<L>) -> Result<(), io::Error> {
- self.persist("network_graph", network_graph)
+ self.write(NETWORK_GRAPH_PERSISTENCE_NAMESPACE,
+ NETWORK_GRAPH_PERSISTENCE_SUB_NAMESPACE,
+ NETWORK_GRAPH_PERSISTENCE_KEY,
+ &network_graph.encode())
}
- /// Persist the given [`WriteableScore`] to disk with name "scorer", returning an error if persistence failed.
+ /// Persist the given [`WriteableScore`] to disk, returning an error if persistence failed.
fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error> {
- self.persist("scorer", &scorer)
+ self.write(SCORER_PERSISTENCE_NAMESPACE,
+ SCORER_PERSISTENCE_SUB_NAMESPACE,
+ SCORER_PERSISTENCE_KEY,
+ &scorer.encode())
}
}
-impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStorePersister> Persist<ChannelSigner> for K {
+impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStore> Persist<ChannelSigner> for K {
// TODO: We really need a way for the persister to inform the user that its time to crash/shut
// down once these start returning failure.
- // A PermanentFailure implies we should probably just shut down the node since we're
- // force-closing channels without even broadcasting!
+ // Then we should return InProgress rather than UnrecoverableError, implying we should probably
+ // just shut down the node since we're not retrying persistence!
fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
- let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
- match self.persist(&key, monitor) {
+ let key = format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
+ match self.write(
+ CHANNEL_MONITOR_PERSISTENCE_NAMESPACE,
+ CHANNEL_MONITOR_PERSISTENCE_SUB_NAMESPACE,
+ &key, &monitor.encode())
+ {
Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
- Err(_) => chain::ChannelMonitorUpdateStatus::PermanentFailure,
+ Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
}
}
fn update_persisted_channel(&self, funding_txo: OutPoint, _update: Option<&ChannelMonitorUpdate>, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
- let key = format!("monitors/{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
- match self.persist(&key, monitor) {
+ let key = format!("{}_{}", funding_txo.txid.to_hex(), funding_txo.index);
+ match self.write(
+ CHANNEL_MONITOR_PERSISTENCE_NAMESPACE,
+ CHANNEL_MONITOR_PERSISTENCE_SUB_NAMESPACE,
+ &key, &monitor.encode())
+ {
Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
- Err(_) => chain::ChannelMonitorUpdateStatus::PermanentFailure,
+ Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
+ }
+ }
+}
+
+/// Read previously persisted [`ChannelMonitor`]s from the store.
+pub fn read_channel_monitors<K: Deref, ES: Deref, SP: Deref>(
+ kv_store: K, entropy_source: ES, signer_provider: SP,
+) -> io::Result<Vec<(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::Signer>)>>
+where
+ K::Target: KVStore,
+ ES::Target: EntropySource + Sized,
+ SP::Target: SignerProvider + Sized,
+{
+ let mut res = Vec::new();
+
+ for stored_key in kv_store.list(
+ CHANNEL_MONITOR_PERSISTENCE_NAMESPACE, CHANNEL_MONITOR_PERSISTENCE_SUB_NAMESPACE)?
+ {
+ if stored_key.len() < 66 {
+ return Err(io::Error::new(
+ io::ErrorKind::InvalidData,
+ "Stored key has invalid length"));
+ }
+
+ let txid = Txid::from_hex(stored_key.split_at(64).0).map_err(|_| {
+ io::Error::new(io::ErrorKind::InvalidData, "Invalid tx ID in stored key")
+ })?;
+
+ let index: u16 = stored_key.split_at(65).1.parse().map_err(|_| {
+ io::Error::new(io::ErrorKind::InvalidData, "Invalid tx index in stored key")
+ })?;
+
+ match <(BlockHash, ChannelMonitor<<SP::Target as SignerProvider>::Signer>)>::read(
+ &mut io::Cursor::new(
+ kv_store.read(CHANNEL_MONITOR_PERSISTENCE_NAMESPACE, CHANNEL_MONITOR_PERSISTENCE_SUB_NAMESPACE, &stored_key)?),
+ (&*entropy_source, &*signer_provider),
+ ) {
+ Ok((block_hash, channel_monitor)) => {
+ if channel_monitor.get_funding_txo().0.txid != txid
+ || channel_monitor.get_funding_txo().0.index != index
+ {
+ return Err(io::Error::new(
+ io::ErrorKind::InvalidData,
+ "ChannelMonitor was stored under the wrong key",
+ ));
+ }
+ res.push((block_hash, channel_monitor));
+ }
+ Err(_) => {
+ return Err(io::Error::new(
+ io::ErrorKind::InvalidData,
+ "Failed to deserialize ChannelMonitor"
+ ))
+ }
}
}
+ Ok(res)
}