From: Elias Rohrer Date: Tue, 1 Aug 2023 08:24:53 +0000 (+0200) Subject: Add `KVStore` interface trait X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=ef7448c3bb8c455cf81a3c36277fed8efeb23da8;p=rust-lightning Add `KVStore` interface trait We upstream the `KVStore` interface trait from LDK Node, which will replace `KVStorePersister` in the coming commits. Besides persistence, `KVStore` implementations will also offer to `list` keys present in a given `namespace` and `read` the stored values. --- diff --git a/lightning/src/util/persist.rs b/lightning/src/util/persist.rs index 435ef30d3..1597258e3 100644 --- a/lightning/src/util/persist.rs +++ b/lightning/src/util/persist.rs @@ -11,6 +11,7 @@ use core::ops::Deref; use bitcoin::hashes::hex::ToHex; use crate::io; +use crate::prelude::{Vec, String}; use crate::routing::scoring::WriteableScore; use crate::chain; @@ -22,7 +23,58 @@ 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}; +use crate::util::logger::Logger; +use crate::util::ser::Writeable; + +/// The namespace under which the [`ChannelManager`] will be persisted. +pub const CHANNEL_MANAGER_PERSISTENCE_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 namespace under which the [`NetworkGraph`] will be persisted. +pub const NETWORK_GRAPH_PERSISTENCE_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 key under which the [`WriteableScore`] will be persisted. +pub const SCORER_PERSISTENCE_KEY: &str = "scorer"; + +/// Provides an interface that allows to store and retrieve persisted values that are associated +/// with given keys. +/// +/// In order to avoid collisions the key space is segmented based on the given `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 and the empty namespace (`""`) is +/// assumed to be valid namespace. +pub trait KVStore { + /// A reader as returned by [`Self::read`]. + type Reader: io::Read; + /// Returns an [`io::Read`] for the given `namespace` and `key` from which [`Readable`]s may be + /// read. + /// + /// Returns an [`ErrorKind::NotFound`] if the given `key` could not be found in the given `namespace`. + /// + /// [`Readable`]: crate::util::ser::Readable + /// [`ErrorKind::NotFound`]: io::ErrorKind::NotFound + fn read(&self, namespace: &str, key: &str) -> io::Result; + /// Persists the given data under the given `key`. + /// + /// Will create the given `namespace` if not already present in the store. + fn write(&self, namespace: &str, key: &str, buf: &[u8]) -> io::Result<()>; + /// Removes any data that had previously been persisted under the given `key`. + fn remove(&self, namespace: &str, key: &str) -> io::Result<()>; + /// Returns a list of keys that are stored under the given `namespace`. + /// + /// Will return an empty list if the `namespace` is unknown. + fn list(&self, namespace: &str) -> io::Result>; +} /// Trait for a key-value store for persisting some writeable object at some key /// Implementing `KVStorePersister` provides auto-implementations for [`Persister`]