Add `read_channel_monitors` utility

This replaces the `FilesystemPersister::read_channelmonitors` method, as
we can now implement a single utility for all `KVStore`s.

diff --git a/lightning/src/util/persist.rs b/lightning/src/util/persist.rs
index 35d19eea46bed18b702af7952396e4d6a7152174..5b122b7a5707cf990ae5126a862a596569ba47f8 100644 (file)
--- a/lightning/src/util/persist.rs
+++ b/lightning/src/util/persist.rs
@@ -9,7 +9,9 @@
 //! 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;
@@ -24,7 +26,7 @@ use crate::ln::channelmanager::ChannelManager;
 use crate::routing::router::Router;
 use crate::routing::gossip::NetworkGraph;
 use crate::util::logger::Logger;
-use crate::util::ser::Writeable;
+use crate::util::ser::{ReadableArgs, Writeable};
 
 /// The alphabet of characters allowed for namespaces and keys.
 pub const KVSTORE_NAMESPACE_KEY_ALPHABET: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
@@ -190,3 +192,52 @@ impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStorePersister> Persist<Ch
                }
        }
 }
+
+/// 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)?
+       {
+               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)
+}