Add test for FilesystemStore-to-FilesystemStore migration

lightning-persister/src/fs_store.rs

@@ -475,7 +475,9 @@ impl MigratableKVStore for FilesystemStore {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::test_utils::{do_read_write_remove_list_persist, do_test_store};
+	use crate::test_utils::{
+		do_read_write_remove_list_persist, do_test_data_migration, do_test_store,
+	};
 
 	use bitcoin::Txid;
 
@@ -508,6 +510,21 @@ mod tests {
 		do_read_write_remove_list_persist(&fs_store);
 	}
 
+	#[test]
+	fn test_data_migration() {
+		for move_data in [true, false] {
+			let mut source_temp_path = std::env::temp_dir();
+			source_temp_path.push("test_data_migration_source");
+			let mut source_store = FilesystemStore::new(source_temp_path);
+
+			let mut target_temp_path = std::env::temp_dir();
+			target_temp_path.push("test_data_migration_target");
+			let mut target_store = FilesystemStore::new(target_temp_path);
+
+			do_test_data_migration(&mut source_store, &mut target_store, move_data);
+		}
+	}
+
 	#[test]
 	fn test_if_monitors_is_not_dir() {
 		let store = FilesystemStore::new("test_monitors_is_not_dir".into());

lightning-persister/src/test_utils.rs

@@ -3,7 +3,10 @@ use lightning::ln::functional_test_utils::{
 	connect_block, create_announced_chan_between_nodes, create_chanmon_cfgs, create_dummy_block,
 	create_network, create_node_cfgs, create_node_chanmgrs, send_payment,
 };
-use lightning::util::persist::{read_channel_monitors, KVStore, KVSTORE_NAMESPACE_KEY_MAX_LEN};
+use lightning::util::persist::{
+	migrate_kv_store_data, read_channel_monitors, KVStore, MigratableKVStore,
+	KVSTORE_NAMESPACE_KEY_ALPHABET, KVSTORE_NAMESPACE_KEY_MAX_LEN,
+};
 use lightning::util::test_utils;
 use lightning::{check_added_monitors, check_closed_broadcast, check_closed_event};
 
@@ -59,6 +62,55 @@ pub(crate) fn do_read_write_remove_list_persist<K: KVStore + RefUnwindSafe>(kv_s
 	assert_eq!(listed_keys.len(), 0);
 }
 
+pub(crate) fn do_test_data_migration<S: MigratableKVStore, T: MigratableKVStore>(
+	source_store: &mut S, target_store: &mut T, move_data: bool,
+) {
+	// We fill the source with some bogus keys.
+	let primary_namespace_base = "testspace".to_string();
+	let secondary_namespace_base = "testsubspace".to_string();
+	let key_base = "testkey".to_string();
+	let alphabet_len = KVSTORE_NAMESPACE_KEY_ALPHABET.len();
+
+	let dummy_data = [42u8; 32];
+
+	let num_primary_namespaces = 5;
+	let num_secondary_namespaces = 5;
+	let num_keys = 10;
+	for i in 0..num_primary_namespaces {
+		let primary_ext = KVSTORE_NAMESPACE_KEY_ALPHABET.chars().nth(i % alphabet_len).unwrap();
+		let mut primary_namespace = primary_namespace_base.clone();
+		primary_namespace.push(primary_ext);
+		for j in 0..num_secondary_namespaces {
+			let secondary_ext =
+				KVSTORE_NAMESPACE_KEY_ALPHABET.chars().nth(j % alphabet_len).unwrap();
+			let mut secondary_namespace = secondary_namespace_base.clone();
+			secondary_namespace.push(secondary_ext);
+			for k in 0..num_keys {
+				let key_ext = KVSTORE_NAMESPACE_KEY_ALPHABET.chars().nth(k % alphabet_len).unwrap();
+				let mut key = key_base.clone();
+				key.push(key_ext);
+
+				source_store
+					.write(&primary_namespace, &secondary_namespace, &key, &dummy_data)
+					.unwrap();
+			}
+		}
+	}
+	let total_num_entries = num_primary_namespaces * num_secondary_namespaces * num_keys;
+	let all_keys = source_store.list_all_keys().unwrap();
+	assert_eq!(all_keys.len(), total_num_entries);
+
+	migrate_kv_store_data(source_store, target_store, move_data).unwrap();
+	if move_data {
+		assert_eq!(source_store.list_all_keys().unwrap().len(), 0);
+	}
+
+	assert_eq!(target_store.list_all_keys().unwrap().len(), total_num_entries);
+	for (p, s, k) in &all_keys {
+		assert_eq!(target_store.read(p, s, k).unwrap(), dummy_data);
+	}
+}
+
 // Integration-test the given KVStore implementation. Test relaying a few payments and check that
 // the persisted data is updated the appropriate number of times.
 pub(crate) fn do_test_store<K: KVStore>(store_0: &K, store_1: &K) {