Implement KVStoreUnpersister

Cargo.toml

@@ -24,6 +24,8 @@ chrono = "0.4"
 futures = "0.3"
 serde_json = { version = "1.0" }
 tokio = { version = "1", features = [ "io-util", "macros", "rt", "rt-multi-thread", "sync", "net", "time" ] }
+libc = "0.2"
+
 
 
 [profile.release]

src/io_utils.rs

@@ -5,11 +5,14 @@ use crate::{FilesystemLogger, LdkLiteConfig, NetworkGraph, Scorer};
 
 use lightning::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
 use lightning::util::ser::{Readable, ReadableArgs};
+use lightning_persister::FilesystemPersister;
 
 use rand::{thread_rng, RngCore};
 
 use std::fs;
 use std::io::{BufReader, Write};
+use std::os::unix::io::AsRawFd;
+use std::path::PathBuf;
 use std::sync::Arc;
 
 pub(crate) fn read_or_generate_seed_file(config: Arc<LdkLiteConfig>) -> Result<[u8; 32], Error> {
@@ -83,3 +86,37 @@ pub(crate) fn read_payment_info(config: Arc<LdkLiteConfig>) -> Result<Vec<Paymen
 
 	Ok(payments)
 }
+
+/// Provides an interface that allows a previously persisted key to be unpersisted.
+pub trait KVStoreUnpersister {
+	/// Unpersist (i.e., remove) the writeable previously persisted under the provided key.
+	/// Returns `true` if the key was present, and `false` otherwise.
+	fn unpersist(&self, key: &str) -> std::io::Result<bool>;
+}
+
+impl KVStoreUnpersister for FilesystemPersister {
+	fn unpersist(&self, key: &str) -> std::io::Result<bool> {
+		let mut dest_file = PathBuf::from(self.get_data_dir());
+		dest_file.push(key);
+
+		if !dest_file.is_file() {
+			return Ok(false);
+		}
+
+		fs::remove_file(&dest_file)?;
+		let parent_directory = dest_file.parent().unwrap();
+		let dir_file = fs::OpenOptions::new().read(true).open(parent_directory)?;
+		#[cfg(not(target_os = "windows"))]
+		{
+			unsafe {
+				libc::fsync(dir_file.as_raw_fd());
+			}
+		}
+
+		if dest_file.is_file() {
+			return Err(std::io::Error::new(std::io::ErrorKind::Other, "Unpersisting key failed"));
+		}
+
+		return Ok(true);
+	}
+}

src/payment_store.rs

@@ -1,4 +1,5 @@
 use crate::hex_utils;
+use crate::io_utils::KVStoreUnpersister;
 use crate::Error;
 
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
@@ -123,12 +124,12 @@ impl Writeable for PaymentStatus {
 /// The payment information will be persisted under this prefix.
 pub(crate) const PAYMENT_INFO_PERSISTENCE_PREFIX: &str = "payments";
 
-pub(crate) struct PaymentInfoStorage<K: KVStorePersister> {
+pub(crate) struct PaymentInfoStorage<K: KVStorePersister + KVStoreUnpersister> {
 	payments: Mutex<HashMap<PaymentHash, PaymentInfo>>,
 	persister: Arc<K>,
 }
 
-impl<K: KVStorePersister> PaymentInfoStorage<K> {
+impl<K: KVStorePersister + KVStoreUnpersister> PaymentInfoStorage<K> {
 	pub(crate) fn new(persister: Arc<K>) -> Self {
 		let payments = Mutex::new(HashMap::new());
 		Self { payments, persister }
@@ -157,9 +158,15 @@ impl<K: KVStorePersister> PaymentInfoStorage<K> {
 		return Ok(());
 	}
 
-	// TODO: Need an `unpersist` method for this?
-	//pub(crate) fn remove_payment(&self, payment_hash: &PaymentHash) -> Result<(), Error> {
-	//}
+	pub(crate) fn remove_payment(&self, payment_hash: &PaymentHash) -> Result<(), Error> {
+		let key = format!(
+			"{}/{}",
+			PAYMENT_INFO_PERSISTENCE_PREFIX,
+			hex_utils::to_string(&payment_hash.0)
+		);
+		self.persister.unpersist(&key)?;
+		Ok(())
+	}
 
 	pub(crate) fn payment(&self, payment_hash: &PaymentHash) -> Option<PaymentInfo> {
 		self.payments.lock().unwrap().get(payment_hash).cloned()