+/// Stores the session_priv for each part of a payment that is still pending. For versions 0.0.102
+/// and later, also stores information for retrying the payment.
+enum PendingOutboundPayment {
+ Legacy {
+ session_privs: HashSet<[u8; 32]>,
+ },
+ Retryable {
+ session_privs: HashSet<[u8; 32]>,
+ payment_hash: PaymentHash,
+ payment_secret: Option<PaymentSecret>,
+ pending_amt_msat: u64,
+ /// The total payment amount across all paths, used to verify that a retry is not overpaying.
+ total_msat: u64,
+ },
+}
+
+impl PendingOutboundPayment {
+ fn remove(&mut self, session_priv: &[u8; 32], part_amt_msat: u64) -> bool {
+ let remove_res = match self {
+ PendingOutboundPayment::Legacy { session_privs } |
+ PendingOutboundPayment::Retryable { session_privs, .. } => {
+ session_privs.remove(session_priv)
+ }
+ };
+ if remove_res {
+ if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, .. } = self {
+ *pending_amt_msat -= part_amt_msat;
+ }
+ }
+ remove_res
+ }
+
+ fn insert(&mut self, session_priv: [u8; 32], part_amt_msat: u64) -> bool {
+ let insert_res = match self {
+ PendingOutboundPayment::Legacy { session_privs } |
+ PendingOutboundPayment::Retryable { session_privs, .. } => {
+ session_privs.insert(session_priv)
+ }
+ };
+ if insert_res {
+ if let PendingOutboundPayment::Retryable { ref mut pending_amt_msat, .. } = self {
+ *pending_amt_msat += part_amt_msat;
+ }
+ }
+ insert_res
+ }
+
+ fn remaining_parts(&self) -> usize {
+ match self {
+ PendingOutboundPayment::Legacy { session_privs } |
+ PendingOutboundPayment::Retryable { session_privs, .. } => {
+ session_privs.len()
+ }
+ }
+ }
+}
+