Remove AvailableBalances::balance_msat

The ChannelMonitor::get_claimable_balances and ChainMonitor::get_claimable_balances
methods provide a more straightforward approach to the balance of a channel, which
satisfies most use cases. The computation of AvailableBalances::balance_msat is
complex and originally had a different purpose that is not applicable
anymore.

Co-authored-by: Willem Van Lint <noreply@wvanlint.dev>

diff --git a/fuzz/src/router.rs b/fuzz/src/router.rs
index 41e8162575aef7ff22e89d542f748ebf4cd3a8f1..df97cbb978a3363c151bdfdd7bbd88d99a1ca8ce 100644 (file)
--- a/fuzz/src/router.rs
+++ b/fuzz/src/router.rs
@@ -242,7 +242,6 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                        is_channel_ready: true,
                                                        is_usable: true,
                                                        is_announced: true,
-                                                       balance_msat: 0,
                                                        outbound_capacity_msat: capacity.saturating_mul(1000),
                                                        next_outbound_htlc_limit_msat: capacity.saturating_mul(1000),
                                                        next_outbound_htlc_minimum_msat: 0,

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 641a61c31402264f8b13f9ccd8b69ed8f38f89cd..13e0e7e5172bf26d708abb2d474fe164d6b07408 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -79,9 +79,6 @@ pub struct ChannelValueStat {
 }
 
 pub struct AvailableBalances {
-       /// The amount that would go to us if we close the channel, ignoring any on-chain fees.
-       #[deprecated(since = "0.0.124", note = "use [`ChainMonitor::get_claimable_balances`] instead")]
-       pub balance_msat: u64,
        /// Total amount available for our counterparty to send to us.
        pub inbound_capacity_msat: u64,
        /// Total amount available for us to send to our counterparty.
@@ -3089,14 +3086,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                let dust_exposure_limiting_feerate = self.get_dust_exposure_limiting_feerate(&fee_estimator);
                let htlc_stats = context.get_pending_htlc_stats(None, dust_exposure_limiting_feerate);
 
-               let mut balance_msat = context.value_to_self_msat;
-               for ref htlc in context.pending_inbound_htlcs.iter() {
-                       if let InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(_)) = htlc.state {
-                               balance_msat += htlc.amount_msat;
-                       }
-               }
-               balance_msat -= htlc_stats.pending_outbound_htlcs_value_msat;
-
                let outbound_capacity_msat = context.value_to_self_msat
                                .saturating_sub(htlc_stats.pending_outbound_htlcs_value_msat)
                                .saturating_sub(
@@ -3238,7 +3227,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: available_capacity_msat,
                        next_outbound_htlc_minimum_msat,
-                       balance_msat,
                }
        }
 

diff --git a/lightning/src/ln/channel_state.rs b/lightning/src/ln/channel_state.rs
index 97e6b0af10cd5c96a3bf27171669d800fcbee6d7..6f5ed5afe8242aba73ee3f372a8acd563868f206 100644 (file)
--- a/lightning/src/ln/channel_state.rs
+++ b/lightning/src/ln/channel_state.rs
@@ -359,25 +359,11 @@ pub struct ChannelDetails {
        ///
        /// This value will be `None` for objects serialized with LDK versions prior to 0.0.115.
        pub feerate_sat_per_1000_weight: Option<u32>,
-       /// Our total balance.  This is the amount we would get if we close the channel.
-       /// This value is not exact. Due to various in-flight changes and feerate changes, exactly this
-       /// amount is not likely to be recoverable on close.
-       ///
-       /// This does not include any pending HTLCs which are not yet fully resolved (and, thus, whose
-       /// balance is not available for inclusion in new outbound HTLCs). This further does not include
-       /// any pending outgoing HTLCs which are awaiting some other resolution to be sent.
-       /// This does not consider any on-chain fees.
-       ///
-       /// See also [`ChannelDetails::outbound_capacity_msat`]
-       #[deprecated(since = "0.0.124", note = "use [`ChainMonitor::get_claimable_balances`] instead")]
-       pub balance_msat: u64,
        /// The available outbound capacity for sending HTLCs to the remote peer. This does not include
        /// any pending HTLCs which are not yet fully resolved (and, thus, whose balance is not
        /// available for inclusion in new outbound HTLCs). This further does not include any pending
        /// outgoing HTLCs which are awaiting some other resolution to be sent.
        ///
-       /// See also [`ChannelDetails::balance_msat`]
-       ///
        /// This value is not exact. Due to various in-flight changes, feerate changes, and our
        /// conflict-avoidance policy, exactly this amount is not likely to be spendable. However, we
        /// should be able to spend nearly this amount.
@@ -387,8 +373,8 @@ pub struct ChannelDetails {
        /// the current state and per-HTLC limit(s). This is intended for use when routing, allowing us
        /// to use a limit as close as possible to the HTLC limit we can currently send.
        ///
-       /// See also [`ChannelDetails::next_outbound_htlc_minimum_msat`],
-       /// [`ChannelDetails::balance_msat`], and [`ChannelDetails::outbound_capacity_msat`].
+       /// See also [`ChannelDetails::next_outbound_htlc_minimum_msat`] and
+       /// [`ChannelDetails::outbound_capacity_msat`].
        pub next_outbound_htlc_limit_msat: u64,
        /// The minimum value for sending a single HTLC to the remote peer. This is the equivalent of
        /// [`ChannelDetails::next_outbound_htlc_limit_msat`] but represents a lower-bound, rather than
@@ -540,7 +526,6 @@ impl ChannelDetails {
                        channel_value_satoshis: context.get_value_satoshis(),
                        feerate_sat_per_1000_weight: Some(context.get_feerate_sat_per_1000_weight()),
                        unspendable_punishment_reserve: to_self_reserve_satoshis,
-                       balance_msat: balance.balance_msat,
                        inbound_capacity_msat: balance.inbound_capacity_msat,
                        outbound_capacity_msat: balance.outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: balance.next_outbound_htlc_limit_msat,
@@ -584,7 +569,7 @@ impl Writeable for ChannelDetails {
                                (10, self.channel_value_satoshis, required),
                                (12, self.unspendable_punishment_reserve, option),
                                (14, user_channel_id_low, required),
-                               (16, self.balance_msat, required),
+                               (16, self.next_outbound_htlc_limit_msat, required), // Forwards compatibility for removed balance_msat field.
                                (18, self.outbound_capacity_msat, required),
                                (19, self.next_outbound_htlc_limit_msat, required),
                                (20, self.inbound_capacity_msat, required),
@@ -623,7 +608,7 @@ impl Readable for ChannelDetails {
                        (10, channel_value_satoshis, required),
                        (12, unspendable_punishment_reserve, option),
                        (14, user_channel_id_low, required),
-                       (16, balance_msat, required),
+                       (16, _balance_msat, option), // Backwards compatibility for removed balance_msat field.
                        (18, outbound_capacity_msat, required),
                        // Note that by the time we get past the required read above, outbound_capacity_msat will be
                        // filled in, so we can safely unwrap it here.
@@ -651,7 +636,8 @@ impl Readable for ChannelDetails {
                let user_channel_id = user_channel_id_low as u128
                        + ((user_channel_id_high_opt.unwrap_or(0 as u64) as u128) << 64);
 
-               #[allow(deprecated)] // TODO: Remove once balance_msat is removed.
+               let _balance_msat: Option<u64> = _balance_msat;
+
                Ok(Self {
                        inbound_scid_alias,
                        channel_id: channel_id.0.unwrap(),
@@ -664,7 +650,6 @@ impl Readable for ChannelDetails {
                        channel_value_satoshis: channel_value_satoshis.0.unwrap(),
                        unspendable_punishment_reserve,
                        user_channel_id,
-                       balance_msat: balance_msat.0.unwrap(),
                        outbound_capacity_msat: outbound_capacity_msat.0.unwrap(),
                        next_outbound_htlc_limit_msat: next_outbound_htlc_limit_msat.0.unwrap(),
                        next_outbound_htlc_minimum_msat: next_outbound_htlc_minimum_msat.0.unwrap(),
@@ -762,7 +747,6 @@ mod tests {
                        inbound_scid_alias: None,
                        channel_value_satoshis: 50_100,
                        user_channel_id: (u64::MAX as u128) + 1, // Gets us into the high bytes
-                       balance_msat: 23_100,
                        outbound_capacity_msat: 24_300,
                        next_outbound_htlc_limit_msat: 20_000,
                        next_outbound_htlc_minimum_msat: 132,

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index a25609c89bbe8f85414989f6abeef2044a58fb89..7e063dc9cee29b241fa585161488b68a6a315a8b 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -3609,7 +3609,6 @@ mod tests {
                        inbound_scid_alias: None,
                        channel_value_satoshis: 0,
                        user_channel_id: 0,
-                       balance_msat: 0,
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: outbound_capacity_msat,
                        next_outbound_htlc_minimum_msat: 0,
@@ -8793,7 +8792,6 @@ pub(crate) mod bench_utils {
                        outbound_scid_alias: None,
                        channel_value_satoshis: 10_000_000_000,
                        user_channel_id: 0,
-                       balance_msat: 10_000_000_000,
                        outbound_capacity_msat: 10_000_000_000,
                        next_outbound_htlc_minimum_msat: 0,
                        next_outbound_htlc_limit_msat: 10_000_000_000,

diff --git a/pending_changelog/3243-remove-balance_msat.txt b/pending_changelog/3243-remove-balance_msat.txt
new file mode 100644 (file)
index 0000000..6378bd7
--- /dev/null
+++ b/pending_changelog/3243-remove-balance_msat.txt
@@ -0,0 +1 @@
+* The `AvailableBalances::balance_msat` field has been removed in favor of `ChainMonitor::get_claimable_balances`. `ChannelDetails` serialized with versions of LDK >= 0.0.125 will have their `balance_msat` field set to `next_outbound_htlc_limit_msat` when read by versions of LDK prior to 0.0.125 (#3243).