Remove AvailableBalances::balance_msat

The ChannelMonitor::get_claimable_balances method provides 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.

diff --git a/fuzz/src/router.rs b/fuzz/src/router.rs
index 653491024d5745d1e687e8ab16e1b46920db57c3..6195e736618520bfaf9e4e87dca9ba2139988d8f 100644 (file)
--- a/fuzz/src/router.rs
+++ b/fuzz/src/router.rs
@@ -232,7 +232,6 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
                                                        force_close_spend_delay: None,
                                                        is_outbound: true, is_channel_ready: true,
                                                        is_usable: true, is_public: 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/chain/chainmonitor.rs b/lightning/src/chain/chainmonitor.rs
index 4514a65cc0e0a1b90630749c9db05752aabc2f74..de50f5777dde9792ae2ad93a0fcc3f3947b6a9b0 100644 (file)
--- a/lightning/src/chain/chainmonitor.rs
+++ b/lightning/src/chain/chainmonitor.rs
@@ -364,8 +364,7 @@ where C::Target: chain::Filter,
        /// claims which are awaiting confirmation.
        ///
        /// Includes the balances from each [`ChannelMonitor`] *except* those included in
-       /// `ignored_channels`, allowing you to filter out balances from channels which are still open
-       /// (and whose balance should likely be pulled from the [`ChannelDetails`]).
+       /// `ignored_channels`.
        ///
        /// See [`ChannelMonitor::get_claimable_balances`] for more details on the exact criteria for
        /// inclusion in the return value.

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 1978467ba57a3ae234944a8f429718a4b551328c..ea7cc1d4e83df160e158ca01e80a9a1cffe4cc9b 100644 (file)
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -65,8 +65,6 @@ pub struct ChannelValueStat {
 }
 
 pub struct AvailableBalances {
-       /// The amount that would go to us if we close the channel, ignoring any on-chain fees.
-       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.
@@ -1611,14 +1609,6 @@ impl<Signer: ChannelSigner> ChannelContext<Signer> {
                let inbound_stats = context.get_inbound_pending_htlc_stats(None);
                let outbound_stats = context.get_outbound_pending_htlc_stats(None);
 
-               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 -= outbound_stats.pending_htlcs_value_msat;
-
                let outbound_capacity_msat = context.value_to_self_msat
                                .saturating_sub(outbound_stats.pending_htlcs_value_msat)
                                .saturating_sub(
@@ -1735,7 +1725,6 @@ impl<Signer: ChannelSigner> ChannelContext<Signer> {
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: available_capacity_msat,
                        next_outbound_htlc_minimum_msat,
-                       balance_msat,
                }
        }
 

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index b7c7e03322725d2d34f957249f1fe049ac18b68f..94bbcf2ae678eb96693ec7a01c1ff4d0a2037bb4 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -1357,6 +1357,12 @@ pub struct ChannelCounterparty {
 }
 
 /// Details of a channel, as returned by [`ChannelManager::list_channels`] and [`ChannelManager::list_usable_channels`]
+///
+/// Balances of a channel are available through [`ChainMonitor::get_claimable_balances`] and
+/// [`ChannelMonitor::get_claimable_balances`], calculated with respect to the corresponding on-chain
+/// transactions.
+///
+/// [`ChainMonitor::get_claimable_balances`]: crate::chain::chainmonitor::ChainMonitor::get_claimable_balances
 #[derive(Clone, Debug, PartialEq)]
 pub struct ChannelDetails {
        /// The channel's ID (prior to funding transaction generation, this is a random 32 bytes,
@@ -1432,24 +1438,11 @@ 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`]
-       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.
@@ -1459,8 +1452,8 @@ 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
@@ -1588,7 +1581,6 @@ 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,
@@ -7621,7 +7613,7 @@ 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),
@@ -7657,7 +7649,7 @@ 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.
@@ -7683,6 +7675,8 @@ 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);
 
+               let _balance_msat: Option<u64> = _balance_msat;
+
                Ok(Self {
                        inbound_scid_alias,
                        channel_id: channel_id.0.unwrap(),
@@ -7695,7 +7689,6 @@ 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(),

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index b4316165bd1460894cad2c183162d363255e5585..04fc9927bb7a9446437d12d8633cc99d39a13434 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -2725,7 +2725,6 @@ 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,
@@ -6794,7 +6793,6 @@ 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/remove_balance_msat.txt b/pending_changelog/remove_balance_msat.txt
new file mode 100644 (file)
index 0000000..2ba5df1
--- /dev/null
+++ b/pending_changelog/remove_balance_msat.txt
@@ -0,0 +1 @@
+* The `AvailableBalances::balance_msat` field has been removed in favor of `ChannelMonitor::get_claimable_balances`. `ChannelDetails` serialized with versions of LDK >= 0.0.117 will have their `balance_msat` field set to `next_outbound_htlc_limit_msat` when read by versions of LDK prior to 0.0.117 (#2476).