Skip to content

Commit 81c31d6

Browse files
tankyleotankyleo
committed
fmt
1 parent 504e727 commit 81c31d6

File tree

2 files changed

+127
-66
lines changed

2 files changed

+127
-66
lines changed

‎lightning/src/ln/channel.rs

Lines changed: 6 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -78,7 +78,9 @@ use crate::ln::types::ChannelId;
7878
use crate::ln::LN_MAX_MSG_LEN;
7979
use crate::routing::gossip::NodeId;
8080
use crate::sign::ecdsa::EcdsaChannelSigner;
81-
use crate::sign::tx_builder::{HTLCAmountDirection, ChannelConstraints, NextCommitmentStats, SpecTxBuilder, TxBuilder};
81+
use crate::sign::tx_builder::{
82+
ChannelConstraints, HTLCAmountDirection, NextCommitmentStats, SpecTxBuilder, TxBuilder,
83+
};
8284
use crate::sign::{ChannelSigner, EntropySource, NodeSigner, Recipient, SignerProvider};
8385
use crate::types::features::{ChannelTypeFeatures, InitFeatures};
8486
use crate::types::payment::{PaymentHash, PaymentPreimage};
@@ -4840,7 +4842,9 @@ where
48404842
fn get_holder_channel_constraints(&self, funding: &FundingScope) -> ChannelConstraints {
48414843
ChannelConstraints {
48424844
dust_limit_satoshis: self.holder_dust_limit_satoshis,
4843-
channel_reserve_satoshis: funding.counterparty_selected_channel_reserve_satoshis.unwrap_or(0),
4845+
channel_reserve_satoshis: funding
4846+
.counterparty_selected_channel_reserve_satoshis
4847+
.unwrap_or(0),
48444848
htlc_minimum_msat: self.holder_htlc_minimum_msat,
48454849
max_accepted_htlcs: self.holder_max_accepted_htlcs as u64,
48464850
max_htlc_value_in_flight_msat: self.holder_max_htlc_value_in_flight_msat,

‎lightning/src/sign/tx_builder.rs

Lines changed: 121 additions & 64 deletions
Original file line numberDiff line numberDiff line change
@@ -126,17 +126,11 @@ pub(crate) struct ChannelConstraints {
126126

127127
pub(crate) trait TxBuilder {
128128
fn get_available_balances(
129-
&self,
130-
is_outbound_from_holder: bool,
131-
channel_value_satoshis: u64,
132-
value_to_holder_msat: u64,
133-
pending_htlcs: &[HTLCAmountDirection],
134-
feerate_per_kw: u32,
135-
dust_exposure_limiting_feerate: Option<u32>,
136-
max_dust_htlc_exposure_msat: u64,
129+
&self, is_outbound_from_holder: bool, channel_value_satoshis: u64,
130+
value_to_holder_msat: u64, pending_htlcs: &[HTLCAmountDirection], feerate_per_kw: u32,
131+
dust_exposure_limiting_feerate: Option<u32>, max_dust_htlc_exposure_msat: u64,
137132
holder_channel_constraints: ChannelConstraints,
138-
counterparty_channel_constraints: ChannelConstraints,
139-
channel_type: &ChannelTypeFeatures,
133+
counterparty_channel_constraints: ChannelConstraints, channel_type: &ChannelTypeFeatures,
140134
) -> crate::ln::channel::AvailableBalances;
141135
fn get_next_commitment_stats(
142136
&self, local: bool, is_outbound_from_holder: bool, channel_value_satoshis: u64,
@@ -159,36 +153,60 @@ pub(crate) struct SpecTxBuilder {}
159153

160154
impl TxBuilder for SpecTxBuilder {
161155
fn get_available_balances(
162-
&self,
163-
is_outbound_from_holder: bool,
164-
channel_value_satoshis: u64,
165-
value_to_holder_msat: u64,
166-
pending_htlcs: &[HTLCAmountDirection],
167-
feerate_per_kw: u32,
168-
dust_exposure_limiting_feerate: Option<u32>,
169-
max_dust_htlc_exposure_msat: u64,
156+
&self, is_outbound_from_holder: bool, channel_value_satoshis: u64,
157+
value_to_holder_msat: u64, pending_htlcs: &[HTLCAmountDirection], feerate_per_kw: u32,
158+
dust_exposure_limiting_feerate: Option<u32>, max_dust_htlc_exposure_msat: u64,
170159
holder_channel_constraints: ChannelConstraints,
171-
counterparty_channel_constraints: ChannelConstraints,
172-
channel_type: &ChannelTypeFeatures,
160+
counterparty_channel_constraints: ChannelConstraints, channel_type: &ChannelTypeFeatures,
173161
) -> crate::ln::channel::AvailableBalances {
174-
let fee_spike_buffer_htlc = if channel_type.supports_anchor_zero_fee_commitments() {
175-
0
176-
} else {
177-
1
178-
};
179-
180-
let local_stats_max_fee = SpecTxBuilder {}.get_next_commitment_stats(true, is_outbound_from_holder, channel_value_satoshis, value_to_holder_msat, pending_htlcs, fee_spike_buffer_htlc + 1, feerate_per_kw, dust_exposure_limiting_feerate, holder_channel_constraints.dust_limit_satoshis, channel_type);
181-
let local_stats_min_fee = SpecTxBuilder {}.get_next_commitment_stats(true, is_outbound_from_holder, channel_value_satoshis, value_to_holder_msat, pending_htlcs, fee_spike_buffer_htlc, feerate_per_kw, dust_exposure_limiting_feerate, holder_channel_constraints.dust_limit_satoshis, channel_type);
182-
let remote_stats = SpecTxBuilder {}.get_next_commitment_stats(false, is_outbound_from_holder, channel_value_satoshis, value_to_holder_msat, pending_htlcs, 1, feerate_per_kw, dust_exposure_limiting_feerate, counterparty_channel_constraints.dust_limit_satoshis, channel_type);
162+
let fee_spike_buffer_htlc =
163+
if channel_type.supports_anchor_zero_fee_commitments() { 0 } else { 1 };
164+
165+
let local_stats_max_fee = SpecTxBuilder {}.get_next_commitment_stats(
166+
true,
167+
is_outbound_from_holder,
168+
channel_value_satoshis,
169+
value_to_holder_msat,
170+
pending_htlcs,
171+
fee_spike_buffer_htlc + 1,
172+
feerate_per_kw,
173+
dust_exposure_limiting_feerate,
174+
holder_channel_constraints.dust_limit_satoshis,
175+
channel_type,
176+
);
177+
let local_stats_min_fee = SpecTxBuilder {}.get_next_commitment_stats(
178+
true,
179+
is_outbound_from_holder,
180+
channel_value_satoshis,
181+
value_to_holder_msat,
182+
pending_htlcs,
183+
fee_spike_buffer_htlc,
184+
feerate_per_kw,
185+
dust_exposure_limiting_feerate,
186+
holder_channel_constraints.dust_limit_satoshis,
187+
channel_type,
188+
);
189+
let remote_stats = SpecTxBuilder {}.get_next_commitment_stats(
190+
false,
191+
is_outbound_from_holder,
192+
channel_value_satoshis,
193+
value_to_holder_msat,
194+
pending_htlcs,
195+
1,
196+
feerate_per_kw,
197+
dust_exposure_limiting_feerate,
198+
counterparty_channel_constraints.dust_limit_satoshis,
199+
channel_type,
200+
);
183201

184-
let outbound_capacity_msat = local_stats_max_fee.holder_balance_before_fee_msat.unwrap_or(0)
185-
.saturating_sub(
186-
holder_channel_constraints.channel_reserve_satoshis * 1000);
202+
let outbound_capacity_msat = local_stats_max_fee
203+
.holder_balance_before_fee_msat
204+
.unwrap_or(0)
205+
.saturating_sub(holder_channel_constraints.channel_reserve_satoshis * 1000);
187206

188207
let mut available_capacity_msat = outbound_capacity_msat;
189-
let (real_htlc_success_tx_fee_sat, real_htlc_timeout_tx_fee_sat) = second_stage_tx_fees_sat(
190-
channel_type, feerate_per_kw
191-
);
208+
let (real_htlc_success_tx_fee_sat, real_htlc_timeout_tx_fee_sat) =
209+
second_stage_tx_fees_sat(channel_type, feerate_per_kw);
192210

193211
if is_outbound_from_holder {
194212
// We should mind channel commit tx fee when computing how much of the available capacity
@@ -199,40 +217,54 @@ impl TxBuilder for SpecTxBuilder {
199217
// dependency.
200218
// This complicates the computation around dust-values, up to the one-htlc-value.
201219

202-
let real_dust_limit_timeout_sat = real_htlc_timeout_tx_fee_sat + holder_channel_constraints.dust_limit_satoshis;
220+
let real_dust_limit_timeout_sat =
221+
real_htlc_timeout_tx_fee_sat + holder_channel_constraints.dust_limit_satoshis;
203222
let mut max_reserved_commit_tx_fee_msat = local_stats_max_fee.commit_tx_fee_sat * 1000;
204223
let mut min_reserved_commit_tx_fee_msat = local_stats_min_fee.commit_tx_fee_sat * 1000;
205224

206225
if !channel_type.supports_anchors_zero_fee_htlc_tx() {
207-
max_reserved_commit_tx_fee_msat *= crate::ln::channel::FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
208-
min_reserved_commit_tx_fee_msat *= crate::ln::channel::FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
226+
max_reserved_commit_tx_fee_msat *=
227+
crate::ln::channel::FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
228+
min_reserved_commit_tx_fee_msat *=
229+
crate::ln::channel::FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
209230
}
210231

211232
// We will first subtract the fee as if we were above-dust. Then, if the resulting
212233
// value ends up being below dust, we have this fee available again. In that case,
213234
// match the value to right-below-dust.
214-
let capacity_minus_max_commitment_fee_msat = available_capacity_msat.saturating_sub(max_reserved_commit_tx_fee_msat);
235+
let capacity_minus_max_commitment_fee_msat =
236+
available_capacity_msat.saturating_sub(max_reserved_commit_tx_fee_msat);
215237
if capacity_minus_max_commitment_fee_msat < real_dust_limit_timeout_sat * 1000 {
216-
let capacity_minus_min_commitment_fee_msat = available_capacity_msat.saturating_sub(min_reserved_commit_tx_fee_msat);
217-
available_capacity_msat = cmp::min(real_dust_limit_timeout_sat * 1000 - 1, capacity_minus_min_commitment_fee_msat);
238+
let capacity_minus_min_commitment_fee_msat =
239+
available_capacity_msat.saturating_sub(min_reserved_commit_tx_fee_msat);
240+
available_capacity_msat = cmp::min(
241+
real_dust_limit_timeout_sat * 1000 - 1,
242+
capacity_minus_min_commitment_fee_msat,
243+
);
218244
} else {
219245
available_capacity_msat = capacity_minus_max_commitment_fee_msat;
220246
}
221247
} else {
222248
// If the channel is inbound (i.e. counterparty pays the fee), we need to make sure
223249
// sending a new HTLC won't reduce their balance below our reserve threshold.
224-
let real_dust_limit_success_sat = real_htlc_success_tx_fee_sat + counterparty_channel_constraints.dust_limit_satoshis;
250+
let real_dust_limit_success_sat =
251+
real_htlc_success_tx_fee_sat + counterparty_channel_constraints.dust_limit_satoshis;
225252
let max_reserved_commit_tx_fee_msat = remote_stats.commit_tx_fee_sat * 1000;
226253

227-
let holder_selected_chan_reserve_msat = counterparty_channel_constraints.channel_reserve_satoshis * 1000;
228-
if remote_stats.counterparty_balance_before_fee_msat.unwrap_or(0) < max_reserved_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
254+
let holder_selected_chan_reserve_msat =
255+
counterparty_channel_constraints.channel_reserve_satoshis * 1000;
256+
if remote_stats.counterparty_balance_before_fee_msat.unwrap_or(0)
257+
< max_reserved_commit_tx_fee_msat + holder_selected_chan_reserve_msat
258+
{
229259
// If another HTLC's fee would reduce the remote's balance below the reserve limit
230260
// we've selected for them, we can only send dust HTLCs.
231-
available_capacity_msat = cmp::min(available_capacity_msat, real_dust_limit_success_sat * 1000 - 1);
261+
available_capacity_msat =
262+
cmp::min(available_capacity_msat, real_dust_limit_success_sat * 1000 - 1);
232263
}
233264
}
234265

235-
let mut next_outbound_htlc_minimum_msat = counterparty_channel_constraints.htlc_minimum_msat;
266+
let mut next_outbound_htlc_minimum_msat =
267+
counterparty_channel_constraints.htlc_minimum_msat;
236268

237269
// If we get close to our maximum dust exposure, we end up in a situation where we can send
238270
// between zero and the remaining dust exposure limit remaining OR above the dust limit.
@@ -242,52 +274,77 @@ impl TxBuilder for SpecTxBuilder {
242274
let mut dust_exposure_dust_limit_msat = 0;
243275

244276
let dust_buffer_feerate = get_dust_buffer_feerate(feerate_per_kw);
245-
let (buffer_htlc_success_tx_fee_sat, buffer_htlc_timeout_tx_fee_sat) = second_stage_tx_fees_sat(
246-
channel_type, dust_buffer_feerate,
247-
);
248-
let buffer_dust_limit_success_sat = buffer_htlc_success_tx_fee_sat + counterparty_channel_constraints.dust_limit_satoshis;
249-
let buffer_dust_limit_timeout_sat = buffer_htlc_timeout_tx_fee_sat + holder_channel_constraints.dust_limit_satoshis;
250-
251-
if let Some(extra_htlc_dust_exposure) = remote_stats.extra_nondust_htlc_on_counterparty_tx_dust_exposure_msat {
277+
let (buffer_htlc_success_tx_fee_sat, buffer_htlc_timeout_tx_fee_sat) =
278+
second_stage_tx_fees_sat(channel_type, dust_buffer_feerate);
279+
let buffer_dust_limit_success_sat =
280+
buffer_htlc_success_tx_fee_sat + counterparty_channel_constraints.dust_limit_satoshis;
281+
let buffer_dust_limit_timeout_sat =
282+
buffer_htlc_timeout_tx_fee_sat + holder_channel_constraints.dust_limit_satoshis;
283+
284+
if let Some(extra_htlc_dust_exposure) =
285+
remote_stats.extra_nondust_htlc_on_counterparty_tx_dust_exposure_msat
286+
{
252287
if extra_htlc_dust_exposure > max_dust_htlc_exposure_msat {
253288
// If adding an extra HTLC would put us over the dust limit in total fees, we cannot
254289
// send any non-dust HTLCs.
255-
available_capacity_msat = cmp::min(available_capacity_msat, buffer_dust_limit_success_sat * 1000);
290+
available_capacity_msat =
291+
cmp::min(available_capacity_msat, buffer_dust_limit_success_sat * 1000);
256292
}
257293
}
258294

259-
if remote_stats.dust_exposure_msat.saturating_add(buffer_dust_limit_success_sat * 1000) > max_dust_htlc_exposure_msat.saturating_add(1) {
295+
if remote_stats.dust_exposure_msat.saturating_add(buffer_dust_limit_success_sat * 1000)
296+
> max_dust_htlc_exposure_msat.saturating_add(1)
297+
{
260298
// Note that we don't use the `counterparty_tx_dust_exposure` (with
261299
// `htlc_dust_exposure_msat`) here as it only applies to non-dust HTLCs.
262300
remaining_msat_below_dust_exposure_limit =
263301
Some(max_dust_htlc_exposure_msat.saturating_sub(remote_stats.dust_exposure_msat));
264-
dust_exposure_dust_limit_msat = cmp::max(dust_exposure_dust_limit_msat, buffer_dust_limit_success_sat * 1000);
302+
dust_exposure_dust_limit_msat =
303+
cmp::max(dust_exposure_dust_limit_msat, buffer_dust_limit_success_sat * 1000);
265304
}
266305

267-
if local_stats_max_fee.dust_exposure_msat as i64 + buffer_dust_limit_timeout_sat as i64 * 1000 - 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value()) {
306+
if local_stats_max_fee.dust_exposure_msat as i64
307+
+ buffer_dust_limit_timeout_sat as i64 * 1000
308+
- 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value())
309+
{
268310
remaining_msat_below_dust_exposure_limit = Some(cmp::min(
269311
remaining_msat_below_dust_exposure_limit.unwrap_or(u64::max_value()),
270-
max_dust_htlc_exposure_msat.saturating_sub(local_stats_max_fee.dust_exposure_msat)));
271-
dust_exposure_dust_limit_msat = cmp::max(dust_exposure_dust_limit_msat, buffer_dust_limit_timeout_sat * 1000);
312+
max_dust_htlc_exposure_msat.saturating_sub(local_stats_max_fee.dust_exposure_msat),
313+
));
314+
dust_exposure_dust_limit_msat =
315+
cmp::max(dust_exposure_dust_limit_msat, buffer_dust_limit_timeout_sat * 1000);
272316
}
273317

274318
if let Some(remaining_limit_msat) = remaining_msat_below_dust_exposure_limit {
275319
if available_capacity_msat < dust_exposure_dust_limit_msat {
276320
available_capacity_msat = cmp::min(available_capacity_msat, remaining_limit_msat);
277321
} else {
278-
next_outbound_htlc_minimum_msat = cmp::max(next_outbound_htlc_minimum_msat, dust_exposure_dust_limit_msat);
322+
next_outbound_htlc_minimum_msat =
323+
cmp::max(next_outbound_htlc_minimum_msat, dust_exposure_dust_limit_msat);
279324
}
280325
}
281326

282-
available_capacity_msat = cmp::min(available_capacity_msat,
283-
counterparty_channel_constraints.max_htlc_value_in_flight_msat - pending_htlcs.iter().filter(|htlc| htlc.outbound).map(|htlc| htlc.amount_msat).sum::<u64>());
327+
available_capacity_msat = cmp::min(
328+
available_capacity_msat,
329+
counterparty_channel_constraints.max_htlc_value_in_flight_msat
330+
- pending_htlcs
331+
.iter()
332+
.filter(|htlc| htlc.outbound)
333+
.map(|htlc| htlc.amount_msat)
334+
.sum::<u64>(),
335+
);
284336

285-
if pending_htlcs.iter().filter(|htlc| htlc.outbound).count() + 1 > counterparty_channel_constraints.max_accepted_htlcs as usize {
337+
if pending_htlcs.iter().filter(|htlc| htlc.outbound).count() + 1
338+
> counterparty_channel_constraints.max_accepted_htlcs as usize
339+
{
286340
available_capacity_msat = 0;
287341
}
288342

289343
crate::ln::channel::AvailableBalances {
290-
inbound_capacity_msat: remote_stats.counterparty_balance_before_fee_msat.unwrap_or(0).saturating_sub(counterparty_channel_constraints.channel_reserve_satoshis * 1000),
344+
inbound_capacity_msat: remote_stats
345+
.counterparty_balance_before_fee_msat
346+
.unwrap_or(0)
347+
.saturating_sub(counterparty_channel_constraints.channel_reserve_satoshis * 1000),
291348
outbound_capacity_msat,
292349
next_outbound_htlc_limit_msat: available_capacity_msat,
293350
next_outbound_htlc_minimum_msat,

0 commit comments

Comments
 (0)