Remove channelReserve.getOrElse(0 sat) (#2432)

With the requirements added by #2430, we can get rid of the superfluous degrees of freedom around channel reserve, while still leaving the model untouched.

eclair-core/src/main/scala/fr/acinq/eclair/channel/Commitments.scala

@@ -86,10 +86,8 @@ case class Commitments(channelId: ByteVector32,
  remotePerCommitmentSecrets: ShaChain) extends AbstractCommitments {
 
  require(channelFeatures.paysDirectlyToWallet == localParams.walletStaticPaymentBasepoint.isDefined, s"localParams.walletStaticPaymentBasepoint must be defined only for commitments that pay directly to our wallet (channel features: $channelFeatures")
- if (channelFeatures.hasFeature(DualFunding)) {
- require(localParams.requestedChannelReserve_opt.isEmpty, "custom local channel reserve is incompatible with dual-funded channels")
- require(remoteParams.requestedChannelReserve_opt.isEmpty, "custom remote channel reserve is incompatible with dual-funded channels")
- }
+ require(channelFeatures.hasFeature(DualFunding) == localParams.requestedChannelReserve_opt.isEmpty, "custom local channel reserve is incompatible with dual-funded channels")
+ require(channelFeatures.hasFeature(DualFunding) == remoteParams.requestedChannelReserve_opt.isEmpty, "custom remote channel reserve is incompatible with dual-funded channels")
 
  def nextRemoteCommit_opt: Option[RemoteCommit] = remoteNextCommitInfo.swap.toOption.map(_.nextRemoteCommit)
 
@@ -222,14 +220,14 @@ case class Commitments(channelId: ByteVector32,
  val localChannelReserve: Satoshi = if (channelFeatures.hasFeature(Features.DualFunding)) {
  (capacity / 100).max(remoteParams.dustLimit)
  } else {
- remoteParams.requestedChannelReserve_opt.getOrElse(0 sat)
+ remoteParams.requestedChannelReserve_opt.get // this is guarded by a require() in Commitments
  }
 
  /** Channel reserve that applies to our peer's funds. */
  val remoteChannelReserve: Satoshi = if (channelFeatures.hasFeature(Features.DualFunding)) {
  (capacity / 100).max(localParams.dustLimit)
  } else {
- localParams.requestedChannelReserve_opt.getOrElse(0 sat)
+ localParams.requestedChannelReserve_opt.get // this is guarded by a require() in Commitments
  }
 
  // NB: when computing availableBalanceForSend and availableBalanceForReceive, the initiator keeps an extra buffer on

eclair-core/src/main/scala/fr/acinq/eclair/channel/Helpers.scala

@@ -419,7 +419,7 @@ object Helpers {
  val reserve = if (channelFeatures.hasFeature(Features.DualFunding)) {
  ((localFundingAmount + remoteFundingAmount) / 100).max(localParams.dustLimit)
  } else {
- localParams.requestedChannelReserve_opt.getOrElse(0 sat)
+ localParams.requestedChannelReserve_opt.get
  }
  val missing = toRemoteMsat.truncateToSatoshi - reserve - fees
  if (missing < Satoshi(0)) {

eclair-core/src/main/scala/fr/acinq/eclair/channel/fsm/ChannelOpenSingleFunded.scala

@@ -88,7 +88,7 @@ trait ChannelOpenSingleFunded extends SingleFundingHandlers with ErrorHandlers {
  pushMsat = input.pushAmount_opt.getOrElse(0 msat),
  dustLimitSatoshis = input.localParams.dustLimit,
  maxHtlcValueInFlightMsat = input.localParams.maxHtlcValueInFlightMsat,
- channelReserveSatoshis = input.localParams.requestedChannelReserve_opt.getOrElse(0 sat),
+ channelReserveSatoshis = input.localParams.requestedChannelReserve_opt.get,
  htlcMinimumMsat = input.localParams.htlcMinimum,
  feeratePerKw = input.commitTxFeerate,
  toSelfDelay = input.localParams.toSelfDelay,
@@ -123,7 +123,7 @@ trait ChannelOpenSingleFunded extends SingleFundingHandlers with ErrorHandlers {
  val accept = AcceptChannel(temporaryChannelId = open.temporaryChannelId,
  dustLimitSatoshis = localParams.dustLimit,
  maxHtlcValueInFlightMsat = localParams.maxHtlcValueInFlightMsat,
- channelReserveSatoshis = localParams.requestedChannelReserve_opt.getOrElse(0 sat),
+ channelReserveSatoshis = localParams.requestedChannelReserve_opt.get,
  minimumDepth = minimumDepth.getOrElse(0),
  htlcMinimumMsat = localParams.htlcMinimum,
  toSelfDelay = localParams.toSelfDelay,

eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala

@@ -481,8 +481,9 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
 object CommitmentsSpec {
 
  def makeCommitments(toLocal: MilliSatoshi, toRemote: MilliSatoshi, feeRatePerKw: FeeratePerKw = FeeratePerKw(0 sat), dustLimit: Satoshi = 0 sat, isInitiator: Boolean = true, announceChannel: Boolean = true): Commitments = {
- val localParams = LocalParams(randomKey().publicKey, DeterministicWallet.KeyPath(Seq(42L)), dustLimit, UInt64.MaxValue, None, 1 msat, CltvExpiryDelta(144), 50, isInitiator, ByteVector.empty, None, Features.empty)
- val remoteParams = RemoteParams(randomKey().publicKey, dustLimit, UInt64.MaxValue, None, 1 msat, CltvExpiryDelta(144), 50, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, Features.empty, None)
+ val channelReserve = (toLocal + toRemote).truncateToSatoshi * 0.01
+ val localParams = LocalParams(randomKey().publicKey, DeterministicWallet.KeyPath(Seq(42L)), dustLimit, UInt64.MaxValue, Some(channelReserve), 1 msat, CltvExpiryDelta(144), 50, isInitiator, ByteVector.empty, None, Features.empty)
+ val remoteParams = RemoteParams(randomKey().publicKey, dustLimit, UInt64.MaxValue, Some(channelReserve), 1 msat, CltvExpiryDelta(144), 50, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, Features.empty, None)
  val commitmentInput = Funding.makeFundingInputInfo(randomBytes32(), 0, (toLocal + toRemote).truncateToSatoshi, randomKey().publicKey, remoteParams.fundingPubKey)
  Commitments(
  channelId = randomBytes32(),
@@ -504,8 +505,9 @@ object CommitmentsSpec {
  }
 
  def makeCommitments(toLocal: MilliSatoshi, toRemote: MilliSatoshi, localNodeId: PublicKey, remoteNodeId: PublicKey, announceChannel: Boolean): Commitments = {
- val localParams = LocalParams(localNodeId, DeterministicWallet.KeyPath(Seq(42L)), 0 sat, UInt64.MaxValue, None, 1 msat, CltvExpiryDelta(144), 50, isInitiator = true, ByteVector.empty, None, Features.empty)
- val remoteParams = RemoteParams(remoteNodeId, 0 sat, UInt64.MaxValue, None, 1 msat, CltvExpiryDelta(144), 50, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, Features.empty, None)
+ val channelReserve = (toLocal + toRemote).truncateToSatoshi * 0.01
+ val localParams = LocalParams(localNodeId, DeterministicWallet.KeyPath(Seq(42L)), 0 sat, UInt64.MaxValue, Some(channelReserve), 1 msat, CltvExpiryDelta(144), 50, isInitiator = true, ByteVector.empty, None, Features.empty)
+ val remoteParams = RemoteParams(remoteNodeId, 0 sat, UInt64.MaxValue, Some(channelReserve), 1 msat, CltvExpiryDelta(144), 50, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, randomKey().publicKey, Features.empty, None)
  val commitmentInput = Funding.makeFundingInputInfo(randomBytes32(), 0, (toLocal + toRemote).truncateToSatoshi, randomKey().publicKey, remoteParams.fundingPubKey)
  Commitments(
  channelId = randomBytes32(),

eclair-core/src/test/scala/fr/acinq/eclair/payment/PaymentPacketSpec.scala

@@ -370,8 +370,9 @@ object PaymentPacketSpec {
  }
 
  def makeCommitments(channelId: ByteVector32, testAvailableBalanceForSend: MilliSatoshi = 50000000 msat, testAvailableBalanceForReceive: MilliSatoshi = 50000000 msat, testCapacity: Satoshi = 100000 sat, channelFeatures: ChannelFeatures = ChannelFeatures()): Commitments = {
- val params = LocalParams(null, null, null, null, None, null, null, 0, isInitiator = true, null, None, null)
- val remoteParams = RemoteParams(randomKey().publicKey, null, null, None, null, null, maxAcceptedHtlcs = 0, null, null, null, null, null, null, None)
+ val channelReserve = testCapacity * 0.01
+ val params = LocalParams(null, null, null, null, Some(channelReserve), null, null, 0, isInitiator = true, null, None, null)
+ val remoteParams = RemoteParams(randomKey().publicKey, null, null, Some(channelReserve), null, null, maxAcceptedHtlcs = 0, null, null, null, null, null, null, None)
  val commitInput = InputInfo(OutPoint(randomBytes32(), 1), TxOut(testCapacity, Nil), Nil)
  val channelFlags = ChannelFlags.Private
  new Commitments(channelId, ChannelConfig.standard, channelFeatures, params, remoteParams, channelFlags, null, null, null, null, 0, 0, Map.empty, null, commitInput, null) {

eclair-core/src/test/scala/fr/acinq/eclair/router/RouterSpec.scala

@@ -695,7 +695,7 @@ class RouterSpec extends BaseRouterSpec {
 
  {
  // Private channels should also update the graph when HTLCs are relayed through them.
- val balances = Set(33000000 msat, 5000000 msat)
+ val balances = Set(4620000 msat, 32620000 msat)
  val commitments = CommitmentsSpec.makeCommitments(33000000 msat, 5000000 msat, a, g, announceChannel = false)
  sender.send(router, AvailableBalanceChanged(sender.ref, channelId_ag_private, scids_ab, commitments))
  sender.send(router, Router.GetRouterData)
@@ -705,7 +705,7 @@ class RouterSpec extends BaseRouterSpec {
  // And the graph should be updated too.
  val edge_ag = data.graphWithBalances.graph.getEdge(ChannelDesc(alias_ag_private, a, g)).get
  assert(edge_ag.capacity == channel_ag.capacity)
- assert(edge_ag.balance_opt.contains(33000000 msat))
+ assert(edge_ag.balance_opt.contains(balances.last))
  }
  }