lnwallet+funding: rename Capacity and FundingAmt

Instead use LocalFundingAmt and RemoteFundingAmt to make it clear who is
contributing funds.

fundingmanager.go

@@ -1087,8 +1087,8 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 		ChainHash:        &chainHash,
 		NodeID:           fmsg.peer.IdentityKey(),
 		NodeAddr:         fmsg.peer.Address(),
-		FundingAmount:   0,
-		Capacity:        amt,
+		LocalFundingAmt:  0,
+		RemoteFundingAmt: amt,
 		CommitFeePerKw:   lnwallet.SatPerKWeight(msg.FeePerKiloWeight),
 		FundingFeePerKw:  0,
 		PushMSat:         msg.PushAmount,
@@ -2786,8 +2786,8 @@ func (f *fundingManager) handleInitFundingMsg(msg *initFundingMsg) {
 		ChainHash:        &msg.chainHash,
 		NodeID:           peerKey,
 		NodeAddr:         msg.peer.Address(),
-		FundingAmount:   localAmt,
-		Capacity:        capacity,
+		LocalFundingAmt:  localAmt,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   commitFeePerKw,
 		FundingFeePerKw:  msg.fundingFeePerKw,
 		PushMSat:         msg.pushAmt,

lnwallet/interface_test.go

@@ -418,8 +418,8 @@ func testDualFundingReservationWorkflow(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   fundingAmount,
-		Capacity:        fundingAmount * 2,
+		LocalFundingAmt:  fundingAmount,
+		RemoteFundingAmt: fundingAmount,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -461,8 +461,8 @@ func testDualFundingReservationWorkflow(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           alicePub,
 		NodeAddr:         aliceAddr,
-		FundingAmount:   fundingAmount,
-		Capacity:        fundingAmount * 2,
+		LocalFundingAmt:  fundingAmount,
+		RemoteFundingAmt: fundingAmount,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -621,8 +621,8 @@ func testFundingTransactionLockedOutputs(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   fundingAmount,
-		Capacity:        fundingAmount,
+		LocalFundingAmt:  fundingAmount,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -643,8 +643,8 @@ func testFundingTransactionLockedOutputs(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   amt,
-		Capacity:        amt,
+		LocalFundingAmt:  amt,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -679,8 +679,8 @@ func testFundingCancellationNotEnoughFunds(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   fundingAmount,
-		Capacity:        fundingAmount,
+		LocalFundingAmt:  fundingAmount,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -769,8 +769,8 @@ func testReservationInitiatorBalanceBelowDustCancel(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   fundingAmount,
-		Capacity:        fundingAmount,
+		LocalFundingAmt:  fundingAmount,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         0,
@@ -850,8 +850,8 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           bobPub,
 		NodeAddr:         bobAddr,
-		FundingAmount:   fundingAmt,
-		Capacity:        fundingAmt,
+		LocalFundingAmt:  fundingAmt,
+		RemoteFundingAmt: 0,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         pushAmt,
@@ -893,8 +893,8 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 		ChainHash:        chainHash,
 		NodeID:           alicePub,
 		NodeAddr:         aliceAddr,
-		FundingAmount:   0,
-		Capacity:        fundingAmt,
+		LocalFundingAmt:  0,
+		RemoteFundingAmt: fundingAmt,
 		CommitFeePerKw:   feePerKw,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         pushAmt,

lnwallet/reservation.go

@@ -127,7 +127,7 @@ type ChannelReservation struct {
 // used only internally by lnwallet. In order to concurrent safety, the
 // creation of all channel reservations should be carried out via the
 // lnwallet.InitChannelReservation interface.
-func NewChannelReservation(capacity, fundingAmt btcutil.Amount,
+func NewChannelReservation(capacity, localFundingAmt btcutil.Amount,
 	commitFeePerKw SatPerKWeight, wallet *LightningWallet,
 	id uint64, pushMSat lnwire.MilliSatoshi, chainHash *chainhash.Hash,
 	flags lnwire.FundingFlag) (*ChannelReservation, error) {
@@ -139,14 +139,16 @@ func NewChannelReservation(capacity, fundingAmt btcutil.Amount,
 	)
 
 	commitFee := commitFeePerKw.FeeForWeight(input.CommitWeight)
-	fundingMSat := lnwire.NewMSatFromSatoshis(fundingAmt)
+	localFundingMSat := lnwire.NewMSatFromSatoshis(localFundingAmt)
+	// TODO(halseth): make method take remote funding amount direcly
+	// instead of inferring it from capacity and local amt.
 	capacityMSat := lnwire.NewMSatFromSatoshis(capacity)
 	feeMSat := lnwire.NewMSatFromSatoshis(commitFee)
 
 	// If we're the responder to a single-funder reservation, then we have
 	// no initial balance in the channel unless the remote party is pushing
 	// some funds to us within the first commitment state.
-	if fundingAmt == 0 {
+	if localFundingAmt == 0 {
 		ourBalance = pushMSat
 		theirBalance = capacityMSat - feeMSat - pushMSat
 		initiator = false
@@ -163,7 +165,7 @@ func NewChannelReservation(capacity, fundingAmt btcutil.Amount,
 		// TODO(roasbeef): need to rework fee structure in general and
 		// also when we "unlock" dual funder within the daemon
 
-		if capacity == fundingAmt {
+		if capacity == localFundingAmt {
 			// If we're initiating a single funder workflow, then
 			// we pay all the initial fees within the commitment
 			// transaction. We also deduct our balance by the
@@ -174,8 +176,8 @@ func NewChannelReservation(capacity, fundingAmt btcutil.Amount,
 			// Otherwise, this is a dual funder workflow where both
 			// slides split the amount funded and the commitment
 			// fee.
-			ourBalance = fundingMSat - (feeMSat / 2)
-			theirBalance = capacityMSat - fundingMSat - (feeMSat / 2) + pushMSat
+			ourBalance = localFundingMSat - (feeMSat / 2)
+			theirBalance = capacityMSat - localFundingMSat - (feeMSat / 2) + pushMSat
 		}
 
 		initiator = true

lnwallet/wallet.go

@@ -69,12 +69,13 @@ type InitFundingReserveMsg struct {
 	// workflow.
 	NodeAddr net.Addr
 
-	// FundingAmount is the amount of funds requested for this channel.
-	FundingAmount btcutil.Amount
+	// LocalFundingAmt is the amount of funds requested from us for this
+	// channel.
+	LocalFundingAmt btcutil.Amount
 
-	// Capacity is the total capacity of the channel which includes the
-	// amount of funds the remote party contributes (if any).
-	Capacity btcutil.Amount
+	// RemoteFundingAmnt is the amount of funds the remote will contribute
+	// to this channel.
+	RemoteFundingAmt btcutil.Amount
 
 	// CommitFeePerKw is the starting accepted satoshis/Kw fee for the set
 	// of initial commitment transactions. In order to ensure timely
@@ -431,7 +432,7 @@ func (l *LightningWallet) InitChannelReservation(
 // validate a funding reservation request.
 func (l *LightningWallet) handleFundingReserveRequest(req *InitFundingReserveMsg) {
 	// It isn't possible to create a channel with zero funds committed.
-	if req.FundingAmount+req.Capacity == 0 {
+	if req.LocalFundingAmt+req.RemoteFundingAmt == 0 {
 		err := ErrZeroCapacity()
 		req.err <- err
 		req.resp <- nil
@@ -449,9 +450,12 @@ func (l *LightningWallet) handleFundingReserveRequest(req *InitFundingReserveMsg
 		return
 	}
 
+	capacity := req.LocalFundingAmt + req.RemoteFundingAmt
+	localFundingAmt := req.LocalFundingAmt
+
 	id := atomic.AddUint64(&l.nextFundingID, 1)
 	reservation, err := NewChannelReservation(
-		req.Capacity, req.FundingAmount, req.CommitFeePerKw, l, id,
+		capacity, localFundingAmt, req.CommitFeePerKw, l, id,
 		req.PushMSat, l.Cfg.NetParams.GenesisHash, req.Flags,
 	)
 	if err != nil {
@@ -470,11 +474,11 @@ func (l *LightningWallet) handleFundingReserveRequest(req *InitFundingReserveMsg
 	// If we're on the receiving end of a single funder channel then we
 	// don't need to perform any coin selection. Otherwise, attempt to
 	// obtain enough coins to meet the required funding amount.
-	if req.FundingAmount != 0 {
+	if req.LocalFundingAmt != 0 {
 		// Coin selection is done on the basis of sat/kw, so we'll use
 		// the fee rate passed in to perform coin selection.
 		err := l.selectCoinsAndChange(
-			req.FundingFeePerKw, req.FundingAmount, req.MinConfs,
+			req.FundingFeePerKw, req.LocalFundingAmt, req.MinConfs,
 			reservation.ourContribution,
 		)
 		if err != nil {