lnwallet: expose output leases on WalletController interface

lnwallet/btcwallet/btcwallet.go

@@ -19,6 +19,7 @@ import (
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
 	"github.com/btcsuite/btcwallet/wallet/txrules"
 	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/btcsuite/btcwallet/wtxmgr"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
@@ -367,6 +368,27 @@ func (b *BtcWallet) UnlockOutpoint(o wire.OutPoint) {
 	b.wallet.UnlockOutpoint(o)
 }
 
+// LeaseOutput locks an output to the given ID, preventing it from being
+// available for any future coin selection attempts. The absolute time of the
+// lock's expiration is returned. The expiration of the lock can be extended by
+// successive invocations of this call. Outputs can be unlocked before their
+// expiration through `ReleaseOutput`.
+//
+// If the output is not known, wtxmgr.ErrUnknownOutput is returned. If the
+// output has already been locked to a different ID, then
+// wtxmgr.ErrOutputAlreadyLocked is returned.
+func (b *BtcWallet) LeaseOutput(id wtxmgr.LockID, op wire.OutPoint) (time.Time,
+	error) {
+	return b.wallet.LeaseOutput(id, op)
+}
+
+// ReleaseOutput unlocks an output, allowing it to be available for coin
+// selection if it remains unspent. The ID should match the one used to
+// originally lock the output.
+func (b *BtcWallet) ReleaseOutput(id wtxmgr.LockID, op wire.OutPoint) error {
+	return b.wallet.ReleaseOutput(id, op)
+}
+
 // ListUnspentWitness returns a slice of all the unspent outputs the wallet
 // controls which pay to witness programs either directly or indirectly.
 //

lnwallet/interface.go

@@ -4,12 +4,14 @@ import (
 	"errors"
 	"fmt"
 	"sync"
+	"time"
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
+	"github.com/btcsuite/btcwallet/wtxmgr"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 )
@@ -221,6 +223,22 @@ type WalletController interface {
 	// eligible for coin selection.
 	UnlockOutpoint(o wire.OutPoint)
 
+	// LeaseOutput locks an output to the given ID, preventing it from being
+	// available for any future coin selection attempts. The absolute time
+	// of the lock's expiration is returned. The expiration of the lock can
+	// be extended by successive invocations of this call. Outputs can be
+	// unlocked before their expiration through `ReleaseOutput`.
+	//
+	// If the output is not known, wtxmgr.ErrUnknownOutput is returned. If
+	// the output has already been locked to a different ID, then
+	// wtxmgr.ErrOutputAlreadyLocked is returned.
+	LeaseOutput(id wtxmgr.LockID, op wire.OutPoint) (time.Time, error)
+
+	// ReleaseOutput unlocks an output, allowing it to be available for coin
+	// selection if it remains unspent. The ID should match the one used to
+	// originally lock the output.
+	ReleaseOutput(id wtxmgr.LockID, op wire.OutPoint) error
+
 	// PublishTransaction performs cursory validation (dust checks, etc),
 	// then finally broadcasts the passed transaction to the Bitcoin network.
 	// If the transaction is rejected because it is conflicting with an

mock.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/chaincfg"
@@ -13,6 +14,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/btcsuite/btcwallet/wallet/txauthor"
+	"github.com/btcsuite/btcwallet/wtxmgr"
 
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/input"
@@ -322,6 +324,14 @@ func (*mockWalletController) ListTransactionDetails(_, _ int32) ([]*lnwallet.Tra
 }
 func (*mockWalletController) LockOutpoint(o wire.OutPoint)   {}
 func (*mockWalletController) UnlockOutpoint(o wire.OutPoint) {}
+
+func (*mockWalletController) LeaseOutput(wtxmgr.LockID, wire.OutPoint) (time.Time, error) {
+	return time.Now(), nil
+}
+func (*mockWalletController) ReleaseOutput(wtxmgr.LockID, wire.OutPoint) error {
+	return nil
+}
+
 func (m *mockWalletController) PublishTransaction(tx *wire.MsgTx, _ string) error {
 	m.publishedTransactions <- tx
 	return nil