wallet: expose persistent output leases

go.sum

@@ -27,6 +27,7 @@ github.com/coreos/bbolt v1.3.3 h1:n6AiVyVRKQFNb6mJlwESEvvLoDyiTzXX7ORAUlkeBdY=
 github.com/coreos/bbolt v1.3.3/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495 h1:6IyqGr3fnd0tM3YxipK27TUskaOVUjU2nG45yzwcQKY=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
@@ -59,6 +60,8 @@ github.com/lightninglabs/gozmq v0.0.0-20191113021534-d20a764486bf h1:HZKvJUHlcXI
 github.com/lightninglabs/gozmq v0.0.0-20191113021534-d20a764486bf/go.mod h1:vxmQPeIQxPf6Jf9rM8R+B4rKBqLA2AjttNxkFBL2Plk=
 github.com/lightninglabs/neutrino v0.11.0 h1:lPpYFCtsfJX2W5zI4pWycPmbbBdr7zU+BafYdLoD6k0=
 github.com/lightninglabs/neutrino v0.11.0/go.mod h1:CuhF0iuzg9Sp2HO6ZgXgayviFTn1QHdSTJlMncK80wg=
+github.com/lightningnetwork/lnd/clock v1.0.1 h1:QQod8+m3KgqHdvVMV+2DRNNZS1GRFir8mHZYA+Z2hFo=
+github.com/lightningnetwork/lnd/clock v1.0.1/go.mod h1:KnQudQ6w0IAMZi1SgvecLZQZ43ra2vpDNj7H/aasemg=
 github.com/lightningnetwork/lnd/queue v1.0.1 h1:jzJKcTy3Nj5lQrooJ3aaw9Lau3I0IwvQR5sqtjdv2R0=
 github.com/lightningnetwork/lnd/queue v1.0.1/go.mod h1:vaQwexir73flPW43Mrm7JOgJHmcEFBWWSl9HlyASoms=
 github.com/lightningnetwork/lnd/ticker v1.0.0 h1:S1b60TEGoTtCe2A0yeB+ecoj/kkS4qpwh6l+AkQEZwU=
@@ -71,6 +74,9 @@ github.com/onsi/gomega v1.4.1 h1:PZSj/UFNaVp3KxrzHOcS7oyuWA7LoOY/77yCTEFu21U=
 github.com/onsi/gomega v1.4.1/go.mod h1:C1qb7wdrVGGVU+Z6iS04AVkA3Q65CEZX59MT0QO5uiA=
 github.com/onsi/gomega v1.4.3 h1:RE1xgDvH7imwFD45h+u2SgIfERHlS2yNG4DObb5BSKU=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 go.etcd.io/bbolt v1.3.3 h1:MUGmc65QhB3pIlaQ5bB4LwqSj6GIonVJXpZiaKNyaKk=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44 h1:9lP3x0pW80sDI6t1UMSLA4to18W7R7imwAI/sWS9S8Q=

wallet/wallet.go

@@ -315,9 +315,9 @@ func (w *Wallet) SetChainSynced(synced bool) {
 // activeData returns the currently-active receiving addresses and all unspent
 // outputs.  This is primarely intended to provide the parameters for a
 // rescan request.
-func (w *Wallet) activeData(dbtx walletdb.ReadTx) ([]btcutil.Address, []wtxmgr.Credit, error) {
+func (w *Wallet) activeData(dbtx walletdb.ReadWriteTx) ([]btcutil.Address, []wtxmgr.Credit, error) {
 	addrmgrNs := dbtx.ReadBucket(waddrmgrNamespaceKey)
-	txmgrNs := dbtx.ReadBucket(wtxmgrNamespaceKey)
+	txmgrNs := dbtx.ReadWriteBucket(wtxmgrNamespaceKey)
 
 	var addrs []btcutil.Address
 	err := w.Manager.ForEachRelevantActiveAddress(
@@ -329,6 +329,16 @@ func (w *Wallet) activeData(dbtx walletdb.ReadTx) ([]btcutil.Address, []wtxmgr.C
 	if err != nil {
 		return nil, nil, err
 	}
+
+	// Before requesting the list of spendable UTXOs, we'll delete any
+	// expired output locks.
+	err = w.TxStore.DeleteExpiredLockedOutputs(
+		dbtx.ReadWriteBucket(wtxmgrNamespaceKey),
+	)
+	if err != nil {
+		return nil, nil, err
+	}
+
 	unspent, err := w.TxStore.UnspentOutputs(txmgrNs)
 	return addrs, unspent, err
 }
@@ -508,7 +518,7 @@ func (w *Wallet) syncWithChain(birthdayStamp *waddrmgr.BlockStamp) error {
 		addrs   []btcutil.Address
 		unspent []wtxmgr.Credit
 	)
-	err = walletdb.View(w.db, func(dbtx walletdb.ReadTx) error {
+	err = walletdb.Update(w.db, func(dbtx walletdb.ReadWriteTx) error {
 		addrs, unspent, err = w.activeData(dbtx)
 		return err
 	})
@@ -2854,6 +2864,42 @@ func (w *Wallet) LockedOutpoints() []btcjson.TransactionInput {
 	return locked
 }
 
+// LeaseOutput locks an output to the given ID, preventing it from being
+// available for coin selection. 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 `UnlockOutput`.
+// Otherwise, they are unlocked lazily through calls which iterate through all
+// known outputs, e.g., `CalculateBalance`, `ListUnspent`.
+//
+// If the output is not known, ErrUnknownOutput is returned. If the output has
+// already been locked to a different ID, then ErrOutputAlreadyLocked is
+// returned.
+//
+// NOTE: This differs from LockOutpoint in that outputs are locked for a limited
+// amount of time and their locks are persisted to disk.
+func (w *Wallet) LeaseOutput(id wtxmgr.LockID, op wire.OutPoint) (time.Time, error) {
+	var expiry time.Time
+	err := walletdb.Update(w.db, func(tx walletdb.ReadWriteTx) error {
+		ns := tx.ReadWriteBucket(wtxmgrNamespaceKey)
+		var err error
+		expiry, err = w.TxStore.LockOutput(ns, id, op)
+		return err
+	})
+	return expiry, err
+}
+
+// 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 (w *Wallet) ReleaseOutput(id wtxmgr.LockID, op wire.OutPoint) error {
+	return walletdb.Update(w.db, func(tx walletdb.ReadWriteTx) error {
+		ns := tx.ReadWriteBucket(wtxmgrNamespaceKey)
+		return w.TxStore.UnlockOutput(ns, id, op)
+	})
+}
+
 // resendUnminedTxs iterates through all transactions that spend from wallet
 // credits that are not known to have been mined into a block, and attempts
 // to send each to the chain server for relay.