reservation: update reservation state machine

This commit updates the reservation statemachine to
allow for locking and spending of the
initial reservation.

instantout/reservation/actions.go

@@ -7,6 +7,7 @@ import (
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightninglabs/loop/fsm"
 	looprpc "github.com/lightninglabs/loop/swapserverrpc"
+	"github.com/lightningnetwork/lnd/chainntnfs"
 )
 
 // InitReservationContext contains the request parameters for a reservation.
@@ -21,18 +22,18 @@ type InitReservationContext struct {
 // InitAction is the action that is executed when the reservation state machine
 // is initialized. It creates the reservation in the database and dispatches the
 // payment to the server.
-func (r *FSM) InitAction(eventCtx fsm.EventContext) fsm.EventType {
+func (f *FSM) InitAction(eventCtx fsm.EventContext) fsm.EventType {
 	// Check if the context is of the correct type.
 	reservationRequest, ok := eventCtx.(*InitReservationContext)
 	if !ok {
-		return r.HandleError(fsm.ErrInvalidContextType)
+		return f.HandleError(fsm.ErrInvalidContextType)
 	}
 
-	keyRes, err := r.cfg.Wallet.DeriveNextKey(
-		r.ctx, KeyFamily,
+	keyRes, err := f.cfg.Wallet.DeriveNextKey(
+		f.ctx, KeyFamily,
 	)
 	if err != nil {
-		return r.HandleError(err)
+		return f.HandleError(err)
 	}
 
 	// Send the client reservation details to the server.
@@ -44,9 +45,9 @@ func (r *FSM) InitAction(eventCtx fsm.EventContext) fsm.EventType {
 		ClientKey:     keyRes.PubKey.SerializeCompressed(),
 	}
 
-	_, err = r.cfg.ReservationClient.OpenReservation(r.ctx, request)
+	_, err = f.cfg.ReservationClient.OpenReservation(f.ctx, request)
 	if err != nil {
-		return r.HandleError(err)
+		return f.HandleError(err)
 	}
 
 	reservation, err := NewReservation(
@@ -59,15 +60,15 @@ func (r *FSM) InitAction(eventCtx fsm.EventContext) fsm.EventType {
 		keyRes.KeyLocator,
 	)
 	if err != nil {
-		return r.HandleError(err)
+		return f.HandleError(err)
 	}
 
-	r.reservation = reservation
+	f.reservation = reservation
 
 	// Create the reservation in the database.
-	err = r.cfg.Store.CreateReservation(r.ctx, reservation)
+	err = f.cfg.Store.CreateReservation(f.ctx, reservation)
 	if err != nil {
-		return r.HandleError(err)
+		return f.HandleError(err)
 	}
 
 	return OnBroadcast
@@ -76,101 +77,163 @@ func (r *FSM) InitAction(eventCtx fsm.EventContext) fsm.EventType {
 // SubscribeToConfirmationAction is the action that is executed when the
 // reservation is waiting for confirmation. It subscribes to the confirmation
 // of the reservation transaction.
-func (r *FSM) SubscribeToConfirmationAction(_ fsm.EventContext) fsm.EventType {
-	pkscript, err := r.reservation.GetPkScript()
+func (f *FSM) SubscribeToConfirmationAction(_ fsm.EventContext) fsm.EventType {
+	pkscript, err := f.reservation.GetPkScript()
 	if err != nil {
-		return r.HandleError(err)
+		return f.HandleError(err)
 	}
 
-	callCtx, cancel := context.WithCancel(r.ctx)
+	callCtx, cancel := context.WithCancel(f.ctx)
 	defer cancel()
 
 	// Subscribe to the confirmation of the reservation transaction.
 	log.Debugf("Subscribing to conf for reservation: %x pkscript: %x, "+
-		"initiation height: %v", r.reservation.ID, pkscript,
-		r.reservation.InitiationHeight)
+		"initiation height: %v", f.reservation.ID, pkscript,
+		f.reservation.InitiationHeight)
 
-	confChan, errConfChan, err := r.cfg.ChainNotifier.RegisterConfirmationsNtfn(
+	confChan, errConfChan, err := f.cfg.ChainNotifier.RegisterConfirmationsNtfn(
 		callCtx, nil, pkscript, DefaultConfTarget,
-		r.reservation.InitiationHeight,
+		f.reservation.InitiationHeight,
 	)
 	if err != nil {
-		r.Errorf("unable to subscribe to conf notification: %v", err)
-		return r.HandleError(err)
+		f.Errorf("unable to subscribe to conf notification: %v", err)
+		return f.HandleError(err)
 	}
 
-	blockChan, errBlockChan, err := r.cfg.ChainNotifier.RegisterBlockEpochNtfn(
+	blockChan, errBlockChan, err := f.cfg.ChainNotifier.RegisterBlockEpochNtfn(
 		callCtx,
 	)
 	if err != nil {
-		r.Errorf("unable to subscribe to block notifications: %v", err)
-		return r.HandleError(err)
+		f.Errorf("unable to subscribe to block notifications: %v", err)
+		return f.HandleError(err)
 	}
 
 	// We'll now wait for the confirmation of the reservation transaction.
 	for {
 		select {
 		case err := <-errConfChan:
-			r.Errorf("conf subscription error: %v", err)
-			return r.HandleError(err)
+			f.Errorf("conf subscription error: %v", err)
+			return f.HandleError(err)
 
 		case err := <-errBlockChan:
-			r.Errorf("block subscription error: %v", err)
-			return r.HandleError(err)
+			f.Errorf("block subscription error: %v", err)
+			return f.HandleError(err)
 
 		case confInfo := <-confChan:
-			r.Debugf("reservation confirmed: %v", confInfo)
-			outpoint, err := r.reservation.findReservationOutput(
+			f.Debugf("confirmed in block %v", confInfo.Block)
+			outpoint, err := f.reservation.findReservationOutput(
 				confInfo.Tx,
 			)
 			if err != nil {
-				return r.HandleError(err)
+				return f.HandleError(err)
 			}
 
-			r.reservation.ConfirmationHeight = confInfo.BlockHeight
-			r.reservation.Outpoint = outpoint
+			f.reservation.ConfirmationHeight = confInfo.BlockHeight
+			f.reservation.Outpoint = outpoint
 
 			return OnConfirmed
 
 		case block := <-blockChan:
-			r.Debugf("block received: %v expiry: %v", block,
-				r.reservation.Expiry)
+			f.Debugf("block received: %v expiry: %v", block,
+				f.reservation.Expiry)
 
-			if uint32(block) >= r.reservation.Expiry {
+			if uint32(block) >= f.reservation.Expiry {
 				return OnTimedOut
 			}
 
-		case <-r.ctx.Done():
+		case <-f.ctx.Done():
 			return fsm.NoOp
 		}
 	}
 }
 
-// ReservationConfirmedAction waits for the reservation to be either expired or
-// waits for other actions to happen.
-func (r *FSM) ReservationConfirmedAction(_ fsm.EventContext) fsm.EventType {
-	blockHeightChan, errEpochChan, err := r.cfg.ChainNotifier.
-		RegisterBlockEpochNtfn(r.ctx)
+// AsyncWaitForExpiredOrSweptAction waits for the reservation to be either
+// expired or swept. This is non-blocking and can be used to wait for the
+// reservation to expire while expecting other events.
+func (f *FSM) AsyncWaitForExpiredOrSweptAction(_ fsm.EventContext,
+) fsm.EventType {
+
+	notifCtx, cancel := context.WithCancel(f.ctx)
+
+	blockHeightChan, errEpochChan, err := f.cfg.ChainNotifier.
+		RegisterBlockEpochNtfn(notifCtx)
 	if err != nil {
-		return r.HandleError(err)
+		cancel()
+		return f.HandleError(err)
 	}
 
+	pkScript, err := f.reservation.GetPkScript()
+	if err != nil {
+		cancel()
+		return f.HandleError(err)
+	}
+
+	spendChan, errSpendChan, err := f.cfg.ChainNotifier.RegisterSpendNtfn(
+		notifCtx, f.reservation.Outpoint, pkScript,
+		f.reservation.InitiationHeight,
+	)
+	if err != nil {
+		cancel()
+		return f.HandleError(err)
+	}
+
+	go func() {
+		defer cancel()
+		op, err := f.handleSubcriptions(
+			notifCtx, blockHeightChan, spendChan, errEpochChan,
+			errSpendChan,
+		)
+		if err != nil {
+			f.handleAsyncError(err)
+			return
+		}
+		if op == fsm.NoOp {
+			return
+		}
+		err = f.SendEvent(op, nil)
+		if err != nil {
+			f.Errorf("Error sending %s event: %v", op, err)
+		}
+	}()
+
+	return fsm.NoOp
+}
+
+func (f *FSM) handleSubcriptions(ctx context.Context,
+	blockHeightChan <-chan int32, spendChan <-chan *chainntnfs.SpendDetail,
+	errEpochChan <-chan error, errSpendChan <-chan error,
+) (fsm.EventType, error) {
+
 	for {
 		select {
 		case err := <-errEpochChan:
-			return r.HandleError(err)
+			return fsm.OnError, err
+
+		case err := <-errSpendChan:
+			return fsm.OnError, err
 
 		case blockHeight := <-blockHeightChan:
-			expired := blockHeight >= int32(r.reservation.Expiry)
-			if expired {
-				r.Debugf("Reservation %v expired",
-					r.reservation.ID)
+			expired := blockHeight >= int32(f.reservation.Expiry)
 
-				return OnTimedOut
+			if expired {
+				f.Debugf("Reservation expired")
+				return OnTimedOut, nil
 			}
 
-		case <-r.ctx.Done():
-			return fsm.NoOp
+		case <-spendChan:
+			return OnSpent, nil
+
+		case <-ctx.Done():
+			return fsm.NoOp, nil
 		}
 	}
 }
+
+func (f *FSM) handleAsyncError(err error) {
+	f.LastActionError = err
+	f.Errorf("Error on async action: %v", err)
+	err2 := f.SendEvent(fsm.OnError, err)
+	if err2 != nil {
+		f.Errorf("Error sending event: %v", err2)
+	}
+}

instantout/reservation/actions_test.go

@@ -129,6 +129,7 @@ func TestInitReservationAction(t *testing.T) {
 	}
 
 	for _, tc := range tests {
+		tc := tc
 		ctxb := context.Background()
 		mockLnd := test.NewMockLnd()
 		mockReservationClient := new(mockReservationClient)
@@ -223,6 +224,7 @@ func TestSubscribeToConfirmationAction(t *testing.T) {
 	}
 
 	for _, tc := range tests {
+		tc := tc
 		t.Run(tc.name, func(t *testing.T) {
 			chainNotifier := new(MockChainNotifier)
 
@@ -304,14 +306,83 @@ func TestSubscribeToConfirmationAction(t *testing.T) {
 	}
 }
 
-// TestReservationConfirmedAction tests the ReservationConfirmedAction of the
+// AsyncWaitForExpiredOrSweptAction tests the AsyncWaitForExpiredOrSweptAction
+// of the reservation state machine.
+func TestAsyncWaitForExpiredOrSweptAction(t *testing.T) {
+	tests := []struct {
+		name          string
+		blockErr      error
+		spendErr      error
+		expectedEvent fsm.EventType
+	}{
+		{
+			name:          "noop",
+			expectedEvent: fsm.NoOp,
+		},
+		{
+			name:          "block error",
+			blockErr:      errors.New("block error"),
+			expectedEvent: fsm.OnError,
+		},
+		{
+			name:          "spend error",
+			spendErr:      errors.New("spend error"),
+			expectedEvent: fsm.OnError,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) { // Create a mock ChainNotifier and Reservation
+			chainNotifier := new(MockChainNotifier)
+
+			// Define your FSM
+			r := NewFSMFromReservation(
+				context.Background(), &Config{
+					ChainNotifier: chainNotifier,
+				},
+				&Reservation{
+					ServerPubkey: defaultPubkey,
+					ClientPubkey: defaultPubkey,
+					Expiry:       defaultExpiry,
+				},
+			)
+
+			// Define the expected return values for your mocks
+			chainNotifier.On("RegisterBlockEpochNtfn", mock.Anything).Return(
+				make(chan int32), make(chan error), tc.blockErr,
+			)
+
+			chainNotifier.On(
+				"RegisterSpendNtfn", mock.Anything,
+				mock.Anything, mock.Anything,
+			).Return(
+				make(chan *chainntnfs.SpendDetail),
+				make(chan error), tc.spendErr,
+			)
+
+			eventType := r.AsyncWaitForExpiredOrSweptAction(nil)
+			// Assert that the return value is as expected
+			require.Equal(t, tc.expectedEvent, eventType)
+		})
+	}
+}
+
+// TesthandleSubcriptions tests the handleSubcriptions function of the
 // reservation state machine.
-func TestReservationConfirmedAction(t *testing.T) {
+func TestHandleSubcriptions(t *testing.T) {
+	var (
+		blockErr = errors.New("block error")
+		spendErr = errors.New("spend error")
+	)
 	tests := []struct {
 		name          string
 		blockHeight   int32
 		blockErr      error
+		spendDetail   *chainntnfs.SpendDetail
+		spendErr      error
 		expectedEvent fsm.EventType
+		expectedErr   error
 	}{
 		{
 			name:          "expired",
@@ -320,13 +391,25 @@ func TestReservationConfirmedAction(t *testing.T) {
 		},
 		{
 			name:          "block error",
-			blockHeight:   0,
-			blockErr:      errors.New("block error"),
+			blockErr:      blockErr,
+			expectedEvent: fsm.OnError,
+			expectedErr:   blockErr,
+		},
+		{
+			name:          "spent",
+			spendDetail:   &chainntnfs.SpendDetail{},
+			expectedEvent: OnSpent,
+		},
+		{
+			name:          "spend error",
+			spendErr:      spendErr,
 			expectedEvent: fsm.OnError,
+			expectedErr:   spendErr,
 		},
 	}
 
 	for _, tc := range tests {
+		tc := tc
 		t.Run(tc.name, func(t *testing.T) {
 			chainNotifier := new(MockChainNotifier)
 
@@ -336,36 +419,41 @@ func TestReservationConfirmedAction(t *testing.T) {
 					ChainNotifier: chainNotifier,
 				},
 				&Reservation{
-					Expiry: defaultExpiry,
+					ServerPubkey: defaultPubkey,
+					ClientPubkey: defaultPubkey,
+					Expiry:       defaultExpiry,
 				},
 			)
 
 			blockChan := make(chan int32)
 			blockErrChan := make(chan error)
 
-			// Define our expected return values for the mocks.
-			chainNotifier.On("RegisterBlockEpochNtfn", mock.Anything).Return(
-				blockChan, blockErrChan, nil,
-			)
+			spendChan := make(chan *chainntnfs.SpendDetail)
+			spendErrChan := make(chan error)
+
 			go func() {
-				// Send the block notification.
 				if tc.blockHeight != 0 {
 					blockChan <- tc.blockHeight
 				}
-			}()
 
-			go func() {
-				// Send the block notification error.
 				if tc.blockErr != nil {
 					blockErrChan <- tc.blockErr
 				}
+
+				if tc.spendDetail != nil {
+					spendChan <- tc.spendDetail
+				}
+				if tc.spendErr != nil {
+					spendErrChan <- tc.spendErr
+				}
 			}()
 
-			eventType := r.ReservationConfirmedAction(nil)
+			eventType, err := r.handleSubcriptions(
+				context.Background(), blockChan, spendChan,
+				blockErrChan, spendErrChan,
+			)
+			require.Equal(t, tc.expectedErr, err)
 			require.Equal(t, tc.expectedEvent, eventType)
-
-			// Assert that the expected functions were called on the mocks
-			chainNotifier.AssertExpectations(t)
 		})
 	}
 }

instantout/reservation/fsm.go

@@ -123,6 +123,18 @@ var (
 	// OnRecover is the event that is triggered when the reservation FSM
 	// recovers from a restart.
 	OnRecover = fsm.EventType("OnRecover")
+
+	// OnSpent is the event that is triggered when the reservation has been
+	// spent.
+	OnSpent = fsm.EventType("OnSpent")
+
+	// OnLocked is the event that is triggered when the reservation has
+	// been locked.
+	OnLocked = fsm.EventType("OnLocked")
+
+	// OnUnlocked is the event that is triggered when the reservation has
+	// been unlocked.
+	OnUnlocked = fsm.EventType("OnUnlocked")
 )
 
 // GetReservationStates returns the statemap that defines the reservation
@@ -153,14 +165,38 @@ func (f *FSM) GetReservationStates() fsm.States {
 		},
 		Confirmed: fsm.State{
 			Transitions: fsm.Transitions{
-				OnTimedOut: TimedOut,
-				OnRecover:  Confirmed,
+				OnSpent:     Spent,
+				OnTimedOut:  TimedOut,
+				OnRecover:   Confirmed,
+				OnLocked:    Locked,
+				fsm.OnError: Confirmed,
+			},
+			Action: f.AsyncWaitForExpiredOrSweptAction,
+		},
+		Locked: fsm.State{
+			Transitions: fsm.Transitions{
+				OnUnlocked:  Confirmed,
+				OnTimedOut:  TimedOut,
+				OnRecover:   Locked,
+				OnSpent:     Spent,
+				fsm.OnError: Locked,
 			},
-			Action: f.ReservationConfirmedAction,
+			Action: f.AsyncWaitForExpiredOrSweptAction,
 		},
 		TimedOut: fsm.State{
+			Transitions: fsm.Transitions{
+				OnTimedOut: TimedOut,
+			},
 			Action: fsm.NoOpAction,
 		},
+
+		Spent: fsm.State{
+			Transitions: fsm.Transitions{
+				OnSpent: Spent,
+			},
+			Action: fsm.NoOpAction,
+		},
+
 		Failed: fsm.State{
 			Action: fsm.NoOpAction,
 		},

instantout/reservation/manager.go

@@ -3,6 +3,7 @@ package reservation
 import (
 	"context"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -35,7 +36,6 @@ func NewManager(cfg *Config) *Manager {
 
 // Run runs the reservation manager.
 func (m *Manager) Run(ctx context.Context, height int32) error {
-	// todo(sputn1ck): recover swaps on startup
 	log.Debugf("Starting reservation manager")
 
 	runCtx, cancel := context.WithCancel(ctx)
@@ -269,3 +269,54 @@ func (m *Manager) RecoverReservations(ctx context.Context) error {
 func (m *Manager) GetReservations(ctx context.Context) ([]*Reservation, error) {
 	return m.cfg.Store.ListReservations(ctx)
 }
+
+// GetReservation returns the reservation for the given id.
+func (m *Manager) GetReservation(ctx context.Context, id ID) (*Reservation,
+	error) {
+
+	return m.cfg.Store.GetReservation(ctx, id)
+}
+
+// LockReservation locks the reservation with the given ID.
+func (m *Manager) LockReservation(ctx context.Context, id ID) error {
+	// Try getting the reservation from the active reservations map.
+	m.Lock()
+	reservation, ok := m.activeReservations[id]
+	m.Unlock()
+
+	if !ok {
+		return fmt.Errorf("reservation not found")
+	}
+
+	// Try to send the lock event to the reservation.
+	err := reservation.SendEvent(OnLocked, nil)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// UnlockReservation unlocks the reservation with the given ID.
+func (m *Manager) UnlockReservation(ctx context.Context, id ID) error {
+	// Try getting the reservation from the active reservations map.
+	m.Lock()
+	reservation, ok := m.activeReservations[id]
+	m.Unlock()
+
+	if !ok {
+		return fmt.Errorf("reservation not found")
+	}
+
+	// Try to send the unlock event to the reservation.
+	err := reservation.SendEvent(OnUnlocked, nil)
+	if err != nil && strings.Contains(err.Error(), "config error") {
+		// If the error is a config error, we can ignore it, as the
+		// reservation is already unlocked.
+		return nil
+	} else if err != nil {
+		return err
+	}
+
+	return nil
+}

instantout/reservation/manager_test.go

@@ -33,7 +33,7 @@ func TestManager(t *testing.T) {
 	}()
 
 	// Create a new reservation.
-	fsm, err := testContext.manager.newReservation(
+	reservationFSM, err := testContext.manager.newReservation(
 		ctxb, uint32(testContext.mockLnd.Height),
 		&swapserverrpc.ServerReservationNotification{
 			ReservationId: defaultReservationId[:],
@@ -45,11 +45,11 @@ func TestManager(t *testing.T) {
 	require.NoError(t, err)
 
 	// We'll expect the spendConfirmation to be sent to the server.
-	pkScript, err := fsm.reservation.GetPkScript()
+	pkScript, err := reservationFSM.reservation.GetPkScript()
 	require.NoError(t, err)
 
-	conf := <-testContext.mockLnd.RegisterConfChannel
-	require.Equal(t, conf.PkScript, pkScript)
+	confReg := <-testContext.mockLnd.RegisterConfChannel
+	require.Equal(t, confReg.PkScript, pkScript)
 
 	confTx := &wire.MsgTx{
 		TxOut: []*wire.TxOut{
@@ -59,23 +59,39 @@ func TestManager(t *testing.T) {
 		},
 	}
 	// We'll now confirm the spend.
-	conf.ConfChan <- &chainntnfs.TxConfirmation{
+	confReg.ConfChan <- &chainntnfs.TxConfirmation{
 		BlockHeight: uint32(testContext.mockLnd.Height),
 		Tx:          confTx,
 	}
 
 	// We'll now expect the reservation to be confirmed.
-	err = fsm.DefaultObserver.WaitForState(ctxb, 5*time.Second, Confirmed)
+	err = reservationFSM.DefaultObserver.WaitForState(ctxb, 5*time.Second, Confirmed)
 	require.NoError(t, err)
 
-	// We'll now expire the reservation.
-	err = testContext.mockLnd.NotifyHeight(
-		testContext.mockLnd.Height + int32(defaultExpiry),
-	)
+	// We'll now expect a spend registration.
+	spendReg := <-testContext.mockLnd.RegisterSpendChannel
+	require.Equal(t, spendReg.PkScript, pkScript)
+
+	go func() {
+		// We'll expect a second spend registration.
+		spendReg = <-testContext.mockLnd.RegisterSpendChannel
+		require.Equal(t, spendReg.PkScript, pkScript)
+	}()
+
+	// We'll now try to lock the reservation.
+	err = testContext.manager.LockReservation(ctxb, defaultReservationId)
 	require.NoError(t, err)
 
+	// We'll try to lock the reservation again, which should fail.
+	err = testContext.manager.LockReservation(ctxb, defaultReservationId)
+	require.Error(t, err)
+
+	testContext.mockLnd.SpendChannel <- &chainntnfs.SpendDetail{
+		SpentOutPoint: spendReg.Outpoint,
+	}
+
 	// We'll now expect the reservation to be expired.
-	err = fsm.DefaultObserver.WaitForState(ctxb, 5*time.Second, TimedOut)
+	err = reservationFSM.DefaultObserver.WaitForState(ctxb, 5*time.Second, Spent)
 	require.NoError(t, err)
 }
 

instantout/reservation/reservation_fsm.md

@@ -2,6 +2,7 @@
 stateDiagram-v2
 [*] --> Init: OnServerRequest
 Confirmed
+Confirmed --> SpendBroadcasted: OnSpendBroadcasted
 Confirmed --> TimedOut: OnTimedOut
 Confirmed --> Confirmed: OnRecover
 Failed
@@ -9,6 +10,9 @@ Init
 Init --> Failed: OnError
 Init --> WaitForConfirmation: OnBroadcast
 Init --> Failed: OnRecover
+SpendBroadcasted
+SpendBroadcasted --> SpendConfirmed: OnSpendConfirmed
+SpendConfirmed
 TimedOut
 WaitForConfirmation
 WaitForConfirmation --> WaitForConfirmation: OnRecover