contractcourt+sweep: offer direct-preimage spend via SweepInput

This commit removes the method `CreateSweepTx` and makes sure when
sweeping the htlc output via the direct-preimage spend, it's offered via
the `SweepInput` interface.

contractcourt/briefcase_test.go

@@ -331,7 +331,6 @@ func TestContractInsertionRetrieval(t *testing.T) {
 		htlc: channeldb.HTLC{
 			RHash: testPreimage,
 		},
-		sweepTx: nil,
 	}
 	resolvers := []ContractResolver{
 		&timeoutResolver,

contractcourt/commit_sweep_resolver_test.go

@@ -156,14 +156,6 @@ func (s *mockSweeper) SweepInput(input input.Input, params sweep.Params) (
 	return result, nil
 }
 
-func (s *mockSweeper) CreateSweepTx(inputs []input.Input,
-	feePref sweep.FeeEstimateInfo) (*wire.MsgTx, error) {
-
-	// We will wait for the test to supply the sweep tx to return.
-	sweepTx := <-s.createSweepTxChan
-	return sweepTx, nil
-}
-
 func (s *mockSweeper) RelayFeePerKW() chainfee.SatPerKWeight {
 	return 253
 }

contractcourt/htlc_success_resolver.go

@@ -51,13 +51,6 @@ type htlcSuccessResolver struct {
 	// historical queries to the chain for spends/confirmations.
 	broadcastHeight uint32
 
-	// sweepTx will be non-nil if we've already crafted a transaction to
-	// sweep a direct HTLC output. This is only a concern if we're sweeping
-	// from the commitment transaction of the remote party.
-	//
-	// TODO(roasbeef): send off to utxobundler
-	sweepTx *wire.MsgTx
-
 	// htlc contains information on the htlc that we are resolving on-chain.
 	htlc channeldb.HTLC
 
@@ -427,12 +420,6 @@ func (h *htlcSuccessResolver) broadcastReSignedSuccessTx() (
 func (h *htlcSuccessResolver) resolveRemoteCommitOutput() (
 	ContractResolver, error) {
 
-	// If we don't already have the sweep transaction constructed, we'll do
-	// so and broadcast it.
-	if h.sweepTx == nil {
-		log.Infof("%T(%x): crafting sweep tx for incoming+remote "+
-			"htlc confirmed", h, h.htlc.RHash[:])
-
 	isTaproot := txscript.IsPayToTaproot(
 		h.htlcResolution.SweepSignDesc.Output.PkScript,
 	)
@@ -460,75 +447,48 @@ func (h *htlcSuccessResolver) resolveRemoteCommitOutput() (
 		))
 	}
 
-		// With the input created, we can now generate the full sweep
-		// transaction, that we'll use to move these coins back into
-		// the backing wallet.
-		//
-		// TODO: Use time-based sweeper and result chan.
-		var err error
-		h.sweepTx, err = h.Sweeper.CreateSweepTx(
-			[]input.Input{inp},
-			sweep.FeeEstimateInfo{
-				ConfTarget: sweepConfTarget,
+	// Calculate the budget for this sweep.
+	budget := calculateBudget(
+		btcutil.Amount(inp.SignDesc().Output.Value),
+		h.Budget.DeadlineHTLCRatio,
+		h.Budget.DeadlineHTLC,
+	)
+
+	deadline := fn.Some(int32(h.htlc.RefundTimeout))
+
+	log.Infof("%T(%x): offering direct-preimage HTLC output to sweeper "+
+		"with deadline=%v, budget=%v", h, h.htlc.RHash[:],
+		h.htlc.RefundTimeout, budget)
+
+	// We'll now offer the direct preimage HTLC to the sweeper.
+	_, err := h.Sweeper.SweepInput(
+		inp,
+		sweep.Params{
+			Budget:         budget,
+			DeadlineHeight: deadline,
 		},
 	)
 	if err != nil {
 		return nil, err
 	}
 
-		log.Infof("%T(%x): crafted sweep tx=%v", h,
-			h.htlc.RHash[:], spew.Sdump(h.sweepTx))
-
-		// TODO(halseth): should checkpoint sweep tx to DB? Since after
-		// a restart we might create a different tx, that will conflict
-		// with the published one.
-	}
-
-	// Register the confirmation notification before broadcasting the sweep
-	// transaction.
-	sweepTXID := h.sweepTx.TxHash()
-	sweepScript := h.sweepTx.TxOut[0].PkScript
-	confNtfn, err := h.Notifier.RegisterConfirmationsNtfn(
-		&sweepTXID, sweepScript, 1, h.broadcastHeight,
+	// Wait for the direct-preimage HTLC sweep tx to confirm.
+	sweepTxDetails, err := waitForSpend(
+		&h.htlcResolution.ClaimOutpoint,
+		h.htlcResolution.SweepSignDesc.Output.PkScript,
+		h.broadcastHeight, h.Notifier, h.quit,
 	)
 	if err != nil {
 		return nil, err
 	}
 
-	// Regardless of whether an existing transaction was found or newly
-	// constructed, we'll broadcast the sweep transaction to the network.
-	label := labels.MakeLabel(
-		labels.LabelTypeChannelClose, &h.ShortChanID,
-	)
-	err = h.PublishTx(h.sweepTx, label)
-	if err != nil {
-		log.Infof("%T(%x): unable to publish tx: %v",
-			h, h.htlc.RHash[:], err)
-		confNtfn.Cancel()
-
-		return nil, err
-	}
-
-	log.Infof("%T(%x): waiting for sweep tx (txid=%v) to be confirmed", h,
-		h.htlc.RHash[:], sweepTXID)
-
-	select {
-	case _, ok := <-confNtfn.Confirmed:
-		if !ok {
-			return nil, errResolverShuttingDown
-		}
-
-	case <-h.quit:
-		return nil, errResolverShuttingDown
-	}
-
 	// Once the transaction has received a sufficient number of
 	// confirmations, we'll mark ourselves as fully resolved and exit.
 	h.resolved = true
 
 	// Checkpoint the resolver, and write the outcome to disk.
 	return nil, h.checkpointClaim(
-		&sweepTXID,
+		sweepTxDetails.SpenderTxHash,
 		channeldb.ResolverOutcomeClaimed,
 	)
 }

contractcourt/htlc_success_resolver_test.go

@@ -181,17 +181,14 @@ func TestHtlcSuccessSingleStage(t *testing.T) {
 			// that our sweep succeeded.
 			preCheckpoint: func(ctx *htlcResolverTestContext,
 				_ bool) error {
-				// The resolver will create and publish a sweep
-				// tx.
-				resolver := ctx.resolver.(*htlcSuccessResolver)
-				resolver.Sweeper.(*mockSweeper).
-					createSweepTxChan <- sweepTx
 
-				// Confirm the sweep, which should resolve it.
-				ctx.notifier.ConfChan <- &chainntnfs.TxConfirmation{
-					Tx:          sweepTx,
-					BlockHeight: testInitialBlockHeight - 1,
+				// The resolver will offer the input to the
+				// sweeper.
+				details := &chainntnfs.SpendDetail{
+					SpendingTx:    sweepTx,
+					SpenderTxHash: &sweepTxid,
 				}
+				ctx.notifier.SpendChan <- details
 
 				return nil
 			},

contractcourt/interfaces.go

@@ -50,12 +50,6 @@ type UtxoSweeper interface {
 	SweepInput(input input.Input, params sweep.Params) (chan sweep.Result,
 		error)
 
-	// CreateSweepTx accepts a list of inputs and signs and generates a txn
-	// that spends from them. This method also makes an accurate fee
-	// estimate before generating the required witnesses.
-	CreateSweepTx(inputs []input.Input,
-		feePref sweep.FeeEstimateInfo) (*wire.MsgTx, error)
-
 	// RelayFeePerKW returns the minimum fee rate required for transactions
 	// to be relayed.
 	RelayFeePerKW() chainfee.SatPerKWeight

sweep/sweeper.go

@@ -1159,47 +1159,6 @@ func (s *UtxoSweeper) handleUpdateReq(req *updateReq) (
 	return resultChan, nil
 }
 
-// CreateSweepTx accepts a list of inputs and signs and generates a txn that
-// spends from them. This method also makes an accurate fee estimate before
-// generating the required witnesses.
-//
-// The created transaction has a single output sending all the funds back to
-// the source wallet, after accounting for the fee estimate.
-//
-// The value of currentBlockHeight argument will be set as the tx locktime.
-// This function assumes that all CLTV inputs will be unlocked after
-// currentBlockHeight. Reasons not to use the maximum of all actual CLTV expiry
-// values of the inputs:
-//
-// - Make handling re-orgs easier.
-// - Thwart future possible fee sniping attempts.
-// - Make us blend in with the bitcoind wallet.
-//
-// TODO(yy): remove this method and only allow sweeping via requests.
-func (s *UtxoSweeper) CreateSweepTx(inputs []input.Input,
-	feePref FeeEstimateInfo) (*wire.MsgTx, error) {
-
-	feePerKw, err := feePref.Estimate(
-		s.cfg.FeeEstimator, s.cfg.MaxFeeRate.FeePerKWeight(),
-	)
-	if err != nil {
-		return nil, err
-	}
-
-	// Generate the receiving script to which the funds will be swept.
-	pkScript, err := s.cfg.GenSweepScript()
-	if err != nil {
-		return nil, err
-	}
-
-	tx, _, err := createSweepTx(
-		inputs, nil, pkScript, uint32(s.currentHeight), feePerKw,
-		s.cfg.MaxFeeRate.FeePerKWeight(), s.cfg.Signer,
-	)
-
-	return tx, err
-}
-
 // ListSweeps returns a list of the sweeps recorded by the sweep store.
 func (s *UtxoSweeper) ListSweeps() ([]chainhash.Hash, error) {
 	return s.cfg.Store.ListSweeps()