swap, swap/chain: use txqueue for cashout

Author: ralph-pichler

swap/cashout.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/metrics"
 	contract "github.com/ethersphere/swarm/contracts/swap"
 	"github.com/ethersphere/swarm/swap/chain"
@@ -30,10 +31,9 @@ import (
 // CashChequeBeneficiaryTransactionCost is the expected gas cost of a CashChequeBeneficiary transaction
 const CashChequeBeneficiaryTransactionCost = 50000
 
-// CashoutProcessor holds all relevant fields needed for processing cashouts
-type CashoutProcessor struct {
-	backend    chain.Backend     // ethereum backend to use
-	privateKey *ecdsa.PrivateKey // private key to use
+var CashoutRequestTypeID = chain.TxRequestTypeID{
+	Handler:     "cashout",
+	RequestType: "CashoutRequest",
 }
 
 // CashoutRequest represents a request for a cashout operation
@@ -42,42 +42,94 @@ type CashoutRequest struct {
 	Destination common.Address // destination for the payout
 }
 
-// ActiveCashout stores the necessary information for a cashout in progess
-type ActiveCashout struct {
-	Request         CashoutRequest // the request that caused this cashout
-	TransactionHash common.Hash    // the hash of the current transaction for this request
+// CashoutProcessor holds all relevant fields needed for processing cashouts
+type CashoutProcessor struct {
+	backend              chain.Backend     // ethereum backend to use
+	txScheduler          chain.TxScheduler // transaction queue to use
+	cashoutResultHandler CashoutResultHandler
+	cashoutDone          chan *CashoutRequest
+}
+
+type CashoutResultHandler interface {
+	HandleCashoutResult(request *CashoutRequest, result *contract.CashChequeResult, receipt *types.Receipt) error
 }
 
 // newCashoutProcessor creates a new instance of CashoutProcessor
-func newCashoutProcessor(backend chain.Backend, privateKey *ecdsa.PrivateKey) *CashoutProcessor {
-	return &CashoutProcessor{
-		backend:    backend,
-		privateKey: privateKey,
+func newCashoutProcessor(txScheduler chain.TxScheduler, backend chain.Backend, privateKey *ecdsa.PrivateKey, cashoutResultHandler CashoutResultHandler) *CashoutProcessor {
+	c := &CashoutProcessor{
+		backend:              backend,
+		txScheduler:          txScheduler,
+		cashoutResultHandler: cashoutResultHandler,
 	}
-}
 
-// cashCheque tries to cash the cheque specified in the request
-// after the transaction is sent it waits on its success
-func (c *CashoutProcessor) cashCheque(ctx context.Context, request *CashoutRequest) error {
-	cheque := request.Cheque
-	opts := bind.NewKeyedTransactor(c.privateKey)
-	opts.Context = ctx
+	txScheduler.SetHandlers(CashoutRequestTypeID, &chain.TxRequestHandlers{
+		Send: func(id uint64, backend chain.Backend, opts *bind.TransactOpts) (common.Hash, error) {
+			var request CashoutRequest
+			if err := c.txScheduler.GetRequest(id, &request); err != nil {
+				return common.Hash{}, err
+			}
+
+			cheque := request.Cheque
+
+			otherSwap, err := contract.InstanceAt(cheque.Contract, backend)
+			if err != nil {
+				return common.Hash{}, err
+			}
+
+			tx, err := otherSwap.CashChequeBeneficiaryStart(opts, request.Destination, cheque.CumulativePayout, cheque.Signature)
+			if err != nil {
+				return common.Hash{}, err
+			}
+			return tx.Hash(), nil
+		},
+		NotifyReceipt: func(ctx context.Context, id uint64, notification *chain.TxReceiptNotification) error {
+			var request *CashoutRequest
+			err := c.txScheduler.GetRequest(id, &request)
+			if err != nil {
+				return err
+			}
+
+			otherSwap, err := contract.InstanceAt(request.Cheque.Contract, c.backend)
+			if err != nil {
+				return err
+			}
+
+			receipt := &notification.Receipt
+			if receipt.Status == 0 {
+				swapLog.Error("cheque cashing transaction reverted", "tx", receipt.TxHash)
+				return nil
+			}
+
+			result := otherSwap.CashChequeBeneficiaryResult(receipt)
+			return c.cashoutResultHandler.HandleCashoutResult(request, result, receipt)
+		},
+	})
+	return c
+}
 
-	otherSwap, err := contract.InstanceAt(cheque.Contract, c.backend)
+func (c *CashoutProcessor) submitCheque(ctx context.Context, request *CashoutRequest) {
+	expectedPayout, transactionCosts, err := c.estimatePayout(ctx, &request.Cheque)
 	if err != nil {
-		return err
+		swapLog.Error("could not estimate payout", "error", err)
+		return
 	}
 
-	tx, err := otherSwap.CashChequeBeneficiaryStart(opts, request.Destination, cheque.CumulativePayout, cheque.Signature)
+	costsMultiplier := uint256.FromUint64(2)
+	costThreshold, err := uint256.New().Mul(transactionCosts, costsMultiplier)
 	if err != nil {
-		return err
+		swapLog.Error("overflow in transaction fee", "error", err)
+		return
 	}
 
-	// this blocks until the cashout has been successfully processed
-	return c.waitForAndProcessActiveCashout(&ActiveCashout{
-		Request:         *request,
-		TransactionHash: tx.Hash(),
-	})
+	// do a payout transaction if we get 2 times the gas costs
+	if expectedPayout.Cmp(costThreshold) == 1 {
+		swapLog.Info("queueing cashout", "cheque", &request.Cheque)
+		_, err := c.txScheduler.ScheduleRequest(CashoutRequestTypeID, request)
+		if err != nil {
+			metrics.GetOrRegisterCounter("swap.cheques.cashed.errors", nil).Inc(1)
+			swapLog.Error("cashing cheque:", "error", err)
+		}
+	}
 }
 
 // estimatePayout estimates the payout for a given cheque as well as the transaction cost
@@ -123,31 +175,3 @@ func (c *CashoutProcessor) estimatePayout(ctx context.Context, cheque *Cheque) (
 
 	return expectedPayout, transactionCosts, nil
 }
-
-// waitForAndProcessActiveCashout waits for activeCashout to complete
-func (c *CashoutProcessor) waitForAndProcessActiveCashout(activeCashout *ActiveCashout) error {
-	ctx, cancel := context.WithTimeout(context.Background(), DefaultTransactionTimeout)
-	defer cancel()
-
-	receipt, err := chain.WaitMined(ctx, c.backend, activeCashout.TransactionHash)
-	if err != nil {
-		return err
-	}
-
-	otherSwap, err := contract.InstanceAt(activeCashout.Request.Cheque.Contract, c.backend)
-	if err != nil {
-		return err
-	}
-
-	result := otherSwap.CashChequeBeneficiaryResult(receipt)
-
-	metrics.GetOrRegisterCounter("swap.cheques.cashed.honey", nil).Inc(result.TotalPayout.Int64())
-
-	if result.Bounced {
-		metrics.GetOrRegisterCounter("swap.cheques.cashed.bounced", nil).Inc(1)
-		swapLog.Warn("cheque bounced", "tx", receipt.TxHash)
-	}
-
-	swapLog.Info("cheque cashed", "honey", activeCashout.Request.Cheque.Honey)
-	return nil
-}

swap/cashout_test.go

@@ -19,9 +19,11 @@ package swap
 import (
 	"context"
 	"testing"
+	"time"
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethersphere/swarm/state"
 	"github.com/ethersphere/swarm/swap/chain"
 	"github.com/ethersphere/swarm/uint256"
 )
@@ -33,8 +35,7 @@ import (
 // afterwards it attempts to cash-in a bouncing cheque
 func TestContractIntegration(t *testing.T) {
 	backend := newTestBackend(t)
-	reset := setupContractTest()
-	defer reset()
+	defer backend.Close()
 
 	payout := uint256.FromUint64(42)
 	chequebook, err := testDeployWithPrivateKey(context.Background(), backend, ownerKey, ownerAddress, payout)
@@ -116,11 +117,18 @@ func TestContractIntegration(t *testing.T) {
 // TestCashCheque creates a valid cheque and feeds it to cashoutProcessor.cashCheque
 func TestCashCheque(t *testing.T) {
 	backend := newTestBackend(t)
-	reset := setupContractTest()
-	defer reset()
+	defer backend.Close()
 
-	cashoutProcessor := newCashoutProcessor(backend, ownerKey)
-	payout := uint256.FromUint64(42)
+	store := state.NewInmemoryStore()
+	defer store.Close()
+
+	transactionQueue := chain.NewTxQueue(store, "queue", backend, ownerKey)
+	transactionQueue.Start()
+	defer transactionQueue.Stop()
+
+	cashoutHandler := newTestCashoutResultHandler(nil)
+	cashoutProcessor := newCashoutProcessor(transactionQueue, backend, ownerKey, cashoutHandler)
+	payout := uint256.FromUint64(CashChequeBeneficiaryTransactionCost*2 + 1)
 
 	chequebook, err := testDeployWithPrivateKey(context.Background(), backend, ownerKey, ownerAddress, payout)
 	if err != nil {
@@ -132,12 +140,14 @@ func TestCashCheque(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = cashoutProcessor.cashCheque(context.Background(), &CashoutRequest{
+	cashoutProcessor.submitCheque(context.Background(), &CashoutRequest{
 		Cheque:      *testCheque,
 		Destination: ownerAddress,
 	})
-	if err != nil {
-		t.Fatal(err)
+
+	select {
+	case <-cashoutHandler.cashChequeDone:
+	case <-time.After(5 * time.Second):
 	}
 
 	paidOut, err := chequebook.PaidOut(nil, ownerAddress)
@@ -154,12 +164,18 @@ func TestCashCheque(t *testing.T) {
 // TestEstimatePayout creates a valid cheque and feeds it to cashoutProcessor.estimatePayout
 func TestEstimatePayout(t *testing.T) {
 	backend := newTestBackend(t)
-	reset := setupContractTest()
-	defer reset()
+	defer backend.Close()
 
-	cashoutProcessor := newCashoutProcessor(backend, ownerKey)
-	payout := uint256.FromUint64(42)
+	store := state.NewInmemoryStore()
+	defer store.Close()
+
+	transactionQueue := chain.NewTxQueue(store, "queue", backend, ownerKey)
+	transactionQueue.Start()
+	defer transactionQueue.Stop()
 
+	cashoutProcessor := newCashoutProcessor(transactionQueue, backend, ownerKey, &testCashoutResultHandler{})
+
+	payout := uint256.FromUint64(42)
 	chequebook, err := testDeployWithPrivateKey(context.Background(), backend, ownerKey, ownerAddress, payout)
 	if err != nil {
 		t.Fatal(err)

swap/common_test.go

@@ -15,10 +15,12 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
 	contractFactory "github.com/ethersphere/go-sw3/contracts-v0-2-0/simpleswapfactory"
+	contract "github.com/ethersphere/swarm/contracts/swap"
 	cswap "github.com/ethersphere/swarm/contracts/swap"
 	"github.com/ethersphere/swarm/network"
 	"github.com/ethersphere/swarm/p2p/protocols"
@@ -34,8 +36,6 @@ type swapTestBackend struct {
 	*mock.TestBackend
 	factoryAddress common.Address // address of the SimpleSwapFactory in the simulated network
 	tokenAddress   common.Address // address of the token in the simulated network
-	// the async cashing go routine needs synchronization for tests
-	cashDone chan struct{}
 }
 
 var defaultBackend = backends.NewSimulatedBackend(core.GenesisAlloc{
@@ -67,7 +67,6 @@ func newTestBackend(t *testing.T) *swapTestBackend {
 		TestBackend:    backend,
 		factoryAddress: factoryAddress,
 		tokenAddress:   tokenAddress,
-		cashDone:       make(chan struct{}),
 	}
 }
 
@@ -105,7 +104,9 @@ func newBaseTestSwapWithParams(t *testing.T, key *ecdsa.PrivateKey, params *Para
 	if err != nil {
 		t.Fatal(err)
 	}
-	swap := newSwapInstance(stateStore, owner, backend, 10, params, factory)
+
+	txqueue := chain.NewTxQueue(stateStore, "chain", backend, owner.privateKey)
+	swap := newSwapInstance(stateStore, owner, backend, 10, params, factory, txqueue)
 	return swap, dir
 }
 
@@ -126,6 +127,7 @@ func newTestSwap(t *testing.T, key *ecdsa.PrivateKey, backend *swapTestBackend)
 		usedBackend = newTestBackend(t)
 	}
 	swap, dir := newBaseTestSwap(t, key, usedBackend)
+	swap.txScheduler.Start()
 	clean := func() {
 		swap.Close()
 		// only close if created by newTestSwap to avoid double close
@@ -206,32 +208,6 @@ func newRandomTestCheque() *Cheque {
 	return cheque
 }
 
-// During tests, because the cashing in of cheques is async, we should wait for the function to be returned
-// Otherwise if we call `handleEmitChequeMsg` manually, it will return before the TX has been committed to the `SimulatedBackend`,
-// causing subsequent TX to possibly fail due to nonce mismatch
-func testCashCheque(s *Swap, cheque *Cheque) {
-	cashCheque(s, cheque)
-	// send to the channel, signals to clients that this function actually finished
-	if stb, ok := s.backend.(*swapTestBackend); ok {
-		if stb.cashDone != nil {
-			stb.cashDone <- struct{}{}
-		}
-	}
-}
-
-// setupContractTest is a helper function for setting up the
-// blockchain wait function for testing
-func setupContractTest() func() {
-	// we also need to store the previous cashCheque function in case this is called multiple times
-	currentCashCheque := defaultCashCheque
-	defaultCashCheque = testCashCheque
-	// overwrite only for the duration of the test, so...
-	return func() {
-		// ...we need to set it back to original when done
-		defaultCashCheque = currentCashCheque
-	}
-}
-
 // deploy for testing (needs simulated backend commit)
 func testDeployWithPrivateKey(ctx context.Context, backend chain.Backend, privateKey *ecdsa.PrivateKey, ownerAddress common.Address, depositAmount *uint256.Uint256) (cswap.Contract, error) {
 	opts := bind.NewKeyedTransactor(privateKey)
@@ -248,9 +224,6 @@ func testDeployWithPrivateKey(ctx context.Context, backend chain.Backend, privat
 		return nil, err
 	}
 
-	// setup the wait for mined transaction function for testing
-	cleanup := setupContractTest()
-	defer cleanup()
 	contract, err := factory.DeploySimpleSwap(opts, ownerAddress, big.NewInt(int64(defaultHarddepositTimeoutDuration)))
 	if err != nil {
 		return nil, err
@@ -315,3 +288,41 @@ func (d *dummyMsgRW) ReadMsg() (p2p.Msg, error) {
 func (d *dummyMsgRW) WriteMsg(msg p2p.Msg) error {
 	return nil
 }
+
+type cashChequeDoneData struct {
+	request *CashoutRequest
+	result  *contract.CashChequeResult
+	receipt *types.Receipt
+}
+
+type testCashoutResultHandler struct {
+	swap           *Swap
+	cashChequeDone chan cashChequeDoneData
+}
+
+func newTestCashoutResultHandler(swap *Swap) *testCashoutResultHandler {
+	return &testCashoutResultHandler{
+		swap:           swap,
+		cashChequeDone: make(chan cashChequeDoneData),
+	}
+}
+
+func (h *testCashoutResultHandler) HandleCashoutResult(request *CashoutRequest, result *contract.CashChequeResult, receipt *types.Receipt) error {
+	if h.swap != nil {
+		if err := h.swap.HandleCashoutResult(request, result, receipt); err != nil {
+			return err
+		}
+	}
+	h.cashChequeDone <- cashChequeDoneData{
+		request: request,
+		result:  result,
+		receipt: receipt,
+	}
+	return nil
+}
+
+func overrideCashoutResultHandler(swap *Swap) *testCashoutResultHandler {
+	cashoutResultHandler := newTestCashoutResultHandler(swap)
+	swap.cashoutProcessor.cashoutResultHandler = cashoutResultHandler
+	return cashoutResultHandler
+}