/
cashout.go
307 lines (269 loc) · 8.92 KB
/
cashout.go
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// Copyright 2020 The Penguin Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package chequebook
import (
"context"
"errors"
"fmt"
"math/big"
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/accounts/abi"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/penguintop/penguin_bsc/pkg/sctx"
"github.com/penguintop/penguin_bsc/pkg/storage"
"github.com/penguintop/penguin_bsc/pkg/transaction"
)
var (
// ErrNoCashout is the error if there has not been any cashout action for the chequebook
ErrNoCashout = errors.New("no prior cashout")
)
// CashoutService is the service responsible for managing cashout actions
type CashoutService interface {
// CashCheque sends a cashing transaction for the last cheque of the chequebook
CashCheque(ctx context.Context, chequebook common.Address, recipient common.Address) (common.Hash, error)
// CashoutStatus gets the status of the latest cashout transaction for the chequebook
CashoutStatus(ctx context.Context, chequebookAddress common.Address) (*CashoutStatus, error)
}
type cashoutService struct {
store storage.StateStorer
backend transaction.Backend
transactionService transaction.Service
chequeStore ChequeStore
}
// LastCashout contains information about the last cashout
type LastCashout struct {
TxHash common.Hash
Cheque SignedCheque // the cheque that was used to cashout which may be different from the latest cheque
Result *CashChequeResult
Reverted bool
}
// CashoutStatus is information about the last cashout and uncashed amounts
type CashoutStatus struct {
Last *LastCashout // last cashout for a chequebook
UncashedAmount *big.Int // amount not yet cashed out
}
// CashChequeResult summarizes the result of a CashCheque or CashChequeBeneficiary call
type CashChequeResult struct {
Beneficiary common.Address // beneficiary of the cheque
Recipient common.Address // address which received the funds
Caller common.Address // caller of cashCheque
TotalPayout *big.Int // total amount that was paid out in this call
CumulativePayout *big.Int // cumulative payout of the cheque that was cashed
CallerPayout *big.Int // payout for the caller of cashCheque
Bounced bool // indicates wether parts of the cheque bounced
}
// cashoutAction is the data we store for a cashout
type cashoutAction struct {
TxHash common.Hash
Cheque SignedCheque // the cheque that was used to cashout which may be different from the latest cheque
}
type chequeCashedEvent struct {
Beneficiary common.Address
Recipient common.Address
Caller common.Address
TotalPayout *big.Int
CumulativePayout *big.Int
CallerPayout *big.Int
}
// NewCashoutService creates a new CashoutService
func NewCashoutService(
store storage.StateStorer,
backend transaction.Backend,
transactionService transaction.Service,
chequeStore ChequeStore,
) CashoutService {
return &cashoutService{
store: store,
backend: backend,
transactionService: transactionService,
chequeStore: chequeStore,
}
}
// cashoutActionKey computes the store key for the last cashout action for the chequebook
func cashoutActionKey(chequebook common.Address) string {
return fmt.Sprintf("swap_cashout_%x", chequebook)
}
func (s *cashoutService) paidOut(ctx context.Context, chequebook, beneficiary common.Address) (*big.Int, error) {
callData, err := chequebookABI.Pack("paidOut", beneficiary)
if err != nil {
return nil, err
}
output, err := s.transactionService.Call(ctx, &transaction.TxRequest{
To: &chequebook,
Data: callData,
})
if err != nil {
return nil, err
}
results, err := chequebookABI.Unpack("paidOut", output)
if err != nil {
return nil, err
}
if len(results) != 1 {
return nil, errDecodeABI
}
paidOut, ok := abi.ConvertType(results[0], new(big.Int)).(*big.Int)
if !ok || paidOut == nil {
return nil, errDecodeABI
}
return paidOut, nil
}
// CashCheque sends a cashout transaction for the last cheque of the chequebook
func (s *cashoutService) CashCheque(ctx context.Context, chequebook, recipient common.Address) (common.Hash, error) {
cheque, err := s.chequeStore.LastCheque(chequebook)
if err != nil {
return common.Hash{}, err
}
callData, err := chequebookABI.Pack("cashChequeBeneficiary", recipient, cheque.CumulativePayout, cheque.Signature)
if err != nil {
return common.Hash{}, err
}
lim := sctx.GetGasLimit(ctx)
if lim == 0 {
// fix for out of gas errors
lim = 300000
}
request := &transaction.TxRequest{
To: &chequebook,
Data: callData,
GasPrice: sctx.GetGasPrice(ctx),
GasLimit: lim,
Value: big.NewInt(0),
}
txHash, err := s.transactionService.Send(ctx, request)
if err != nil {
return common.Hash{}, err
}
err = s.store.Put(cashoutActionKey(chequebook), &cashoutAction{
TxHash: txHash,
Cheque: *cheque,
})
if err != nil {
return common.Hash{}, err
}
return txHash, nil
}
// CashoutStatus gets the status of the latest cashout transaction for the chequebook
func (s *cashoutService) CashoutStatus(ctx context.Context, chequebookAddress common.Address) (*CashoutStatus, error) {
cheque, err := s.chequeStore.LastCheque(chequebookAddress)
if err != nil {
return nil, err
}
var action cashoutAction
err = s.store.Get(cashoutActionKey(chequebookAddress), &action)
if err != nil {
if errors.Is(err, storage.ErrNotFound) {
return &CashoutStatus{
Last: nil,
UncashedAmount: cheque.CumulativePayout, // if we never cashed out, assume everything is uncashed
}, nil
}
return nil, err
}
_, pending, err := s.backend.TransactionByHash(ctx, action.TxHash)
if err != nil {
// treat not found as pending
if !errors.Is(err, ethereum.NotFound) {
return nil, err
}
pending = true
}
if pending {
return &CashoutStatus{
Last: &LastCashout{
TxHash: action.TxHash,
Cheque: action.Cheque,
Result: nil,
Reverted: false,
},
// uncashed is the difference since the last sent cashout. we assume that the entire cheque will clear in the pending transaction.
UncashedAmount: new(big.Int).Sub(cheque.CumulativePayout, action.Cheque.CumulativePayout),
}, nil
}
receipt, err := s.backend.TransactionReceipt(ctx, action.TxHash)
if err != nil {
return nil, err
}
if receipt.Status == types.ReceiptStatusFailed {
// if a tx failed (should be almost impossible in practice) we no longer have the necessary information to compute uncashed locally
// assume there are no pending transactions and that the on-chain paidOut is the last cashout action
paidOut, err := s.paidOut(ctx, chequebookAddress, cheque.Beneficiary)
if err != nil {
return nil, err
}
return &CashoutStatus{
Last: &LastCashout{
TxHash: action.TxHash,
Cheque: action.Cheque,
Result: nil,
Reverted: true,
},
UncashedAmount: new(big.Int).Sub(cheque.CumulativePayout, paidOut),
}, nil
}
result, err := s.parseCashChequeBeneficiaryReceipt(chequebookAddress, receipt)
if err != nil {
return nil, err
}
return &CashoutStatus{
Last: &LastCashout{
TxHash: action.TxHash,
Cheque: action.Cheque,
Result: result,
Reverted: false,
},
// uncashed is the difference since the last sent (and confirmed) cashout.
UncashedAmount: new(big.Int).Sub(cheque.CumulativePayout, result.CumulativePayout),
}, nil
}
// parseCashChequeBeneficiaryReceipt processes the receipt from a CashChequeBeneficiary transaction
func (s *cashoutService) parseCashChequeBeneficiaryReceipt(chequebookAddress common.Address, receipt *types.Receipt) (*CashChequeResult, error) {
result := &CashChequeResult{
Bounced: false,
}
var cashedEvent chequeCashedEvent
err := transaction.FindSingleEvent(&chequebookABI, receipt, chequebookAddress, chequeCashedEventType, &cashedEvent)
if err != nil {
return nil, err
}
result.Beneficiary = cashedEvent.Beneficiary
result.Caller = cashedEvent.Caller
result.CallerPayout = cashedEvent.CallerPayout
result.TotalPayout = cashedEvent.TotalPayout
result.CumulativePayout = cashedEvent.CumulativePayout
result.Recipient = cashedEvent.Recipient
err = transaction.FindSingleEvent(&chequebookABI, receipt, chequebookAddress, chequeBouncedEventType, nil)
if err == nil {
result.Bounced = true
} else if !errors.Is(err, transaction.ErrEventNotFound) {
return nil, err
}
return result, nil
}
// Equal compares to CashChequeResults
func (r *CashChequeResult) Equal(o *CashChequeResult) bool {
if r.Beneficiary != o.Beneficiary {
return false
}
if r.Bounced != o.Bounced {
return false
}
if r.Caller != o.Caller {
return false
}
if r.CallerPayout.Cmp(o.CallerPayout) != 0 {
return false
}
if r.CumulativePayout.Cmp(o.CumulativePayout) != 0 {
return false
}
if r.Recipient != o.Recipient {
return false
}
if r.TotalPayout.Cmp(o.TotalPayout) != 0 {
return false
}
return true
}