contracts/chequebook: polishes and naked return removals

This commit is contained in:
Péter Szilágyi 2019-02-07 13:14:24 +02:00
parent 53b823afc8
commit 159e991196
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@ -109,12 +109,12 @@ type Chequebook struct {
log log.Logger // contextual logger with the contract address embedded
}
func (chbook *Chequebook) String() string {
return fmt.Sprintf("contract: %s, owner: %s, balance: %v, signer: %x", chbook.contractAddr.Hex(), chbook.owner.Hex(), chbook.balance, chbook.prvKey.PublicKey)
func (cb *Chequebook) String() string {
return fmt.Sprintf("contract: %s, owner: %s, balance: %v, signer: %x", cb.contractAddr.Hex(), cb.owner.Hex(), cb.balance, cb.prvKey.PublicKey)
}
// NewChequebook creates a new Chequebook.
func NewChequebook(path string, contractAddr common.Address, prvKey *ecdsa.PrivateKey, backend Backend) (self *Chequebook, err error) {
func NewChequebook(path string, contractAddr common.Address, prvKey *ecdsa.PrivateKey, backend Backend) (*Chequebook, error) {
balance := new(big.Int)
sent := make(map[common.Address]*big.Int)
@ -128,7 +128,7 @@ func NewChequebook(path string, contractAddr common.Address, prvKey *ecdsa.Priva
TransactOpts: *transactOpts,
}
self = &Chequebook{
cb := &Chequebook{
prvKey: prvKey,
balance: balance,
contractAddr: contractAddr,
@ -140,42 +140,39 @@ func NewChequebook(path string, contractAddr common.Address, prvKey *ecdsa.Priva
session: session,
log: log.New("contract", contractAddr),
}
if (contractAddr != common.Address{}) {
self.setBalanceFromBlockChain()
self.log.Trace("New chequebook initialised", "owner", self.owner, "balance", self.balance)
cb.setBalanceFromBlockChain()
cb.log.Trace("New chequebook initialised", "owner", cb.owner, "balance", cb.balance)
}
return
return cb, nil
}
func (chbook *Chequebook) setBalanceFromBlockChain() {
balance, err := chbook.backend.BalanceAt(context.TODO(), chbook.contractAddr, nil)
func (cb *Chequebook) setBalanceFromBlockChain() {
balance, err := cb.backend.BalanceAt(context.TODO(), cb.contractAddr, nil)
if err != nil {
log.Error("Failed to retrieve chequebook balance", "err", err)
} else {
chbook.balance.Set(balance)
cb.balance.Set(balance)
}
}
// LoadChequebook loads a chequebook from disk (file path).
func LoadChequebook(path string, prvKey *ecdsa.PrivateKey, backend Backend, checkBalance bool) (self *Chequebook, err error) {
var data []byte
data, err = ioutil.ReadFile(path)
if err != nil {
return
}
self, _ = NewChequebook(path, common.Address{}, prvKey, backend)
err = json.Unmarshal(data, self)
func LoadChequebook(path string, prvKey *ecdsa.PrivateKey, backend Backend, checkBalance bool) (*Chequebook, error) {
data, err := ioutil.ReadFile(path)
if err != nil {
return nil, err
}
cb, _ := NewChequebook(path, common.Address{}, prvKey, backend)
if err = json.Unmarshal(data, cb); err != nil {
return nil, err
}
if checkBalance {
self.setBalanceFromBlockChain()
cb.setBalanceFromBlockChain()
}
log.Trace("Loaded chequebook from disk", "path", path)
return
return cb, nil
}
// chequebookFile is the JSON representation of a chequebook.
@ -187,19 +184,19 @@ type chequebookFile struct {
}
// UnmarshalJSON deserialises a chequebook.
func (chbook *Chequebook) UnmarshalJSON(data []byte) error {
func (cb *Chequebook) UnmarshalJSON(data []byte) error {
var file chequebookFile
err := json.Unmarshal(data, &file)
if err != nil {
return err
}
_, ok := chbook.balance.SetString(file.Balance, 10)
_, ok := cb.balance.SetString(file.Balance, 10)
if !ok {
return fmt.Errorf("cumulative amount sent: unable to convert string to big integer: %v", file.Balance)
}
chbook.contractAddr = common.HexToAddress(file.Contract)
cb.contractAddr = common.HexToAddress(file.Contract)
for addr, sent := range file.Sent {
chbook.sent[common.HexToAddress(addr)], ok = new(big.Int).SetString(sent, 10)
cb.sent[common.HexToAddress(addr)], ok = new(big.Int).SetString(sent, 10)
if !ok {
return fmt.Errorf("beneficiary %v cumulative amount sent: unable to convert string to big integer: %v", addr, sent)
}
@ -208,14 +205,14 @@ func (chbook *Chequebook) UnmarshalJSON(data []byte) error {
}
// MarshalJSON serialises a chequebook.
func (chbook *Chequebook) MarshalJSON() ([]byte, error) {
func (cb *Chequebook) MarshalJSON() ([]byte, error) {
var file = &chequebookFile{
Balance: chbook.balance.String(),
Contract: chbook.contractAddr.Hex(),
Owner: chbook.owner.Hex(),
Balance: cb.balance.String(),
Contract: cb.contractAddr.Hex(),
Owner: cb.owner.Hex(),
Sent: make(map[string]string),
}
for addr, sent := range chbook.sent {
for addr, sent := range cb.sent {
file.Sent[addr.Hex()] = sent.String()
}
return json.Marshal(file)
@ -223,76 +220,78 @@ func (chbook *Chequebook) MarshalJSON() ([]byte, error) {
// Save persists the chequebook on disk, remembering balance, contract address and
// cumulative amount of funds sent for each beneficiary.
func (chbook *Chequebook) Save() (err error) {
data, err := json.MarshalIndent(chbook, "", " ")
func (cb *Chequebook) Save() error {
data, err := json.MarshalIndent(cb, "", " ")
if err != nil {
return err
}
chbook.log.Trace("Saving chequebook to disk", chbook.path)
cb.log.Trace("Saving chequebook to disk", cb.path)
return ioutil.WriteFile(chbook.path, data, os.ModePerm)
return ioutil.WriteFile(cb.path, data, os.ModePerm)
}
// Stop quits the autodeposit go routine to terminate
func (chbook *Chequebook) Stop() {
defer chbook.lock.Unlock()
chbook.lock.Lock()
if chbook.quit != nil {
close(chbook.quit)
chbook.quit = nil
func (cb *Chequebook) Stop() {
defer cb.lock.Unlock()
cb.lock.Lock()
if cb.quit != nil {
close(cb.quit)
cb.quit = nil
}
}
// Issue creates a cheque signed by the chequebook owner's private key. The
// signer commits to a contract (one that they own), a beneficiary and amount.
func (chbook *Chequebook) Issue(beneficiary common.Address, amount *big.Int) (ch *Cheque, err error) {
defer chbook.lock.Unlock()
chbook.lock.Lock()
func (cb *Chequebook) Issue(beneficiary common.Address, amount *big.Int) (*Cheque, error) {
defer cb.lock.Unlock()
cb.lock.Lock()
if amount.Sign() <= 0 {
return nil, fmt.Errorf("amount must be greater than zero (%v)", amount)
}
if chbook.balance.Cmp(amount) < 0 {
err = fmt.Errorf("insufficient funds to issue cheque for amount: %v. balance: %v", amount, chbook.balance)
var (
ch *Cheque
err error
)
if cb.balance.Cmp(amount) < 0 {
err = fmt.Errorf("insufficient funds to issue cheque for amount: %v. balance: %v", amount, cb.balance)
} else {
var sig []byte
sent, found := chbook.sent[beneficiary]
sent, found := cb.sent[beneficiary]
if !found {
sent = new(big.Int)
chbook.sent[beneficiary] = sent
cb.sent[beneficiary] = sent
}
sum := new(big.Int).Set(sent)
sum.Add(sum, amount)
sig, err = crypto.Sign(sigHash(chbook.contractAddr, beneficiary, sum), chbook.prvKey)
sig, err = crypto.Sign(sigHash(cb.contractAddr, beneficiary, sum), cb.prvKey)
if err == nil {
ch = &Cheque{
Contract: chbook.contractAddr,
Contract: cb.contractAddr,
Beneficiary: beneficiary,
Amount: sum,
Sig: sig,
}
sent.Set(sum)
chbook.balance.Sub(chbook.balance, amount) // subtract amount from balance
cb.balance.Sub(cb.balance, amount) // subtract amount from balance
}
}
// auto deposit if threshold is set and balance is less then threshold
// note this is called even if issuing cheque fails
// so we reattempt depositing
if chbook.threshold != nil {
if chbook.balance.Cmp(chbook.threshold) < 0 {
send := new(big.Int).Sub(chbook.buffer, chbook.balance)
chbook.deposit(send)
if cb.threshold != nil {
if cb.balance.Cmp(cb.threshold) < 0 {
send := new(big.Int).Sub(cb.buffer, cb.balance)
cb.deposit(send)
}
}
return
return ch, err
}
// Cash is a convenience method to cash any cheque.
func (chbook *Chequebook) Cash(ch *Cheque) (txhash string, err error) {
return ch.Cash(chbook.session)
func (cb *Chequebook) Cash(ch *Cheque) (string, error) {
return ch.Cash(cb.session)
}
// data to sign: contract address, beneficiary, cumulative amount of funds ever sent
@ -309,73 +308,73 @@ func sigHash(contract, beneficiary common.Address, sum *big.Int) []byte {
}
// Balance returns the current balance of the chequebook.
func (chbook *Chequebook) Balance() *big.Int {
defer chbook.lock.Unlock()
chbook.lock.Lock()
return new(big.Int).Set(chbook.balance)
func (cb *Chequebook) Balance() *big.Int {
defer cb.lock.Unlock()
cb.lock.Lock()
return new(big.Int).Set(cb.balance)
}
// Owner returns the owner account of the chequebook.
func (chbook *Chequebook) Owner() common.Address {
return chbook.owner
func (cb *Chequebook) Owner() common.Address {
return cb.owner
}
// Address returns the on-chain contract address of the chequebook.
func (chbook *Chequebook) Address() common.Address {
return chbook.contractAddr
func (cb *Chequebook) Address() common.Address {
return cb.contractAddr
}
// Deposit deposits money to the chequebook account.
func (chbook *Chequebook) Deposit(amount *big.Int) (string, error) {
defer chbook.lock.Unlock()
chbook.lock.Lock()
return chbook.deposit(amount)
func (cb *Chequebook) Deposit(amount *big.Int) (string, error) {
defer cb.lock.Unlock()
cb.lock.Lock()
return cb.deposit(amount)
}
// deposit deposits amount to the chequebook account.
// The caller must hold self.lock.
func (chbook *Chequebook) deposit(amount *big.Int) (string, error) {
// The caller must hold lock.
func (cb *Chequebook) deposit(amount *big.Int) (string, error) {
// since the amount is variable here, we do not use sessions
depositTransactor := bind.NewKeyedTransactor(chbook.prvKey)
depositTransactor := bind.NewKeyedTransactor(cb.prvKey)
depositTransactor.Value = amount
chbookRaw := &contract.ChequebookRaw{Contract: chbook.contract}
chbookRaw := &contract.ChequebookRaw{Contract: cb.contract}
tx, err := chbookRaw.Transfer(depositTransactor)
if err != nil {
chbook.log.Warn("Failed to fund chequebook", "amount", amount, "balance", chbook.balance, "target", chbook.buffer, "err", err)
cb.log.Warn("Failed to fund chequebook", "amount", amount, "balance", cb.balance, "target", cb.buffer, "err", err)
return "", err
}
// assume that transaction is actually successful, we add the amount to balance right away
chbook.balance.Add(chbook.balance, amount)
chbook.log.Trace("Deposited funds to chequebook", "amount", amount, "balance", chbook.balance, "target", chbook.buffer)
cb.balance.Add(cb.balance, amount)
cb.log.Trace("Deposited funds to chequebook", "amount", amount, "balance", cb.balance, "target", cb.buffer)
return tx.Hash().Hex(), nil
}
// AutoDeposit (re)sets interval time and amount which triggers sending funds to the
// chequebook. Contract backend needs to be set if threshold is not less than buffer, then
// deposit will be triggered on every new cheque issued.
func (chbook *Chequebook) AutoDeposit(interval time.Duration, threshold, buffer *big.Int) {
defer chbook.lock.Unlock()
chbook.lock.Lock()
chbook.threshold = threshold
chbook.buffer = buffer
chbook.autoDeposit(interval)
func (cb *Chequebook) AutoDeposit(interval time.Duration, threshold, buffer *big.Int) {
defer cb.lock.Unlock()
cb.lock.Lock()
cb.threshold = threshold
cb.buffer = buffer
cb.autoDeposit(interval)
}
// autoDeposit starts a goroutine that periodically sends funds to the chequebook
// contract caller holds the lock the go routine terminates if Chequebook.quit is closed.
func (chbook *Chequebook) autoDeposit(interval time.Duration) {
if chbook.quit != nil {
close(chbook.quit)
chbook.quit = nil
func (cb *Chequebook) autoDeposit(interval time.Duration) {
if cb.quit != nil {
close(cb.quit)
cb.quit = nil
}
// if threshold >= balance autodeposit after every cheque issued
if interval == time.Duration(0) || chbook.threshold != nil && chbook.buffer != nil && chbook.threshold.Cmp(chbook.buffer) >= 0 {
if interval == time.Duration(0) || cb.threshold != nil && cb.buffer != nil && cb.threshold.Cmp(cb.buffer) >= 0 {
return
}
ticker := time.NewTicker(interval)
chbook.quit = make(chan bool)
quit := chbook.quit
cb.quit = make(chan bool)
quit := cb.quit
go func() {
for {
@ -383,15 +382,15 @@ func (chbook *Chequebook) autoDeposit(interval time.Duration) {
case <-quit:
return
case <-ticker.C:
chbook.lock.Lock()
if chbook.balance.Cmp(chbook.buffer) < 0 {
amount := new(big.Int).Sub(chbook.buffer, chbook.balance)
txhash, err := chbook.deposit(amount)
cb.lock.Lock()
if cb.balance.Cmp(cb.buffer) < 0 {
amount := new(big.Int).Sub(cb.buffer, cb.balance)
txhash, err := cb.deposit(amount)
if err == nil {
chbook.txhash = txhash
cb.txhash = txhash
}
}
chbook.lock.Unlock()
cb.lock.Unlock()
}
}
}()
@ -404,8 +403,8 @@ type Outbox struct {
}
// NewOutbox creates an outbox.
func NewOutbox(chbook *Chequebook, beneficiary common.Address) *Outbox {
return &Outbox{chbook, beneficiary}
func NewOutbox(cb *Chequebook, beneficiary common.Address) *Outbox {
return &Outbox{cb, beneficiary}
}
// Issue creates cheque.
@ -445,7 +444,7 @@ type Inbox struct {
// NewInbox creates an Inbox. An Inboxes is not persisted, the cumulative sum is updated
// from blockchain when first cheque is received.
func NewInbox(prvKey *ecdsa.PrivateKey, contractAddr, beneficiary common.Address, signer *ecdsa.PublicKey, abigen bind.ContractBackend) (self *Inbox, err error) {
func NewInbox(prvKey *ecdsa.PrivateKey, contractAddr, beneficiary common.Address, signer *ecdsa.PublicKey, abigen bind.ContractBackend) (*Inbox, error) {
if signer == nil {
return nil, fmt.Errorf("signer is null")
}
@ -461,7 +460,7 @@ func NewInbox(prvKey *ecdsa.PrivateKey, contractAddr, beneficiary common.Address
}
sender := transactOpts.From
self = &Inbox{
inbox := &Inbox{
contract: contractAddr,
beneficiary: beneficiary,
sender: sender,
@ -470,8 +469,8 @@ func NewInbox(prvKey *ecdsa.PrivateKey, contractAddr, beneficiary common.Address
cashed: new(big.Int).Set(common.Big0),
log: log.New("contract", contractAddr),
}
self.log.Trace("New chequebook inbox initialized", "beneficiary", self.beneficiary, "signer", hexutil.Bytes(crypto.FromECDSAPub(signer)))
return
inbox.log.Trace("New chequebook inbox initialized", "beneficiary", inbox.beneficiary, "signer", hexutil.Bytes(crypto.FromECDSAPub(signer)))
return inbox, nil
}
func (i *Inbox) String() string {
@ -489,13 +488,15 @@ func (i *Inbox) Stop() {
}
// Cash attempts to cash the current cheque.
func (i *Inbox) Cash() (txhash string, err error) {
if i.cheque != nil {
txhash, err = i.cheque.Cash(i.session)
i.log.Trace("Cashing in chequebook cheque", "amount", i.cheque.Amount, "beneficiary", i.beneficiary)
i.cashed = i.cheque.Amount
func (i *Inbox) Cash() (string, error) {
if i.cheque == nil {
return "", nil
}
return
txhash, err := i.cheque.Cash(i.session)
i.log.Trace("Cashing in chequebook cheque", "amount", i.cheque.Amount, "beneficiary", i.beneficiary)
i.cashed = i.cheque.Amount
return txhash, err
}
// AutoCash (re)sets maximum time and amount which triggers cashing of the last uncashed
@ -509,7 +510,7 @@ func (i *Inbox) AutoCash(cashInterval time.Duration, maxUncashed *big.Int) {
// autoCash starts a loop that periodically clears the last cheque
// if the peer is trusted. Clearing period could be 24h or a week.
// The caller must hold self.lock.
// The caller must hold lock.
func (i *Inbox) autoCash(cashInterval time.Duration) {
if i.quit != nil {
close(i.quit)
@ -632,7 +633,7 @@ func (ch *Cheque) Cash(session *contract.ChequebookSession) (string, error) {
// ValidateCode checks that the on-chain code at address matches the expected chequebook
// contract code. This is used to detect suicided chequebooks.
func ValidateCode(ctx context.Context, b Backend, address common.Address) (ok bool, err error) {
func ValidateCode(ctx context.Context, b Backend, address common.Address) (bool, error) {
code, err := b.CodeAt(ctx, address, nil)
if err != nil {
return false, err