transaction

Documentation

Index

• Variables
• func FindSingleEvent(abi *abi.ABI, receipt *types.Receipt, contractAddress common.Address, ...) error
• func IsSynced(ctx context.Context, backend Backend, maxDelay time.Duration) (bool, time.Time, error)
• func ParseABIUnchecked(json string) abi.ABI
• func ParseEvent(a *abi.ABI, eventName string, c interface{}, e types.Log) error
• func WaitBlockAfterTransaction(ctx context.Context, backend Backend, pollingInterval time.Duration, ...) (*types.Header, error)
• func WaitSynced(ctx context.Context, logger log.Logger, backend Backend, ...) error
• type Backend
• type Monitor
  • func NewMonitor(logger log.Logger, backend Backend, sender common.Address, ...) Monitor
• type Service
  • func NewService(logger log.Logger, backend Backend, signer crypto.Signer, ...) (Service, error)
• type StoredTransaction
• type TxRequest

Variables

var (
	ErrEventNotFound = errors.New("event not found")
	ErrNoTopic       = errors.New("no topic")
)

var (
	// ErrTransactionReverted denotes that the sent transaction has been
	// reverted.
	ErrTransactionReverted = errors.New("transaction reverted")
	ErrUnknownTransaction  = errors.New("unknown transaction")
	ErrAlreadyImported     = errors.New("already imported")
	ErrGasPriceTooLow      = errors.New("gas price too low")
)

var ErrMonitorClosed = errors.New("monitor closed")

var ErrTransactionCancelled = errors.New("transaction cancelled")

Functions

func FindSingleEvent

func FindSingleEvent(abi *abi.ABI, receipt *types.Receipt, contractAddress common.Address, event abi.Event, out interface{}) error

FindSingleEvent will find the first event of the given kind.

func IsSynced

func IsSynced(ctx context.Context, backend Backend, maxDelay time.Duration) (bool, time.Time, error)

IsSynced will check if we are synced with the given blockchain backend. This is true if the current wall clock is after the block time of last block with the given maxDelay as the maximum duration we can be behind the block time.

func ParseABIUnchecked

func ParseABIUnchecked(json string) abi.ABI

ParseABIUnchecked will parse a valid json abi. Only use this with string constants known to be correct.

func ParseEvent

func ParseEvent(a *abi.ABI, eventName string, c interface{}, e types.Log) error

ParseEvent will parse the specified abi event from the given log

func WaitBlockAfterTransaction

func WaitBlockAfterTransaction(ctx context.Context, backend Backend, pollingInterval time.Duration, txHash common.Hash, additionalConfirmations uint64) (*types.Header, error)

func WaitSynced

func WaitSynced(ctx context.Context, logger log.Logger, backend Backend, maxDelay time.Duration) error

WaitSynced will wait until we are synced with the given blockchain backend, with the given maxDelay duration as the maximum time we can be behind the last block.

Types

type Backend

type Backend interface {
	CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
	CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
	HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error)
	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
	SuggestGasPrice(ctx context.Context) (*big.Int, error)
	EstimateGas(ctx context.Context, call ethereum.CallMsg) (gas uint64, err error)
	SendTransaction(ctx context.Context, tx *types.Transaction) error
	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
	TransactionByHash(ctx context.Context, hash common.Hash) (tx *types.Transaction, isPending bool, err error)
	BlockNumber(ctx context.Context) (uint64, error)
	BalanceAt(ctx context.Context, address common.Address, block *big.Int) (*big.Int, error)
	NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error)
	FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error)
	ChainID(ctx context.Context) (*big.Int, error)

	Close()
}

Backend is the minimum of blockchain backend functions we need.

type Monitor

type Monitor interface {
	io.Closer
	// WatchTransaction watches the transaction until either there is 1 confirmation or a competing transaction with cancellationDepth confirmations.
	WatchTransaction(txHash common.Hash, nonce uint64) (<-chan types.Receipt, <-chan error, error)
}

Monitor is a nonce-based watcher for transaction confirmations. Instead of watching transactions individually, the senders nonce is monitored and transactions are checked based on this. The idea is that if the nonce is still lower than that of a pending transaction, there is no point in actually checking the transaction for a receipt. At the same time if the nonce was already used and this was a few blocks ago we can reasonably assume that it will never confirm.

func NewMonitor

func NewMonitor(logger log.Logger, backend Backend, sender common.Address, pollingInterval time.Duration, cancellationDepth uint64) Monitor

type Service

type Service interface {
	io.Closer
	// Send creates a transaction based on the request and sends it.
	Send(ctx context.Context, request *TxRequest) (txHash common.Hash, err error)
	// Call simulate a transaction based on the request.
	Call(ctx context.Context, request *TxRequest) (result []byte, err error)
	// WaitForReceipt waits until either the transaction with the given hash has been mined or the context is cancelled.
	// This is only valid for transaction sent by this service.
	WaitForReceipt(ctx context.Context, txHash common.Hash) (receipt *types.Receipt, err error)
	// WatchSentTransaction start watching the given transaction.
	// This wraps the monitors watch function by loading the correct nonce from the store.
	// This is only valid for transaction sent by this service.
	WatchSentTransaction(txHash common.Hash) (<-chan types.Receipt, <-chan error, error)
	// StoredTransaction retrieves the stored information for the transaction
	StoredTransaction(txHash common.Hash) (*StoredTransaction, error)
	// PendingTransactions retrieves the list of all pending transaction hashes
	PendingTransactions() ([]common.Hash, error)
	// ResendTransaction resends a previously sent transaction
	// This operation can be useful if for some reason the transaction vanished from the eth networks pending pool
	ResendTransaction(ctx context.Context, txHash common.Hash) error
	// CancelTransaction cancels a previously sent transaction by double-spending its nonce with zero-transfer one
	CancelTransaction(ctx context.Context, originalTxHash common.Hash) (common.Hash, error)
}

Service is the service to send transactions. It takes care of gas price, gas limit and nonce management.

func NewService

func NewService(logger log.Logger, backend Backend, signer crypto.Signer, store storage.StateStorer, chainID *big.Int, monitor Monitor) (Service, error)

NewService creates a new transaction service.

type StoredTransaction

type StoredTransaction struct {
	To          *common.Address // recipient of the transaction
	Data        []byte          // transaction data
	GasPrice    *big.Int        // used gas price
	GasLimit    uint64          // used gas limit
	Value       *big.Int        // amount of wei to send
	Nonce       uint64          // used nonce
	Created     int64           // creation timestamp
	Description string          // description
}

type TxRequest

type TxRequest struct {
	To          *common.Address // recipient of the transaction
	Data        []byte          // transaction data
	GasPrice    *big.Int        // gas price or nil if suggested gas price should be used
	GasLimit    uint64          // gas limit or 0 if it should be estimated
	Value       *big.Int        // amount of wei to send
	Description string          // optional description
}

TxRequest describes a request for a transaction that can be executed.