go-ethereum/accounts/abi/bind/backend.go
2018-01-24 10:54:13 +02:00

113 lines
5.3 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package bind
import (
"context"
"errors"
"math/big"
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
)
var (
// ErrNoCode is returned by call and transact operations for which the requested
// recipient contract to operate on does not exist in the state db or does not
// have any code associated with it (i.e. suicided).
ErrNoCode = errors.New("no contract code at given address")
// This error is raised when attempting to perform a pending state action
// on a backend that doesn't implement PendingContractCaller.
ErrNoPendingState = errors.New("backend does not support pending state")
// This error is returned by WaitDeployed if contract creation leaves an
// empty contract behind.
ErrNoCodeAfterDeploy = errors.New("no contract code after deployment")
)
// ContractCaller defines the methods needed to allow operating with contract on a read
// only basis.
type ContractCaller interface {
// CodeAt returns the code of the given account. This is needed to differentiate
// between contract internal errors and the local chain being out of sync.
CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
// ContractCall executes an Ethereum contract call with the specified data as the
// input.
CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
}
// PendingContractCaller defines methods to perform contract calls on the pending state.
// Call will try to discover this interface when access to the pending state is requested.
// If the backend does not support the pending state, Call returns ErrNoPendingState.
type PendingContractCaller interface {
// PendingCodeAt returns the code of the given account in the pending state.
PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error)
// PendingCallContract executes an Ethereum contract call against the pending state.
PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error)
}
// ContractTransactor defines the methods needed to allow operating with contract
// on a write only basis. Beside the transacting method, the remainder are helpers
// used when the user does not provide some needed values, but rather leaves it up
// to the transactor to decide.
type ContractTransactor interface {
// PendingCodeAt returns the code of the given account in the pending state.
PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
// PendingNonceAt retrieves the current pending nonce associated with an account.
PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
// SuggestGasPrice retrieves the currently suggested gas price to allow a timely
// execution of a transaction.
SuggestGasPrice(ctx context.Context) (*big.Int, error)
// EstimateGas tries to estimate the gas needed to execute a specific
// transaction based on the current pending state of the backend blockchain.
// There is no guarantee that this is the true gas limit requirement as other
// transactions may be added or removed by miners, but it should provide a basis
// for setting a reasonable default.
EstimateGas(ctx context.Context, call ethereum.CallMsg) (gas uint64, err error)
// SendTransaction injects the transaction into the pending pool for execution.
SendTransaction(ctx context.Context, tx *types.Transaction) error
}
// ContractFilterer defines the methods needed to access log events using one-off
// queries or continuous event subscriptions.
type ContractFilterer interface {
// FilterLogs executes a log filter operation, blocking during execution and
// returning all the results in one batch.
//
// TODO(karalabe): Deprecate when the subscription one can return past data too.
FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error)
// SubscribeFilterLogs creates a background log filtering operation, returning
// a subscription immediately, which can be used to stream the found events.
SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error)
}
// DeployBackend wraps the operations needed by WaitMined and WaitDeployed.
type DeployBackend interface {
TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
}
// ContractBackend defines the methods needed to work with contracts on a read-write basis.
type ContractBackend interface {
ContractCaller
ContractTransactor
ContractFilterer
}