port over blockchian interfaces

utils/blockchain.go

@@ -0,0 +1,46 @@
+package utils
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// Blockchain is a generalized interface for interacting with the ethereum blockchain
+type Blockchain 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)
+	// 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)
+	// 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
+	// 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)
+	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
+}