package transactions import ( "context" "math/big" ethereum "github.com/ethereum/go-ethereum" "github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/common/hexutil" "github.com/ethereum/go-ethereum/core/types" "github.com/ethereum/go-ethereum/rlp" "github.com/status-im/status-go/geth/rpc" ) // rpcWrapper wraps provides convenient interface for ethereum RPC APIs we need for sending transactions type rpcWrapper struct { rpcClient *rpc.Client } func newRPCWrapper(client *rpc.Client) *rpcWrapper { return &rpcWrapper{rpcClient: client} } // PendingNonceAt returns the account nonce of the given account in the pending state. // This is the nonce that should be used for the next transaction. func (w *rpcWrapper) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) { var result hexutil.Uint64 err := w.rpcClient.CallContext(ctx, &result, "eth_getTransactionCount", account, "pending") return uint64(result), err } // SuggestGasPrice retrieves the currently suggested gas price to allow a timely // execution of a transaction. func (w *rpcWrapper) SuggestGasPrice(ctx context.Context) (*big.Int, error) { var hex hexutil.Big if err := w.rpcClient.CallContext(ctx, &hex, "eth_gasPrice"); err != nil { return nil, err } return (*big.Int)(&hex), nil } // 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. func (w *rpcWrapper) EstimateGas(ctx context.Context, msg ethereum.CallMsg) (uint64, error) { var hex hexutil.Uint64 err := w.rpcClient.CallContext(ctx, &hex, "eth_estimateGas", toCallArg(msg)) if err != nil { return 0, err } return uint64(hex), nil } // SendTransaction injects a signed transaction into the pending pool for execution. // // If the transaction was a contract creation use the TransactionReceipt method to get the // contract address after the transaction has been mined. func (w *rpcWrapper) SendTransaction(ctx context.Context, tx *types.Transaction) error { data, err := rlp.EncodeToBytes(tx) if err != nil { return err } return w.rpcClient.CallContext(ctx, nil, "eth_sendRawTransaction", common.ToHex(data)) } func toCallArg(msg ethereum.CallMsg) interface{} { arg := map[string]interface{}{ "from": msg.From, "to": msg.To, } if len(msg.Data) > 0 { arg["data"] = hexutil.Bytes(msg.Data) } if msg.Value != nil { arg["value"] = (*hexutil.Big)(msg.Value) } if msg.Gas != 0 { arg["gas"] = hexutil.Uint64(msg.Gas) } if msg.GasPrice != nil { arg["gasPrice"] = (*hexutil.Big)(msg.GasPrice) } return arg }