ipld-eth-server/pkg/geth/contract.go
Rob Mulholand 042f1142c0 Handle headers from POA chain
- Fetching headers from Kovan requires custom type without mixHash/Nonce
2018-09-19 11:00:20 -05:00

43 lines
1.0 KiB
Go

package geth
import (
"errors"
"context"
"math/big"
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/common"
)
var (
ErrInvalidStateAttribute = errors.New("invalid state attribute")
)
func (blockChain *BlockChain) FetchContractData(abiJSON string, address string, method string, methodArg interface{}, result interface{}, blockNumber int64) error {
parsed, err := ParseAbi(abiJSON)
if err != nil {
return err
}
var input []byte
if methodArg != nil {
input, err = parsed.Pack(method, methodArg)
} else {
input, err = parsed.Pack(method)
}
if err != nil {
return err
}
output, err := blockChain.callContract(address, input, big.NewInt(blockNumber))
if err != nil {
return err
}
return parsed.Unpack(result, method, output)
}
func (blockChain *BlockChain) callContract(contractHash string, input []byte, blockNumber *big.Int) ([]byte, error) {
to := common.HexToAddress(contractHash)
msg := ethereum.CallMsg{To: &to, Data: input}
return blockChain.ethClient.CallContract(context.Background(), msg, blockNumber)
}