MariusVanDerWijden

// Connect to a node
backend, err := ethclient.Dial("/tmp/geth.ipc")
// Get the contract address from hex string
addr := common.HexToAddress("0x000")
// Bind to an already deployed contract
ctr, err := contract.NewContract(addr, backend)

MariusVanDerWijden

> abigen --pkg coolcontract --sol CoolContract.sol --out ./coolcontract/CoolContract.go

MariusVanDerWijden

pragma solidity ^0.6.0;
contract CoolContract {
    uint256 balance;
    event Deposited(address addr);
    
    function Deposit() public payable {
        balance += msg.value;
        emit Deposited(msg.sender);
    }
    

MariusVanDerWijden

// If you have a bind.TransactOpts object you can sign a transaction
sigTx, err := opts.Signer(types.NewEIP155Signer(nil), senderAddr, tx)

MariusVanDerWijden

// Open Keystore
ks := keystore.NewKeyStore("/home/matematik/keystore", keystore.StandardScryptN, keystore.StandardScryptP)
// Create an account
acc, err := ks.NewAccount("password")
// List all accounts
accs := ks.Accounts()
// Unlock an account
ks.Unlock(accs[0], "password")
// Create a TransactOpts object
ksOpts, err := bind.NewKeyStoreTransactor(ks, accs[0])

MariusVanDerWijden

// Use secret key hex string to sign a raw transaction
SK := "0x0000"
sk := crypto.ToECDSAUnsafe(common.FromHex(SK))// Sign the transaction
signedTx, err := types.SignTx(tx, types.NewEIP155Signer(nil), sk)
// You could also create a TransactOpts object
opts := bind.NewKeyedTransactor(sk)
// To get the address corresponding to your private key
addr := crypto.PubkeyToAddress(sk.PublicKey)

MariusVanDerWijden

// Retrieve the pending nonce for an account
nonce, err := cl.NonceAt(ctx, addr, nil)
to := common.HexToAddress("0xABCD")
amount := big.NewInt(10 * params.GWei)
gasLimit := uint64(21000)
gasPrice := big.NewInt(10 * params.GWei)
data := []byte{}
// Create a raw unsigned transaction
tx := types.NewTransaction(nonce, to, amount, gasLimit, gasPrice, data)

MariusVanDerWijden

// Retrieve a block by number
ctx := context.Background()
block, err := cl.BlockByNumber(ctx, big.NewInt(123))
// Get Balance of an account (nil means at newest block)
addr := common.HexToAddress("0xb02A2EdA1b317FBd16760...")
balance, err := cl.BalanceAt(ctx, addr, nil)
// Send transaction
tx := new(types.Transaction)
err = cl.SendTransaction(ctx, tx)
// Get sync progress of the node

MariusVanDerWijden

// Use a local node:
cl, err := ethclient.Dial(“/tmp/geth.ipc”)
// Use infura:
infura := “wss://goerli.infura.io/ws/v3/xxxxxx”
cl, err := ethclient.Dial(infura)
// Use a non-local node:
cl, err := ethclient.Dial("http://192.168.1.2:8545")

MariusVanDerWijden

BenchmarkPrecompiledEcrecover/-Gas=3000-16	7512	157717 ns/op	3000 gas/op	 11.9 mgas/s	1.85 s/op	1280 B/op	9 allocs/op
BenchmarkPrecompiledSha256/128-Gas=108-16	 1608877	783 ns/op	108 gas/op	 66.5 mgas/s	2.60 s/op	32 B/op	1 allocs/op
BenchmarkPrecompiledRipeMD/128-Gas=1080-16	489368	2066 ns/op	1080 gas/op	4745 mgas/s	0.111 s/op	 176 B/op	3 allocs/op
BenchmarkPrecompiledIdentity/128-Gas=27-16	61946466	 20.3 ns/op	 27.0 gas/op	647 mgas/s	2.58 s/op	0 B/op	0 allocs/op
BenchmarkPrecompiledModExp/eip_example1-Gas=13056-16	 21351	 51260 ns/op	 13056 gas/op	294 mgas/s	0.945 s/op	2689 B/op	41 allocs/op
BenchmarkPrecompiledModExp/nagydani-1-qube-Gas=204-16 	305833	3821 ns/op	204 gas/op	 36.8 mgas/s	1.69 s/op	1473 B/op	22 allocs/op
BenchmarkPrecompiledBn256Add/chfast1-Gas=150-16	 64232	 18761 ns/op	150 gas/op	4.39 mgas/s	2.05 s/op	 784 B/op	16 allocs/op
BenchmarkPrecompiledBn256Add/cdetrio5-Gas=150-16 	706676	1517 ns/op	150 gas/op	147 mgas/s	0.723 s/op	 624 B/op	11 allocs/op