// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the provided address. When the address
// is nil, the coinbase transaction will instead be redeemable by anyone.
//
// See the comment for NewBlockTemplate for more information about why the nil
// address handling is useful.
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int64, addr btcutil.Address) (*btcutil.Tx, error) {
// Create the script to pay to the provided payment address if one was
// specified. Otherwise create a script that allows the coinbase to be
// redeemable by anyone.
var pkScript []byte
if addr != nil {
var err error
pkScript, err = btcscript.PayToAddrScript(addr)
if err != nil {
return nil, err
}
} else {
scriptBuilder := btcscript.NewScriptBuilder()
pkScript = scriptBuilder.AddOp(btcscript.OP_TRUE).Script()
}
tx := btcwire.NewMsgTx()
tx.AddTxIn(&btcwire.TxIn{
// Coinbase transactions have no inputs, so previous outpoint is
// zero hash and max index.
PreviousOutPoint: *btcwire.NewOutPoint(&btcwire.ShaHash{},
btcwire.MaxPrevOutIndex),
SignatureScript: coinbaseScript,
Sequence: btcwire.MaxTxInSequenceNum,
})
tx.AddTxOut(&btcwire.TxOut{
Value: btcchain.CalcBlockSubsidy(nextBlockHeight,
activeNetParams.Params),
PkScript: pkScript,
})
return btcutil.NewTx(tx), nil
}
// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the passed public key. It also accepts
// an extra nonce value for the signature script. This extra nonce helps ensure
// the transaction is not a duplicate transaction (paying the same value to the
// same public key address would otherwise be an identical transaction for
// block version 1).
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int64, addr btcutil.Address) (*btcutil.Tx, error) {
// Create a script to pay to the specific address.
pkScript, err := btcscript.PayToAddrScript(addr)
if err != nil {
return nil, err
}
tx := btcwire.NewMsgTx()
tx.AddTxIn(&btcwire.TxIn{
// Coinbase transactions have no inputs, so previous outpoint is
// zero hash and max index.
PreviousOutpoint: *btcwire.NewOutPoint(&btcwire.ShaHash{},
btcwire.MaxPrevOutIndex),
SignatureScript: coinbaseScript,
Sequence: btcwire.MaxTxInSequenceNum,
})
tx.AddTxOut(&btcwire.TxOut{
Value: btcchain.CalcBlockSubsidy(nextBlockHeight,
activeNetParams.Params),
PkScript: pkScript,
})
return btcutil.NewTx(tx), nil
}