lnd/sweep/interface.go
Olaoluwa Osuntokun eaea11e48f
sweep: update sweeper to use AuxSweeper to add extra change addr
In this commit, we start to use the AuxSweeper (if present) to obtain a
new extra change addr we should add to the sweeping transaction. With
this, we'll take the set of inputs and our change addr, and then maybe
gain a new change addr to add to the sweep transaction.

The extra change addr will be treated as an extra required tx out,
shared across all the relevant inputs. This'll also be used in
NeedWalletInput to make sure that we add an extra input if needed to be
able to pay for the change addr.
2024-10-02 18:09:58 -07:00

98 lines
3.9 KiB
Go

package sweep
import (
"github.com/btcsuite/btcd/btcutil"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/fn"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lnwallet"
)
// Wallet contains all wallet related functionality required by sweeper.
type Wallet interface {
// PublishTransaction performs cursory validation (dust checks, etc) and
// broadcasts the passed transaction to the Bitcoin network.
PublishTransaction(tx *wire.MsgTx, label string) error
// ListUnspentWitnessFromDefaultAccount returns all unspent outputs
// which are version 0 witness programs from the default wallet account.
// The 'minConfs' and 'maxConfs' parameters indicate the minimum
// and maximum number of confirmations an output needs in order to be
// returned by this method.
ListUnspentWitnessFromDefaultAccount(minConfs, maxConfs int32) (
[]*lnwallet.Utxo, error)
// WithCoinSelectLock will execute the passed function closure in a
// synchronized manner preventing any coin selection operations from
// proceeding while the closure is executing. This can be seen as the
// ability to execute a function closure under an exclusive coin
// selection lock.
WithCoinSelectLock(f func() error) error
// RemoveDescendants removes any wallet transactions that spends
// outputs created by the specified transaction.
RemoveDescendants(*wire.MsgTx) error
// FetchTx returns the transaction that corresponds to the transaction
// hash passed in. If the transaction can't be found then a nil
// transaction pointer is returned.
FetchTx(chainhash.Hash) (*wire.MsgTx, error)
// CancelRebroadcast is used to inform the rebroadcaster sub-system
// that it no longer needs to try to rebroadcast a transaction. This is
// used to ensure that invalid transactions (inputs spent) aren't
// retried in the background.
CancelRebroadcast(tx chainhash.Hash)
// CheckMempoolAcceptance checks whether a transaction follows mempool
// policies and returns an error if it cannot be accepted into the
// mempool.
CheckMempoolAcceptance(tx *wire.MsgTx) error
// GetTransactionDetails returns a detailed description of a tx given
// its transaction hash.
GetTransactionDetails(txHash *chainhash.Hash) (
*lnwallet.TransactionDetail, error)
// BackEnd returns a name for the wallet's backing chain service,
// which could be e.g. btcd, bitcoind, neutrino, or another consensus
// service.
BackEnd() string
}
// SweepOutput is an output used to sweep funds from a channel output.
type SweepOutput struct { //nolint:revive
wire.TxOut
// IsExtra indicates whether this output is an extra output that was
// added by a party other than the sweeper.
IsExtra bool
// InternalKey is the taproot internal key of the extra output. This is
// None, if this isn't a taproot output.
InternalKey fn.Option[keychain.KeyDescriptor]
}
// AuxSweeper is used to enable a 3rd party to further shape the sweeping
// transaction by adding a set of extra outputs to the sweeping transaction.
type AuxSweeper interface {
// DeriveSweepAddr takes a set of inputs, and the change address we'd
// use to sweep them, and maybe results an extra sweep output that we
// should add to the sweeping transaction.
DeriveSweepAddr(inputs []input.Input,
change lnwallet.AddrWithKey) fn.Result[SweepOutput]
// ExtraBudgetForInputs is used to determine the extra budget that
// should be allocated to sweep the given set of inputs. This can be
// used to add extra funds to the sweep transaction, for example to
// cover fees for additional outputs of custom channels.
ExtraBudgetForInputs(inputs []input.Input) fn.Result[btcutil.Amount]
// NotifyBroadcast is used to notify external callers of the broadcast
// of a sweep transaction, generated by the passed BumpRequest.
NotifyBroadcast(req *BumpRequest, tx *wire.MsgTx,
totalFees btcutil.Amount) error
}