lnd/watchtower/lookout/interface.go
2019-06-13 17:40:04 -07:00

70 lines
2.6 KiB
Go

package lookout
import (
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/watchtower/blob"
"github.com/lightningnetwork/lnd/watchtower/wtdb"
)
// Service abstracts the lookout functionality, supporting the ability to start
// and stop. All communication and actions are driven via the database or chain
// events.
type Service interface {
// Start safely starts up the Interface.
Start() error
// Stop safely stops the Interface.
Stop() error
}
// BlockFetcher supports the ability to fetch blocks from the backend or
// network.
type BlockFetcher interface {
// GetBlock fetches the block given the target block hash.
GetBlock(*chainhash.Hash) (*wire.MsgBlock, error)
}
// DB abstracts the required persistent calls expected by the lookout. DB
// provides the ability to search for state updates that correspond to breach
// transactions confirmed in a particular block.
type DB interface {
// GetLookoutTip returns the last block epoch at which the tower
// performed a match. If no match has been done, a nil epoch will be
// returned.
GetLookoutTip() (*chainntnfs.BlockEpoch, error)
// QueryMatches searches its database for any state updates matching the
// provided breach hints. If any matches are found, they will be
// returned along with encrypted blobs so that justice can be exacted.
QueryMatches([]blob.BreachHint) ([]wtdb.Match, error)
// SetLookoutTip writes the best epoch for which the watchtower has
// queried for breach hints.
SetLookoutTip(*chainntnfs.BlockEpoch) error
}
// EpochRegistrar supports the ability to register for events corresponding to
// newly created blocks.
type EpochRegistrar interface {
// RegisterBlockEpochNtfn registers for a new block epoch subscription.
// The implementation must support historical dispatch, starting from
// the provided chainntnfs.BlockEpoch when it is non-nil. The
// notifications should be delivered in-order, and deliver reorged
// blocks.
RegisterBlockEpochNtfn(
*chainntnfs.BlockEpoch) (*chainntnfs.BlockEpochEvent, error)
}
// Punisher handles the construction and publication of justice transactions
// once they have been detected by the Service.
type Punisher interface {
// Punish accepts a JusticeDescriptor, constructs the justice
// transaction, and publishes the transaction to the network so it can
// be mined. The second parameter is a quit channel so that long-running
// operations required to track the confirmation of the transaction can
// be canceled on shutdown.
Punish(*JusticeDescriptor, <-chan struct{}) error
}