lnd.xprv/lnwire/update_fulfill_htlc.go

105 lines
2.7 KiB
Go

package lnwire
import (
"io"
"github.com/roasbeef/btcd/wire"
)
// UpdateFufillHTLC is sent by Alice to Bob when she wishes to settle a
// particular HTLC referenced by its HTLCKey within a specific active channel
// referenced by ChannelPoint. A subsequent CommitSig message will be sent by
// Alice to "lock-in" the removal of the specified HTLC, possible containing a
// batch signature covering several settled HTLC's.
type UpdateFufillHTLC struct {
// ChannelPoint references an active channel which holds the HTLC to be
// settled.
ChannelPoint wire.OutPoint
// ID denotes the exact HTLC stage within the receiving node's
// commitment transaction to be removed.
ID uint64
// PaymentPreimage is the R-value preimage required to fully settle an
// HTLC.
PaymentPreimage [32]byte
}
// NewUpdateFufillHTLC returns a new empty UpdateFufillHTLC.
func NewUpdateFufillHTLC(chanPoint wire.OutPoint, id uint64,
preimage [32]byte) *UpdateFufillHTLC {
return &UpdateFufillHTLC{
ChannelPoint: chanPoint,
ID: id,
PaymentPreimage: preimage,
}
}
// A compile time check to ensure UpdateFufillHTLC implements the lnwire.Message
// interface.
var _ Message = (*UpdateFufillHTLC)(nil)
// Decode deserializes a serialized UpdateFufillHTLC message stored in the passed
// io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFufillHTLC) Decode(r io.Reader, pver uint32) error {
// ChannelPoint(8)
// ID(8)
// PaymentPreimage(32)
err := readElements(r,
&c.ChannelPoint,
&c.ID,
c.PaymentPreimage[:],
)
if err != nil {
return err
}
return nil
}
// Encode serializes the target UpdateFufillHTLC into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFufillHTLC) Encode(w io.Writer, pver uint32) error {
err := writeElements(w,
c.ChannelPoint,
c.ID,
c.PaymentPreimage[:],
)
if err != nil {
return err
}
return nil
}
// Command returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFufillHTLC) Command() uint32 {
return CmdUpdateFufillHTLC
}
// MaxPayloadLength returns the maximum allowed payload size for a UpdateFufillHTLC
// complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFufillHTLC) MaxPayloadLength(uint32) uint32 {
// 36 + 8 + (32 * 15)
return 524
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the UpdateFufillHTLC are valid.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFufillHTLC) Validate() error {
// We're good!
return nil
}