lnd.xprv/lnwire/update_fulfill_htlc.go

89 lines
2.5 KiB
Go

package lnwire
import (
"io"
)
// UpdateFulfillHTLC 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 UpdateFulfillHTLC struct {
// ChanID references an active channel which holds the HTLC to be
// settled.
ChanID ChannelID
// 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
}
// NewUpdateFulfillHTLC returns a new empty UpdateFulfillHTLC.
func NewUpdateFulfillHTLC(chanID ChannelID, id uint64,
preimage [32]byte) *UpdateFulfillHTLC {
return &UpdateFulfillHTLC{
ChanID: chanID,
ID: id,
PaymentPreimage: preimage,
}
}
// A compile time check to ensure UpdateFulfillHTLC implements the lnwire.Message
// interface.
var _ Message = (*UpdateFulfillHTLC)(nil)
// Decode deserializes a serialized UpdateFulfillHTLC message stored in the passed
// io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFulfillHTLC) Decode(r io.Reader, pver uint32) error {
return ReadElements(r,
&c.ChanID,
&c.ID,
c.PaymentPreimage[:],
)
}
// Encode serializes the target UpdateFulfillHTLC into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFulfillHTLC) Encode(w io.Writer, pver uint32) error {
return WriteElements(w,
c.ChanID,
c.ID,
c.PaymentPreimage[:],
)
}
// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFulfillHTLC) MsgType() MessageType {
return MsgUpdateFulfillHTLC
}
// MaxPayloadLength returns the maximum allowed payload size for an UpdateFulfillHTLC
// complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *UpdateFulfillHTLC) MaxPayloadLength(uint32) uint32 {
// 32 + 8 + 32
return 72
}
// TargetChanID returns the channel id of the link for which this message is
// intended.
//
// NOTE: Part of peer.LinkUpdater interface.
func (c *UpdateFulfillHTLC) TargetChanID() ChannelID {
return c.ChanID
}