lnd.xprv/lnwire/shutdown.go

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package lnwire
import (
"io"
)
// Shutdown is sent by either side in order to initiate the cooperative closure
// of a channel. This message is sparse as both sides implicitly have the
// information necessary to construct a transaction that will send the settled
// funds of both parties to the final delivery addresses negotiated during the
// funding workflow.
type Shutdown struct {
// ChannelID serves to identify which channel is to be closed.
ChannelID ChannelID
// Address is the script to which the channel funds will be paid.
Address DeliveryAddress
}
// DeliveryAddress is used to communicate the address to which funds from a
// closed channel should be sent. The address can be a p2wsh, p2pkh, p2sh or
// p2wpkh.
type DeliveryAddress []byte
// deliveryAddressMaxSize is the maximum expected size in bytes of a
// DeliveryAddress based on the types of scripts we know.
// Following are the known scripts and their sizes in bytes.
// - pay to witness script hash: 34
// - pay to pubkey hash: 25
// - pay to script hash: 22
// - pay to witness pubkey hash: 22.
const deliveryAddressMaxSize = 34
// NewShutdown creates a new Shutdown message.
func NewShutdown(cid ChannelID, addr DeliveryAddress) *Shutdown {
return &Shutdown{
ChannelID: cid,
Address: addr,
}
}
// A compile-time check to ensure Shutdown implements the lnwire.Message
// interface.
var _ Message = (*Shutdown)(nil)
// Decode deserializes a serialized Shutdown stored in the passed io.Reader
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (s *Shutdown) Decode(r io.Reader, pver uint32) error {
return ReadElements(r, &s.ChannelID, &s.Address)
}
// Encode serializes the target Shutdown into the passed io.Writer observing
// the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (s *Shutdown) Encode(w io.Writer, pver uint32) error {
return WriteElements(w, s.ChannelID, s.Address)
}
// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (s *Shutdown) MsgType() MessageType {
return MsgShutdown
}
// MaxPayloadLength returns the maximum allowed payload size for this message
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (s *Shutdown) MaxPayloadLength(pver uint32) uint32 {
var length uint32
// ChannelID - 32bytes
length += 32
// Len - 2 bytes
length += 2
// ScriptPubKey - maximum delivery address size.
length += deliveryAddressMaxSize
return length
}