@node-dlc/wire/lib/serialize/address/serializeIPv4.ts

Lightning Network Wire Protocol

import { BufferWriter } from '@node-dlc/bufio';

import { AddressIPv4 } from '../../domain/AddressIPv4';
import { ipv4StringToBuffer } from './ipv4StringToBuffer';

/**
 * Serializes an IPv4 address in a Buffer that can be sent
 * over the wire.
 */
export function serializeIPv4(address: AddressIPv4): Buffer {
  const writer = new BufferWriter(Buffer.alloc(7));

  const hostBytes = ipv4StringToBuffer(address.host);

  writer.writeUInt8(address.type);
  writer.writeBytes(hostBytes);
  writer.writeUInt16BE(address.port);

  return writer.toBuffer();
}