/// <summary>
/// Advertise that we can provide the CID to the X closest peers
/// of the CID.
/// </summary>
/// <param name="cid">
/// The CID to advertise.
/// </param>
/// <remarks>
/// This starts a background process to send the AddProvider message
/// to the 4 closest peers to the <paramref name="cid"/>.
/// </remarks>
public void Advertise(Cid cid)
{
_ = Task.Run(async() =>
{
int advertsNeeded = 4;
var message = new DhtMessage
{
Type = MessageType.AddProvider,
Key = cid.Hash.ToArray(),
ProviderPeers = new DhtPeerMessage[]
{
new DhtPeerMessage
{
Id = Swarm.LocalPeer.Id.ToArray(),
Addresses = Swarm.LocalPeer.Addresses
.Select(a => a.WithoutPeerId().ToArray())
.ToArray()
}
}
};
var peers = RoutingTable
.NearestPeers(cid.Hash)
.Where(p => p != Swarm.LocalPeer);
foreach (var peer in peers)
{
try
{
using (var stream = await Swarm.DialAsync(peer, this.ToString()))
{
ProtoBuf.Serializer.SerializeWithLengthPrefix(stream, message, PrefixStyle.Base128);
await stream.FlushAsync();
}
if (--advertsNeeded == 0)
{
break;
}
}
catch (Exception)
{
// eat it. This is fire and forget.
}
}
});
}
async Task SendWantListAsync(Peer peer, IEnumerable <WantedBlock> wants, bool full)
{
log.Debug($"sending want list to {peer}");
// Send the want list to the peer on any bitswap protocol
// that it supports.
foreach (var protocol in protocols)
{
try
{
using (var stream = await Swarm.DialAsync(peer, protocol.ToString()))
{
await protocol.SendWantsAsync(stream, wants, full : full);
}
return;
}
catch (Exception e)
{
log.Debug($"{peer} refused {protocol}", e);
}
}
log.Warn($"{peer} does not support any bitswap protocol");
}