/// <summary>
/// Looks for a route to the given peer address.
/// </summary>
/// <param name="peerAddresses">Nodes that should be asked first for a route.</param>
/// <param name="routingBuilder"></param>
/// <param name="type"></param>
/// <param name="cc"></param>
/// <returns>A task object that is set to complete if the route has been found.</returns>
private TcsRouting Routing(ICollection <PeerAddress> peerAddresses, RoutingBuilder routingBuilder,
Message.Message.MessageType type, ChannelCreator cc)
{
try
{
if (peerAddresses == null)
{
throw new ArgumentException("Some nodes/addresses need to be specified.");
}
bool randomSearch = routingBuilder.LocationKey == null;
IComparer <PeerAddress> comparer;
if (randomSearch)
{
comparer = _peerBean.PeerMap.CreateComparer();
}
else
{
comparer = PeerMap.CreateComparer(routingBuilder.LocationKey);
}
var queueToAsk = new SortedSet <PeerAddress>(comparer);
var alreadyAsked = new SortedSet <PeerAddress>(comparer);
// As presented by Kazuyuki Shudo at AIMS 2009, it is better to ask random
// peers with the data than ask peers that are ordered by distance.
// -> this balances load
var directHits = new SortedDictionary <PeerAddress, DigestInfo>(comparer);
var potentialHits = new SortedSet <PeerAddress>(comparer);
// fill initially
queueToAsk.AddAll(peerAddresses);
alreadyAsked.Add(_peerBean.ServerPeerAddress);
potentialHits.Add(_peerBean.ServerPeerAddress);
// domain key can be null if we bootstrap
if (type == Message.Message.MessageType.Request2 &&
routingBuilder.DomainKey != null &&
!randomSearch &&
_peerBean.DigestStorage != null)
{
Number640 from;
Number640 to;
if (routingBuilder.From != null && routingBuilder.To != null)
{
from = routingBuilder.From;
to = routingBuilder.To;
}
else if (routingBuilder.ContentKey == null)
{
from = new Number640(routingBuilder.LocationKey, routingBuilder.DomainKey, Number160.Zero, Number160.Zero);
to = new Number640(routingBuilder.LocationKey, routingBuilder.DomainKey, Number160.MaxValue, Number160.MaxValue);
}
else
{
from = new Number640(routingBuilder.LocationKey, routingBuilder.DomainKey, routingBuilder.ContentKey, Number160.Zero);
to = new Number640(routingBuilder.LocationKey, routingBuilder.DomainKey, routingBuilder.ContentKey, Number160.MaxValue);
}
var digestBean = _peerBean.DigestStorage.Digest(from, to, -1, true);
if (digestBean.Size > 0)
{
directHits.Add(_peerBean.ServerPeerAddress, digestBean);
}
}
else if (type == Message.Message.MessageType.Request3 &&
!randomSearch &&
_peerBean.DigestTracker != null)
{
var digestInfo = _peerBean.DigestTracker.Digest(routingBuilder.LocationKey, routingBuilder.DomainKey,
routingBuilder.ContentKey);
// we always put ourselfs to the tracker list, so we need to check
// if we know also other peers on our trackers
if (digestInfo.Size > 0)
{
directHits.Add(_peerBean.ServerPeerAddress, digestInfo);
}
}
var tcsRouting = new TcsRouting();
if (peerAddresses.Count == 0)
{
tcsRouting.SetNeighbors(directHits, potentialHits, alreadyAsked, routingBuilder.IsBootstrap, false);
}
else
{
// If a peer bootstraps to itself, then the size of peer addresses is 1
// and it contains itself. Check for that because we need to know if we
// are routing, bootstrapping and bootstrapping to ourselfs, to return
// the correct status for the task.
var isRoutingOnlyToSelf = peerAddresses.Count == 1 &&
peerAddresses.First().Equals(_peerBean.ServerPeerAddress);
var routingMechanism = routingBuilder.CreateRoutingMechanism(tcsRouting);
routingMechanism.SetQueueToAsk(queueToAsk);
routingMechanism.SetPotentialHits(potentialHits);
routingMechanism.SetDirectHits(directHits);
routingMechanism.SetAlreadyAsked(alreadyAsked);
routingBuilder.SetIsRoutingOnlyToSelf(isRoutingOnlyToSelf);
RoutingRec(routingBuilder, routingMechanism, type, cc);
}
return(tcsRouting);
}
catch (Exception ex)
{
Logger.Error("An exception occurred during routing.", ex);
throw;
}
}
