public void MoveObjectCallBack(object state)
{
Node targetNode = (Node)state;
string nodeKeyHash = Hasher.GetHash(targetNode.EndPoint.ToString());
string previousNodeHash = Hasher.GetHash(_nodeResolver.GetPreviousItemInCircle(targetNode.EndPoint.ToString()));
//if self is B, typical scenarios -> A-newnode-MID-B, MID-A-newnode-B-C
//A being the previous node, B being the current node and newnode being the new node.
string lowerBound = previousNodeHash;
string upperBound = nodeKeyHash;
IEnumerable <KeyValuePair <string, ServerCacheItem> > candidateList = _cache.Where <KeyValuePair <string, ServerCacheItem> >(x =>
((x.Value.Hash.CompareTo(upperBound) < 0) &&
(x.Value.Hash.CompareTo(lowerBound) > 0)));
//special case: A-MID-newnode-B
if (lowerBound.CompareTo(upperBound) > 0)
{
candidateList = _cache.Where <KeyValuePair <string, ServerCacheItem> >(x =>
((x.Value.Hash.CompareTo(upperBound) < 0) ||
(x.Value.Hash.CompareTo(lowerBound) > 0)));
}
if (candidateList.Count() == 0)
{
return;
}
Node self = new Node()
{
EndPoint = TcpHelper.SelfIPAddress, NodeState = NodeState.Active
};
//prepare the connection
string endPoint = string.Format("net.tcp://{0}:{1}/HoCCacheService", targetNode.EndPoint.ToString(), targetNode.ServicePort);
CacheServiceReference.CacheServiceClient nodeService = new CacheServiceReference.CacheServiceClient(new NetTcpBinding(SecurityMode.None), new EndpointAddress(endPoint));
try
{
//move each of the object to the other node async
foreach (KeyValuePair <string, ServerCacheItem> valuePair in candidateList)
{
nodeService.DoInterNodeObjectTransfer(self, valuePair.Key, valuePair.Value);
valuePair.Value.ItemState = CacheItemState.Moved;
valuePair.Value.RelocatedTo = targetNode;
}
;
nodeService.EndInterNodeObjectTransfer(self);
Thread.Sleep(2000);//wait the current thread - note that this is not the main thread
RemoveOrResetMovedItems(targetNode);
//note that any object update that happens during this time is handled by the CacheService.
//basically it copies the update to the new node too.
}
catch
{
ResetMovedObjectState(); //in case of any issues revert back to normal state.
}
}
