IMemcachedNode INodeLocator.Locate(string key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
var id = this._lookupData;
switch (id.Servers.Length)
{
case 0:
return(null);
case 1:
var tmp = id.Servers[0];
return(tmp.IsAlive ? tmp : null);
}
var node = KetamaNodeLocator.LocateNode(id, this.GetKeyHash(key));
// if the result is not alive then try to mutate the item key and
// find another node this way we do not have to reinitialize every
// time a node dies/comes back
// (DefaultServerPool will resurrect the nodes in the background without affecting the hashring)
if (!node.IsAlive)
{
for (var i = 0; i < id.Servers.Length; i++)
{
// -- this is from spymemcached so we select the same node for the same items
var tmpKey = (ulong)GetKeyHash(i + key);
tmpKey += (uint)(tmpKey ^ (tmpKey >> 32));
tmpKey &= 0xffffffffL; /* truncate to 32-bits */
// -- end
node = KetamaNodeLocator.LocateNode(id, (uint)tmpKey);
if (node.IsAlive)
{
return(node);
}
}
}
return(node.IsAlive ? node : null);
}
public void TestLocator()
{
String[] servers = new[]{
"10.0.1.1:11211",
"10.0.1.2:11211",
"10.0.1.3:11211",
"10.0.1.4:11211",
"10.0.1.5:11211",
"10.0.1.6:11211",
"10.0.1.7:11211",
"10.0.1.8:11211"};
var nodes = servers.
Select(s => new MockNode(new IPEndPoint(IPAddress.Parse(s.Substring(0, s.IndexOf(":"))), 11211))).
Cast<IMemcachedNode>().
ToList();
IMemcachedNodeLocator ketama = new KetamaNodeLocator();
ketama.Initialize(nodes.ToList());
foreach (var pair in exp)
{
var node = ketama.Locate(pair[0]);
Assert.AreEqual(node.EndPoint.ToString(), pair[1]);
}
}
