public static string GetSequencePrefix(IDataLayer dataLayer)
{
if (dataLayer == null)
{
throw new ArgumentNullException("dataLayer");
}
lock (SyncRoot) {
if (dataLayerForCachedServerPrefix /*.Target*/ != dataLayer)
{
using (Session session = new Session(dataLayer)) {
XpoServerId sid = session.GetObjectByKey <XpoServerId>(0);
if (sid == null)
{
// we can throw exception here instead of creating random prefix
sid = new XpoServerId(session);
sid.SequencePrefix = XpoDefault.NewGuid().ToString();
try {
sid.Save();
}
catch {
sid = session.GetObjectByKey <XpoServerId>(0, true);
if (sid == null)
{
throw;
}
}
}
cachedSequencePrefix = sid.SequencePrefix;
dataLayerForCachedServerPrefix = dataLayer;
// dataLayerForCachedServerPrefix.Target = dataLayer; <<< if WeakReference
}
}
return(cachedSequencePrefix);
}
}
static void Do(string seqPrefix)
{
int nextUniqueValue = XpoServerId.GetNextUniqueValue(seqPrefix);
Console.WriteLine("seq '{0}': {1}", seqPrefix, nextUniqueValue);
}