/// <summary>
/// Returns a MessageStreamListener instance based on this instance's configuration (timeout, bucket name etc.)
///
/// When multiple listeners are requested with the exact same parameters (usually when multiple clients are instantiated from the same configuration),
/// the same listener will be returned each time.
/// </summary>
/// <returns></returns>
private MessageStreamListener GetPooledListener()
{
// create a unique key based on the parameters
// to find out if we already have a listener attached to this pool
var hcc = new HashCodeCombiner();
hcc.Add(this.Timeout);
hcc.Add(this.DeadTimeout);
hcc.Add(this.RetryCount);
hcc.Add(this.RetryTimeout.GetHashCode());
hcc.Add(this.bucketName.GetHashCode());
if (credential != null)
{
hcc.Add((this.credential.UserName ?? String.Empty).GetHashCode());
hcc.Add((this.credential.Password ?? String.Empty).GetHashCode());
hcc.Add((this.credential.Domain ?? String.Empty).GetHashCode());
}
for (var i = 0; i < this.poolUrls.Length; i++)
{
hcc.Add(this.poolUrls[i].GetHashCode());
}
var hash = hcc.CurrentHash;
MessageStreamListener retval;
lock (ListenerSync)
if (listeners.TryGetValue(hash, out retval))
{
listenerRefs[retval].RefCount++;
retval.Subscribe(this.HandleMessage);
}
else
{
var name = this.bucketName;
// create a new listener for the pool urls
retval = new MessageStreamListener(poolUrls, heartbeatUri, heartbeatInterval, isHeartbeatEnabled,
(client, root) => ResolveBucketUri(client, root, name));
retval.ConnectionTimeout = this.Timeout;
retval.DeadTimeout = this.DeadTimeout;
retval.Credentials = this.credential;
retval.RetryCount = this.RetryCount;
retval.RetryTimeout = this.RetryTimeout;
retval.Subscribe(this.HandleMessage);
listeners[hash] = retval;
listenerRefs[retval] = new ListenerInfo {
RefCount = 1, HashKey = hash
};
retval.Start();
}
return(retval);
}
private void HandleMessage(string message, MessageStreamListener listener)
{
// everything failed
if (String.IsNullOrEmpty(message))
{
this.lastHash = null;
this.RaiseConfigChanged(null);
return;
}
// deserialize the buckets
var jss = new JavaScriptSerializer();
jss.RegisterConverters(KnownConverters);
var config = jss.Deserialize <ClusterConfig>(message);
// check if the config is the same as the previous
// we cannot compare the messages because they have more information than we deserialize from them
var configHash = config.GetHashCode();
if (lastHash != configHash)
{
lastHash = configHash;
this.RaiseConfigChanged(config);
listener.UpdateNodes(config);
}
else if (log.IsDebugEnabled)
{
log.Debug("Last message was the same as current, ignoring.");
}
}
/// <summary>
/// Starts listening for configuration data. This method blocks until the initial configuration is received. (Or until all pool urls fail.)
/// </summary>
public void Start()
{
var reset = this.mre = new ManualResetEvent(false);
// subscribe to the config url
this.listener = this.GetPooledListener();
// this will be signaled by the config changed event handler
reset.WaitOne();
// set to null, then dispose, so RaiseConfigChanged will not
// fail at Set when the config changes while we're cleaning up here
this.mre = null;
((IDisposable)reset).Dispose();
}
/// <summary>
/// Unsubscribes from a pooled listener, and destroys it if no additional subscribers are present.
/// </summary>
/// <param name="listener"></param>
private void ReleaseListener(MessageStreamListener listener)
{
lock (ListenerSync)
{
listener.Unsubscribe(this.HandleMessage);
var info = listenerRefs[listener];
if (info.RefCount == 1)
{
listenerRefs.Remove(listener);
listeners.Remove(info.HashKey);
try { using (listener) listener.Stop(); }
catch (Exception e) { log.Error(e); }
}
else
{
info.RefCount--;
}
}
}
/// <summary>
/// Unsubscibes from a pooled listener, and destrpys it if no additionals subscribers are present.
/// </summary>
/// <param name="listener"></param>
private void ReleaseListener(MessageStreamListener listener)
{
lock (ListenerSync)
{
listener.Unsubscribe(this.HandleMessage);
var info = listenerRefs[listener];
if (info.RefCount == 1)
{
listenerRefs.Remove(listener);
listeners.Remove(info.HashKey);
try { using (listener) listener.Stop(); }
catch { }
}
else
{
info.RefCount--;
}
}
}
/// <summary>
/// Returns a MessageStreamListener instance based on this instance's configuratino (timeout, bucket name etc.)
///
/// When multiple listeners are requested with the exact same parameters (usually when multiple clients are instantiated from the same configuration),
/// the same listener will be returned each time.
/// </summary>
/// <returns></returns>
private MessageStreamListener GetPooledListener()
{
// create a unique key based on the parameters
// to find out if we already have a listener attached to this pool
var hcc = new HashCodeCombiner();
hcc.Add(this.Timeout);
hcc.Add(this.DeadTimeout);
hcc.Add(this.RetryCount);
hcc.Add(this.RetryTimeout.GetHashCode());
hcc.Add(this.bucketName.GetHashCode());
if (credential != null)
{
hcc.Add((this.credential.UserName ?? String.Empty).GetHashCode());
hcc.Add((this.credential.Password ?? String.Empty).GetHashCode());
hcc.Add((this.credential.Domain ?? String.Empty).GetHashCode());
}
for (var i = 0; i < this.poolUrls.Length; i++)
hcc.Add(this.poolUrls[i].GetHashCode());
var hash = hcc.CurrentHash;
MessageStreamListener retval;
lock (ListenerSync)
if (listeners.TryGetValue(hash, out retval))
{
listenerRefs[retval].RefCount++;
retval.Subscribe(this.HandleMessage);
}
else
{
var name = this.bucketName;
// create a new listener for the pool urls
retval = new MessageStreamListener(poolUrls, heartbeatUri, heartbeatInterval, isHeartbeatEnabled,
(client, root) => ResolveBucketUri(client, root, name));
retval.ConnectionTimeout = this.Timeout;
retval.DeadTimeout = this.DeadTimeout;
retval.Credentials = this.credential;
retval.RetryCount = this.RetryCount;
retval.RetryTimeout = this.RetryTimeout;
retval.Subscribe(this.HandleMessage);
listeners[hash] = retval;
listenerRefs[retval] = new ListenerInfo { RefCount = 1, HashKey = hash };
retval.Start();
}
return retval;
}
public void Stop()
{
this.ReleaseListener(this.listener);
this.listener = null;
}
/// <summary>
/// Starts listening for configuration data. This method blocks until the initial configuration is received. (Or until all pool urls fail.)
/// </summary>
public void Start()
{
var reset = this.mre = new ManualResetEvent(false);
// subscribe to the config url
this.listener = this.GetPooledListener();
// this will be signaled by the config changed event handler
reset.WaitOne();
// set to null, then dispose, so RaiseConfigChanged will not
// fail at Set when the config changes while we're cleaning up here
this.mre = null;
((IDisposable)reset).Dispose();
}
public void Stop()
{
this.ReleaseListener(this.listener);
this.listener = null;
}
private void HandleMessage(string message, MessageStreamListener listener)
{
// everything failed
if (String.IsNullOrEmpty(message))
{
this.lastHash = null;
this.RaiseConfigChanged(null);
return;
}
// deserialize the buckets
var jss = new JavaScriptSerializer();
jss.RegisterConverters(KnownConverters);
var config = jss.Deserialize<ClusterConfig>(message);
// check if the config is the same as the previous
// we cannot compare the messages because they have more information than we deserialize from them
var configHash = config.GetHashCode();
if (lastHash != configHash)
{
lastHash = configHash;
this.RaiseConfigChanged(config);
listener.UpdateNodes(config);
}
else if (log.IsDebugEnabled)
log.Debug("Last message was the same as current, ignoring.");
}
