/// <summary>
/// Receives new response messages from broker
/// </summary>
/// <param name="response">Response message</param>
void IResponseServiceCallback.SendResponse(Message response)
{
MessageBuffer messageBuffer = null;
EndOfResponses endOfResponses = null;
Exception clientSideException = null;
bool isEOM = false;
// Reset the heartbeat since operation just succeeded
this.session.ResetHeartbeat();
try
{
// Check whether this is an EOM message
isEOM = Utility.IsEOM(response);
if (!isEOM)
{
// If not EOM, create a copy of the message's buffer so it can be deserialized
// A copy is needed because WCF will dispose this message when the callback returns
// Alternatively we could deserialize the entire message but we want
// callback to be quick and we may wind up deserializing messages the user
// never looks at (i.e. just checks user data or exits enum early)
try
{
messageBuffer = response.CreateBufferedCopy(Constant.MaxBufferSize);
}
catch (Exception e)
{
SessionBase.TraceSource.TraceEvent(TraceEventType.Error, 0, "[Session:{0}][BrokerResponseEnumerator] Failed to create message buffer from the response message: {1}", this.session.Id, e);
clientSideException = e;
}
}
else
{
// If EOM, deserialize EndOfResponses message
endOfResponses = (EndOfResponses)this.endOfResponsesConverter.FromMessage(response);
}
string messageId = String.Empty;
try
{
messageId = SoaHelper.GetMessageId(response).ToString();
}
catch
{
// Swallow possible ObjectDisposedException
}
SessionBase.TraceSource.TraceEvent(TraceEventType.Verbose, 0, "[Session:{0}][BrokerResponseEnumerator] Response received from broker. IsEOM = {1}, MessageId = {2}", this.session.Id, isEOM, messageId);
lock (this.responsesLock)
{
// If the enumerator is disposing or disposed, return
if (this.isDisposeCalled)
{
return;
}
// If this is not an EOM message
if (!isEOM)
{
string actionFromResponse = BrokerClientBase.GetActionFromResponseMessage(response);
// Save the response in the current window
MessageWindowItem messageItem = new MessageWindowItem(
messageBuffer,
actionFromResponse,
!response.IsFault ? response.Headers.Action : String.Empty,
response.Headers.RelatesTo == null ? SoaHelper.GetMessageId(response) : response.Headers.RelatesTo);
// Bug #15946: handling client side exception thrown from WebResponseHandler(when talking to rest service)
// To propagate the client side exception to BrokerResponseEnumerator api, store the exception in MessageWindowItem
if (string.Equals(response.Headers.Action, Constant.WebAPI_ClientSideException, StringComparison.Ordinal))
{
clientSideException = response.Properties[Constant.WebAPI_ClientSideException] as Exception;
}
messageItem.CarriedException = clientSideException;
this.currentReceiveWindow.Enqueue(messageItem);
// Increment the current number of responses
this.currentResponseCount++;
// Lower number of outstanding requests
if (Interlocked.Decrement(ref this.outstandingRequestCount) == 0)
{
try
{
this.GetMoreResponses(false, ResponseWindowSize);
}
catch (Exception e)
{
SessionBase.TraceSource.TraceEvent(TraceEventType.Error,
0, "[Session:{0}][BrokerResponseEnumerator] Failed to get more responses in SendResponse context: {1}", this.session.Id, e);
// Send broker down signal since connection to broker might be bad
((IResponseServiceCallback)this).SendBrokerDownSignal(false);
}
}
// If the current window is full or there are no more responses
if (this.currentReceiveWindow.Count == ResponseWindowSize ||
this.currentResponseCount == this.totalResponseCount)
{
// Disable the flush timer
this.flushResponsesTimer.Change(Timeout.Infinite, Timeout.Infinite);
// Immediately flush the receive window
this.FlushCurrentReceiveWindow();
}
// Otherwise reset the flushtimer to the full interval
else
{
this.flushResponsesTimer.Change(this.flushResponsesTimerInterval, Timeout.Infinite);
}
}
else
{
// If we already received an EOM, ignore any others. We may get multiple EOM since
// more responses are requested until we get EOM. This can lead to overrequesting.
if (this.totalResponseCount != -1)
{
return;
}
// Save total response count
this.totalResponseCount = endOfResponses.Count;
this.endOfResponsesReason = endOfResponses.Reason;
// If there are no more responses
if (this.currentResponseCount == this.totalResponseCount)
{
// Make the current receive window available to enumerator if it has responses
if (this.currentReceiveWindow.Count != 0)
{
this.responsesWindows.Enqueue(this.currentReceiveWindow);
this.currentReceiveWindow = new Queue <MessageWindowItem>();
}
// Notify enumerator that a new window is available. Notify even if
// its empty since it allows MoveNext to exit and return there are no
// more items
this.newResponseWindowOrEOM.Set();
}
}
}
}
catch (Exception e)
{
// If we get an exception here log and dispose the enum
this.Dispose();
SessionBase.TraceSource.TraceEvent(TraceEventType.Error, 0, "[Session:{0}][BrokerResponseEnumerator] Unhandled exception in response enumerator callback :{1}", this.session.Id, e);
}
}
/// <summary>
/// <para>Advances the enumerator to the next element of the collection.</para>
/// </summary>
/// <returns>
/// <para>
/// <see cref="System.Boolean" /> object that specifies whether the enumerator successfully advanced to the next element.
/// True indicates that the enumerator successfully advanced to the next element.
/// False indicates that the enumerator passed the end of the collection.</para>
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// <para>The collection was modified after the enumerator was created. </para>
/// </exception>
/// <remarks>
/// <para>After you create the enumerator or call the
///
/// <see cref="Reset" /> method, the enumerator is positioned before the first element of the collection, and the first call to the
///
/// <see cref="MoveNext" /> method moves the enumerator over the first element of the collection.</para>
/// <para>If
///
/// <see cref="MoveNext" /> passes the end of the collection, the enumerator is positioned after the last element in the collection, and
/// <see cref="MoveNext" /> returns
/// False. When the enumerator is at this position, subsequent calls to
/// <see cref="MoveNext" /> also returns
/// False until you call
/// <see cref="Reset" />.</para>
/// <para>An enumerator remains valid as long as the collection remains unchanged. If you make changes to
/// the collection, such as adding, modifying, or deleting elements, the enumerator is irrecoverably invalidated and the next call to
/// <see cref="MoveNext" /> or
/// <see cref="Reset" /> results in an
/// <see cref="System.InvalidOperationException" />.</para>
/// </remarks>
/// <seealso cref="Reset" />
/// <seealso cref="System.Collections.IEnumerator.MoveNext" />
public bool MoveNext()
{
// If the corresponding BrokerClient is closed or disposed, return no more items
if (this.close)
{
if (!this.session.IsBrokerAvailable)
{
throw SessionBase.GetHeartbeatException(this.isBrokerNodeDown);
}
else
{
return(false);
}
}
ThrowIfNeed(this.endOfResponsesReason);
bool flag1, flag2, flag3;
lock (this.responsesLock)
{
flag1 = this.currentEnumWindow == null || this.currentEnumWindow.Count == 0;
flag2 = this.responsesWindows.Count == 0;
flag3 = this.totalResponseCount != this.currentResponseCount;
}
// If there is no current window for enumeration or the current one is empty
if (flag1)
{
// If there are no other windows ready for enumeration
if (flag2)
{
// If all responses have not been returned
if (flag3)
{
// Wait for more response windows to be ready for enumeration
int ret = WaitHandle.WaitAny(new WaitHandle[] { this.newResponseWindowOrEOM, this.signalBrokerDown }, this.newResponsesTimeout, false);
// If the timeout expires,
if (ret == WaitHandle.WaitTimeout)
{
// Check to see if the receive window has messages
if (this.currentReceiveWindow.Count == 0)
{
// If not return that there are no more messages
// RICHCI: 6/7/9 : Changed from returning false to throwing timeout exception
// so user can distinguish between timeout and no more responses
throw new TimeoutException(String.Format(SR.TimeoutGetResponse, this.newResponsesTimeout.TotalMilliseconds));
}
else
{
// If there are response messages, move the partially filled receive window to
// the "ready to read" response windows queue
lock (this.responsesLock)
{
this.responsesWindows.Enqueue(this.currentReceiveWindow);
this.currentReceiveWindow = new Queue <MessageWindowItem>();
}
// Fall through to pulling a new window for the current enum window
}
}
// If the broker down event is signaled, throw exception
if (ret == 1)
{
var faultException = this.exceptionCauseBrokerDown as FaultException <SessionFault>;
if (faultException != null)
{
throw Utility.TranslateFaultException(faultException);
}
else
{
throw SessionBase.GetHeartbeatException(this.isBrokerNodeDown);
}
}
ThrowIfNeed(this.endOfResponsesReason);
// If the BrokerClient is disposed or closed, return there are no more responses
if (this.close)
{
return(false);
}
// If all we were waiting for was EOM, return there are no more responses
if (this.responsesWindows.Count == 0)
{
return(false);
}
// Else fall through to pulling a new window for the current enum window
}
else
{
// If there are no responses pending, return that there are no more responses
return(false);
}
}
int responseWindowCount = 0;
// Get a new current enum window
lock (this.responsesLock)
{
this.currentEnumWindow = this.responsesWindows.Dequeue();
responseWindowCount = this.responsesWindows.Count;
}
// If this was the last window
if (responseWindowCount == 0)
{
// Reset the event so subsequent calls to Move wait
this.newResponseWindowOrEOM.Reset();
// Do not ask for more responses. The enumerator would ask for more
// responses only when outstanding responses is 0.
}
}
// Dequeue the current message
MessageWindowItem messageWindowItem = this.currentEnumWindow.Dequeue();
// Bug #15946: handling client side exception thrown from WebResponseHandler(when talking to rest service)
if (messageWindowItem.CarriedException != null)
{
throw messageWindowItem.CarriedException;
}
// Create a BrokerResponse object from Message
this.currentResponse = this.CreateResponse(messageWindowItem.ActionFromResponse, messageWindowItem.ReplyAction, messageWindowItem.MessageBuffer, messageWindowItem.RelatesTo);
// Return true since Current will have a new element
return(true);
}
