/// <summary>
///
/// </summary>
/// <returns>Retrieved work item or null if not found, didn't pass pre-check, etc.</returns>
private WorkItem GetWorkItemFromQueue
()
{
//TODO: Pay great attention here, now workItemCandidate is an instance field!!! (SD)
workItemCandidate = null;
#region Get message from queue
var transaction = new CommittableTransaction();
try
{
Job job;
using (DependentTransaction dependentTransaction =
transaction.DependentClone(DependentCloneOption.BlockCommitUntilComplete))
{
using (var scope = new TransactionScope(dependentTransaction))
{
job = ItemProvider.GetNextItem();
scope.Complete();
}
dependentTransaction.Complete();
}
if (job != null)
{
PerformanceHandler.HandleEvent("Reads From Queue/sec", 1);
workItemCandidate = new RequestWorkItem(job.ContextIdentifier.InternalId,
0, WorkItemState.AvailableForProcessing,
SubmissionPriority.Normal, null, false, false, "test",
new ContextIdentifier());
// Set transaction on the work item
workItemCandidate.Transaction = transaction;
workItemCandidate.RetrievedAt = DateTime.Now;
workItemCandidate.MessageBody = SerializationUtility.Serialize2ByteArray(job);
}
else
{
workItemCandidate = null;
}
FailureExceptionHandler.ResetState();
}
catch (Exception ex)
{
try
{
// Rollback the commitable transaction
transaction.Rollback(ex);
}
finally
{
transaction.Dispose();
}
Log.Source.TraceData(TraceEventType.Error,
ProducerMessage.ErrorDuringObtainingTheWorkItem,
new ContextualLogEntry
{
Message =
"Exception happened when trying to get item from the message queue (" +
"queue.QueuePath" + "). " + Environment.NewLine + ex
,
ContextIdentifier =
((workItemCandidate != null)
? workItemCandidate.ContextIdentifier
:
new ContextIdentifier())
});
// To review what is the required handling here for us (SD)
if (ExecutionState == ProcessExecutionState.Running)
{
FailureExceptionType type = FailureExceptionHandler.HandleFailure(ex);
if (type == FailureExceptionType.NonRecoverable)
Stop();
}
else
{
if (workItemCandidate != null)
{
Log.Source.TraceData(TraceEventType.Information,
ProducerMessage.RetrievedMessageReturnedToTheRetrievalQueue,
new ContextualLogEntry
{
Message =
string.Format
(
"'{0}': Retrieved Recurrence(Id = {1}) Successfully Saved to the {2} queue",
Name,
workItemCandidate.Id,
""
),
ContextIdentifier = workItemCandidate.ContextIdentifier
});
return null;
}
}
if (workItemCandidate == null) return null;
}
#endregion Get message from queue
#region Pre-processing checks
WorkItem workItem = AssignWorkItemFromCandidate(workItemCandidate);
#endregion Pre-processing checks
// Return retrieved work item (or null)
return workItem;
}
public void ExplicitTransactionWithDependentTransaction()
{
using (var t = new CommittableTransaction())
using (new TxScope(t, NullLogger.Instance))
{
Console.WriteLine("T1 STATUS: {0}", t.TransactionInformation.Status);
using (var c = GetConnection())
using (var cmd = c.CreateCommand())
{
cmd.CommandText = "SELECT TOP 1 Val FROM Thing";
var scalar = (double)cmd.ExecuteScalar();
Console.WriteLine("T1 STATUS: {0}", t.TransactionInformation.Status);
Console.WriteLine("got val {0}, disposing command and connection", scalar);
}
using (var t2 = t.DependentClone(DependentCloneOption.RollbackIfNotComplete))
using (new TxScope(t2, NullLogger.Instance))
using (var c = GetConnection())
using (var cmd = c.CreateCommand())
{
t2.TransactionCompleted +=
(s, ea) =>
Console.WriteLine("::: T2 TransactionCompleted: {0}", ea.Transaction.TransactionInformation.LocalIdentifier);
cmd.CommandText = "DELETE FROM Thing";
Console.WriteLine("T2: EXECUTING NON QUERY");
cmd.ExecuteNonQuery();
Console.WriteLine("T2: Enlisting volatile");
t2.EnlistVolatile(new VolatileResource(false), EnlistmentOptions.None);
Console.WriteLine("T2: COMPLETE-CALL");
t2.Complete();
Console.WriteLine("T2 STATUS: {0}", t2.TransactionInformation.Status);
}
Console.WriteLine("T1: COMMITTING, status: {0}", t.TransactionInformation.Status);
try
{
t.Commit();
}
catch (TransactionAbortedException e)
{
Console.WriteLine("TransactionAbortedException, {0}", e);
t.Rollback(e);
}
Console.WriteLine("T1 STATUS: {0}", t.TransactionInformation.Status);
Console.WriteLine("T1: DISPOSING");
}
}
/// <summary>
///
/// </summary>
/// <param name="priority"></param>
/// <returns>Retrieved work item or null if not found, didn't pass pre-check, etc.</returns>
private WorkItem GetWorkItemFromQueue(SubmissionPriority priority)
{
//TODO: Pay great attention here, now workItemCandidate is an instance field!!! (SD)
workItemCandidate = null;
WorkItem workItem = null;
Tools.Commands.Implementation.IF1.req item = null;
Trace.CorrelationManager.ActivityId = Guid.NewGuid();
#region Get message from queue
var transaction = new CommittableTransaction();
try
{
#region Get next job from the queue
//var
using (DependentTransaction dependentTransaction =
transaction.DependentClone(DependentCloneOption.BlockCommitUntilComplete))
{
using (var scope = new TransactionScope(dependentTransaction))
{
//TODO: (SD) Provide timeout option
item = new Tools.Commands.Implementation.IF1.req
{
reqId = (++IdSequence).ToString(),
processingStatus = "P",
errorDesc = "ok",
returnValue = "ok",
updateMechanism = "JMS"
};
scope.Complete();
}
dependentTransaction.Complete();
if (item == null)
{
// if token is equal to null then commit here, as
// consumer will not get to the item anyway.
if (transaction.TransactionInformation.Status == TransactionStatus.Active)
transaction.Commit();
}
}
#endregion
#region If job is not null create a work item for it
if (item != null)
{
workItemCandidate = new RequestWorkItem(0, 0, WorkItemState.AvailableForProcessing,
SubmissionPriority.Normal, Encoding.UTF8.GetBytes(SerializationUtility.Serialize2String(item)), false, false, this.Name,
new ContextIdentifier { InternalId = 0, ExternalReference = IdSequence.ToString(), ExternalId = IdSequence.ToString() })
{
Transaction = transaction,
RetrievedAt = DateTime.Now
};
//**Trace.CorrelationManager.ActivityId = .ContextUid;
Log.Source.TraceEvent(TraceEventType.Start, 0, "Received the item " + item);
// Set transaction on the work item
}
#endregion
this.FailureExceptionHandler.ResetState();
}
catch (Exception ex)
{
try
{
// Rollback the commitable transaction
transaction.Rollback(ex);
}
finally
{
transaction.Dispose();
}
Log.TraceData(Log.Source,
TraceEventType.Error,
ProducerMessage.ErrorDuringObtainingTheWorkItem,
new ContextualLogEntry
{
Message =
"Exception happened when trying to get item " + Environment.NewLine + ex,
ContextIdentifier = ((workItemCandidate != null) ? workItemCandidate.ContextIdentifier : new ContextIdentifier())
});
// To review what is the required handling here for us (SD)
if (ExecutionState == ProcessExecutionState.Running)
{
FailureExceptionType type = this.FailureExceptionHandler.HandleFailure(ex);
if (type == FailureExceptionType.NonRecoverable)
this.Stop();
}
else
{
if (workItemCandidate != null)
{
Log.TraceData(Log.Source, System.Diagnostics.TraceEventType.Information,
ProducerMessage.RetrievedMessageReturnedToTheRetrievalQueue,
new ContextualLogEntry
{
Message = string.Format(
"'{0}': Retrieved Recurrence(Id = {1}) Successfully Saved to the {2} queue",
Name,
workItemCandidate.Id,
""
),
ContextIdentifier = workItemCandidate.ContextIdentifier
});
return null;
}
}
}
#endregion Get message from queue
#region Pre-processing checks
// Convert queue message to work item
// In case sql broker no need to do (SD)
if (workItemCandidate != null)
{
#region WorkItem Diagnostics
workItemCandidate.AttachNote("Received from the " + priority + " Queue ");
#endregion WorkItem Diagnostics
// TODO: //**SD1 - Provide the check for
// No checks done now, see the DB driven implementation for the checks samples (SD)
// It means as well that we can simply assign item candidate to be our work item
workItem = workItemCandidate;
// TODO: (SD) Message body will be the xml retrieved from the sql broker
//**message.GetObjectProperty
}
#endregion Pre-processing checks
// Return retrieved work item (or null)
return workItem;
}
