/// <summary>Initializes this <see cref="BatchedJoinBlock{T1,T2}"/> with the specified configuration.</summary>
/// <param name="batchSize">The number of items to group into a batch.</param>
/// <param name="dataflowBlockOptions">The options with which to configure this <see cref="BatchedJoinBlock{T1,T2}"/>.</param>
/// <exception cref="System.ArgumentOutOfRangeException">The <paramref name="batchSize"/> must be positive.</exception>
/// <exception cref="System.ArgumentNullException">The <paramref name="dataflowBlockOptions"/> is null (Nothing in Visual Basic).</exception>
public BatchedJoinBlock(int batchSize, GroupingDataflowBlockOptions dataflowBlockOptions)
{
// Validate arguments
if (batchSize < 1)
{
throw new ArgumentOutOfRangeException(nameof(batchSize), SR.ArgumentOutOfRange_GenericPositive);
}
if (dataflowBlockOptions == null)
{
throw new ArgumentNullException(nameof(dataflowBlockOptions));
}
if (!dataflowBlockOptions.Greedy)
{
throw new ArgumentException(SR.Argument_NonGreedyNotSupported, nameof(dataflowBlockOptions));
}
if (dataflowBlockOptions.BoundedCapacity != DataflowBlockOptions.Unbounded)
{
throw new ArgumentException(SR.Argument_BoundedCapacityNotSupported, nameof(dataflowBlockOptions));
}
// Store arguments
_batchSize = batchSize;
dataflowBlockOptions = dataflowBlockOptions.DefaultOrClone();
// Configure the source
_source = new SourceCore <Tuple <IList <T1>, IList <T2> > >(
this, dataflowBlockOptions, owningSource => ((BatchedJoinBlock <T1, T2>)owningSource).CompleteEachTarget());
// The action to run when a batch should be created. This is typically called
// when we have a full batch, but it will also be called when we're done receiving
// messages, and thus when there may be a few stragglers we need to make a batch out of.
Action createBatchAction = () =>
{
if (_target1.Count > 0 || _target2.Count > 0)
{
_source.AddMessage(Tuple.Create(_target1.GetAndEmptyMessages(), _target2.GetAndEmptyMessages()));
}
};
// Configure the targets
_sharedResources = new BatchedJoinBlockTargetSharedResources(
batchSize, dataflowBlockOptions,
createBatchAction,
() =>
{
createBatchAction();
_source.Complete();
},
_source.AddException,
Complete);
_target1 = new BatchedJoinBlockTarget <T1>(_sharedResources);
_target2 = new BatchedJoinBlockTarget <T2>(_sharedResources);
// It is possible that the source half may fault on its own, e.g. due to a task scheduler exception.
// In those cases we need to fault the target half to drop its buffered messages and to release its
// reservations. This should not create an infinite loop, because all our implementations are designed
// to handle multiple completion requests and to carry over only one.
_source.Completion.ContinueWith((completed, state) =>
{
var thisBlock = ((BatchedJoinBlock <T1, T2>)state !) as IDataflowBlock;
Debug.Assert(completed.IsFaulted, "The source must be faulted in order to trigger a target completion.");
thisBlock.Fault(completed.Exception !);
}, this, CancellationToken.None, Common.GetContinuationOptions() | TaskContinuationOptions.OnlyOnFaulted, TaskScheduler.Default);
// Handle async cancellation requests by declining on the target
Common.WireCancellationToComplete(
dataflowBlockOptions.CancellationToken, _source.Completion, state => ((BatchedJoinBlock <T1, T2>)state !).CompleteEachTarget(), this);
#if FEATURE_TRACING
DataflowEtwProvider etwLog = DataflowEtwProvider.Log;
if (etwLog.IsEnabled())
{
etwLog.DataflowBlockCreated(this, dataflowBlockOptions);
}
#endif
}
/// <summary>Initializes the <see cref="TransformManyBlock{TInput,TOutput}"/> with the specified function and <see cref="ExecutionDataflowBlockOptions"/>.</summary>
/// <param name="transformSync">The synchronous function to invoke with each data element received.</param>
/// <param name="transformAsync">The asynchronous function to invoke with each data element received.</param>
/// <param name="dataflowBlockOptions">The options with which to configure this <see cref="TransformManyBlock{TInput,TOutput}"/>.</param>
/// <exception cref="System.ArgumentNullException">The <paramref name="transformSync"/> and <paramref name="transformAsync"/> are both null (Nothing in Visual Basic).</exception>
/// <exception cref="System.ArgumentNullException">The <paramref name="dataflowBlockOptions"/> is null (Nothing in Visual Basic).</exception>
private TransformManyBlock(Func <TInput, IEnumerable <TOutput> > transformSync, Func <TInput, Task <IEnumerable <TOutput> > > transformAsync, ExecutionDataflowBlockOptions dataflowBlockOptions)
{
// Validate arguments. It's ok for the filterFunction to be null, but not the other parameters.
if (transformSync == null && transformAsync == null)
{
throw new ArgumentNullException("transform");
}
if (dataflowBlockOptions == null)
{
throw new ArgumentNullException("dataflowBlockOptions");
}
Contract.Requires(transformSync == null ^ transformAsync == null, "Exactly one of transformSync and transformAsync must be null.");
Contract.EndContractBlock();
// Ensure we have options that can't be changed by the caller
dataflowBlockOptions = dataflowBlockOptions.DefaultOrClone();
// Initialize onItemsRemoved delegate if necessary
Action <ISourceBlock <TOutput>, int> onItemsRemoved = null;
if (dataflowBlockOptions.BoundedCapacity > 0)
{
onItemsRemoved = (owningSource, count) => ((TransformManyBlock <TInput, TOutput>)owningSource)._target.ChangeBoundingCount(-count);
}
// Initialize source component
_source = new SourceCore <TOutput>(this, dataflowBlockOptions,
owningSource => ((TransformManyBlock <TInput, TOutput>)owningSource)._target.Complete(exception: null, dropPendingMessages: true),
onItemsRemoved);
// If parallelism is employed, we will need to support reordering messages that complete out-of-order.
if (dataflowBlockOptions.SupportsParallelExecution)
{
_reorderingBuffer = new ReorderingBuffer <IEnumerable <TOutput> >(
this, (source, messages) => ((TransformManyBlock <TInput, TOutput>)source)._source.AddMessages(messages));
}
// Create the underlying target and source
if (transformSync != null) // sync
{
// If an enumerable function was provided, we can use synchronous completion, meaning
// that the target will consider a message fully processed as soon as the
// delegate returns.
_target = new TargetCore <TInput>(this,
messageWithId => ProcessMessage(transformSync, messageWithId),
_reorderingBuffer, dataflowBlockOptions, TargetCoreOptions.None);
}
else // async
{
Debug.Assert(transformAsync != null, "Incorrect delegate type.");
// If a task-based function was provided, we need to use asynchronous completion, meaning
// that the target won't consider a message completed until the task
// returned from that delegate has completed.
_target = new TargetCore <TInput>(this,
messageWithId => ProcessMessageWithTask(transformAsync, messageWithId),
_reorderingBuffer, dataflowBlockOptions, TargetCoreOptions.UsesAsyncCompletion);
}
// Link up the target half with the source half. In doing so,
// ensure exceptions are propagated, and let the source know no more messages will arrive.
// As the target has completed, and as the target synchronously pushes work
// through the reordering buffer when async processing completes,
// we know for certain that no more messages will need to be sent to the source.
#if NET_4_0_ABOVE
_target.Completion.ContinueWith((completed, state) =>
{
var sourceCore = (SourceCore <TOutput>)state;
if (completed.IsFaulted)
{
sourceCore.AddAndUnwrapAggregateException(completed.Exception);
}
sourceCore.Complete();
}, _source, CancellationToken.None, Common.GetContinuationOptions(), TaskScheduler.Default);
#else
Action <Task> continuationAction1 = completed =>
{
if (completed.IsFaulted)
{
_source.AddAndUnwrapAggregateException(completed.Exception);
}
_source.Complete();
};
_target.Completion.ContinueWith(continuationAction1, CancellationToken.None, Common.GetContinuationOptions(), TaskScheduler.Default);
#endif
// It is possible that the source half may fault on its own, e.g. due to a task scheduler exception.
// In those cases we need to fault the target half to drop its buffered messages and to release its
// reservations. This should not create an infinite loop, because all our implementations are designed
// to handle multiple completion requests and to carry over only one.
#if NET_4_0_ABOVE
_source.Completion.ContinueWith((completed, state) =>
{
var thisBlock = ((TransformManyBlock <TInput, TOutput>)state) as IDataflowBlock;
Debug.Assert(completed.IsFaulted, "The source must be faulted in order to trigger a target completion.");
thisBlock.Fault(completed.Exception);
}, this, CancellationToken.None, Common.GetContinuationOptions() | TaskContinuationOptions.OnlyOnFaulted, TaskScheduler.Default);
#else
Action <Task> continuationAction2 = completed =>
{
var thisBlock = this as IDataflowBlock;
Debug.Assert(completed.IsFaulted, "The source must be faulted in order to trigger a target completion.");
thisBlock.Fault(completed.Exception);
};
_source.Completion.ContinueWith(continuationAction2, CancellationToken.None, Common.GetContinuationOptions() | TaskContinuationOptions.OnlyOnFaulted, TaskScheduler.Default);
#endif
// Handle async cancellation requests by declining on the target
Common.WireCancellationToComplete(
dataflowBlockOptions.CancellationToken, Completion, state => ((TargetCore <TInput>)state).Complete(exception: null, dropPendingMessages: true), _target);
#if FEATURE_TRACING
DataflowEtwProvider etwLog = DataflowEtwProvider.Log;
if (etwLog.IsEnabled())
{
etwLog.DataflowBlockCreated(this, dataflowBlockOptions);
}
#endif
}
