Class UnionAllTransform<TInputOutput>

A dataflow worker with multiple input ports and one Output port, all of the same type, that sends all incoming rows to the single output. Any duplicates are preserved.

Note: Use the factory methods in UnionAllTransformFactory to create instances of this class.

Ports will automatically get a Limited buffering mode, unless the user explicitly sets it to Full.

Note that input ports can be added after the worker is created (but before it or its siblings have started) by repeatedly calling Create<TInput>(String, OutputPortBase<TInput>). This can be particularly useful when generating workers in a loop.

Rows are consumed in a round-robin order among the inputs that have rows available, taking up to BufferCapacity rows at a time.

Note: To instead concatenate the input rows, i.e. to exhaust each input fully before forwarding any rows from other inputs, in a predefined order, use MergeSortedTransform<TInputOutput> and ensure that the sort key range for each input does not overlap with the sort key range for any other input, and that the sort key values matches your desired input port row order. One simple option is to add a constant integer property to each input row type, and use that as the sort key.

Inheritance
Object
WorkerParent
WorkerBase
WorkerBase<UnionAllTransform<TInputOutput>>
UnionAllTransform<TInputOutput>
Implements
Inherited Members
Namespace: actionETL
Assembly: actionETL.dll
Syntax
public class UnionAllTransform<TInputOutput> : WorkerBase<UnionAllTransform<TInputOutput>>, IDisposeOnFinished where TInputOutput : class
Type Parameters
Name Description
TInputOutput

The type of each incoming and Output row.

Properties

Output

Gets the output port for sending rows to the downstream worker.

Declaration
public OutputPort<TInputOutput> Output { get; }
Property Value
Type Description
OutputPort<TInputOutput>

TypedInputs

Gets the typed input ports.

Declaration
public InputPortCollection<TInputOutput> TypedInputs { get; }
Property Value
Type Description
InputPortCollection<TInputOutput>

Methods

RunAsync()

This method can be overridden to add custom functionality to the derived worker that runs before and after the row processing. In this case, the base class base.RunAsync() must be called for the worker to function correctly.

Note however that the worker uses a AddStartingChildrenCallback(Func<WorkerParent, Task<ProgressStatus>>) callback to set port buffering modes, which runs before RunAsync().

Typically, this worker is used without overriding this method.

Declaration
protected override Task<OutcomeStatus> RunAsync()
Returns
Type Description
Task<OutcomeStatus>

A Task describing the success or failure of the worker. An asynchronous async implementation would e.g. return OutcomeStatus.Succeeded on success, while a synchronous implementation would return OutcomeStatus.SucceededTask.
Overrides

Implements

See Also