func (pipeline *Pipeline) DispatchIf(fn stream.PredicateFn, writables ...stream.Writable) *Pipeline {
return &Pipeline{
Context: pipeline.Context,
Stream: dispatchers.New(pipeline.Context).If(fn).Dispatch(pipeline.Stream, writables...),
parallel: pipeline.parallel,
}
}
func (pipeline *Pipeline) Dispatch(writables ...stream.Writable) *Pipeline {
return &Pipeline{
Context: pipeline.Context,
Stream: dispatchers.New(pipeline.Context).Always().Dispatch(pipeline.Stream, writables...),
parallel: pipeline.parallel,
}
}
func (pipeline *Pipeline) Partition(fn stream.PredicateFn) (*Pipeline, *Pipeline) {
lhsIn, lhsOut := stream.New(pipeline.Stream.Capacity())
rhsIn := dispatchers.New(pipeline.Context).If(fn).Dispatch(pipeline.Stream, lhsOut)
lhsPipeline := &Pipeline{Context: pipeline.Context, Stream: lhsIn, parallel: pipeline.parallel}
rhsPipeline := &Pipeline{Context: pipeline.Context, Stream: rhsIn, parallel: pipeline.parallel}
return lhsPipeline, rhsPipeline
}
func (pipeline *Pipeline) SplitN(n int) []*Pipeline {
pipelines := make([]*Pipeline, n)
writables := make([]stream.Writable, n)
for i := 0; i < n; i++ {
readable, writable := stream.New(pipeline.Stream.Capacity())
writables[i] = writable
pipelines[i] = &Pipeline{
Context: pipeline.Context,
Stream: readable,
parallel: pipeline.parallel,
}
}
dispatchers.New(pipeline.Context).Always().Dispatch(pipeline.Stream, writables...)
return pipelines
}
func TestIfDispatcher(t *testing.T) {
evens := func(d stream.T) bool { return d.(int)%2 == 0 }
Convey("Given I have a context", t, func() {
context := rivers.NewContext()
Convey("And a stream of data", func() {
in, out := stream.New(3)
out <- 2
out <- 3
out <- 4
close(out)
Convey("When I apply an if dispatcher", func() {
evensIn, evensOut := stream.New(3)
sink := dispatchers.New(context).If(evens).Dispatch(in, evensOut)
Convey("Then items matching the condition are dispatched to the corresponding stream", func() {
data := evensIn.ReadAll()
So(data, should.Contain, 2)
So(data, should.Contain, 4)
Convey("And items not matching the condition are dispatched to the sink stream", func() {
So(sink.ReadAll(), ShouldResemble, []stream.T{3})
})
})
})
Convey("When I apply an always dispatcher", func() {
streamIn1, streamOut1 := stream.New(3)
streamIn2, streamOut2 := stream.New(3)
sink := dispatchers.New(context).Always().Dispatch(in, streamOut1, streamOut2)
Convey("Then all items are dispatched to the corresponding streams", func() {
streamIn1Items := streamIn1.ReadAll()
streamIn2Items := streamIn2.ReadAll()
So(streamIn1Items, should.Contain, 2)
So(streamIn1Items, should.Contain, 3)
So(streamIn1Items, should.Contain, 4)
So(streamIn2Items, should.Contain, 2)
So(streamIn2Items, should.Contain, 3)
So(streamIn2Items, should.Contain, 4)
Convey("And no item is dispatched to the sink stream", func() {
So(sink.ReadAll(), ShouldBeEmpty)
})
})
})
Convey("When I close the context", func() {
context.Close(stream.Done)
Convey("And I apply the transformer to the stream", func() {
evensIn, evensOut := stream.New(3)
sink := dispatchers.New(context).If(evens).Dispatch(in, evensOut)
Convey("Then no item is sent to the next stage", func() {
So(evensIn.ReadAll(), ShouldBeEmpty)
So(sink.ReadAll(), ShouldBeEmpty)
})
})
})
})
})
}
