Manipulate a network in running

[brucekim]

@trustmaster

Hello, I would like to know how to dynamically manipulate a network in running.

I tested with a simple code below. However inserting a new process into the network already initialized doesn't change after the network running. I am not sure whether this is a nature of design for flow based programming.

In addition, I would like to hear whether implementing such dynamic manipulating a network is meaningful or not.

type SrcTest struct {
    Out chan<- byte
}

type FilterTest1 struct {
    In <-chan byte
    Out chan<- byte
}

type FilterTest2 struct {
    In <-chan byte
    Out chan<- byte
}

type SinkTest struct {
    In <-chan byte
}

func (s *SrcTest) Process() {
    for {
        s.Out <- 'a'
        time.Sleep(100 * time.Millisecond)
    }
}

func (f *FilterTest1) Process() {
    for in := range f.In {
        _ = in
        f.Out <- 'b'
    }
}

func (f *FilterTest2) Process() {
    for in := range f.In {
        _ = in
        log.Infof("f2 f2")
        f.Out <- 'c'
    }
}

func (s *SinkTest) Process() {
    for in := range s.In {
        log.Infof("recv: %c", in)
    }
}

func TestStreamData(t *testing.T) {
    n := goflow.NewGraph()
    n.Add("src", new(SrcTest))
    n.Add("f1", new(FilterTest1))
    n.Add("sink", new(SinkTest))
    n.Connect("src", "Out", "f1", "In")
    n.Connect("f1", "Out", "sink", "In")

    wait := goflow.Run(n)
    go func() {
        time.Sleep(2 * time.Second)
        log.Infof("insert f2")

        n.Add("f2", new(FilterTest2))
        //n.Connect("f1", "Out", "f2", "In")
        n.Connect("src", "Out", "f2", "In")
        n.Connect("f2", "Out", "sink", "In")

    }()

    <-wait
}