remove map

pubsub/pt.go

@@ -15,17 +15,6 @@ const (
 	Done
 )
 
-type subChan struct {
-	c               chan<- string
-	lastUpdateIndex int
-}
-
-type subscriberState struct {
-	step Step
-	m    sync.Mutex
-	sc   []subChan
-}
-
 type InvalidState struct{ Step Step }
 
 func (i InvalidState) Error() string {
@@ -37,46 +26,42 @@ func (i InvalidState) Error() string {
 type ProgressTracker interface {
 	// Only one publisher sends update. Should close when done
 	// Error if there is/was existing publisher
-	Publish(id string) (chan<- string, error)
+	Publish() (chan<- string, error)
 
 	// Can subscribe even if there no publisher yet
 	// If already done, nil channel is returned
 	// channel will be closed when done
-	Subscribe(id string) <-chan string
+	Subscribe() <-chan string
+}
+
+type subChan struct {
+	c               chan<- string
+	lastUpdateIndex int
 }
 
 type progressTracker struct {
-	subscribers map[string]*subscriberState
-	m           sync.Mutex
+	step Step
+	m    sync.Mutex
+	sc   []subChan
 }
 
 func NewProgressTracker() ProgressTracker {
 	return &progressTracker{
-		subscribers: map[string]*subscriberState{},
+		step: NotStarted,
 	}
 }
 
-func (pt *progressTracker) Publish(id string) (chan<- string, error) {
-	var state *subscriberState
-	func() {
+func (pt *progressTracker) Publish() (chan<- string, error) {
+	err := func() error {
 		pt.m.Lock()
 		defer pt.m.Unlock()
-		state = pt.subscribers[id]
-		if state == nil {
-			state = &subscriberState{step: NotStarted}
-			pt.subscribers[id] = state
+		if pt.step != NotStarted {
+			return InvalidState{pt.step}
 		}
-	}()
-
-	err := func() error {
-		state.m.Lock()
-		defer state.m.Unlock()
-		if state.step != NotStarted {
-			return InvalidState{state.step}
-		}
-		state.step = Publishing
+		pt.step = Publishing
 		return nil
 	}()
+
 	if err != nil {
 		return nil, err
 	}
@@ -100,17 +85,17 @@ func (pt *progressTracker) Publish(id string) (chan<- string, error) {
 			}
 			var scs []subChan
 			func() {
-				state.m.Lock()
-				defer state.m.Unlock()
-				scs = state.sc
+				pt.m.Lock()
+				defer pt.m.Unlock()
+				scs = pt.sc
 				if !prodChanOpen {
-					for _, subChan := range scs {
-						close(subChan.c)
-					}
-					state.step = Done
+					pt.step = Done
 				}
 			}()
 			if !prodChanOpen {
+				for _, subChan := range scs {
+					close(subChan.c)
+				}
 				return
 			}
 			for _, subChan := range scs {
@@ -127,29 +112,14 @@ func (pt *progressTracker) Publish(id string) (chan<- string, error) {
 	return prodChan, nil
 }
 
-func (pt *progressTracker) Subscribe(id string) <-chan string {
+func (pt *progressTracker) Subscribe() <-chan string {
 	c := make(chan string, 1)
 	sc := subChan{c: c}
-	var state *subscriberState
-	func() {
-		pt.m.Lock()
-		defer pt.m.Unlock()
-		state = pt.subscribers[id]
-		if state == nil {
-			pt.subscribers[id] = &subscriberState{
-				step: NotStarted,
-				sc:   []subChan{sc},
-			}
-		}
-	}()
-	if state == nil {
-		return c
-	}
-	state.m.Lock()
-	defer state.m.Unlock()
-	if state.step == Done {
+	pt.m.Lock()
+	defer pt.m.Unlock()
+	if pt.step == Done {
 		return nil
 	}
-	state.sc = append(state.sc, sc)
+	pt.sc = append(pt.sc, sc)
 	return c
 }

pubsub/pt_test.go

@@ -9,47 +9,43 @@ import (
 func TestDupePublisher(t *testing.T) {
 	pt := NewProgressTracker()
 
-	if _, err := pt.Publish("foo"); err != nil {
+	if _, err := pt.Publish(); err != nil {
 		t.Fatalf("First publisher should not give error, err:%v", err)
 	}
 
-	if _, err := pt.Publish("foo"); err == nil {
+	if _, err := pt.Publish(); err == nil {
 		t.Fatal("Dupe publisher should give error but got nil")
 	} else {
 		t.Logf("Got err: %v", err)
 	}
-
-	if _, err := pt.Publish("bar"); err != nil {
-		t.Fatalf("Different publisher should not give error, err:%v", err)
-	}
 }
 
 func TestSubSub(t *testing.T) {
 	pt := NewProgressTracker()
-	c1 := pt.Subscribe("foo")
+	c1 := pt.Subscribe()
 	select {
 	case <-c1:
 	default:
 	}
 	if c1 == nil {
-		t.Fatal("Subscriber should not get a closed channel")
+		t.Fatal("Subscriber should not get a nil channel")
 	}
-	c2 := pt.Subscribe("foo")
+	c2 := pt.Subscribe()
 	if c2 == nil {
-		t.Fatal("Subscriber should not get a closed channel")
+		t.Fatal("Subscriber should not get a nil channel")
 	}
 }
 
 func TestPubSub(t *testing.T) {
 	pt := NewProgressTracker()
-	pc, err := pt.Publish("foo")
+	pc, err := pt.Publish()
 	if err != nil {
 		t.Fatalf("Unexpected err: %v", err)
 	}
 	if pc == nil {
 		t.Fatal("Should not get nil channel")
 	}
-	sc := pt.Subscribe("foo")
+	sc := pt.Subscribe()
 	if sc == nil {
 		t.Fatal("Should not get nil channel")
 	}
@@ -70,8 +66,6 @@ func TestPubSub(t *testing.T) {
 		pc <- "blah"
 		time.Sleep(166 * time.Millisecond)
 		if i == 5 {
-			// time.Sleep(100 * time.Millisecond)
-			//time.Sleep(1 * time.Second)
 			<-testc
 		}
 	}
@@ -81,7 +75,7 @@ func TestPubSub(t *testing.T) {
 		t.Fatal("There should be atleast one update")
 	}
 	t.Logf("c is :%d", c)
-	sc2 := pt.Subscribe("foo")
+	sc2 := pt.Subscribe()
 	if sc2 != nil {
 		t.Fatal("Subscriber after publisher done should return nil")
 	}