pooler now accepts channels

done channels used to clean up pooler if GUI goes down

InitPooler() added to Remote type, useful for reinitiating the Pooler.
For this reason Pooler now defined as singleton type.

publisher.go

@@ -6,40 +6,14 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-// observer defines the interface any registered observers must satisfy
-type observer interface {
-	OnUpdate(subject string)
-}
-
-// publisher defines methods that support observers
+// publisher defines the list of observer channels
 type publisher struct {
-	observerList []observer
+	observers []chan string
 }
 
-// Register adds an observer to observerList
-func (p *publisher) Register(o observer) {
-	p.observerList = append(p.observerList, o)
-}
-
-// Deregister removes an observer from observerList
-func (p *publisher) Deregister(o observer) {
-	var indexToRemove int
-
-	for i, observer := range p.observerList {
-		if observer == o {
-			indexToRemove = i
-			break
-		}
-	}
-
-	p.observerList = append(p.observerList[:indexToRemove], p.observerList[indexToRemove+1:]...)
-}
-
-// notify updates observers of any changes
-func (p *publisher) notify(subject string) {
-	for _, observer := range p.observerList {
-		observer.OnUpdate(subject)
-	}
+// Register adds an observer channel to the channelList
+func (p *publisher) Register(channel chan string) {
+	p.observers = append(p.observers, channel)
 }
 
 type event struct {
@@ -85,32 +59,81 @@ func (e *event) Remove(events ...string) {
 	}
 }
 
-// pooler continuously polls the dirty paramters
+var p *pooler
+
+// pooler continuously polls the dirty parameters
 // it is expected to be run in a goroutine
 type pooler struct {
 	k          *kind
 	run        bool
 	event      *event
+	pdirtyDone chan bool
+	mdirtyDone chan bool
+	midiDone   chan bool
+	ldirtyDone chan bool
 	publisher
 }
 
 func newPooler(k *kind) *pooler {
-	p := &pooler{
+	if p == nil {
+		p = &pooler{
 			k:          k,
 			run:        true,
 			event:      newEvent(),
+			pdirtyDone: make(chan bool),
+			mdirtyDone: make(chan bool),
+			midiDone:   make(chan bool),
+			ldirtyDone: make(chan bool),
 		}
+		go p.done()
 		go p.parameters()
 		go p.macrobuttons()
 		go p.midi()
 		go p.levels()
+	}
 	return p
 }
 
+func (p *pooler) done() {
+	for {
+		select {
+		case _, ok := <-p.pdirtyDone:
+			if !ok {
+				p.pdirtyDone = nil
+			}
+		case _, ok := <-p.mdirtyDone:
+			if !ok {
+				p.mdirtyDone = nil
+			}
+		case _, ok := <-p.midiDone:
+			if !ok {
+				p.midiDone = nil
+			}
+		case _, ok := <-p.ldirtyDone:
+			if !ok {
+				p.ldirtyDone = nil
+			}
+		}
+		if p.pdirtyDone == nil && p.mdirtyDone == nil && p.midiDone == nil && p.ldirtyDone == nil {
+			for _, ch := range p.observers {
+				close(ch)
+			}
+			break
+		}
+	}
+}
+
 func (p *pooler) parameters() {
 	for p.run {
-		if p.event.pdirty && pdirty() {
-			p.notify("pdirty")
+		pdirty, err := pdirty()
+		if err != nil {
+			close(p.pdirtyDone)
+			break
+		}
+		if p.event.pdirty && pdirty {
+			for _, ch := range p.observers {
+				ch <- "pdirty"
+			}
 		}
 		time.Sleep(33 * time.Millisecond)
 	}
@@ -118,8 +141,15 @@ func (p *pooler) parameters() {
 
 func (p *pooler) macrobuttons() {
 	for p.run {
-		if p.event.mdirty && mdirty() {
-			p.notify("mdirty")
+		mdirty, err := mdirty()
+		if err != nil {
+			close(p.mdirtyDone)
+			break
+		}
+		if p.event.mdirty && mdirty {
+			for _, ch := range p.observers {
+				ch <- "mdirty"
+			}
 		}
 		time.Sleep(33 * time.Millisecond)
 	}
@@ -127,8 +157,15 @@ func (p *pooler) macrobuttons() {
 
 func (p *pooler) midi() {
 	for p.run {
-		if p.event.midi && getMidiMessage() {
-			p.notify("midi")
+		midi, err := getMidiMessage()
+		if err != nil {
+			close(p.midiDone)
+			break
+		}
+		if p.event.midi && midi {
+			for _, ch := range p.observers {
+				ch <- "midi"
+			}
 		}
 		time.Sleep(33 * time.Millisecond)
 	}
@@ -138,10 +175,17 @@ func (p *pooler) levels() {
 	_levelCache = newLevelCache(p.k)
 
 	for p.run {
-		if p.event.ldirty && ldirty(p.k) {
+		ldirty, err := ldirty(p.k)
+		if err != nil {
+			close(p.ldirtyDone)
+			break
+		}
+		if p.event.ldirty && ldirty {
 			update(_levelCache.stripLevels, _levelCache.stripLevelsBuff, (2*p.k.PhysIn)+(8*p.k.VirtIn))
 			update(_levelCache.busLevels, _levelCache.busLevelsBuff, 8*p.k.NumBus())
-			p.notify("ldirty")
+			for _, ch := range p.observers {
+				ch <- "ldirty"
+			}
 		}
 		time.Sleep(33 * time.Millisecond)
 	}

remote.go

@@ -35,7 +35,7 @@ func (r *Remote) Login() error {
 	if err != nil {
 		return err
 	}
-	r.pooler = newPooler(r.Kind)
+	r.InitPooler()
 	return nil
 }
 
@@ -50,6 +50,11 @@ func (r *Remote) Logout() error {
 	return nil
 }
 
+// InitPooler initiates the Pooler
+func (r *Remote) InitPooler() {
+	r.pooler = newPooler(r.Kind)
+}
+
 // Type returns the type of Voicemeeter (basic, banana, potato)
 func (r *Remote) Type() string {
 	val, err := getVMType()
@@ -69,20 +74,21 @@ func (r *Remote) Version() string {
 }
 
 // Pdirty returns true iff a parameter value has changed
-func (r *Remote) Pdirty() bool {
-	return pdirty()
+func (r *Remote) Pdirty() (bool, error) {
+	pdirty, err := pdirty()
+	return pdirty, err
 }
 
 // Mdirty returns true iff a macrobutton value has changed
-func (r *Remote) Mdirty() bool {
-	return mdirty()
+func (r *Remote) Mdirty() (bool, error) {
+	mdirty, err := mdirty()
+	return mdirty, err
 }
 
 // Sync is a helper method that waits for dirty parameters to clear
 func (r *Remote) Sync() {
 	time.Sleep(time.Duration(vmdelay) * time.Millisecond)
-	for r.Pdirty() || r.Mdirty() {
-	}
+	clear()
 }
 
 // GetFloat gets a float parameter value
@@ -131,13 +137,8 @@ func (r *Remote) SendText(script string) error {
 }
 
 // Register forwards the register method to Pooler
-func (r *Remote) Register(o observer) {
-	r.pooler.Register(o)
-}
-
-// Deregister forwards the deregister method to Pooler
-func (r *Remote) Deregister(o observer) {
-	r.pooler.Deregister(o)
+func (r *Remote) Register(channel chan string) {
+	r.pooler.Register(channel)
 }
 
 // EventAdd adds events to the Pooler
@@ -346,7 +347,7 @@ func init() {
 // NewRemote returns a Remote type for a kind
 // this is the interface entry point
 func NewRemote(kindId string, delay int) (*Remote, error) {
-	_kind, ok := kindMap[kindId]
+	kind, ok := kindMap[kindId]
 	if !ok {
 		err := fmt.Errorf("unknown Voicemeeter kind '%s'", kindId)
 		return nil, err
@@ -359,13 +360,13 @@ func NewRemote(kindId string, delay int) (*Remote, error) {
 	vmdelay = delay
 
 	director := director{}
-	switch _kind.Name {
+	switch kind.Name {
 	case "basic":
-		director.SetBuilder(&basicBuilder{genericBuilder{_kind, Remote{}}})
+		director.SetBuilder(&basicBuilder{genericBuilder{kind, Remote{}}})
 	case "banana":
-		director.SetBuilder(&bananaBuilder{genericBuilder{_kind, Remote{}}})
+		director.SetBuilder(&bananaBuilder{genericBuilder{kind, Remote{}}})
 	case "potato":
-		director.SetBuilder(&potatoBuilder{genericBuilder{_kind, Remote{}}})
+		director.SetBuilder(&potatoBuilder{genericBuilder{kind, Remote{}}})
 	}
 	director.Construct()
 	return director.Get(), nil