Use central timer for collectors and router. Add expressions to router

internal/multiChanTicker/multiChanTicker.go

@@ -0,0 +1,39 @@
+package multiChanTicker
+
+import (
+    "time"
+)
+
+type multiChanTicker struct {
+    ticker *time.Ticker
+    channels []chan time.Time
+}
+
+type MultiChanTicker interface {
+    Init(duration time.Duration)
+    AddChannel(chan time.Time)
+}
+
+func (t *multiChanTicker) Init(duration time.Duration) {
+    t.ticker = time.NewTicker(duration)
+    go func() {
+        for {
+            select {
+            case ts := <-t.ticker.C:
+                for _, c := range t.channels {
+                    c <- ts
+                }
+            }
+        }
+    }()
+}
+
+func (t *multiChanTicker) AddChannel(channel chan time.Time) {
+    t.channels = append(t.channels, channel)
+}
+
+func NewTicker(duration time.Duration) MultiChanTicker {
+    t := &multiChanTicker{}
+    t.Init(duration)
+    return t
+}