cleanup

adapative.go

@@ -64,174 +64,46 @@ func (a *adaptive) nightshiftTO() time.Duration {
 	return to
 }
 
-// ensure that a single client does not get freed if using it
+func (a *adaptive) nightshift(s Stats) time.Duration {
-// ensure that eventually gets collected if not using it
-// ensure that the background job is not running forever
-// handle load as well
-
-func (a *adaptive) nightshift(s Stats, now time.Time) time.Duration {
-	// idle, inactive, uninitialized     => not idle, initialize, 0
-	// idle, inactive, initialized       => to
-	// idle, active, uninitialized       => not idle, initialize, 0
-	// idle, active, initialized         => not idle, initialize, 0
-	// not idle, inactive, uninitialized => not idle, initialize, 0
-	// not idle, inactive, initialized   => idle, new to
-	// not idle, active, uninitialized   => not idle, initialize, 0
-	// not idle, active, initialized     => 0
-
-	// idle := a.idle
-	// active := s.Active > 0
-	// initialized := !a.activeTime.IsZero()
-	// if !initialized {
-	// 	a.idle = false
-	// 	a.activeTime = now
-	// 	return 0
-	// }
-
-	// if idle && !active {
-	// 	return a.nsTO
-	// }
-
-	// if idle {
-	// 	a.idle = false
-	// 	a.nsTO = 0
-	// 	a.activeTime = now
-	// 	return 0
-	// }
-
-	// if active {
-	// 	return 0
-	// }
-
-	// a.idle = true
-	// a.nsTO = nightshiftTO(a.activeTime, now)
-	// return a.nsTO
-
-	// --
-
-	// state flags:
-	// - initialized
-	// - pempty
-	// - pactive
-	// - empty
-	// - active
-	// actions:
-	// - start active
-	// - call to
-	// - update prev state on every call
-	// states:
-	// X not initialized, not pempty, not pactive, not empty, not active
-	// X not initialized, not pempty, not pactive, not empty, active
-	// X not initialized, not pempty, not pactive, empty, not active
-	// X not initialized, not pempty, not pactive, empty, active
-	// X not initialized, not pempty, pactive, not empty, not active
-	// X not initialized, not pempty, pactive, not empty, active
-	// X not initialized, not pempty, pactive, empty, not active
-	// X not initialized, not pempty, pactive, empty, active
-	// * not initialized, pempty, not pactive, not empty, not active => start active, call to
-	// * not initialized, pempty, not pactive, not empty, active     => start active
-	// X not initialized, pempty, not pactive, empty, not active
-	// X not initialized, pempty, not pactive, empty, active
-	// X not initialized, pempty, pactive, not empty, not active
-	// X not initialized, pempty, pactive, not empty, active
-	// X not initialized, pempty, pactive, empty, not active
-	// X not initialized, pempty, pactive, empty, active
-	// * initialized, not pempty, not pactive, not empty, not active => end active, call to
-	// * initialized, not pempty, not pactive, not empty, active     => start active
-	// * initialized, not pempty, not pactive, empty, not active     => noop
-	// * initialized, not pempty, not pactive, empty, active         => start active
-	// * initialized, not pempty, pactive, not empty, not active     => end active, call to
-	// * initialized, not pempty, pactive, not empty, active         => noop
-	// * initialized, not pempty, pactive, empty, not active         => end active, noop
-	// * initialized, not pempty, pactive, empty, active             => noop
-	// * initialized, pempty, not pactive, not empty, not active     => call to
-	// * initialized, pempty, not pactive, not empty, active         => start active
-	// * initialized, pempty, not pactive, empty, not active         => noop
-	// * initialized, pempty, not pactive, empty, active             => start active
-	// * initialized, pempty, pactive, not empty, not active         => end active, call to
-	// * initialized, pempty, pactive, not empty, active             => noop
-	// - initialized, pempty, pactive, empty, not active             => end active, noop
-	// * initialized, pempty, pactive, empty, active                 => noop
-
-	pempty := a.prevState.Idle == 0
 	pactive := a.prevState.Active > 0
 	empty := s.Idle == 0
 	active := s.Active > 0
 	a.prevState = s
 
-	// not initialized, pempty, not pactive, not empty, not active => start active, call to
+	// on the first put we need to set an active start time:
-	if !a.initialized && pempty && !pactive && !empty && !active {
-		a.initialized = true
-		a.activeStart = now
-		return a.nightshiftTO()
-	}
-
-	// not initialized, pempty, not pactive, not empty, active => start active
-	if !a.initialized && pempty && !pactive && !empty && active {
-		a.initialized = true
-		a.activeStart = now
-		return 0
-	}
-
 	if !a.initialized {
+		a.initialized = true
+		a.activeStart = a.clock.Now()
+		if active {
 			return 0
 		}
 
-	// initialized, not pempty, not pactive, not empty, not active => end active, call to
-	if !pempty && !pactive && !empty && !active {
-		ns := a.nightshiftTO()
-		return ns
-	}
-
-	// initialized, not pempty, not pactive, not empty, active => start active
-	// initialized, not pempty, not pactive, empty, active => start active
-	if !pempty && !pactive && active {
-		a.activeStart = now
-		return 0
-	}
-
-	// initialized, not pempty, pactive, not empty, not active => end active, call to
-	if !pempty && pactive && !empty && !active {
-		a.activeEnd = now
-		ns := a.nightshiftTO()
-		return ns
-	}
-
-	// initialized, not pempty, pactive, empty, not active => end active, noop
-	if !pempty && pactive && empty && !active {
-		a.activeEnd = now
-		return 0
-	}
-
-	// initialized, pempty, not pactive, not empty, not active => call to
-	if pempty && !pactive && !empty && !active {
 		return a.nightshiftTO()
 	}
 
-	// initialized, pempty, not pactive, not empty, active => start active
+	if !pactive && !active && !empty {
-	// initialized, pempty, not pactive, empty, active => start active
-	if pempty && !pactive && active {
-		a.activeStart = now
-		return 0
-	}
-
-	// initialized, pempty, pactive, not empty, not active => end active, call to
-	if pempty && pactive && !empty && !active {
-		a.activeEnd = now
 		return a.nightshiftTO()
 	}
 
-	// initialized, pempty, pactive, empty, not active => end active, noop
+	if !pactive && active {
-	if pempty && pactive && empty && !active {
+		a.activeStart = a.clock.Now()
-		a.activeEnd = now
 		return 0
 	}
 
+	if pactive && !active {
+		a.activeEnd = a.clock.Now()
+		if empty {
+			return 0
+		}
+
+		return a.nightshiftTO()
+	}
+
 	return 0
 }
 
 func (a *adaptive) Target(s Stats) (int, time.Duration) {
-	t := a.target(s) // handle when t < 2
+	t := a.target(s)
 
 	// magic number 2: we allow max 2 idle items to be collected only by the nightshift, to provide better
 	// support for sporadic requests, when it's active or just going inactive:
@@ -239,9 +111,7 @@ func (a *adaptive) Target(s Stats) (int, time.Duration) {
 		t = 2
 	}
 
-	// TODO: optimize, only take the clock when necessary
+	ns := a.nightshift(s)
-	ns := a.nightshift(s, a.clock.Now())
-
 	return t, ns
 }
 
@@ -251,5 +121,5 @@ func (a *adaptive) Load(n int) {
 	a.average += float64(n)
 	s := a.prevState
 	s.Idle += n
-	a.nightshift(s, a.clock.Now())
+	a.nightshift(s)
 }