metrics: added NewCounterForced (#17919)

metrics/counter.go

 package metrics
 
-import "sync/atomic"
+import (
+	"sync/atomic"
+)
 
 // Counters hold an int64 value that can be incremented and decremented.
 type Counter interface {
@@ -20,6 +22,17 @@ func GetOrRegisterCounter(name string, r Registry) Counter {
 	return r.GetOrRegister(name, NewCounter).(Counter)
 }
 
+// GetOrRegisterCounterForced returns an existing Counter or constructs and registers a
+// new Counter no matter the global switch is enabled or not.
+// Be sure to unregister the counter from the registry once it is of no use to
+// allow for garbage collection.
+func GetOrRegisterCounterForced(name string, r Registry) Counter {
+	if nil == r {
+		r = DefaultRegistry
+	}
+	return r.GetOrRegister(name, NewCounterForced).(Counter)
+}
+
 // NewCounter constructs a new StandardCounter.
 func NewCounter() Counter {
 	if !Enabled {
@@ -28,6 +41,12 @@ func NewCounter() Counter {
 	return &StandardCounter{0}
 }
 
+// NewCounterForced constructs a new StandardCounter and returns it no matter if
+// the global switch is enabled or not.
+func NewCounterForced() Counter {
+	return &StandardCounter{0}
+}
+
 // NewRegisteredCounter constructs and registers a new StandardCounter.
 func NewRegisteredCounter(name string, r Registry) Counter {
 	c := NewCounter()
@@ -38,6 +57,19 @@ func NewRegisteredCounter(name string, r Registry) Counter {
 	return c
 }
 
+// NewRegisteredCounterForced constructs and registers a new StandardCounter
+// and launches a goroutine no matter the global switch is enabled or not.
+// Be sure to unregister the counter from the registry once it is of no use to
+// allow for garbage collection.
+func NewRegisteredCounterForced(name string, r Registry) Counter {
+	c := NewCounterForced()
+	if nil == r {
+		r = DefaultRegistry
+	}
+	r.Register(name, c)
+	return c
+}
+
 // CounterSnapshot is a read-only copy of another Counter.
 type CounterSnapshot int64