feature: keep track of and export total time observed by a timer (#949)

feature: keep track of and export total time observed by a timer (#772)

Co-authored-by: Ömer Faruk Irmak <omerfirmak@gmail.com>

metrics/inactive.go

@@ -16,6 +16,8 @@
 
 package metrics
 
+import "time"
+
 // compile-time checks that interfaces are implemented.
 var (
 	_ SampleSnapshot    = (*emptySnapshot)(nil)
@@ -46,3 +48,4 @@ func (*emptySnapshot) Rate1() float64                     { return 0.0 }
 func (*emptySnapshot) Rate5() float64                     { return 0.0 }
 func (*emptySnapshot) Rate15() float64                    { return 0.0 }
 func (*emptySnapshot) RateMean() float64                  { return 0.0 }
+func (*emptySnapshot) Total() time.Duration               { return 0 }

metrics/influxdb/influxdb.go

@@ -95,6 +95,7 @@ func readMeter(namespace, name string, i interface{}) (string, map[string]interf
 			"m5":       ms.Rate5(),
 			"m15":      ms.Rate15(),
 			"meanrate": ms.RateMean(),
+			"total":    int64(ms.Total()),
 		}
 		return measurement, fields
 	case metrics.ResettingTimer:

metrics/influxdb/influxdbv2.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"time"
 
-	"github.com/scroll-tech/go-ethereum/log"
-	"github.com/scroll-tech/go-ethereum/metrics"
 	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
 	"github.com/influxdata/influxdb-client-go/v2/api"
+	"github.com/scroll-tech/go-ethereum/log"
+	"github.com/scroll-tech/go-ethereum/metrics"
 )
 
 type v2Reporter struct {

metrics/timer.go

@@ -8,6 +8,7 @@ import (
 type TimerSnapshot interface {
 	HistogramSnapshot
 	MeterSnapshot
+	Total() time.Duration
 }
 
 // Timers capture the duration and rate of events.
@@ -17,6 +18,7 @@ type Timer interface {
 	Time(func())
 	UpdateSince(time.Time)
 	Update(time.Duration)
+	Total() time.Duration
 }
 
 // GetOrRegisterTimer returns an existing Timer or constructs and registers a
@@ -76,11 +78,14 @@ func (NilTimer) Time(f func())           { f() }
 func (NilTimer) Update(time.Duration)    {}
 func (NilTimer) UpdateSince(time.Time)   {}
 
+func (NilTimer) Total() time.Duration { return time.Duration(0) }
+
 // StandardTimer is the standard implementation of a Timer and uses a Histogram
 // and Meter.
 type StandardTimer struct {
 	histogram Histogram
 	meter     Meter
+	total     time.Duration
 	mutex     sync.Mutex
 }
 
@@ -91,6 +96,7 @@ func (t *StandardTimer) Snapshot() TimerSnapshot {
 	return &timerSnapshot{
 		histogram: t.histogram.Snapshot(),
 		meter:     t.meter.Snapshot(),
+		total:     t.total,
 	}
 }
 
@@ -112,20 +118,24 @@ func (t *StandardTimer) Update(d time.Duration) {
 	defer t.mutex.Unlock()
 	t.histogram.Update(int64(d))
 	t.meter.Mark(1)
+	t.total += d
 }
 
 // Record the duration of an event that started at a time and ends now.
 func (t *StandardTimer) UpdateSince(ts time.Time) {
-	t.mutex.Lock()
+	t.Update(time.Since(ts))
-	defer t.mutex.Unlock()
+}
-	t.histogram.Update(int64(time.Since(ts)))
+
-	t.meter.Mark(1)
+// Total returns the total time that events observed by this timer took
+func (t *StandardTimer) Total() time.Duration {
+	return t.total
 }
 
 // timerSnapshot is a read-only copy of another Timer.
 type timerSnapshot struct {
 	histogram HistogramSnapshot
 	meter     MeterSnapshot
+	total     time.Duration
 }
 
 // Count returns the number of events recorded at the time the snapshot was
@@ -182,3 +192,8 @@ func (t *timerSnapshot) Sum() int64 { return t.histogram.Sum() }
 // Variance returns the variance of the values at the time the snapshot was
 // taken.
 func (t *timerSnapshot) Variance() float64 { return t.histogram.Variance() }
+
+// Total returns the total time that events observed by this timer took
+func (t *timerSnapshot) Total() time.Duration {
+	return t.total
+}

metrics/timer_test.go

@@ -112,3 +112,18 @@ func ExampleGetOrRegisterTimer() {
 	t.Update(47)
 	fmt.Println(t.Snapshot().Max()) // Output: 47
 }
+
+func TestTimerSum(t *testing.T) {
+	tm := GetOrRegisterTimer("test.timer.sum", nil)
+	times := 5000000
+	for i := 0; i < times; i++ {
+		tm.Update(time.Second)
+	}
+	ss := tm.Snapshot()
+	if total := tm.Total().Seconds(); total != float64(times) {
+		t.Errorf("tm.Total().Seconds(): 5000000.0 != %v\n", total)
+	}
+	if total := ss.Total().Seconds(); total != float64(times) {
+		t.Errorf("ss.Total().Seconds(): 5000000.0 != %v\n", total)
+	}
+}