metrics: pull library and introduce ResettingTimer and InfluxDB reporter (#15910)

* go-metrics: fork library and introduce ResettingTimer and InfluxDB reporter.

* vendor: change nonsense/go-metrics to ethersphere/go-metrics

* go-metrics: add tests. move ResettingTimer logic from reporter to type.

* all, metrics: pull in metrics package in go-ethereum

* metrics/test: make sure metrics are enabled for tests

* metrics: apply gosimple rules

* metrics/exp, internal/debug: init expvar endpoint when starting pprof server

* internal/debug: tiny comment formatting fix

1 files changed, 0 insertions, 311 deletions

diff --git a/vendor/github.com/rcrowley/go-metrics/timer.go b/vendor/github.com/rcrowley/go-metrics/timer.go
deleted file mode 100644
index 17db8f8d2..000000000
--- a/vendor/github.com/rcrowley/go-metrics/timer.go
+++ /dev/null
@@ -1,311 +0,0 @@
-package metrics
-
-import (
-	"sync"
-	"time"
-)
-
-// Timers capture the duration and rate of events.
-type Timer interface {
-	Count() int64
-	Max() int64
-	Mean() float64
-	Min() int64
-	Percentile(float64) float64
-	Percentiles([]float64) []float64
-	Rate1() float64
-	Rate5() float64
-	Rate15() float64
-	RateMean() float64
-	Snapshot() Timer
-	StdDev() float64
-	Sum() int64
-	Time(func())
-	Update(time.Duration)
-	UpdateSince(time.Time)
-	Variance() float64
-}
-
-// GetOrRegisterTimer returns an existing Timer or constructs and registers a
-// new StandardTimer.
-func GetOrRegisterTimer(name string, r Registry) Timer {
-	if nil == r {
-		r = DefaultRegistry
-	}
-	return r.GetOrRegister(name, NewTimer).(Timer)
-}
-
-// NewCustomTimer constructs a new StandardTimer from a Histogram and a Meter.
-func NewCustomTimer(h Histogram, m Meter) Timer {
-	if UseNilMetrics {
-		return NilTimer{}
-	}
-	return &StandardTimer{
-		histogram: h,
-		meter:     m,
-	}
-}
-
-// NewRegisteredTimer constructs and registers a new StandardTimer.
-func NewRegisteredTimer(name string, r Registry) Timer {
-	c := NewTimer()
-	if nil == r {
-		r = DefaultRegistry
-	}
-	r.Register(name, c)
-	return c
-}
-
-// NewTimer constructs a new StandardTimer using an exponentially-decaying
-// sample with the same reservoir size and alpha as UNIX load averages.
-func NewTimer() Timer {
-	if UseNilMetrics {
-		return NilTimer{}
-	}
-	return &StandardTimer{
-		histogram: NewHistogram(NewExpDecaySample(1028, 0.015)),
-		meter:     NewMeter(),
-	}
-}
-
-// NilTimer is a no-op Timer.
-type NilTimer struct {
-	h Histogram
-	m Meter
-}
-
-// Count is a no-op.
-func (NilTimer) Count() int64 { return 0 }
-
-// Max is a no-op.
-func (NilTimer) Max() int64 { return 0 }
-
-// Mean is a no-op.
-func (NilTimer) Mean() float64 { return 0.0 }
-
-// Min is a no-op.
-func (NilTimer) Min() int64 { return 0 }
-
-// Percentile is a no-op.
-func (NilTimer) Percentile(p float64) float64 { return 0.0 }
-
-// Percentiles is a no-op.
-func (NilTimer) Percentiles(ps []float64) []float64 {
-	return make([]float64, len(ps))
-}
-
-// Rate1 is a no-op.
-func (NilTimer) Rate1() float64 { return 0.0 }
-
-// Rate5 is a no-op.
-func (NilTimer) Rate5() float64 { return 0.0 }
-
-// Rate15 is a no-op.
-func (NilTimer) Rate15() float64 { return 0.0 }
-
-// RateMean is a no-op.
-func (NilTimer) RateMean() float64 { return 0.0 }
-
-// Snapshot is a no-op.
-func (NilTimer) Snapshot() Timer { return NilTimer{} }
-
-// StdDev is a no-op.
-func (NilTimer) StdDev() float64 { return 0.0 }
-
-// Sum is a no-op.
-func (NilTimer) Sum() int64 { return 0 }
-
-// Time is a no-op.
-func (NilTimer) Time(func()) {}
-
-// Update is a no-op.
-func (NilTimer) Update(time.Duration) {}
-
-// UpdateSince is a no-op.
-func (NilTimer) UpdateSince(time.Time) {}
-
-// Variance is a no-op.
-func (NilTimer) Variance() float64 { return 0.0 }
-
-// StandardTimer is the standard implementation of a Timer and uses a Histogram
-// and Meter.
-type StandardTimer struct {
-	histogram Histogram
-	meter     Meter
-	mutex     sync.Mutex
-}
-
-// Count returns the number of events recorded.
-func (t *StandardTimer) Count() int64 {
-	return t.histogram.Count()
-}
-
-// Max returns the maximum value in the sample.
-func (t *StandardTimer) Max() int64 {
-	return t.histogram.Max()
-}
-
-// Mean returns the mean of the values in the sample.
-func (t *StandardTimer) Mean() float64 {
-	return t.histogram.Mean()
-}
-
-// Min returns the minimum value in the sample.
-func (t *StandardTimer) Min() int64 {
-	return t.histogram.Min()
-}
-
-// Percentile returns an arbitrary percentile of the values in the sample.
-func (t *StandardTimer) Percentile(p float64) float64 {
-	return t.histogram.Percentile(p)
-}
-
-// Percentiles returns a slice of arbitrary percentiles of the values in the
-// sample.
-func (t *StandardTimer) Percentiles(ps []float64) []float64 {
-	return t.histogram.Percentiles(ps)
-}
-
-// Rate1 returns the one-minute moving average rate of events per second.
-func (t *StandardTimer) Rate1() float64 {
-	return t.meter.Rate1()
-}
-
-// Rate5 returns the five-minute moving average rate of events per second.
-func (t *StandardTimer) Rate5() float64 {
-	return t.meter.Rate5()
-}
-
-// Rate15 returns the fifteen-minute moving average rate of events per second.
-func (t *StandardTimer) Rate15() float64 {
-	return t.meter.Rate15()
-}
-
-// RateMean returns the meter's mean rate of events per second.
-func (t *StandardTimer) RateMean() float64 {
-	return t.meter.RateMean()
-}
-
-// Snapshot returns a read-only copy of the timer.
-func (t *StandardTimer) Snapshot() Timer {
-	t.mutex.Lock()
-	defer t.mutex.Unlock()
-	return &TimerSnapshot{
-		histogram: t.histogram.Snapshot().(*HistogramSnapshot),
-		meter:     t.meter.Snapshot().(*MeterSnapshot),
-	}
-}
-
-// StdDev returns the standard deviation of the values in the sample.
-func (t *StandardTimer) StdDev() float64 {
-	return t.histogram.StdDev()
-}
-
-// Sum returns the sum in the sample.
-func (t *StandardTimer) Sum() int64 {
-	return t.histogram.Sum()
-}
-
-// Record the duration of the execution of the given function.
-func (t *StandardTimer) Time(f func()) {
-	ts := time.Now()
-	f()
-	t.Update(time.Since(ts))
-}
-
-// Record the duration of an event.
-func (t *StandardTimer) Update(d time.Duration) {
-	t.mutex.Lock()
-	defer t.mutex.Unlock()
-	t.histogram.Update(int64(d))
-	t.meter.Mark(1)
-}
-
-// Record the duration of an event that started at a time and ends now.
-func (t *StandardTimer) UpdateSince(ts time.Time) {
-	t.mutex.Lock()
-	defer t.mutex.Unlock()
-	t.histogram.Update(int64(time.Since(ts)))
-	t.meter.Mark(1)
-}
-
-// Variance returns the variance of the values in the sample.
-func (t *StandardTimer) Variance() float64 {
-	return t.histogram.Variance()
-}
-
-// TimerSnapshot is a read-only copy of another Timer.
-type TimerSnapshot struct {
-	histogram *HistogramSnapshot
-	meter     *MeterSnapshot
-}
-
-// Count returns the number of events recorded at the time the snapshot was
-// taken.
-func (t *TimerSnapshot) Count() int64 { return t.histogram.Count() }
-
-// Max returns the maximum value at the time the snapshot was taken.
-func (t *TimerSnapshot) Max() int64 { return t.histogram.Max() }
-
-// Mean returns the mean value at the time the snapshot was taken.
-func (t *TimerSnapshot) Mean() float64 { return t.histogram.Mean() }
-
-// Min returns the minimum value at the time the snapshot was taken.
-func (t *TimerSnapshot) Min() int64 { return t.histogram.Min() }
-
-// Percentile returns an arbitrary percentile of sampled values at the time the
-// snapshot was taken.
-func (t *TimerSnapshot) Percentile(p float64) float64 {
-	return t.histogram.Percentile(p)
-}
-
-// Percentiles returns a slice of arbitrary percentiles of sampled values at
-// the time the snapshot was taken.
-func (t *TimerSnapshot) Percentiles(ps []float64) []float64 {
-	return t.histogram.Percentiles(ps)
-}
-
-// Rate1 returns the one-minute moving average rate of events per second at the
-// time the snapshot was taken.
-func (t *TimerSnapshot) Rate1() float64 { return t.meter.Rate1() }
-
-// Rate5 returns the five-minute moving average rate of events per second at
-// the time the snapshot was taken.
-func (t *TimerSnapshot) Rate5() float64 { return t.meter.Rate5() }
-
-// Rate15 returns the fifteen-minute moving average rate of events per second
-// at the time the snapshot was taken.
-func (t *TimerSnapshot) Rate15() float64 { return t.meter.Rate15() }
-
-// RateMean returns the meter's mean rate of events per second at the time the
-// snapshot was taken.
-func (t *TimerSnapshot) RateMean() float64 { return t.meter.RateMean() }
-
-// Snapshot returns the snapshot.
-func (t *TimerSnapshot) Snapshot() Timer { return t }
-
-// StdDev returns the standard deviation of the values at the time the snapshot
-// was taken.
-func (t *TimerSnapshot) StdDev() float64 { return t.histogram.StdDev() }
-
-// Sum returns the sum at the time the snapshot was taken.
-func (t *TimerSnapshot) Sum() int64 { return t.histogram.Sum() }
-
-// Time panics.
-func (*TimerSnapshot) Time(func()) {
-	panic("Time called on a TimerSnapshot")
-}
-
-// Update panics.
-func (*TimerSnapshot) Update(time.Duration) {
-	panic("Update called on a TimerSnapshot")
-}
-
-// UpdateSince panics.
-func (*TimerSnapshot) UpdateSince(time.Time) {
-	panic("UpdateSince called on a TimerSnapshot")
-}
-
-// Variance returns the variance of the values at the time the snapshot was
-// taken.
-func (t *TimerSnapshot) Variance() float64 { return t.histogram.Variance() }