metrics: fix gauge

core/rawdb/freezer_table.go

@@ -116,7 +116,7 @@ type freezerTable struct {
 	headBytes  int64          // Number of bytes written to the head file
 	readMeter  metrics.Meter  // Meter for measuring the effective amount of data read
 	writeMeter metrics.Meter  // Meter for measuring the effective amount of data written
-	sizeGauge  metrics.Gauge // Gauge for tracking the combined size of all freezer tables
+	sizeGauge  *metrics.Gauge // Gauge for tracking the combined size of all freezer tables
 
 	logger log.Logger   // Logger with database path and table name embedded
 	lock   sync.RWMutex // Mutex protecting the data file descriptors
@@ -124,13 +124,13 @@ type freezerTable struct {
 
 // newFreezerTable opens the given path as a freezer table.
 func newFreezerTable(path, name string, disableSnappy, readonly bool) (*freezerTable, error) {
-	return newTable(path, name, metrics.NilMeter{}, metrics.NilMeter{}, metrics.NilGauge{}, freezerTableSize, disableSnappy, readonly)
+	return newTable(path, name, metrics.NilMeter{}, metrics.NilMeter{}, metrics.NewGauge(), freezerTableSize, disableSnappy, readonly)
 }
 
 // newTable opens a freezer table, creating the data and index files if they are
 // non-existent. Both files are truncated to the shortest common length to ensure
 // they don't go out of sync.
-func newTable(path string, name string, readMeter metrics.Meter, writeMeter metrics.Meter, sizeGauge metrics.Gauge, maxFilesize uint32, noCompression, readonly bool) (*freezerTable, error) {
+func newTable(path string, name string, readMeter metrics.Meter, writeMeter metrics.Meter, sizeGauge *metrics.Gauge, maxFilesize uint32, noCompression, readonly bool) (*freezerTable, error) {
 	// Ensure the containing directory exists and open the indexEntry file
 	if err := os.MkdirAll(path, 0755); err != nil {
 		return nil, err

ethdb/leveldb/leveldb.go

@@ -67,16 +67,16 @@ type Database struct {
 	compWriteMeter      metrics.Meter  // Meter for measuring the data written during compaction
 	writeDelayNMeter    metrics.Meter  // Meter for measuring the write delay number due to database compaction
 	writeDelayMeter     metrics.Meter  // Meter for measuring the write delay duration due to database compaction
-	diskSizeGauge       metrics.Gauge // Gauge for tracking the size of all the levels in the database
+	diskSizeGauge       *metrics.Gauge // Gauge for tracking the size of all the levels in the database
 	diskReadMeter       metrics.Meter  // Meter for measuring the effective amount of data read
 	diskWriteMeter      metrics.Meter  // Meter for measuring the effective amount of data written
-	memCompGauge        metrics.Gauge // Gauge for tracking the number of memory compaction
+	memCompGauge        *metrics.Gauge // Gauge for tracking the number of memory compaction
-	level0CompGauge     metrics.Gauge // Gauge for tracking the number of table compaction in level0
+	level0CompGauge     *metrics.Gauge // Gauge for tracking the number of table compaction in level0
-	nonlevel0CompGauge  metrics.Gauge // Gauge for tracking the number of table compaction in non0 level
+	nonlevel0CompGauge  *metrics.Gauge // Gauge for tracking the number of table compaction in non0 level
-	seekCompGauge       metrics.Gauge // Gauge for tracking the number of table compaction caused by read opt
+	seekCompGauge       *metrics.Gauge // Gauge for tracking the number of table compaction caused by read opt
-	manualMemAllocGauge metrics.Gauge // Gauge to track the amount of memory that has been manually allocated (not a part of runtime/GC)
+	manualMemAllocGauge *metrics.Gauge // Gauge to track the amount of memory that has been manually allocated (not a part of runtime/GC)
 
-	levelsGauge []metrics.Gauge // Gauge for tracking the number of tables in levels
+	levelsGauge []*metrics.Gauge // Gauge for tracking the number of tables in levels
 
 	quitLock sync.Mutex      // Mutex protecting the quit channel access
 	quitChan chan chan error // Quit channel to stop the metrics collection before closing the database

ethdb/pebble/pebble.go

@@ -63,16 +63,16 @@ type Database struct {
 	compWriteMeter      metrics.Meter  // Meter for measuring the data written during compaction
 	writeDelayNMeter    metrics.Meter  // Meter for measuring the write delay number due to database compaction
 	writeDelayMeter     metrics.Meter  // Meter for measuring the write delay duration due to database compaction
-	diskSizeGauge       metrics.Gauge // Gauge for tracking the size of all the levels in the database
+	diskSizeGauge       *metrics.Gauge // Gauge for tracking the size of all the levels in the database
 	diskReadMeter       metrics.Meter  // Meter for measuring the effective amount of data read
 	diskWriteMeter      metrics.Meter  // Meter for measuring the effective amount of data written
-	memCompGauge        metrics.Gauge // Gauge for tracking the number of memory compaction
+	memCompGauge        *metrics.Gauge // Gauge for tracking the number of memory compaction
-	level0CompGauge     metrics.Gauge // Gauge for tracking the number of table compaction in level0
+	level0CompGauge     *metrics.Gauge // Gauge for tracking the number of table compaction in level0
-	nonlevel0CompGauge  metrics.Gauge // Gauge for tracking the number of table compaction in non0 level
+	nonlevel0CompGauge  *metrics.Gauge // Gauge for tracking the number of table compaction in non0 level
-	seekCompGauge       metrics.Gauge // Gauge for tracking the number of table compaction caused by read opt
+	seekCompGauge       *metrics.Gauge // Gauge for tracking the number of table compaction caused by read opt
-	manualMemAllocGauge metrics.Gauge // Gauge for tracking amount of non-managed memory currently allocated
+	manualMemAllocGauge *metrics.Gauge // Gauge for tracking amount of non-managed memory currently allocated
 
-	levelsGauge []metrics.Gauge // Gauge for tracking the number of tables in levels
+	levelsGauge []*metrics.Gauge // Gauge for tracking the number of tables in levels
 
 	quitLock sync.RWMutex    // Mutex protecting the quit channel and the closed flag
 	quitChan chan chan error // Quit channel to stop the metrics collection before closing the database

metrics/debug.go

@@ -8,11 +8,11 @@ import (
 var (
 	debugMetrics struct {
 		GCStats struct {
-			LastGC Gauge
+			LastGC *Gauge
-			NumGC  Gauge
+			NumGC  *Gauge
 			Pause  Histogram
 			//PauseQuantiles Histogram
-			PauseTotal Gauge
+			PauseTotal *Gauge
 		}
 		ReadGCStats Timer
 	}

metrics/exp/exp.go

@@ -192,7 +192,7 @@ func (exp *exp) syncToExpvar() {
 			exp.publishCounter(name, i.Snapshot())
 		case *metrics.CounterFloat64:
 			exp.publishCounterFloat64(name, i.Snapshot())
-		case metrics.Gauge:
+		case *metrics.Gauge:
 			exp.publishGauge(name, i.Snapshot())
 		case metrics.GaugeFloat64:
 			exp.publishGaugeFloat64(name, i.Snapshot())

metrics/gauge.go

@@ -2,97 +2,69 @@ package metrics
 
 import "sync/atomic"
 
-// GaugeSnapshot contains a readonly int64.
+// GaugeSnapshot is a read-only copy of a Gauge.
-type GaugeSnapshot interface {
+type GaugeSnapshot int64
-	Value() int64
-}
 
-// Gauge holds an int64 value that can be set arbitrarily.
+// Value returns the value at the time the snapshot was taken.
-type Gauge interface {
+func (g GaugeSnapshot) Value() int64 { return int64(g) }
-	Snapshot() GaugeSnapshot
-	Update(int64)
-	UpdateIfGt(int64)
-	Dec(int64)
-	Inc(int64)
-}
 
 // GetOrRegisterGauge returns an existing Gauge or constructs and registers a
-// new StandardGauge.
+// new Gauge.
-func GetOrRegisterGauge(name string, r Registry) Gauge {
+func GetOrRegisterGauge(name string, r Registry) *Gauge {
-	if nil == r {
+	if r == nil {
 		r = DefaultRegistry
 	}
-	return r.GetOrRegister(name, NewGauge).(Gauge)
+	return r.GetOrRegister(name, NewGauge).(*Gauge)
 }
 
-// NewGauge constructs a new StandardGauge.
+// NewGauge constructs a new Gauge.
-func NewGauge() Gauge {
+func NewGauge() *Gauge {
-	if !Enabled {
+	return &Gauge{}
-		return NilGauge{}
-	}
-	return &StandardGauge{}
 }
 
-// NewRegisteredGauge constructs and registers a new StandardGauge.
+// NewRegisteredGauge constructs and registers a new Gauge.
-func NewRegisteredGauge(name string, r Registry) Gauge {
+func NewRegisteredGauge(name string, r Registry) *Gauge {
 	c := NewGauge()
-	if nil == r {
+	if r == nil {
 		r = DefaultRegistry
 	}
 	r.Register(name, c)
 	return c
 }
 
-// gaugeSnapshot is a read-only copy of another Gauge.
+// Gauge and uses the sync/atomic package to manage a single int64 value.
-type gaugeSnapshot int64
+type Gauge atomic.Int64
-
-// Value returns the value at the time the snapshot was taken.
-func (g gaugeSnapshot) Value() int64 { return int64(g) }
-
-// NilGauge is a no-op Gauge.
-type NilGauge struct{}
-
-func (NilGauge) Snapshot() GaugeSnapshot { return (*emptySnapshot)(nil) }
-func (NilGauge) Update(v int64)          {}
-func (NilGauge) UpdateIfGt(v int64)      {}
-func (NilGauge) Dec(i int64)             {}
-func (NilGauge) Inc(i int64)             {}
-
-// StandardGauge is the standard implementation of a Gauge and uses the
-// sync/atomic package to manage a single int64 value.
-type StandardGauge struct {
-	value atomic.Int64
-}
 
 // Snapshot returns a read-only copy of the gauge.
-func (g *StandardGauge) Snapshot() GaugeSnapshot {
+func (g *Gauge) Snapshot() GaugeSnapshot {
-	return gaugeSnapshot(g.value.Load())
+	return GaugeSnapshot((*atomic.Int64)(g).Load())
 }
 
 // Update updates the gauge's value.
-func (g *StandardGauge) Update(v int64) {
+func (g *Gauge) Update(v int64) {
-	g.value.Store(v)
+	(*atomic.Int64)(g).Store(v)
 }
 
 // UpdateIfGt updates the gauge's value if v is larger then the current value.
-func (g *StandardGauge) UpdateIfGt(v int64) {
+func (g *Gauge) UpdateIfGt(v int64) {
+	value := (*atomic.Int64)(g)
 	for {
-		exist := g.value.Load()
+		exist := value.Load()
 		if exist >= v {
 			break
 		}
-		if g.value.CompareAndSwap(exist, v) {
+		if value.CompareAndSwap(exist, v) {
 			break
 		}
 	}
 }
 
 // Dec decrements the gauge's current value by the given amount.
-func (g *StandardGauge) Dec(i int64) {
+func (g *Gauge) Dec(i int64) {
-	g.value.Add(-i)
+	(*atomic.Int64)(g).Add(-i)
 }
 
 // Inc increments the gauge's current value by the given amount.
-func (g *StandardGauge) Inc(i int64) {
+func (g *Gauge) Inc(i int64) {
-	g.value.Add(i)
+	(*atomic.Int64)(g).Add(i)
 }

metrics/graphite.go

@@ -69,7 +69,7 @@ func graphite(c *GraphiteConfig) error {
 			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, metric.Snapshot().Count(), now)
 		case *CounterFloat64:
 			fmt.Fprintf(w, "%s.%s.count %f %d\n", c.Prefix, name, metric.Snapshot().Count(), now)
-		case Gauge:
+		case *Gauge:
 			fmt.Fprintf(w, "%s.%s.value %d %d\n", c.Prefix, name, metric.Snapshot().Value(), now)
 		case GaugeFloat64:
 			fmt.Fprintf(w, "%s.%s.value %f %d\n", c.Prefix, name, metric.Snapshot().Value(), now)

metrics/inactive.go

@@ -20,7 +20,6 @@ package metrics
 var (
 	_ SampleSnapshot    = (*emptySnapshot)(nil)
 	_ HistogramSnapshot = (*emptySnapshot)(nil)
-	_ GaugeSnapshot     = (*emptySnapshot)(nil)
 	_ MeterSnapshot     = (*emptySnapshot)(nil)
 	_ TimerSnapshot     = (*emptySnapshot)(nil)
 )

metrics/influxdb/influxdb.go

@@ -20,7 +20,7 @@ func readMeter(namespace, name string, i interface{}) (string, map[string]interf
 			"value": metric.Snapshot().Count(),
 		}
 		return measurement, fields
-	case metrics.Gauge:
+	case *metrics.Gauge:
 		measurement := fmt.Sprintf("%s%s.gauge", namespace, name)
 		fields := map[string]interface{}{
 			"value": metric.Snapshot().Value(),

metrics/log.go

@@ -27,7 +27,7 @@ func LogScaled(r Registry, freq time.Duration, scale time.Duration, l Logger) {
 			case *CounterFloat64:
 				l.Printf("counter %s\n", name)
 				l.Printf("  count:       %f\n", metric.Snapshot().Count())
-			case Gauge:
+			case *Gauge:
 				l.Printf("gauge %s\n", name)
 				l.Printf("  value:       %9d\n", metric.Snapshot().Value())
 			case GaugeFloat64:

metrics/opentsdb.go

@@ -68,7 +68,7 @@ func (c *OpenTSDBConfig) writeRegistry(w io.Writer, now int64, shortHostname str
 			fmt.Fprintf(w, "put %s.%s.count %d %d host=%s\n", c.Prefix, name, now, metric.Snapshot().Count(), shortHostname)
 		case *CounterFloat64:
 			fmt.Fprintf(w, "put %s.%s.count %d %f host=%s\n", c.Prefix, name, now, metric.Snapshot().Count(), shortHostname)
-		case Gauge:
+		case *Gauge:
 			fmt.Fprintf(w, "put %s.%s.value %d %d host=%s\n", c.Prefix, name, now, metric.Snapshot().Value(), shortHostname)
 		case GaugeFloat64:
 			fmt.Fprintf(w, "put %s.%s.value %d %f host=%s\n", c.Prefix, name, now, metric.Snapshot().Value(), shortHostname)

metrics/prometheus/collector.go

@@ -55,7 +55,7 @@ func (c *collector) Add(name string, i any) error {
 		c.addCounter(name, m.Snapshot())
 	case *metrics.CounterFloat64:
 		c.addCounterFloat64(name, m.Snapshot())
-	case metrics.Gauge:
+	case *metrics.Gauge:
 		c.addGauge(name, m.Snapshot())
 	case metrics.GaugeFloat64:
 		c.addGaugeFloat64(name, m.Snapshot())

metrics/registry.go

@@ -153,7 +153,7 @@ func (r *StandardRegistry) GetAll() map[string]map[string]interface{} {
 			values["count"] = metric.Snapshot().Count()
 		case *CounterFloat64:
 			values["count"] = metric.Snapshot().Count()
-		case Gauge:
+		case *Gauge:
 			values["value"] = metric.Snapshot().Value()
 		case GaugeFloat64:
 			values["value"] = metric.Snapshot().Value()
@@ -214,7 +214,7 @@ func (r *StandardRegistry) Unregister(name string) {
 
 func (r *StandardRegistry) loadOrRegister(name string, i interface{}) (interface{}, bool, bool) {
 	switch i.(type) {
-	case *Counter, *CounterFloat64, Gauge, GaugeFloat64, GaugeInfo, Healthcheck, Histogram, Meter, Timer, ResettingTimer:
+	case *Counter, *CounterFloat64, *Gauge, GaugeFloat64, GaugeInfo, Healthcheck, Histogram, Meter, Timer, ResettingTimer:
 	default:
 		return nil, false, false
 	}

metrics/syslog.go

@@ -19,7 +19,7 @@ func Syslog(r Registry, d time.Duration, w *syslog.Writer) {
 				w.Info(fmt.Sprintf("counter %s: count: %d", name, metric.Snapshot().Count()))
 			case *CounterFloat64:
 				w.Info(fmt.Sprintf("counter %s: count: %f", name, metric.Snapshot().Count()))
-			case Gauge:
+			case *Gauge:
 				w.Info(fmt.Sprintf("gauge %s: value: %d", name, metric.Snapshot().Value()))
 			case GaugeFloat64:
 				w.Info(fmt.Sprintf("gauge %s: value: %f", name, metric.Snapshot().Value()))

metrics/writer.go

@@ -32,7 +32,7 @@ func WriteOnce(r Registry, w io.Writer) {
 		case *CounterFloat64:
 			fmt.Fprintf(w, "counter %s\n", namedMetric.name)
 			fmt.Fprintf(w, "  count:       %f\n", metric.Snapshot().Count())
-		case Gauge:
+		case *Gauge:
 			fmt.Fprintf(w, "gauge %s\n", namedMetric.name)
 			fmt.Fprintf(w, "  value:       %9d\n", metric.Snapshot().Value())
 		case GaugeFloat64:

p2p/metrics.go

@@ -37,9 +37,9 @@ const (
 )
 
 var (
-	activePeerGauge         metrics.Gauge = metrics.NilGauge{}
+	activePeerGauge         = metrics.NewGauge()
-	activeInboundPeerGauge  metrics.Gauge = metrics.NilGauge{}
+	activeInboundPeerGauge  = metrics.NewGauge()
-	activeOutboundPeerGauge metrics.Gauge = metrics.NilGauge{}
+	activeOutboundPeerGauge = metrics.NewGauge()
 
 	ingressTrafficMeter = metrics.NewRegisteredMeter("p2p/ingress", nil)
 	egressTrafficMeter  = metrics.NewRegisteredMeter("p2p/egress", nil)