Official Go implementation of the Ethereum protocol
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go-ethereum/metrics/gauge_float64.go

124 lines
3.2 KiB

package metrics
import (
"math"
"sync/atomic"
)
// GaugeFloat64s hold a float64 value that can be set arbitrarily.
type GaugeFloat64 interface {
Snapshot() GaugeFloat64
Update(float64)
Value() float64
}
// GetOrRegisterGaugeFloat64 returns an existing GaugeFloat64 or constructs and registers a
// new StandardGaugeFloat64.
func GetOrRegisterGaugeFloat64(name string, r Registry) GaugeFloat64 {
if nil == r {
r = DefaultRegistry
}
return r.GetOrRegister(name, NewGaugeFloat64()).(GaugeFloat64)
}
// NewGaugeFloat64 constructs a new StandardGaugeFloat64.
func NewGaugeFloat64() GaugeFloat64 {
if !Enabled {
return NilGaugeFloat64{}
}
return &StandardGaugeFloat64{}
}
// NewRegisteredGaugeFloat64 constructs and registers a new StandardGaugeFloat64.
func NewRegisteredGaugeFloat64(name string, r Registry) GaugeFloat64 {
c := NewGaugeFloat64()
if nil == r {
r = DefaultRegistry
}
r.Register(name, c)
return c
}
// NewFunctionalGauge constructs a new FunctionalGauge.
func NewFunctionalGaugeFloat64(f func() float64) GaugeFloat64 {
if !Enabled {
return NilGaugeFloat64{}
}
return &FunctionalGaugeFloat64{value: f}
}
// NewRegisteredFunctionalGauge constructs and registers a new StandardGauge.
func NewRegisteredFunctionalGaugeFloat64(name string, r Registry, f func() float64) GaugeFloat64 {
c := NewFunctionalGaugeFloat64(f)
if nil == r {
r = DefaultRegistry
}
r.Register(name, c)
return c
}
// GaugeFloat64Snapshot is a read-only copy of another GaugeFloat64.
type GaugeFloat64Snapshot float64
// Snapshot returns the snapshot.
func (g GaugeFloat64Snapshot) Snapshot() GaugeFloat64 { return g }
// Update panics.
func (GaugeFloat64Snapshot) Update(float64) {
panic("Update called on a GaugeFloat64Snapshot")
}
// Value returns the value at the time the snapshot was taken.
func (g GaugeFloat64Snapshot) Value() float64 { return float64(g) }
// NilGauge is a no-op Gauge.
type NilGaugeFloat64 struct{}
// Snapshot is a no-op.
func (NilGaugeFloat64) Snapshot() GaugeFloat64 { return NilGaugeFloat64{} }
// Update is a no-op.
func (NilGaugeFloat64) Update(v float64) {}
// Value is a no-op.
func (NilGaugeFloat64) Value() float64 { return 0.0 }
// StandardGaugeFloat64 is the standard implementation of a GaugeFloat64 and uses
// atomic to manage a single float64 value.
type StandardGaugeFloat64 struct {
floatBits atomic.Uint64
}
// Snapshot returns a read-only copy of the gauge.
func (g *StandardGaugeFloat64) Snapshot() GaugeFloat64 {
return GaugeFloat64Snapshot(g.Value())
}
// Update updates the gauge's value.
func (g *StandardGaugeFloat64) Update(v float64) {
g.floatBits.Store(math.Float64bits(v))
}
// Value returns the gauge's current value.
func (g *StandardGaugeFloat64) Value() float64 {
return math.Float64frombits(g.floatBits.Load())
}
// FunctionalGaugeFloat64 returns value from given function
type FunctionalGaugeFloat64 struct {
value func() float64
}
// Value returns the gauge's current value.
func (g FunctionalGaugeFloat64) Value() float64 {
return g.value()
}
// Snapshot returns the snapshot.
func (g FunctionalGaugeFloat64) Snapshot() GaugeFloat64 { return GaugeFloat64Snapshot(g.Value()) }
// Update panics.
func (FunctionalGaugeFloat64) Update(float64) {
panic("Update called on a FunctionalGaugeFloat64")
}