VOL-2496 Add "event listen" command to voltctl
Change-Id: I8f1fb34b55f56c8125142ac289e2f19fc170d804
diff --git a/vendor/github.com/rcrowley/go-metrics/gauge_float64.go b/vendor/github.com/rcrowley/go-metrics/gauge_float64.go
new file mode 100644
index 0000000..3962e6d
--- /dev/null
+++ b/vendor/github.com/rcrowley/go-metrics/gauge_float64.go
@@ -0,0 +1,125 @@
+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 UseNilMetrics {
+ return NilGaugeFloat64{}
+ }
+ return &StandardGaugeFloat64{
+ value: 0.0,
+ }
+}
+
+// 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 UseNilMetrics {
+ 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
+// sync.Mutex to manage a single float64 value.
+type StandardGaugeFloat64 struct {
+ value 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) {
+ atomic.StoreUint64(&g.value, math.Float64bits(v))
+}
+
+// Value returns the gauge's current value.
+func (g *StandardGaugeFloat64) Value() float64 {
+ return math.Float64frombits(atomic.LoadUint64(&g.value))
+}
+
+// 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")
+}