diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/rcrowley/go-metrics/gauge_float64.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/rcrowley/go-metrics/gauge_float64.go | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/rcrowley/go-metrics/gauge_float64.go b/Godeps/_workspace/src/github.com/rcrowley/go-metrics/gauge_float64.go new file mode 100644 index 000000000..47c3566c2 --- /dev/null +++ b/Godeps/_workspace/src/github.com/rcrowley/go-metrics/gauge_float64.go @@ -0,0 +1,91 @@ +package metrics + +import "sync" + +// 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 +} + +// 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 { + mutex sync.Mutex + value float64 +} + +// 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.mutex.Lock() + defer g.mutex.Unlock() + g.value = v +} + +// Value returns the gauge's current value. +func (g *StandardGaugeFloat64) Value() float64 { + g.mutex.Lock() + defer g.mutex.Unlock() + return g.value +} |