85 lines
2.1 KiB
Go
85 lines
2.1 KiB
Go
package metrics
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import (
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"encoding/json"
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"sync"
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)
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type GaugeInfoSnapshot interface {
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Value() GaugeInfoValue
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}
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// GaugeInfo holds a GaugeInfoValue value that can be set arbitrarily.
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type GaugeInfo interface {
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Update(GaugeInfoValue)
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Snapshot() GaugeInfoSnapshot
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}
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// GaugeInfoValue is a mapping of keys to values
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type GaugeInfoValue map[string]string
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func (val GaugeInfoValue) String() string {
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data, _ := json.Marshal(val)
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return string(data)
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}
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// GetOrRegisterGaugeInfo returns an existing GaugeInfo or constructs and registers a
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// new StandardGaugeInfo.
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func GetOrRegisterGaugeInfo(name string, r Registry) GaugeInfo {
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if nil == r {
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r = DefaultRegistry
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}
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return r.GetOrRegister(name, NewGaugeInfo()).(GaugeInfo)
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}
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// NewGaugeInfo constructs a new StandardGaugeInfo.
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func NewGaugeInfo() GaugeInfo {
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if !Enabled {
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return NilGaugeInfo{}
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}
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return &StandardGaugeInfo{
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value: GaugeInfoValue{},
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}
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}
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// NewRegisteredGaugeInfo constructs and registers a new StandardGaugeInfo.
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func NewRegisteredGaugeInfo(name string, r Registry) GaugeInfo {
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c := NewGaugeInfo()
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if nil == r {
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r = DefaultRegistry
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}
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r.Register(name, c)
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return c
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}
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// gaugeInfoSnapshot is a read-only copy of another GaugeInfo.
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type gaugeInfoSnapshot GaugeInfoValue
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// Value returns the value at the time the snapshot was taken.
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func (g gaugeInfoSnapshot) Value() GaugeInfoValue { return GaugeInfoValue(g) }
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type NilGaugeInfo struct{}
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func (NilGaugeInfo) Snapshot() GaugeInfoSnapshot { return NilGaugeInfo{} }
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func (NilGaugeInfo) Update(v GaugeInfoValue) {}
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func (NilGaugeInfo) Value() GaugeInfoValue { return GaugeInfoValue{} }
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// StandardGaugeInfo is the standard implementation of a GaugeInfo and uses
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// sync.Mutex to manage a single string value.
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type StandardGaugeInfo struct {
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mutex sync.Mutex
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value GaugeInfoValue
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}
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// Snapshot returns a read-only copy of the gauge.
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func (g *StandardGaugeInfo) Snapshot() GaugeInfoSnapshot {
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return gaugeInfoSnapshot(g.value)
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}
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// Update updates the gauge's value.
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func (g *StandardGaugeInfo) Update(v GaugeInfoValue) {
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g.mutex.Lock()
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defer g.mutex.Unlock()
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g.value = v
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}
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