145 lines
3.6 KiB
Go
145 lines
3.6 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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// GaugeInfos hold a GaugeInfoValue value that can be set arbitrarily.
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type GaugeInfo interface {
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Snapshot() GaugeInfo
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Update(GaugeInfoValue)
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Value() GaugeInfoValue
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}
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// GaugeInfoValue is a mappng of (string) keys to (string) 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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// NewFunctionalGauge constructs a new FunctionalGauge.
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func NewFunctionalGaugeInfo(f func() GaugeInfoValue) GaugeInfo {
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if !Enabled {
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return NilGaugeInfo{}
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}
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return &FunctionalGaugeInfo{value: f}
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}
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// NewRegisteredFunctionalGauge constructs and registers a new StandardGauge.
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func NewRegisteredFunctionalGaugeInfo(name string, r Registry, f func() GaugeInfoValue) GaugeInfo {
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c := NewFunctionalGaugeInfo(f)
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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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// Snapshot returns the snapshot.
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func (g GaugeInfoSnapshot) Snapshot() GaugeInfo { return g }
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// Update panics.
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func (GaugeInfoSnapshot) Update(GaugeInfoValue) {
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panic("Update called on a GaugeInfoSnapshot")
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}
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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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// NilGauge is a no-op Gauge.
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type NilGaugeInfo struct{}
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// Snapshot is a no-op.
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func (NilGaugeInfo) Snapshot() GaugeInfo { return NilGaugeInfo{} }
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// Update is a no-op.
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func (NilGaugeInfo) Update(v GaugeInfoValue) {}
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// Value is a no-op.
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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() GaugeInfo {
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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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// Value returns the gauge's current value.
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func (g *StandardGaugeInfo) Value() GaugeInfoValue {
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g.mutex.Lock()
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defer g.mutex.Unlock()
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return g.value
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}
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// FunctionalGaugeInfo returns value from given function
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type FunctionalGaugeInfo struct {
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value func() GaugeInfoValue
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}
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// Value returns the gauge's current value.
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func (g FunctionalGaugeInfo) Value() GaugeInfoValue {
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return g.value()
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}
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// Value returns the gauge's current value in JSON string format
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func (g FunctionalGaugeInfo) ValueJsonString() string {
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data, _ := json.Marshal(g.value())
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return string(data)
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}
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// Snapshot returns the snapshot.
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func (g FunctionalGaugeInfo) Snapshot() GaugeInfo { return GaugeInfoSnapshot(g.Value()) }
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// Update panics.
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func (FunctionalGaugeInfo) Update(GaugeInfoValue) {
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panic("Update called on a FunctionalGaugeInfo")
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}
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