88 lines
1.8 KiB
Go
88 lines
1.8 KiB
Go
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// Copyright (c) 2012, Matt T. Proud
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// All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// gauge.go provides a scalar metric that one can monitor. It is useful for
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// certain cases, such as instantaneous temperature.
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package metrics
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import (
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"fmt"
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"sync"
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)
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// A gauge metric merely provides an instantaneous representation of a scalar
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// value or an accumulation. For instance, if one wants to expose the current
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// temperature or the hitherto bandwidth used, this would be the metric for such
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// circumstances.
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type GaugeMetric struct {
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value float64
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mutex sync.RWMutex
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}
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func (metric *GaugeMetric) Humanize() string {
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formatString := "[GaugeMetric; value=%f]"
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metric.mutex.RLock()
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defer metric.mutex.RUnlock()
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return fmt.Sprintf(formatString, metric.value)
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}
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func (metric *GaugeMetric) Set(value float64) float64 {
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metric.mutex.Lock()
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defer metric.mutex.Unlock()
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metric.value = value
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return metric.value
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}
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func (metric *GaugeMetric) IncrementBy(value float64) float64 {
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metric.mutex.Lock()
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defer metric.mutex.Unlock()
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metric.value += value
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return metric.value
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}
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func (metric *GaugeMetric) Increment() float64 {
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return metric.IncrementBy(1)
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}
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func (metric *GaugeMetric) DecrementBy(value float64) float64 {
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metric.mutex.Lock()
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defer metric.mutex.Unlock()
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metric.value -= value
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return metric.value
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}
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func (metric *GaugeMetric) Decrement() float64 {
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return metric.DecrementBy(1)
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}
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func (metric *GaugeMetric) Get() float64 {
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metric.mutex.RLock()
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defer metric.mutex.RUnlock()
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return metric.value
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}
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func (metric *GaugeMetric) Marshallable() map[string]interface{} {
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metric.mutex.RLock()
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defer metric.mutex.RUnlock()
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v := make(map[string]interface{}, 2)
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v["value"] = metric.value
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v["type"] = "gauge"
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return v
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}
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