caddy-log-exporter/vendor/github.com/VictoriaMetrics/metrics/floatcounter.go

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2024-09-19 11:21:05 +02:00
package metrics
import (
"fmt"
"io"
"sync"
)
// NewFloatCounter registers and returns new counter of float64 type with the given name.
//
// name must be valid Prometheus-compatible metric with possible labels.
// For instance,
//
// - foo
// - foo{bar="baz"}
// - foo{bar="baz",aaa="b"}
//
// The returned counter is safe to use from concurrent goroutines.
func NewFloatCounter(name string) *FloatCounter {
return defaultSet.NewFloatCounter(name)
}
// FloatCounter is a float64 counter guarded by RWmutex.
//
// It may be used as a gauge if Add and Sub are called.
type FloatCounter struct {
mu sync.Mutex
n float64
}
// Add adds n to fc.
func (fc *FloatCounter) Add(n float64) {
fc.mu.Lock()
fc.n += n
fc.mu.Unlock()
}
// Sub substracts n from fc.
func (fc *FloatCounter) Sub(n float64) {
fc.mu.Lock()
fc.n -= n
fc.mu.Unlock()
}
// Get returns the current value for fc.
func (fc *FloatCounter) Get() float64 {
fc.mu.Lock()
n := fc.n
fc.mu.Unlock()
return n
}
// Set sets fc value to n.
func (fc *FloatCounter) Set(n float64) {
fc.mu.Lock()
fc.n = n
fc.mu.Unlock()
}
// marshalTo marshals fc with the given prefix to w.
func (fc *FloatCounter) marshalTo(prefix string, w io.Writer) {
v := fc.Get()
fmt.Fprintf(w, "%s %g\n", prefix, v)
}
func (fc *FloatCounter) metricType() string {
return "counter"
}
// GetOrCreateFloatCounter returns registered FloatCounter with the given name
// or creates new FloatCounter if the registry doesn't contain FloatCounter with
// the given name.
//
// name must be valid Prometheus-compatible metric with possible labels.
// For instance,
//
// - foo
// - foo{bar="baz"}
// - foo{bar="baz",aaa="b"}
//
// The returned FloatCounter is safe to use from concurrent goroutines.
//
// Performance tip: prefer NewFloatCounter instead of GetOrCreateFloatCounter.
func GetOrCreateFloatCounter(name string) *FloatCounter {
return defaultSet.GetOrCreateFloatCounter(name)
}