clientmetric

Documentation

Overview

Package clientmetric provides client-side metrics whose values get occasionally logged.

Index

• func EncodeLogTailMetricsDelta() string
• func WritePrometheusExpositionFormat(w io.Writer)
• type Metric
  • func Metrics() []*Metric
  • func NewCounter(name string) *Metric
  • func NewGauge(name string) *Metric
  • func NewUnpublished(name string, typ Type) *Metric
  • func (m *Metric) Add(n int64)
  • func (m *Metric) Name() string
  • func (m *Metric) Publish()
  • func (m *Metric) Set(v int64)
  • func (m *Metric) Type() Type
  • func (m *Metric) Value() int64
• type Type

Functions

func EncodeLogTailMetricsDelta

func EncodeLogTailMetricsDelta() string

EncodeLogTailMetricsDelta return an encoded string representing the metrics differences since the previous call.

It implements the requirements of a logtail.Config.MetricsDelta func. Notably, its output is safe to embed in a JSON string literal without further escaping.

The current encoding is:

• name immediately following metric: 'N' + hex(varint(len(name))) + name
• set value of a metric: 'S' + hex(varint(wireid)) + hex(varint(value))
• increment a metric: (decrements if negative) 'I' + hex(varint(wireid)) + hex(varint(value))

func WritePrometheusExpositionFormat

func WritePrometheusExpositionFormat(w io.Writer)

WritePrometheusExpositionFormat writes all client metrics to w in the Prometheus text-based exposition format.

See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md

Types

type Metric

type Metric struct {
	// contains filtered or unexported fields
}

Metric is an integer metric value that's tracked over time.

It's safe for concurrent use.

func Metrics

func Metrics() []*Metric

Metrics returns the sorted list of metrics.

The returned slice should not be mutated.

func NewCounter

func NewCounter(name string) *Metric

NewCounter returns a new metric that can only increment.

func NewGauge

func NewGauge(name string) *Metric

NewGauge returns a new metric that can both increment and decrement.

func NewUnpublished

func NewUnpublished(name string, typ Type) *Metric

NewUnpublished initializes a new Metric without calling Publish on it.

func (*Metric) Add

func (m *Metric) Add(n int64)

Add increments m's value by n.

If m is of type counter, n should not be negative.

func (*Metric) Name

func (m *Metric) Name() string

func (*Metric) Publish

func (m *Metric) Publish()

Publish registers a metric in the global map. It panics if the name is a duplicate anywhere in the process.

func (*Metric) Set

func (m *Metric) Set(v int64)

Set sets m's value to v.

If m is of type counter, Set should not be used.

func (*Metric) Type

func (m *Metric) Type() Type

func (*Metric) Value

func (m *Metric) Value() int64

type Type

type Type uint8

Type is a metric type: counter or gauge.

const (
	TypeGauge Type = iota
	TypeCounter
)