metrics

Documentation

Overview

Package metrics defines a concurrently-accessible metrics collector.

A *metrics.M value exports methods to track integer counters and maximum values. A metric has a caller-assigned string name that is not interpreted by the collector except to locate its stored value.

Index

• type M
  • func New() *M
  • func (m *M) Count(name string, n int64)
  • func (m *M) CountAndSetMax(name string, n int64)
  • func (m *M) SetLabel(name, value string)
  • func (m *M) SetMaxValue(name string, n int64)
  • func (m *M) Snapshot(snap Snapshot)
• type Snapshot

Types

type M

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

An M collects counters and maximum value trackers. A nil *M is valid, and discards all metrics. The methods of an *M are safe for concurrent use by multiple goroutines.

func New

func New() *M

New creates a new, empty metrics collector.

func (*M) Count

func (m *M) Count(name string, n int64)

Count adds n to the current value of the counter named, defining the counter if it does not already exist.

func (*M) CountAndSetMax

func (m *M) CountAndSetMax(name string, n int64)

CountAndSetMax adds n to the current value of the counter named, and also updates a max value tracker with the same name in a single step.

func (*M) SetLabel

func (m *M) SetLabel(name, value string)

SetLabel sets the specified label to value. If value == "" the label is removed from the set.

func (*M) SetMaxValue

func (m *M) SetMaxValue(name string, n int64)

SetMaxValue sets the maximum value metric named to the greater of n and its current value, defining the value if it does not already exist.

func (*M) Snapshot

func (m *M) Snapshot(snap Snapshot)

Snapshot copies an atomic snapshot of the collected metrics into the non-nil fields of the provided snapshot value. Only the fields of snap that are not nil are snapshotted.

type Snapshot

type Snapshot struct {
	Counter  map[string]int64
	MaxValue map[string]int64
	Label    map[string]string
}

A Snapshot represents a point-in-time snapshot of a metrics collector. The fields of this type are filled in by the Snapshot method of *M.