glean/docs/user/metrics/counter.md

Counter

Used to count how often something happens, say how often a certain button was pressed. A counter always starts from 0. Each time you record to a counter, its value is incremented.

Configuration

Say you're adding a new counter for how often the refresh button is pressed. First you need to add an entry for the counter to the metrics.yaml file:

controls:
  refresh_pressed:
    type: counter
    description: >
      Counts how often the refresh button is pressed.      
    ...

API

import org.mozilla.yourApplication.GleanMetrics.Controls

Controls.refreshPressed.add() // Adds 1 to the counter.
Controls.refreshPressed.add(5) // Adds 5 to the counter.

There are test APIs available too:

import org.mozilla.yourApplication.GleanMetrics.Controls

// Was anything recorded?
assertTrue(Controls.refreshPressed.testHasValue())
// Does the counter have the expected value?
assertEquals(6, Controls.refreshPressed.testGetValue())

Limits

• Only increments, saturates at the limits of a 32-bit signed integer.

Examples

• How often a certain button was pressed?

Recorded errors

• None.

Reference

• Kotlin API docs