Quantity

Used to record a single non-negative integer value or 0. For example, the width of the display in pixels.

IMPORTANT If you need to count something (e.g. number of tabs open or number of times a button is pressed) prefer using the Counter metric type, which has a specific API for counting things and also takes care of resetting the count at the correct time.

Configuration

Say you're adding a new quantity for the width of the display in pixels. First you need to add an entry for the quantity to the metrics.yaml file:

display:
  width:
    type: quantity
    description: >
      The width of the display, in pixels.
    unit: pixels
    ...

Note that quantities have a required unit parameter, which is a free-form string for documentation purposes.

API

import org.mozilla.yourApplication.GleanMetrics.Display

Display.width.set(width)

There are test APIs available too:

import org.mozilla.yourApplication.GleanMetrics.Display

// Was anything recorded?
assertTrue(Display.width.testHasValue())
// Does the quantity have the expected value?
assertEquals(6, Display.width.testGetValue())
// Did it record an error due to a negative value?
assertEquals(1, Display.width.testGetNumRecordedErrors(ErrorType.InvalidValue))

import org.mozilla.yourApplication.GleanMetrics.Display;

Display.INSTANCE.width.set(width);

There are test APIs available too:

import org.mozilla.yourApplication.GleanMetrics.Display;

// Was anything recorded?
assertTrue(Display.INSTANCE.width.testHasValue());
// Does the quantity have the expected value?
assertEquals(6, Display.INSTANCE.width.testGetValue());
// Did the quantity record a negative value?
assertEquals(
    1, Display.INSTANCE.width.testGetNumRecordedErrors(ErrorType.InvalidValue)
);

Display.width.set(width)

There are test APIs available too:

@testable import Glean

// Was anything recorded?
XCTAssert(Display.width.testHasValue())
// Does the quantity have the expected value?
XCTAssertEqual(6, try Display.width.testGetValue())
// Did the quantity record a negative value?
XCTAssertEqual(1, Display.width.testGetNumRecordedErrors(.invalidValue))

from glean import load_metrics
metrics = load_metrics("metrics.yaml")

metrics.display.width.set(width)

There are test APIs available too:

# Was anything recorded?
assert metrics.display.width.test_has_value()
# Does the quantity have the expected value?
assert 6 == metrics.display.width.test_get_value()
# Did the quantity record an negative value?
from glean.testing import ErrorType
assert 1 == metrics.display.width.test_get_num_recorded_errors(
    ErrorType.INVALID_VALUE
)

using static Mozilla.YourApplication.GleanMetrics.Display;

Display.width.Set(width);

There are test APIs available too:

using static Mozilla.YourApplication.GleanMetrics.Display;

// Was anything recorded?
Assert.True(Display.width.TestHasValue());
// Does the counter have the expected value?
Assert.Equal(6, Display.width.TestGetValue());
// Did the counter record an negative value?
Assert.Equal(
    1, Display.width.TestGetNumRecordedErrors(ErrorType.InvalidValue)
);

Limits

Examples

Recorded errors

Reference