koma

implementation 'io.github.yukimatsumura:koma:0.2'

"koma" is an Android library that visualizes the UI rendering performance of your app. It can also output a special log if the UI rendering performance is worse than you expect.

UI rendering performance is measured using the FrameMetrics class. Therefore, this library will be automatically disabled in Android SDKs below 24.

Measuring UI rendering performance

Performance measurements are logged, along with information such as slow rendering (jank) and screen freezes.

 Frame metrics │ count │ ratio   │ max    │ min    │ sum    │ avg      │ median   │ mode
───────────────┼───────┼─────────┼────────┼────────┼────────┼──────────┼──────────┼───────────────
         Total │   7 F │ 100.0 % │ 601 ms │   2 ms │ 758 ms │ 108.3 ms │  17.0 ms │         13 ms
          Jank │   3 F │  17.0 % │  92 ms │  17 ms │ 129 ms │  43.0 ms │  20.0 ms │ 17, 20, 92 ms
        Frozen │   1 F │  79.3 % │ 601 ms │ 601 ms │ 601 ms │ 601.0 ms │ 601.0 ms │        601 ms

 Validation name │ result │ value │ threshold
─────────────────┼────────┼───────┼───────────
 test validation │     NG │   1.0 │       1.0

 Misc.                           │ value
─────────────────────────────────┼────────
                      Frame rate │ 60 fps
 Frozen frame duration threshold │ 600 ms
   Jank frame duration threshold │  16 ms

Log format can be customized.

Koma.init(
  frameMetricsListener = { id, config, aggregate, validate ->
    Log.d("koma", "$id total=${aggregate.total?.durations}")
  },
  ...
)

Here's how to start UI rendering performance measurement

val process = Koma.newProcess()
val id = FrameMetricsId.Custom("koma id")
process.start(id = id, activity = activity)
...
process.stop(id)

If you send Broadcast Intent with ADB command while the app is in front, you can measure it without adding any code.

Koma.init(
  enableCommandReceiver = true,
  ...
)

// adb shell am broadcast -a <YOUR_APP_PACKAGE_NAME>.START
// adb shell am broadcast -a <YOUR_APP_PACKAGE_NAME>.STOP

// e.g. adb shell am broadcast -a jp.yuki312.koma.app.START

You can also automatically measure the performance of all Activities and Fragments. Exclude those that do not need to be measured.

Koma.init(
  enableUiComponentMetrics = true,
  activityFrameMetricsFilter = ActivityFrameMetricsFilter { activity -> ... },
  fragmentFrameMetricsFilter = FragmentFrameMetricsFilter { false },
  ...
)

Validating UI rendering performance

Use ValidateFunction to validate the UI rendering performance. You can determine that the performance does not meet your expectations.

Koma.init(
  validateFunction = {
    val avg = it.total?.avgDuration ?: 0.0
    ValidateResult.create(
      id = it.id,
      ValidateItem(
        isPassed = avg <= THRESHOLD,
        ...
      )
    )
  },
  frameMetricsListener = { id, config, aggregate, validate ->
    if (!validate.isAllPassed()) Log.d("koma", ";(")
  },
  ...
)

By default, PercentileValidation is specified, which means that the 90th percentile of the rendering time should be within 32ms. You can change it to match the level you expect from your app.

Koma.init(
  validateFunction = PercentileValidation(85.0, 16),
  ...
)

Configuration

You can specify the configuration of the measurement with KomaConfig.

Koma.init(
  defaultConfig = KomaConfig(
    frameRate = 120, // set for 120fps devices
    analyzeMode = true, // display more detailed measurement results
    frozenFrameDurationThreshold = 600, // Specify the number of milliseconds to consider the screen frozen
  )
  ...
)