TraceMetric

@ExperimentalMetricApi
public abstract class TraceMetric extends Metric

class ActivityResumeMetric : TraceMetric() {
    override fun getMeasurements(
        captureInfo: CaptureInfo,
        traceSession: TraceProcessor.Session
    ): List<Measurement> {
        val rowSequence = traceSession.query(
            """
            SELECT
                slice.name as name,
                slice.ts as ts,
                slice.dur as dur
            FROM slice
                INNER JOIN thread_track on slice.track_id = thread_track.id
                INNER JOIN thread USING(utid)
                INNER JOIN process USING(upid)
            WHERE
                process.name LIKE ${captureInfo.targetPackageName}
                    AND slice.name LIKE "activityResume"
            """.trimIndent()
        )
        // this metric queries a single slice type to produce submetrics, but could be extended
        // to capture timing of every component of activity lifecycle
        val activityResultNs = rowSequence.firstOrNull()?.double("dur")
        return if (activityResultMs != null) {
            listOf(Measurement("activityResumeMs", activityResultNs / 1_000_000.0))
        } else {
            emptyList()
        }
    }
}