TraceMetric


@ExperimentalMetricApi
abstract class TraceMetric : Metric

Known direct subclasses
MemoryCountersMetric

Captures the number of page faults over time for a target package name.

MemoryUsageMetric

Metric for tracking the memory usage of the target application.


Metric which captures results from a Perfetto trace with custom PerfettoTraceProcessor queries.

This is a more customizable version of TraceSectionMetric which can perform arbitrary queries against the captured PerfettoTrace.

Sample metric which finds the duration of the first "activityResume" trace section for the traced package:

class ActivityResumeMetric : TraceMetric() {
override fun getMeasurements(
captureInfo: CaptureInfo,
traceSession: PerfettoTraceProcessor.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()
}
}
}

Summary

Public constructors

Public functions

abstract List<Metric.Measurement>
getMeasurements(
    captureInfo: Metric.CaptureInfo,
    traceSession: PerfettoTraceProcessor.Session
)

Get the metric result for a given iteration given information about the target process and a TraceProcessor session

Public constructors

TraceMetric

Added in 1.2.0
TraceMetric()

Public functions

getMeasurements

Added in 1.3.0
abstract fun getMeasurements(
    captureInfo: Metric.CaptureInfo,
    traceSession: PerfettoTraceProcessor.Session
): List<Metric.Measurement>

Get the metric result for a given iteration given information about the target process and a TraceProcessor session