name: benchmark

# The macrobenchmark run, on an emulator rather than on a phone.
#
# Three reasons this exists as a workflow and not as a local step:
#
# * **It reports the jank metric.** `frameDurationCpuMs` and `frameOverrunMs` need frame timelines, which
#   this project's phone sometimes supplies and sometimes does not — the run that does is the one worth
#   looking at, and a CI emulator supplies it every time.
# * **It takes the phone out of the loop.** No MIUI install prompts, no AVD to keep alive, no cable.
# * **It is a second opinion.** The numbers in docs/PERFORMANCE.md come from one handset; an emulator run
#   is a different device and build, so a regression that is the app's shows up in both.
#
# It is not on every pull request: one run is the four benchmarks × five iterations, which is minutes of
# measurement and considerably more of waiting for an emulator to boot.
on:
  workflow_dispatch:
  schedule:
    # Monday, early: the week starts with a number, not with a guess.
    - cron: '41 4 * * 1'

concurrency:
  group: benchmark
  cancel-in-progress: false

jobs:
  emulator:
    runs-on: ubuntu-latest
    timeout-minutes: 75
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          distribution: temurin
          # detekt 1.23 cannot parse JDK 25's version string, and the gate runs on 21 — keep them equal
          # so a benchmark run cannot fail for a reason unrelated to the benchmark.
          java-version: '21'
      - uses: android-actions/setup-android@v3
      - uses: gradle/actions/setup-gradle@v4

      # Built before the emulator starts: Gradle is quick on the runner, emulator boot is not, and the
      # two would otherwise queue behind each other.
      - name: Build the APKs
        run: ./gradlew :app:assembleBenchmark :benchmark:assembleBenchmark --console=plain

      - name: Measure on an emulator
        uses: reactivecircus/android-emulator-runner@v2
        with:
          api-level: 35
          # google_apis, not google_apis_playstore: the benchmark toggles the app's all-files access in
          # Settings, and a Play image has no such page for a sideloaded app.
          target: google_apis
          arch: x86_64
          profile: pixel_6
          disable-animations: true
          emulator-boot-timeout: 1200
          # SwiftShader because the runner has no GPU: software rendering makes the milliseconds
          # incomparable with a phone's, which is stated where the numbers are read. What survives is the
          # shape — which benchmark is slow relative to the others — and the existence of the metric.
          emulator-options: >-
            -no-snapshot -no-window -gpu swiftshader_indirect -noaudio -no-boot-anim
            -camera-back none -camera-front none
          script: |
            set -o pipefail
            # The fixture is built through adb because UiAutomation's shell runs as the app, not the shell
            # user, and cannot write to /sdcard (see tools/benchmark-fixture.sh).
            ./tools/benchmark-fixture.sh
            adb install -r app/build/outputs/apk/benchmark/app-benchmark.apk
            adb install -r benchmark/build/outputs/apk/benchmark/benchmark-benchmark.apk
            # The "never run" baseline: no profile, so what is measured has not been compiled by use.
            # Clearing profile data is a system operation, so it needs adbd as root — which a google_apis
            # image allows and a user build (the phone) does not, where this silently stays best-effort.
            adb root || true
            adb wait-for-device
            adb shell cmd package compile --reset de.softwareapp_hb.filemanager || true
            # Instrumented directly rather than through connectedBenchmarkAndroidTest, because that task
            # installs the app itself — which would undo the compile reset above. `CompilationMode.Ignore()`
            # in the test means nothing else installs either.
            adb shell am instrument -w -r \
              -e class de.softwareapp_hb.filemanager.benchmark.BrowserBenchmark \
              de.softwareapp_hb.filemanager.benchmark/androidx.test.runner.AndroidJUnitRunner \
              | tee instrument.log
            status=${PIPESTATUS[0]}
            mkdir -p benchmark-results
            adb pull /sdcard/Android/media/de.softwareapp_hb.filemanager.benchmark benchmark-results/ || true
            # The jank metric is the reason this job exists, so its absence fails the run rather than
            # becoming a footnote in a log nobody opens.
            python3 tools/benchmark-report.py --require-frame-duration benchmark-results > summary.md || status=1
            cat summary.md
            exit $status

      - name: Keep the numbers
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: benchmark-results
          path: |
            benchmark-results
            instrument.log
            summary.md
          if-no-files-found: warn

      - name: Put the table on the run page
        if: always()
        run: |
          if [ -f summary.md ]; then
            cat summary.md >> "$GITHUB_STEP_SUMMARY"
          else
            echo "No summary: the benchmark did not get far enough to write one. See instrument.log." \
              >> "$GITHUB_STEP_SUMMARY"
          fi