perf.yml

name: Performance

# Posts a sticky comment with driver-side benchmark numbers. The base commit and the PR merge
# commit are measured on the same runner, three interleaved rounds each, so the comparison survives
# shared-runner noise. The job is informational: regressions are flagged, not failed.

on:
  pull_request:
    types: [opened, synchronize, reopened]

permissions:
  contents: read

concurrency:
  group: perf-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  benchmark:
    name: Codec & JDBC benchmark
    runs-on: ubuntu-latest
    timeout-minutes: 25
    permissions:
      contents: read
      pull-requests: write
    steps:
      - name: Check out base
        uses: actions/checkout@v7
        with:
          ref: ${{ github.event.pull_request.base.sha }}
          path: base
          persist-credentials: false

      # The default pull_request ref is the merge commit, which isolates the PR changes when the
      # base is the base branch tip. It also works for pull requests from forks.
      - name: Check out PR merge commit
        uses: actions/checkout@v7
        with:
          path: head
          persist-credentials: false

      - name: Set up Amazon Corretto 25
        uses: actions/setup-java@v6
        with:
          distribution: 'corretto'
          java-version: '25'
          cache: 'maven'

      - name: Build benchmarkable modules
        run: |
          set -euo pipefail
          if [ -d base/libsql-perf ]; then
            (cd base && ./mvnw --batch-mode --quiet -Dmaven.test.skip=true -pl libsql-perf -am package)
            echo "BASE_BENCHMARK=1" >> "$GITHUB_ENV"
          else
            echo "Base commit has no libsql-perf module yet; this run reports head numbers only."
          fi
          (cd head && ./mvnw --batch-mode --quiet -Dmaven.test.skip=true -pl libsql-perf -am package)

      - name: Run benchmark (three interleaved rounds)
        run: |
          set -euo pipefail
          mkdir -p results
          run() {
            local dir=$1 out=$2 sha=$3
            java -Xms1g -Xmx1g \
              -cp "$dir/libsql-perf/target/classes:$dir/libsql-perf/target/lib/*" \
              io.github.magnusp.libsql.perf.PerfBenchmark \
              --quiet --json "$out" --commit "$sha"
          }
          for i in 1 2 3; do
            if [ "${BASE_BENCHMARK:-0}" = "1" ]; then
              run base "results/base-$i.json" "${{ github.event.pull_request.base.sha }}"
            fi
            run head "results/head-$i.json" "${{ github.sha }}"
          done

      - name: Render comment
        run: |
          set -euo pipefail
          if [ "${BASE_BENCHMARK:-0}" = "1" ]; then
            python3 head/tools/perf/render-comment.py \
              --base results/base-1.json results/base-2.json results/base-3.json \
              --head results/head-1.json results/head-2.json results/head-3.json \
              --base-sha "${{ github.event.pull_request.base.sha }}" \
              --head-sha "${{ github.sha }}" \
              --out comment.md
          else
            python3 head/tools/perf/render-comment.py \
              --head results/head-1.json results/head-2.json results/head-3.json \
              --base-sha "${{ github.event.pull_request.base.sha }}" \
              --head-sha "${{ github.sha }}" \
              --out comment.md
          fi
          cat comment.md >> "$GITHUB_STEP_SUMMARY"

      - name: Post or update PR comment
        if: github.event.pull_request.head.repo.full_name == github.repository
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          head/tools/perf/comment.sh \
            "${{ github.repository }}" \
            "${{ github.event.pull_request.number }}" \
            comment.md

      - name: Upload benchmark results
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: perf-results
          path: results/
          if-no-files-found: warn