micro-benchmark.yml

name: Micro-Benchmark

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

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

permissions:
  issues: write
  pull-requests: write

jobs:
  benchmark:
    strategy:
      matrix:
        os: [ubuntu-latest] # `macos-latest` is too unstable to be useful for benchmark, the variance is always huge.
    name: Run benchmark on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    steps:
      - name: Checkout Main Branch
        uses: actions/checkout@v4
        with:
          ref: main # Checkout main first because the cache is warm

      - name: Install Rust Toolchain
        uses: ./.github/actions/rustup
        with:
          shared-key: micro-benchmark

      - name: Compile
        run: cargo build --release --bin=micro-benchmark

      - name: Sleep for CPU cooldown
        shell: bash
        run: sleep 15s

      - name: Run Bench on Main Branch
        run: cargo run --bin=micro-benchmark --release -- --save-baseline main

      - name: Checkout PR Branch
        uses: actions/checkout@v4
        with:
          clean: false
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Compile
        run: cargo build --release --bin=micro-benchmark

      - name: Sleep for CPU cooldown
        shell: bash
        run: sleep 15s

      - name: Run Bench on PR Branch
        run: cargo run --bin=micro-benchmark --release -- --save-baseline pr

      - name: Upload benchmark results
        uses: actions/upload-artifact@v3
        with:
          name: benchmark-results-${{ matrix.os }}
          path: ./target/criterion

  benchmark-compare:
    runs-on: ubuntu-latest
    name: Compare Benchmarks
    needs:
      - benchmark

    steps:
      - name: Install critcmp
        uses: taiki-e/install-action@v2
        with:
          tool: critcmp

      - name: Linux | Download PR benchmark results
        uses: actions/download-artifact@v4
        with:
          name: benchmark-results-ubuntu-latest
          path: ./target/criterion

      - name: Linux | Compare benchmark results
        shell: bash
        run: |
          echo "## Micro-Benchmark Results" >> summary.md
          echo "### Linux" >> summary.md
          echo "\`\`\`" >> summary.md
          critcmp main pr >> summary.md
          echo "\`\`\`" >> summary.md
          echo "" >> summary.md

      - name: Linux | Cleanup benchmark results
        run: rm -rf ./target/criterion

      - name: Find Comment
        # Check if the event is not triggered by a fork
        if: github.event.pull_request.head.repo.full_name == github.repository
        uses: peter-evans/find-comment@v2
        id: fc
        with:
          issue-number: ${{ github.event.pull_request.number }}
          comment-author: 'github-actions[bot]'
          body-includes: Micro-Benchmark Results

      - name: Create or update comment
        # Check if the event is not triggered by a fork
        if: github.event.pull_request.head.repo.full_name == github.repository
        uses: peter-evans/create-or-update-comment@v3
        with:
          issue-number: ${{ github.event.pull_request.number }}
          edit-mode: replace
          comment-id: ${{ steps.fc.outputs.comment-id }}
          body-file: summary.md