benchmark.yml

name: Benchmark
on:
  workflow_dispatch:  # Manual triggering with options
    inputs:
      force-run:
        description: 'Force benchmarks to run'
        required: true
        type: boolean
        default: false
  push:
    branches: [ "master" ]
    paths:
      - 'src/**/*.rs'
      # Only run on changes that could affect performance
      - '!src/tests/**'
      - 'benches/**/*.rs'
      # Only consider direct dependency changes
      - 'Cargo.toml'
      - '.github/workflows/benchmark.yml'
  pull_request:
    types: [opened, synchronize, reopened]
    branches: [ "master" ]
    paths:
      - 'src/**/*.rs'
      - '!src/tests/**'
      - 'benches/**/*.rs'
      - 'Cargo.toml'
      - '.github/workflows/benchmark.yml'

# Add concurrency to cancel outdated runs
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read
  # Add required permissions for commenting on PRs if we want to post results
  pull-requests: write

env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: "-D warnings"

jobs:
  check-changes:
    runs-on: ubuntu-latest
    outputs:
      should-run: ${{ steps.check.outputs.should-run }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Needed for git diff

      # Get default branch name
      - name: Get default branch name
        id: default-branch
        run: |
          DEFAULT_BRANCH=$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)
          echo "name=$DEFAULT_BRANCH" >> $GITHUB_OUTPUT

      - name: Fetch all branches
        run: |
          git fetch --all
          git branch -a

      - id: check
        name: Check if benchmarks are needed
        run: |
          DEFAULT_BRANCH="${{ steps.default-branch.outputs.name }}"
          echo "Default branch is: $DEFAULT_BRANCH"
          echo "Current ref is: ${{ github.ref }}"
          echo "Event type is: ${{ github.event_name }}"

          # Manual trigger check
          if [[ "${{ github.event_name }}" == "workflow_dispatch" && "${{ inputs.force-run }}" == "true" ]]; then
            echo "Manual run requested with force-run=true"
            echo "should-run=true" >> $GITHUB_OUTPUT
            exit 0
          fi

          # Get list of changed files
          if [[ "${{ github.ref }}" == "refs/heads/$DEFAULT_BRANCH" ]]; then
            echo "On default branch, comparing with previous commit"
            if git rev-parse HEAD^ >/dev/null 2>&1; then
              git diff --name-only HEAD^ HEAD > changes.txt
            else
              git ls-files > changes.txt
            fi
          elif [[ "${{ github.event_name }}" == "pull_request" ]]; then
            echo "On PR, comparing with default branch"
            git diff --name-only origin/$DEFAULT_BRANCH... > changes.txt
          else
            echo "On feature branch, comparing with default branch"
            git diff --name-only origin/$DEFAULT_BRANCH... > changes.txt
          fi

          echo "Changed files:"
          cat changes.txt

          # Check for performance-critical changes
          if grep -q "src/lib.rs\|src/parser.rs\|src/packet.rs" changes.txt; then
            echo "Core functionality changed"
            echo "should-run=true" >> $GITHUB_OUTPUT
          elif grep -q "^benches/" changes.txt; then
            echo "Benchmark code changed"
            echo "should-run=true" >> $GITHUB_OUTPUT
          elif grep -q "Cargo.toml" changes.txt && grep -q "^\[dependencies\]" Cargo.toml; then
            echo "Dependencies changed"
            echo "should-run=true" >> $GITHUB_OUTPUT
          else
            echo "No performance-critical changes"
            echo "should-run=false" >> $GITHUB_OUTPUT
          fi

  benchmark:
    needs: check-changes
    if: needs.check-changes.outputs.should-run == 'true'
    name: Run benchmarks
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install stable toolchain
        uses: dtolnay/rust-toolchain@stable

      - name: Cache cargo
        uses: Swatinem/rust-cache@v2

      # Only run full benchmarks on master or if explicitly requested
      - name: Run quick benchmarks
        if: github.ref != 'refs/heads/master' && github.event_name != 'workflow_dispatch'
        run: |
          # Run with fewer samples for PR checks
          cargo bench --workspace -- --warm-up-time 1 --measurement-time 2 --sample-size 10
          cargo bench --workspace --features="async" -- --warm-up-time 1 --measurement-time 2 --sample-size 10

      - name: Run full benchmarks
        if: github.ref == 'refs/heads/master' || github.event_name == 'workflow_dispatch'
        run: |
          cargo bench --workspace
          cargo bench --workspace --features="async"

      - name: Store benchmark result
        uses: actions/upload-artifact@v4
        with:
          name: benchmark-results
          path: target/criterion/**/*.json
          retention-days: 30