ci.yml

# There are two kinds of continuous integration jobs in this project:
#
# - Every code submission or master push passes continuous integration on the
#   minimal supported Rust version and the current stable Rust version.
# - Two times a month, a scheduled job makes sure that the code remains
#   compatible and lint-free on upcoming Rust toolchains (beta and nightly).

name: Continuous Integration

on:
  push:
  pull_request:
  schedule:
    - cron: '0 0 3/15 * *'

# Cancel existing jobs on new pushes to the same branch
concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

env:
  RUSTFLAGS: -D warnings
  RUSTDOCFLAGS: -D warnings
  MINIMAL_RUST: 1.70.0  # Minimal Supported Rust Version
  MDBOOK_VERSION: 0.4.40

jobs:
  # Workaround for github CI dropping env var expansion in matrix strategy
  matrix_vars:
    runs-on: ubuntu-latest
    outputs:
      MINIMAL_RUST: ${{ env.MINIMAL_RUST }}
    steps:
      - name: Forward env var to output
        run: echo "MINIMAL_RUST=${{ env.MINIMAL_RUST }}" >> $GITHUB_OUTPUT


  # Render the book
  render-book:
    # Don't run CI twice when a PR is created from a branch internal to the repo
    # Don't run on a schedule, book doesn't change on its own.
    if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository

    runs-on: ubuntu-latest

    steps:
      - name: Checkout sources
        uses: actions/checkout@v4

      - name: Install mdbook
        run: |
          mkdir bin
          curl -sSL https://github.com/rust-lang/mdBook/releases/download/v${MDBOOK_VERSION}/mdbook-v${MDBOOK_VERSION}-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=bin
          echo "$(pwd)/bin" >> ${GITHUB_PATH}

      - name: Render the book
        run: mkdir public && mdbook build -d public

      - name: Upload the book
        uses: actions/upload-artifact@v3
        with:
          name: book
          path: ./public
          if-no-files-found: error

  # Format doesn't depend on configuration. Lints don't depend target flags, and
  # don't depend on the OS as there's no OS-specific code path in this crate.
  #
  # We don't care about warnings on the minimum supported Rust version, only
  # about building and running correctly.
  format-lints:
    # Don't run CI twice when a PR is created from a branch internal to the repo
    if: github.event_name == 'push' || github.event_name == 'schedule' || github.event.pull_request.head.repo.full_name != github.repository

    runs-on: ubuntu-latest

    defaults:
      run:
        working-directory: ./counter

    steps:
      - name: Checkout sources
        uses: actions/checkout@v4

      - uses: awalsh128/cache-apt-pkgs-action@latest
        with:
          version: 1.0
          packages: libhwloc-dev

      - name: Set up stable toolchain
        if: github.event_name != 'schedule'
        uses: actions-rust-lang/setup-rust-toolchain@v1
        with:
          components: rustfmt,clippy

      - name: Set up nightly toolchain
        if: github.event_name == 'schedule'
        uses: actions-rust-lang/setup-rust-toolchain@v1
        with:
          toolchain: nightly
          components: rustfmt,clippy

      - name: Check code formatting
        run: cargo fmt --all --check

      - name: Check clippy lints
        run: cargo clippy --workspace --all-targets -- -D warnings


  # Run the tests on all supported OSes and Rust versions (main CI)
  test-contrib:
    # Don't run CI twice when a PR is created from a branch internal to the repo
    # Don't run in scheduled jobs, that's what test-scheduled is for
    if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository

    runs-on: ubuntu-latest

    needs: matrix_vars

    strategy:
      matrix:
        target-flags:
          - ""
          - "-C target-cpu=native"
        rust:
          - stable
          - ${{ needs.matrix_vars.outputs.MINIMAL_RUST }}

    env:
      RUSTFLAGS: "-D warnings ${{ matrix.target-flags }}"

    defaults:
      run:
        working-directory: ./counter

    steps:
      - name: Checkout sources
        uses: actions/checkout@v4

      - uses: awalsh128/cache-apt-pkgs-action@latest
        with:
          version: 1.0
          packages: libhwloc-dev

      - name: Set up toolchain
        uses: actions-rust-lang/setup-rust-toolchain@v1
        with:
          toolchain: ${{ matrix.rust }}

      - name: Run tests
        run: cargo test

      - name: Check that benchmarks build
        run: cargo build --benches


  deploy-book:
    # Don't run on a schedule, book doesn't change on its own.
    # Don't run on pull request events, they don't have permission to deploy
    if: github.event_name == 'push' && github.ref == 'refs/heads/main'

    runs-on: ubuntu-latest

    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}

    needs: ["render-book", "format-lints", "test-contrib"]

    # Grant GITHUB_TOKEN the permissions required to make a Pages deployment
    permissions:
      pages: write      # to deploy to Pages
      id-token: write   # to verify the deployment originates from an appropriate source

    steps:
      - name: Download the book
        uses: actions/download-artifact@v3
        with:
          name: book
          path: .

      - name: Configure github pages
        uses: actions/configure-pages@v1

      - name: Upload book to github pages
        uses: actions/upload-pages-artifact@v1
        with:
          path: .

      - name: Deploy github pages
        id: deployment
        uses: actions/deploy-pages@v1


  # Check compatibility with newer Rust/deps versions (scheduled CI)
  #
  # FIXME: There should be a way to use conditional build matrices without
  #        duplicating the whole job recipe...
  #
  test-scheduled:
    if: github.event_name == 'schedule'

    runs-on: ubuntu-latest

    needs: matrix_vars

    strategy:
      matrix:
        rustflags:
          - "-D warnings"
          - "-D warnings -C target-cpu=native"
        rust:
          - beta
          - nightly
          - ${{ needs.matrix_vars.outputs.MINIMAL_RUST }}

    env:
      RUSTFLAGS: ${{ matrix.rustflags }}

    defaults:
      run:
        working-directory: ./counter

    steps:
      - name: Checkout sources
        uses: actions/checkout@v4

      - uses: awalsh128/cache-apt-pkgs-action@latest
        with:
          version: 1.0
          packages: libhwloc-dev

      - name: Set up toolchain
        uses: actions-rust-lang/setup-rust-toolchain@v1
        with:
          toolchain: ${{ matrix.rust }}

      - name: Run tests
        run: cargo test

      - name: Check that benchmarks build
        run: cargo build --benches