name: benchmark-run

# Runs the committed benchmark (`just bench`) and records the numbers.
#
# This is a measurement, not a test: nothing here fails the build. Unlike
# benchmark-ab, which compares two refs inside one job, this just reports the
# absolute throughput of the current ref alongside Crow for reference.
#
# Absolute req/s is only meaningful against other runs on the same runner type,
# so compare like with like when reading the history.
#
# Non-SSL only. Windows is excluded: benchmark/Makefile depends on `nc`, `&`
# and `kill`, so it would need a PowerShell rewrite first.

on:
  workflow_dispatch:
    inputs:
      duration:
        description: "Load duration per server"
        required: false
        default: "5s"
      connections:
        description: "Concurrent connections"
        required: false
        default: "10"
      crow:
        description: "Also benchmark Crow v1.3.1 for reference"
        type: boolean
        required: false
        default: true

permissions:
  contents: read

jobs:
  bench:
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest]
    runs-on: ${{ matrix.os }}
    steps:
      - name: checkout
        uses: actions/checkout@v4

      # macos runners ship without Go.
      - name: setup Go
        uses: actions/setup-go@v5
        with:
          go-version: stable

      - name: install bombardier
        run: go install github.com/codesenberg/bombardier@latest

      # crow_all.h includes <asio.hpp>, which no runner has out of the box.
      - name: install asio
        if: ${{ inputs.crow }}
        run: |
          if [ "$RUNNER_OS" = "Linux" ]; then
            sudo apt-get update && sudo apt-get install -y libasio-dev
          else
            brew install asio
          fi

      - name: run benchmark
        run: |
          # Without pipefail the `tee` below swallows a build failure and the
          # job reports success having measured nothing.
          set -o pipefail
          export PATH="$(go env GOPATH)/bin:$PATH"
          CROW_FLAGS="-std=c++17"
          if [ "$RUNNER_OS" = "macOS" ]; then
            CROW_FLAGS="$CROW_FLAGS -I$(brew --prefix asio)/include"
          fi
          if [ "${{ inputs.crow }}" = "true" ]; then TARGET=bench-all; else TARGET=bench; fi
          make -C benchmark "$TARGET" \
            CROW_CXXFLAGS="$CROW_FLAGS" \
            BENCH="bombardier -c ${{ inputs.connections }} -d ${{ inputs.duration }} localhost:8080" \
            2>&1 | tee /tmp/bench.txt

      # pipefail only catches a failed build. Each Makefile recipe ends in
      # `kill`, so a bombardier that never ran still leaves make happy — check
      # that the measurements are actually there.
      - name: check results were produced
        run: |
          expected=1
          if [ "${{ inputs.crow }}" = "true" ]; then expected=2; fi
          got=$(grep -c "Reqs/sec" /tmp/bench.txt || true)
          if [ "$got" -lt "$expected" ]; then
            echo "::error::expected $expected benchmark result(s), found $got"
            exit 1
          fi

      - name: record results
        if: always()
        run: |
          {
            echo "## Benchmark (${{ matrix.os }})"
            echo ""
            echo "- ref: \`${{ github.ref_name }}\` (${{ github.sha }})"
            echo "- connections=${{ inputs.connections }} duration=${{ inputs.duration }}"
            echo ""
            echo '```'
            cat /tmp/bench.txt
            echo '```'
          } >> "$GITHUB_STEP_SUMMARY"