cache-kit 0.9.0

name: Performance Benchmarks

on:
  workflow_dispatch: # Only allow manual triggering to avoid slowing down CI

env:
  RUST_BACKTRACE: 1

jobs:
  benchmark:
    name: Run Performance Benchmarks
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v6

      - uses: dtolnay/rust-toolchain@stable

      - uses: Swatinem/rust-cache@v2
        with:
          cache-on-failure: true

      - name: Run benchmarks
        run: cargo bench --no-fail-fast

      - name: Upload benchmark results
        uses: actions/upload-artifact@v4
        if: always()
        with:
          name: benchmark-results
          path: target/criterion/
          retention-days: 30

      - name: Generate benchmark summary
        if: github.event_name == 'pull_request'
        run: |
          echo "## 📊 Performance Benchmark Results" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "Benchmarks completed successfully." >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "### Benchmark Groups Run:" >> $GITHUB_STEP_SUMMARY
          echo "- ✅ InMemory Backend (set, get, delete, exists)" >> $GITHUB_STEP_SUMMARY
          echo "- ✅ CacheExpander (refresh_hit, refresh_miss, invalidate, bypass)" >> $GITHUB_STEP_SUMMARY
          echo "- ✅ Serialization (performance)" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "📁 Full results available in workflow artifacts" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "_View detailed HTML report in artifacts: \`target/criterion/report/index.html\`_" >> $GITHUB_STEP_SUMMARY

      - name: Comment PR with benchmark info
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const message = `## 📊 Performance Benchmark Results

            ✅ Benchmarks completed successfully.

            ### What was tested:
            - **InMemory Backend**: set, get_hit, get_miss, delete, exists
            - **CacheExpander**: refresh_hit, refresh_miss, invalidate, bypass, fresh_hit
            - **Serialization**: Postcard performance across payload sizes (100B - 100KB)

            📁 **View detailed results**: Download \`benchmark-results\` artifact from the workflow run.

            💡 **Tip**: To compare against baseline locally:
            \`\`\`bash
            make perf-save    # Save current as baseline
            make perf-diff    # Compare after changes
            \`\`\`

            ---
            🤖 _Automated benchmark run on commit ${context.sha.substring(0, 7)}_`;

            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: message
            });

  # Optional: Performance regression check
  # This job compares current benchmarks against a saved baseline
  regression-check:
    name: Check for Performance Regressions
    runs-on: ubuntu-latest
    if: github.event_name == 'pull_request'

    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0 # Need full history for baseline comparison

      - uses: dtolnay/rust-toolchain@stable

      - uses: Swatinem/rust-cache@v2

      # Try to restore baseline from cache
      - name: Restore baseline from cache
        id: cache-baseline
        uses: actions/cache@v4
        with:
          path: target/criterion
          key: benchmark-baseline-${{ github.base_ref || 'main' }}

      - name: Run benchmarks with baseline comparison
        if: steps.cache-baseline.outputs.cache-hit == 'true'
        run: |
          echo "📊 Comparing against cached baseline..."
          cargo bench --no-fail-fast -- --baseline main || true

      - name: Run benchmarks without baseline
        if: steps.cache-baseline.outputs.cache-hit != 'true'
        run: |
          echo "⚠️  No baseline found - running benchmarks to establish one"
          cargo bench --no-fail-fast -- --save-baseline main

      - name: Save new baseline
        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
        uses: actions/cache@v4
        with:
          path: target/criterion
          key: benchmark-baseline-main-${{ github.sha }}