From 8b1299d03d10d7e012b1170ff67599b1b4af9997 Mon Sep 17 00:00:00 2001
From: Ewout ter Hoeven <E.M.terHoeven@student.tudelft.nl>
Date: Sat, 20 Jan 2024 22:31:01 +0100
Subject: [PATCH] Add CI workflow for performance benchmarks

This commit introduces a new GitHub Actions workflow for performance benchmarking. The workflow is triggered on `pull_request_target` events and can be triggered with a "/rerun-benchmarks" comment in the PR. It should be compatible with PRs from both forks and the main repository. It includes steps for setting up the environment, checking out the PR and main branches, installing dependencies, and running benchmarks on both branches. The results are then compared, encoded, and posted as a comment on the PR.
---
 .github/workflows/benchmarks.yml | 77 ++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 .github/workflows/benchmarks.yml

diff --git a/.github/workflows/benchmarks.yml b/.github/workflows/benchmarks.yml
new file mode 100644
index 00000000000..f64f853a62f
--- /dev/null
+++ b/.github/workflows/benchmarks.yml
@@ -0,0 +1,77 @@
+name: Performance benchmarks
+
+on:
+  pull_request_target:
+    types: [opened, ready_for_review]
+    branches:
+      - main
+  issue_comment:
+    types: [created]
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  run-benchmarks:
+    if: >
+      github.event_name == 'pull_request_target' ||
+      (github.event_name == 'issue_comment' && contains(github.event.comment.body, '/rerun-benchmarks'))
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout PR branch
+        uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+      - name: Add project directory to PYTHONPATH
+        run: echo "PYTHONPATH=$PYTHONPATH:$(pwd)" >> $GITHUB_ENV
+      - name: Install dependencies
+        run: pip install numpy pandas tqdm tabulate
+      - name: Checkout main branch
+        uses: actions/checkout@v4
+        with:
+          ref: main
+          repository: EwoutH/mesa
+      - name: Run benchmarks on main branch
+        working-directory: benchmarks
+        run: python global_benchmark.py
+      - name: Upload benchmark results
+        uses: actions/upload-artifact@v4
+        with:
+          name: timings-main
+          path: benchmarks/timings_1.pickle
+      - name: Checkout PR branch
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
+          fetch-depth: 0
+          persist-credentials: false
+          clean: false
+      - name: Download benchmark results
+        uses: actions/download-artifact@v4
+        with:
+          name: timings-main
+          path: benchmarks
+      - name: Run benchmarks on PR branch
+        working-directory: benchmarks
+        run: python global_benchmark.py
+      - name: Run compare timings and encode output
+        working-directory: benchmarks
+        run: |
+          TIMING_COMPARISON=$(python compare_timings.py | base64 -w 0)  # Base64 encode the output
+          echo "TIMING_COMPARISON=$TIMING_COMPARISON" >> $GITHUB_ENV
+      - name: Comment PR
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const output = Buffer.from(process.env.TIMING_COMPARISON, 'base64').toString('utf-8');
+            const issue_number = context.issue.number;
+            github.rest.issues.createComment({
+              issue_number: issue_number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: 'Performance benchmarks:\n\n' + output
+            });