From 5d562083bd8b508a30c11a1fdddeae8163054c11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20R=C3=BCger?= <manuel@rueg.eu>
Date: Wed, 6 Nov 2024 09:46:34 +0100
Subject: [PATCH] chore: Integrate benchmark output in GHA

The code comes from @ivanvc in https://github.com/etcd-io/bbolt/pull/750
---
 .github/workflows/ci.yml    | 12 +++++++++++-
 tests/compare_benchmarks.sh |  8 ++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a42280f7f..59711b570 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -164,7 +164,17 @@ jobs:
 
     - name: Benchmark tests
       run: |
-        make test-benchmark-compare
+        BENCHSTAT_OUTPUT_FILE=result.txt make test-benchmark-compare
+    - run: |
+        echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+        cat result.txt >> "$GITHUB_STEP_SUMMARY"
+        echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+        cat <<EOL >> "$GITHUB_STEP_SUMMARY"
+        <hr />
+        The table shows the median and 90% confidence interval (CI) summaries for each benchmark comparing the HEAD and the BASE, and an A/B comparison under "vs base". The last column shows the statistical p-value with ten runs (n=10).
+        The last row has the Geometric Mean (geomean) for the given rows in the table.
+        Refer to [benchstat's documentation](https://pkg.go.dev/golang.org/x/perf/cmd/benchstat) for more help.
+        EOL
 
   ci-build-kube-state-metrics:
     name: ci-build-kube-state-metrics
diff --git a/tests/compare_benchmarks.sh b/tests/compare_benchmarks.sh
index b501e77d0..fcf5f0280 100755
--- a/tests/compare_benchmarks.sh
+++ b/tests/compare_benchmarks.sh
@@ -9,7 +9,7 @@ set -u
 [[ "$#" -le 2 ]] || echo "At least one argument required, $# provided."
 
 REF_CURRENT="$(git rev-parse --abbrev-ref HEAD)"
-REF_TO_COMPARE=$1
+REF_TO_COMPARE="${1}"
 
 COUNT=${2:-"1"}
 
@@ -42,4 +42,8 @@ echo ""
 echo "### Result"
 echo "old=${REF_TO_COMPARE} new=${REF_CURRENT}"
 
-benchstat "${RESULT_TO_COMPARE}" "${RESULT_CURRENT}"
+if [[ -z "${BENCHSTAT_OUTPUT_FILE}" ]]; then
+	benchstat BASE="${RESULT_TO_COMPARE}" HEAD="${RESULT_CURRENT}" | tee "${BENCHSTAT_OUTPUT_FILE}"
+else
+	benchstat BASE="${RESULT_TO_COMPARE}" HEAD="${RESULT_CURRENT}"
+fi