Issue #14599: Create performance regression test CI

.ci/baseline_benchmark.txt

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+Running benchmark 1/3...
+================== BENCHMARK RESULT #1 ==================
+Execution Time: 8.82 s
+============================================================
+Running benchmark 2/3...
+================== BENCHMARK RESULT #2 ==================
+Execution Time: 8.37 s
+============================================================
+Running benchmark 3/3...
+================== BENCHMARK RESULT #3 ==================
+Execution Time: 8.50 s
+============================================================
+===================== BENCHMARK SUMMARY ====================
+Average Execution Time: 8.56 s
+============================================================

.ci/benchmark-config.xml

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+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+  "http://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">
+<module name="Checker">
+  <module name="TreeWalker"/>
+</module>

.ci/check-performance-regression.sh

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+#!/bin/bash
+
+set -e
+
+# max % difference tolerance
+MAX_DIFFERENCE=10
+
+# parse benchmark result at the given path
+parse_benchmark_result() {
+  BENCHMARK_PATH=$1
+  EXECUTION_TIME=$(awk '/Average Execution Time:/ {print $4}' "$BENCHMARK_PATH")
+
+  local RESULT_ARRAY=($EXECUTION_TIME)
+  echo "${RESULT_ARRAY[@]}"
+}
+
+# compare baseline and patch benchmarks
+compare_results() {
+  # Calculate percentage difference for execution time
+  EXECUTION_TIME_DIFFERENCE=$(echo "scale=4; ((${PATCH[0]} - ${BASELINE[0]}) / ${BASELINE[0]}) * 100" | bc)
+  echo "Execution Time Difference: $EXECUTION_TIME_DIFFERENCE%"
+
+  # Check if differences exceed the maximum allowed difference
+  if (( $(echo "$EXECUTION_TIME_DIFFERENCE > $MAX_DIFFERENCE" | bc -l) )); then
+    echo "Differences exceed the maximum allowed difference (${MAX_DIFFERENCE}%)!"
+    exit 1
+  else
+    echo "Differences are within the maximum allowed difference."
+    exit 0
+  fi
+}
+
+# parse baseline benchmark
+BASELINE=($(parse_benchmark_result "./.ci/baseline_benchmark.txt"))
+
+# package patch
+export MAVEN_OPTS='-Xmx2000m'
+mvn -e --no-transfer-progress -Passembly,no-validations package
+
+# run benchmark and parse result
+JAR_FILE=$(find "./target/" -type f -name "checkstyle-*-all.jar")
+bash ./.ci/run-benchmark.sh "${JAR_FILE}"
+PATCH=($(parse_benchmark_result "./patch_benchmark.txt"))
+
+# compare two metrics
+compare_results
+exit $?

.ci/run-benchmark.sh

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+#!/bin/bash
+
+set -e
+
+# check if jar path is provided
+JAR_PATH=$1
+if [ -z "$JAR_PATH" ]; then
+    echo "Usage: $0 <target jar path>"
+    exit 1
+fi
+
+# Sample project path
+SAMPLE_PROJECT="./.ci/jdk22"
+
+# run a command and time it
+time_command() {
+  # Run the command with time
+  TEST_COMMAND=$1
+  TIME_OUTPUT=$(command time -p $TEST_COMMAND 2>&1)
+  # Extract execution time
+  EXECUTION_TIME=$(echo "$TIME_OUTPUT" | awk '/real/ {print $2}')
+
+  local RESULT_ARRAY=($EXECUTION_TIME)
+  echo "${RESULT_ARRAY[@]}"
+}
+
+# run the benchmark a few times to calculate the average metrics
+run_benchmark() {
+  local TOTAL_TIME=0
+  local NUM_RUNS=3
+
+  [ ! -d "$SAMPLE_PROJECT" ] && echo "Directory $SAMPLE_PROJECT DOES NOT exists." && exit 1
+  for ((i = 1; i <= NUM_RUNS; i++)); do
+    echo "Running benchmark ${i}/${NUM_RUNS}..."
+    local BENCHMARK=($(time_command "java -jar $JAR_PATH -c ./.ci/benchmark-config.xml $SAMPLE_PROJECT"))
+    TOTAL_TIME=$(echo "$TOTAL_TIME + ${BENCHMARK[0]}" | bc)
+    echo "================== BENCHMARK RESULT #${i} =================="
+    echo "Execution Time: ${BENCHMARK[0]} s"
+    echo "============================================================"
+  done
+
+  local AVG_TIME=$(echo "scale=2; $TOTAL_TIME / $NUM_RUNS" | bc)
+
+  echo "===================== BENCHMARK SUMMARY ===================="
+  echo "Average Execution Time: ${AVG_TIME} s"
+  echo "============================================================"
+}
+
+# save the benchmark result
+run_benchmark | tee ./patch_benchmark.txt
+exit $?
+

.github/workflows/check-performance-regression.yml

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+#####################################################################################
+# GitHub Action to test performance regression.
+#
+# Workflow starts when:
+# 1) push to master
+# 2) PR created or pushed
+#
+#####################################################################################
+name: Check-Performance-Regression
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches: '*'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up JDK 11
+        uses: actions/setup-java@v4
+        with:
+          java-version: 11
+          distribution: 'temurin'
+
+      - name: Checkout patch
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          path: ./checkstyle
+
+      - name: Clone JDK 22 Repo
+        uses: actions/checkout@v4
+        with:
+          repository: openjdk/jdk22
+          path: ./checkstyle/.ci/jdk22
+
+      - name: Setup local maven cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.m2/repository
+          key: checkstyle-maven-cache-${{ hashFiles('**/pom.xml') }}
+
+      - name: Run performance test
+        run: |
+          cd checkstyle
+          bash ./.ci/check-performance-regression.sh