From bf0d77d7d448e964e9716d5af67c48f3d014f090 Mon Sep 17 00:00:00 2001
From: Filip Wandzio <contact@philw.dev>
Date: Sun, 1 Mar 2026 01:03:39 +0100
Subject: Scaffold basic project tree, implement benchmarking logic

Implement unit testing guardian
---
 benchmark/benchmark.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 benchmark/benchmark.c

(limited to 'benchmark/benchmark.c')

diff --git a/benchmark/benchmark.c b/benchmark/benchmark.c
new file mode 100644
index 0000000..2fe3163
--- /dev/null
+++ b/benchmark/benchmark.c
@@ -0,0 +1,101 @@
+#define _POSIX_C_SOURCE 199309L
+#include "benchmark.h"
+#include "resource_usage.h"
+#include <stdio.h>
+
+#if defined(_WIN32) || defined(_WIN64)
+#include <windows.h>
+#else
+#include <time.h>
+#endif
+
+/* ANSI color codes */
+const char* COLOR_RED = "\033[31m";
+const char* COLOR_GREEN = "\033[32m";
+const char* COLOR_YELLOW = "\033[33m";
+const char* COLOR_RESET = "\033[0m";
+
+/* Maximum allowed average execution time per call in milliseconds */
+const double MAX_ALLOWED_MS = 0.05;
+
+/* Default benchmark iteration counts */
+const size_t DEFAULT_BENCHMARKS = 100;
+const size_t ITERATIONS_FAST = 1000;
+const size_t ITERATIONS_SLOW = 10;
+
+/* Volatile sink to prevent compiler optimizations removing the function call */
+static volatile int sink;
+
+/**
+ * @brief Cross-platform monotonic time in milliseconds
+ */
+static double now_ms(void)
+{
+#if defined(_WIN32) || defined(_WIN64)
+	LARGE_INTEGER freq, counter;
+	QueryPerformanceFrequency(&freq);
+	QueryPerformanceCounter(&counter);
+	return (double)counter.QuadPart * 1000.0 / (double)freq.QuadPart;
+#else
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000.0 + ts.tv_nsec / 1e6;
+#endif
+}
+
+double benchmark_func(const function_to_benchmark func,
+		      const char* arg,
+		      size_t benchmarks)
+{
+	if (!func)
+		return 0.0;
+	if (benchmarks == 0)
+		benchmarks = DEFAULT_BENCHMARKS;
+	size_t warmup = benchmarks / 10;
+	if (warmup > 1000)
+		warmup = 1000;
+	for (size_t i = 0; i < warmup; ++i)
+		sink = func(arg);
+	const double start = now_ms();
+	for (size_t i = 0; i < benchmarks; ++i)
+		sink = func(arg);
+	const double end = now_ms();
+	return (end - start) / benchmarks;
+}
+
+void report_result(const char* test_name,
+		   const int passed,
+		   const double avg_ms,
+		   const double max_allowed_ms)
+{
+	const int is_pass = passed && (avg_ms <= max_allowed_ms);
+	const char* status_color = is_pass ? COLOR_GREEN : COLOR_RED;
+	const char* status_text = is_pass ? "PASS" : "FAIL";
+
+	if (!is_pass && avg_ms > max_allowed_ms)
+		status_text = "SLOW";
+
+	printf("[avg %.6f ms] %s%s: %s%s\n",
+	       avg_ms,
+	       status_color,
+	       status_text,
+	       test_name,
+	       COLOR_RESET);
+
+	if (!is_pass && avg_ms > max_allowed_ms) {
+		printf("  %sReason:%s exceeded %.3f ms limit\n",
+		       COLOR_YELLOW,
+		       COLOR_RESET,
+		       max_allowed_ms);
+	}
+}
+
+void benchmark_func_with_resources(const function_to_benchmark func,
+				   const char* arg,
+				   const size_t benchmarks,
+				   const char* label)
+{
+	const double avg_ms = benchmark_func(func, arg, benchmarks);
+	printf("[Benchmark] %s avg %.6f ms\n", label, avg_ms);
+	print_resource_usage(label);
+}
-- 
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