chore: add struct array traversal benchmark

Co-authored-by: blueloveTH <28104173+blueloveTH@users.noreply.github.com>

benchmarks/struct_array_traverse.c

@@ -0,0 +1,53 @@
+#define _POSIX_C_SOURCE 199309L
+#include <stdint.h>
+#include <stdio.h>
+#include <time.h>
+
+static inline uint64_t nanos(void) {
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return (uint64_t)ts.tv_sec * 1000000000ull + (uint64_t)ts.tv_nsec;
+}
+
+static uint64_t bench_int(void) {
+    int arr[1000];
+    for (int i = 0; i < 1000; ++i) arr[i] = 1;
+
+    volatile long long total = 0;
+    uint64_t start = nanos();
+    for (int round = 0; round < 1000; ++round) {
+        long long sum = 0;
+        for (int i = 0; i < 1000; ++i) sum += arr[i];
+        total += sum;
+    }
+    uint64_t end = nanos();
+    // prevent optimization
+    if (total == 0) printf("unused: %lld\n", total);
+    return (end - start) / 1000;
+}
+
+static uint64_t bench_char(void) {
+    char arr[1000];
+    for (int i = 0; i < 1000; ++i) arr[i] = 1;
+
+    volatile long long total = 0;
+    uint64_t start = nanos();
+    for (int round = 0; round < 1000; ++round) {
+        long long sum = 0;
+        for (int i = 0; i < 1000; ++i) sum += arr[i];
+        total += sum;
+    }
+    uint64_t end = nanos();
+    if (total == 0) printf("unused: %lld\n", total);
+    return (end - start) / 1000;
+}
+
+int main(void) {
+    uint64_t int_avg = bench_int();
+    uint64_t char_avg = bench_char();
+    printf("int[1000] average traversal (ns): %llu\n",
+           (unsigned long long)int_avg);
+    printf("char[1000] average traversal (ns): %llu\n",
+           (unsigned long long)char_avg);
+    return 0;
+}