perf: add microbenchmarks for crc32c and MRD reads

packages/google-cloud-storage/tests/perf/microbenchmarks/benchmark_crc32c.py

@@ -0,0 +1,107 @@
+import argparse
+import os
+import statistics
+import sys
+import time
+
+try:
+    import google_crc32c
+except ImportError:
+    print("Error: google_crc32c package is not installed in the python environment.", file=sys.stderr)
+    sys.exit(1)
+
+
+def parse_size(size_str: str) -> int:
+    size_str = size_str.strip().upper()
+    if size_str.endswith("KIB"):
+        return int(float(size_str[:-3]) * 1024)
+    elif size_str.endswith("MIB"):
+        return int(float(size_str[:-3]) * 1024 * 1024)
+    elif size_str.endswith("GIB"):
+        return int(float(size_str[:-3]) * 1024 * 1024 * 1024)
+    elif size_str.endswith("KB"):
+        return int(float(size_str[:-2]) * 1000)
+    elif size_str.endswith("MB"):
+        return int(float(size_str[:-2]) * 1000 * 1000)
+    elif size_str.endswith("GB"):
+        return int(float(size_str[:-2]) * 1000 * 1000 * 1000)
+    elif size_str.endswith("B"):
+        return int(size_str[:-1])
+    else:
+        try:
+            return int(size_str)
+        except ValueError:
+            raise ValueError(f"Unknown size format: {size_str}")
+
+
+def format_time(seconds: float) -> str:
+    if seconds < 1e-6:
+        return f"{seconds * 1e9:.2f} ns"
+    elif seconds < 1e-3:
+        return f"{seconds * 1e6:.2f} \u03bcs"
+    elif seconds < 1.0:
+        return f"{seconds * 1e3:.2f} ms"
+    else:
+        return f"{seconds:.2f} s"
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Benchmark google_crc32c.value execution time.")
+    parser.add_argument(
+        "--sizes",
+        type=str,
+        default="1KiB,100KiB,2MiB",
+        help="Comma-separated list of sizes (e.g. '1KiB,100KiB,2MiB')"
+    )
+    parser.add_argument(
+        "--iterations",
+        type=int,
+        default=100,
+        help="Number of iterations for benchmark (default: 100)"
+    )
+    args = parser.parse_args()
+
+    # Ensure google_crc32c uses accelerated C code
+    impl = getattr(google_crc32c, "implementation", None)
+    print(f"google_crc32c implementation: {impl}")
+    if impl != "c":
+        print(f"Error: google_crc32c is not using the accelerated C code (got '{impl}').", file=sys.stderr)
+        sys.exit(1)
+
+    sizes_to_test = []
+    for s in args.sizes.split(","):
+        try:
+            sizes_to_test.append((s.strip(), parse_size(s)))
+        except ValueError as e:
+            print(f"Error parsing size '{s}': {e}", file=sys.stderr)
+            sys.exit(1)
+
+    print(f"Benchmarking google_crc32c.value(data) with {args.iterations} iterations:")
+    print("-" * 80)
+    print(f"{'Size (String)':<15} | {'Size (Bytes)':<12} | {'Min':<10} | {'Max':<10} | {'Mean':<10} | {'Median':<10}")
+    print("-" * 80)
+
+    for size_str, size_bytes in sizes_to_test:
+        data = os.urandom(size_bytes)
+
+        durations = []
+        for _ in range(args.iterations):
+            start = time.perf_counter()
+            _ = google_crc32c.value(data)
+            end = time.perf_counter()
+            durations.append(end - start)
+
+        min_time = min(durations)
+        max_time = max(durations)
+        mean_time = statistics.mean(durations)
+        median_time = statistics.median(durations)
+
+        print(
+            f"{size_str:<15} | {size_bytes:<12} | "
+            f"{format_time(min_time):<10} | {format_time(max_time):<10} | "
+            f"{format_time(mean_time):<10} | {format_time(median_time):<10}"
+        )
+
+
+if __name__ == "__main__":
+    main()