tests: Add benchmark for sys/base64

tests/bench_sys_base64/Makefile

@@ -0,0 +1,7 @@
+include ../Makefile.tests_common
+
+USEMODULE += base64
+USEMODULE += fmt
+USEMODULE += xtimer
+
+include $(RIOTBASE)/Makefile.include

tests/bench_sys_base64/main.c

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+/*
+ * Copyright (C) 2020 Otto-von-Guericke-Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     tests
+ * @{
+ *
+ * @file
+ * @brief       Benchmark for the base64 lib
+ *
+ * @author      Marian Buschsieweke <marian.buschsieweke@ovgu.de>
+ *
+ * @}
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "base64.h"
+#include "fmt.h"
+#include "xtimer.h"
+
+#define MIN(a, b) (a < b) ? a : b
+
+static char buf[128];
+
+static const char input[96] = "This is an extremely, enormously, greatly, "
+                              "immensely, tremendously, remarkably lengthy "
+                              "sentence!";
+static const char base64[128] =
+"VGhpcyBpcyBhbiBleHRyZW1lbHksIGVub3Jtb3VzbHksIGdyZWF0bHksIGltbWVuc2VseSwgdHJl"
+"bWVuZG91c2x5LCByZW1hcmthYmx5IGxlbmd0aHkgc2VudGVuY2Uh";
+
+int main(void) {
+    uint32_t start, stop;
+    size_t size;
+
+    /* We don't want check return value in the benchmark loop, so we just do
+     * a simple self test now. */
+    print_str("Verifying that base64 encoding works for benchmark input: ");
+    size = sizeof(buf);
+    if ((BASE64_SUCCESS != base64_encode(input, sizeof(input), buf, &size)) ||
+        (size != sizeof(buf)) ||
+        (0 != memcmp(base64, buf, sizeof(base64))))
+        {
+        print_str("FAIL\nGot:      \"");
+        print(buf, MIN(size, sizeof(base64)));
+        print_str("\"\nExpected: \"");
+        print(base64, sizeof(base64));
+        print_str("\"\n");
+    }
+    else {
+        print_str("OK\n");
+    }
+
+    print_str("Verifying that base64 decoding works for benchmark input: ");
+    size = sizeof(buf);
+    if ((BASE64_SUCCESS != base64_decode(base64, sizeof(base64), buf, &size)) ||
+        (size != sizeof(input)) ||
+        (0 != memcmp(input, buf, sizeof(input))))
+        {
+        print_str("FAIL\nGot:      \"");
+        print(buf, MIN(size, sizeof(input)));
+        print_str("\"\nExpected: \"");
+        print(input, sizeof(input));
+        print_str("\"\n");
+    }
+    else {
+        print_str("OK\n");
+    }
+
+    start = xtimer_now_usec();
+    for (unsigned i = 0; i < 10000; i++) {
+        size = sizeof(buf);
+        base64_encode(input, sizeof(input), buf, &size);
+    }
+    stop = xtimer_now_usec();
+
+    print_str("Encoding 10.000 x 96 bytes (128 bytes in base64): ");
+    print_u32_dec(stop - start);
+    print_str(" µs\n");
+
+    start = xtimer_now_usec();
+    for (unsigned i = 0; i < 10000; i++) {
+        size = sizeof(buf);
+        base64_decode(base64, sizeof(base64), buf, &size);
+    }
+    stop = xtimer_now_usec();
+
+    print_str("Decoding 10.000 x 96 bytes (128 bytes in base64): ");
+    print_u32_dec(stop - start);
+    print_str(" µs\n");
+    return 0;
+}

tests/bench_sys_base64/tests/01-run.py

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+#!/usr/bin/env python3
+
+# Copyright (C) 2020 Otto-von-Guericke-Universität Magdeburg
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+import sys
+from testrunner import run
+
+
+def testfunc(child):
+    child.expect_exact("Verifying that base64 encoding works for benchmark input: OK\r\n")
+    child.expect_exact("Verifying that base64 decoding works for benchmark input: OK\r\n")
+    child.expect(r"Encoding 10\.000 x 96 bytes \(128 bytes in base64\): [0-9]+ µs\r\n")
+    child.expect(r"Decoding 10\.000 x 96 bytes \(128 bytes in base64\): [0-9]+ µs\r\n")
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc))