Add benchmark for base64

For performance monitoring, added benchmark for base64. Those benchmarks
include testing encoding, decoding and decoding ignoring garbage
characters.

Signed-off-by: Andrea Calabrese <andrea.calabrese@amarulasolutions.com>

Author: Andrea Calabrese

Cargo.lock

@@ -23,6 +23,15 @@ uucore = { workspace = true, features = ["encoding"] }
 uu_base32 = { workspace = true }
 fluent = { workspace = true }
 
+[dev-dependencies]
+divan = { workspace = true }
+tempfile = { workspace = true }
+uucore = { workspace = true, features = ["benchmark"] }
+
 [[bin]]
 name = "base64"
 path = "src/main.rs"
+
+[[bench]]
+name = "base64_bench"
+harness = false

src/uu/base64/Cargo.toml

@@ -0,0 +1,72 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use divan::{Bencher, black_box};
+use std::ffi::OsString;
+use uu_base64::uumain;
+use uucore::benchmark::{create_test_file, run_util_function, text_data};
+
+fn create_tmp_file(size_mb: usize) -> String {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let data = text_data::generate_by_size(size_mb, 80);
+    let file_path = create_test_file(&data, temp_dir.path());
+    String::from(file_path.to_str().unwrap())
+}
+
+/// Benchmark for base64 encoding
+#[divan::bench()]
+fn b64_encode_synthetic(bencher: Bencher) {
+    let file_path_str = &create_tmp_file(5_000);
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &[file_path_str]));
+    });
+}
+
+// Benchmark for base64 decoding
+#[divan::bench()]
+fn b64_decode_synthetic(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let file_path_str = &create_tmp_file(5_000);
+    let in_file = create_test_file(b"", temp_dir.path());
+    let in_file_str = in_file.to_str().unwrap();
+    uumain(
+        [
+            OsString::from(file_path_str),
+            OsString::from(format!(">{in_file_str}")),
+        ]
+        .iter()
+        .map(|x| (*x).clone()),
+    );
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["-d", in_file_str]));
+    });
+}
+
+// Benchmark different file sizes for base64 decoding ignoring garbage characters
+#[divan::bench()]
+fn b64_decode_ignore_garbage_synthetic(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let file_path_str = &create_tmp_file(5_000);
+    let in_file = create_test_file(b"", temp_dir.path());
+    let in_file_str = in_file.to_str().unwrap();
+    uumain(
+        [
+            OsString::from(file_path_str),
+            OsString::from(format!(">{in_file_str}")),
+        ]
+        .iter()
+        .map(|x| (*x).clone()),
+    );
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["-d", "-i", in_file_str]));
+    });
+}
+
+fn main() {
+    divan::main();
+}