date: add benchmark (#9911)

* date: add benchmark

* date: register benchmark in github actions list

---------

Co-authored-by: Sylvestre Ledru <[email protected]>

Author: CrazyRoka

.github/workflows/benchmarks.yml

@@ -45,6 +45,7 @@ jobs:
           - { package: uu_uniq }
           - { package: uu_wc }
           - { package: uu_factor }
+          - { package: uu_date }
     steps:
       - uses: actions/checkout@v6
         with:

Cargo.lock

@@ -41,3 +41,12 @@ windows-sys = { workspace = true, features = [
 [[bin]]
 name = "date"
 path = "src/main.rs"
+
+[dev-dependencies]
+divan = { workspace = true }
+tempfile = { workspace = true }
+uucore = { workspace = true, features = ["benchmark"] }
+
+[[bench]]
+name = "date_bench"
+harness = false

src/uu/date/Cargo.toml

@@ -0,0 +1,76 @@
+// 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::io::Write;
+use tempfile::NamedTempFile;
+use uu_date::uumain;
+use uucore::benchmark::run_util_function;
+
+/// Helper to create a temporary file containing N lines of date strings.
+fn setup_date_file(lines: usize, date_format: &str) -> NamedTempFile {
+    let mut file = NamedTempFile::new().unwrap();
+    for _ in 0..lines {
+        writeln!(file, "{date_format}").unwrap();
+    }
+    file
+}
+
+/// Benchmarks processing a file containing simple ISO dates.
+#[divan::bench(args = [100, 1_000, 10_000])]
+fn file_iso_dates(bencher: Bencher, count: usize) {
+    let file = setup_date_file(count, "2023-05-10 12:00:00");
+    let path = file.path().to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["-f", path]));
+    });
+}
+
+/// Benchmarks processing a file containing dates with Timezone abbreviations.
+#[divan::bench(args = [100, 1_000, 10_000])]
+fn file_tz_abbreviations(bencher: Bencher, count: usize) {
+    // "EST" triggers the abbreviation lookup and double-parsing logic
+    let file = setup_date_file(count, "2023-05-10 12:00:00 EST");
+    let path = file.path().to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["-f", path]));
+    });
+}
+
+/// Benchmarks formatting speed using a custom output format.
+#[divan::bench(args = [1_000])]
+fn file_custom_format(bencher: Bencher, count: usize) {
+    let file = setup_date_file(count, "2023-05-10 12:00:00");
+    let path = file.path().to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["-f", path, "+%A %d %B %Y"]));
+    });
+}
+
+/// Benchmarks the overhead of starting the utility for a single date (no file).
+#[divan::bench]
+fn single_date_now(bencher: Bencher) {
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &[]));
+    });
+}
+
+/// Benchmarks parsing a complex relative date string passed as an argument.
+#[divan::bench]
+fn complex_relative_date(bencher: Bencher) {
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["--date=last friday 12:00 + 2 days"],
+        ));
+    });
+}
+
+fn main() {
+    divan::main();
+}