csplit: add benchmarks for line number and regex pattern splitting (#10927)

Author: sylvestre

.github/workflows/benchmarks.yml

@@ -52,7 +52,8 @@ jobs:
           uu_uniq,
           uu_wc,
           uu_factor,
-          uu_date
+          uu_date,
+          uu_csplit
         ]
     steps:
       - uses: actions/checkout@v6

Cargo.lock

@@ -28,3 +28,12 @@ fluent = { workspace = true }
 [[bin]]
 name = "csplit"
 path = "src/main.rs"
+
+[dev-dependencies]
+divan = { workspace = true }
+tempfile = { workspace = true }
+uucore = { workspace = true, features = ["benchmark"] }
+
+[[bench]]
+name = "csplit_bench"
+harness = false

src/uu/csplit/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 tempfile::TempDir;
+use uu_csplit::uumain;
+use uucore::benchmark::{run_util_function, setup_test_file, text_data};
+
+/// Benchmark splitting by line number
+#[divan::bench]
+fn csplit_line_number(bencher: Bencher) {
+    let data = text_data::generate_by_lines(100_000, 80);
+    let file_path = setup_test_file(&data);
+
+    bencher
+        .with_inputs(|| {
+            let output_dir = TempDir::new().unwrap();
+            let prefix = output_dir.path().join("xx");
+            (output_dir, prefix.to_str().unwrap().to_string())
+        })
+        .bench_values(|(output_dir, prefix)| {
+            black_box(run_util_function(
+                uumain,
+                &[
+                    "-f",
+                    &prefix,
+                    file_path.to_str().unwrap(),
+                    "10000",
+                    "50000",
+                    "90000",
+                ],
+            ));
+            drop(output_dir);
+        });
+}
+
+/// Benchmark splitting by regex pattern
+#[divan::bench]
+fn csplit_regex_pattern(bencher: Bencher) {
+    // Generate data with periodic marker lines that we can split on
+    let mut data = Vec::new();
+    for i in 0..100_000 {
+        if i % 10_000 == 0 && i > 0 {
+            data.extend_from_slice(format!("SECTION {i}\n").as_bytes());
+        } else {
+            data.extend_from_slice(format!("line {i} with some content to process\n").as_bytes());
+        }
+    }
+    let file_path = setup_test_file(&data);
+
+    bencher
+        .with_inputs(|| {
+            let output_dir = TempDir::new().unwrap();
+            let prefix = output_dir.path().join("xx");
+            (output_dir, prefix.to_str().unwrap().to_string())
+        })
+        .bench_values(|(output_dir, prefix)| {
+            black_box(run_util_function(
+                uumain,
+                &[
+                    "-f",
+                    &prefix,
+                    file_path.to_str().unwrap(),
+                    "/^SECTION/",
+                    "{*}",
+                ],
+            ));
+            drop(output_dir);
+        });
+}
+
+fn main() {
+    divan::main();
+}