Add lexer benchmark (#7132)

crates/ruff_benchmark/Cargo.toml

@@ -18,6 +18,10 @@ bench = false
 name = "linter"
 harness = false
 
+[[bench]]
+name = "lexer"
+harness = false
+
 [[bench]]
 name = "parser"
 harness = false

crates/ruff_benchmark/benches/lexer.rs

@@ -0,0 +1,62 @@
+use ruff_benchmark::criterion::{
+    criterion_group, criterion_main, measurement::WallTime, BenchmarkId, Criterion, Throughput,
+};
+use ruff_benchmark::{TestCase, TestFile, TestFileDownloadError};
+use ruff_python_parser::{lexer, Mode};
+
+#[cfg(target_os = "windows")]
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
+#[cfg(all(
+    not(target_os = "windows"),
+    not(target_os = "openbsd"),
+    any(
+        target_arch = "x86_64",
+        target_arch = "aarch64",
+        target_arch = "powerpc64"
+    )
+))]
+#[global_allocator]
+static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
+
+fn create_test_cases() -> Result<Vec<TestCase>, TestFileDownloadError> {
+    Ok(vec![
+        TestCase::fast(TestFile::try_download("numpy/globals.py", "https://raw.githubusercontent.com/numpy/numpy/89d64415e349ca75a25250f22b874aa16e5c0973/numpy/_globals.py")?),
+        TestCase::fast(TestFile::try_download("unicode/pypinyin.py", "https://raw.githubusercontent.com/mozillazg/python-pinyin/9521e47d96e3583a5477f5e43a2e82d513f27a3f/pypinyin/standard.py")?),
+        TestCase::normal(TestFile::try_download(
+            "pydantic/types.py",
+            "https://raw.githubusercontent.com/pydantic/pydantic/83b3c49e99ceb4599d9286a3d793cea44ac36d4b/pydantic/types.py",
+        )?),
+        TestCase::normal(TestFile::try_download("numpy/ctypeslib.py", "https://raw.githubusercontent.com/numpy/numpy/e42c9503a14d66adfd41356ef5640c6975c45218/numpy/ctypeslib.py")?),
+        TestCase::slow(TestFile::try_download(
+            "large/dataset.py",
+            "https://raw.githubusercontent.com/DHI/mikeio/b7d26418f4db2909b0aa965253dbe83194d7bb5b/tests/test_dataset.py",
+        )?),
+    ])
+}
+
+fn benchmark_lexer(criterion: &mut Criterion<WallTime>) {
+    let test_cases = create_test_cases().unwrap();
+    let mut group = criterion.benchmark_group("lexer");
+
+    for case in test_cases {
+        group.throughput(Throughput::Bytes(case.code().len() as u64));
+        group.bench_with_input(
+            BenchmarkId::from_parameter(case.name()),
+            &case,
+            |b, case| {
+                b.iter(|| {
+                    let result =
+                        lexer::lex(case.code(), Mode::Module).find(std::result::Result::is_err);
+                    assert_eq!(result, None, "Input to be a valid Python program");
+                });
+            },
+        );
+    }
+
+    group.finish();
+}
+
+criterion_group!(lexer, benchmark_lexer);
+criterion_main!(lexer);