1 files changed, 164 insertions, 0 deletions
diff --git a/library/alloc/benches/string.rs b/library/alloc/benches/string.rs
new file mode 100644
index 000000000..5c95160ba
--- /dev/null
+++ b/library/alloc/benches/string.rs
@@ -0,0 +1,164 @@
+use std::iter::repeat;
+use test::{black_box, Bencher};
+
+#[bench]
+fn bench_with_capacity(b: &mut Bencher) {
+    b.iter(|| String::with_capacity(100));
+}
+
+#[bench]
+fn bench_push_str(b: &mut Bencher) {
+    let s = "ศไทย中华Việt Nam; Mary had a little lamb, Little lamb";
+    b.iter(|| {
+        let mut r = String::new();
+        r.push_str(s);
+    });
+}
+
+const REPETITIONS: u64 = 10_000;
+
+#[bench]
+fn bench_push_str_one_byte(b: &mut Bencher) {
+    b.bytes = REPETITIONS;
+    b.iter(|| {
+        let mut r = String::new();
+        for _ in 0..REPETITIONS {
+            r.push_str("a")
+        }
+    });
+}
+
+#[bench]
+fn bench_push_char_one_byte(b: &mut Bencher) {
+    b.bytes = REPETITIONS;
+    b.iter(|| {
+        let mut r = String::new();
+        for _ in 0..REPETITIONS {
+            r.push('a')
+        }
+    });
+}
+
+#[bench]
+fn bench_push_char_two_bytes(b: &mut Bencher) {
+    b.bytes = REPETITIONS * 2;
+    b.iter(|| {
+        let mut r = String::new();
+        for _ in 0..REPETITIONS {
+            r.push('â')
+        }
+    });
+}
+
+#[bench]
+fn from_utf8_lossy_100_ascii(b: &mut Bencher) {
+    let s = b"Hello there, the quick brown fox jumped over the lazy dog! \
+              Lorem ipsum dolor sit amet, consectetur. ";
+
+    assert_eq!(100, s.len());
+    b.iter(|| {
+        let _ = String::from_utf8_lossy(s);
+    });
+}
+
+#[bench]
+fn from_utf8_lossy_100_multibyte(b: &mut Bencher) {
+    let s = "𐌀𐌖𐌋𐌄𐌑𐌉ปรدولة الكويتทศไทย中华𐍅𐌿𐌻𐍆𐌹𐌻𐌰".as_bytes();
+    assert_eq!(100, s.len());
+    b.iter(|| {
+        let _ = String::from_utf8_lossy(s);
+    });
+}
+
+#[bench]
+fn from_utf8_lossy_invalid(b: &mut Bencher) {
+    let s = b"Hello\xC0\x80 There\xE6\x83 Goodbye";
+    b.iter(|| {
+        let _ = String::from_utf8_lossy(s);
+    });
+}
+
+#[bench]
+fn from_utf8_lossy_100_invalid(b: &mut Bencher) {
+    let s = repeat(0xf5).take(100).collect::<Vec<_>>();
+    b.iter(|| {
+        let _ = String::from_utf8_lossy(&s);
+    });
+}
+
+#[bench]
+fn bench_exact_size_shrink_to_fit(b: &mut Bencher) {
+    let s = "Hello there, the quick brown fox jumped over the lazy dog! \
+             Lorem ipsum dolor sit amet, consectetur. ";
+    // ensure our operation produces an exact-size string before we benchmark it
+    let mut r = String::with_capacity(s.len());
+    r.push_str(s);
+    assert_eq!(r.len(), r.capacity());
+    b.iter(|| {
+        let mut r = String::with_capacity(s.len());
+        r.push_str(s);
+        r.shrink_to_fit();
+        r
+    });
+}
+
+#[bench]
+fn bench_from_str(b: &mut Bencher) {
+    let s = "Hello there, the quick brown fox jumped over the lazy dog! \
+             Lorem ipsum dolor sit amet, consectetur. ";
+    b.iter(|| String::from(s))
+}
+
+#[bench]
+fn bench_from(b: &mut Bencher) {
+    let s = "Hello there, the quick brown fox jumped over the lazy dog! \
+             Lorem ipsum dolor sit amet, consectetur. ";
+    b.iter(|| String::from(s))
+}
+
+#[bench]
+fn bench_to_string(b: &mut Bencher) {
+    let s = "Hello there, the quick brown fox jumped over the lazy dog! \
+             Lorem ipsum dolor sit amet, consectetur. ";
+    b.iter(|| s.to_string())
+}
+
+#[bench]
+fn bench_insert_char_short(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert(6, black_box(' '));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_char_long(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert(6, black_box('❤'));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_str_short(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert_str(6, black_box(" "));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_str_long(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert_str(6, black_box(" rustic "));
+        x
+    })
+}