src/libcollections/benches/string.rs

   1 // Copyright 2017 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use std::iter::repeat;
  12 use test::Bencher;
  13
  14 #[bench]
  15 fn bench_with_capacity(b: &mut Bencher) {
  16     b.iter(|| String::with_capacity(100));
  17 }
  18
  19 #[bench]
  20 fn bench_push_str(b: &mut Bencher) {
  21     let s = "ศไทย中华Việt Nam; Mary had a little lamb, Little lamb";
  22     b.iter(|| {
  23         let mut r = String::new();
  24         r.push_str(s);
  25     });
  26 }
  27
  28 const REPETITIONS: u64 = 10_000;
  29
  30 #[bench]
  31 fn bench_push_str_one_byte(b: &mut Bencher) {
  32     b.bytes = REPETITIONS;
  33     b.iter(|| {
  34         let mut r = String::new();
  35         for _ in 0..REPETITIONS {
  36             r.push_str("a")
  37         }
  38     });
  39 }
  40
  41 #[bench]
  42 fn bench_push_char_one_byte(b: &mut Bencher) {
  43     b.bytes = REPETITIONS;
  44     b.iter(|| {
  45         let mut r = String::new();
  46         for _ in 0..REPETITIONS {
  47             r.push('a')
  48         }
  49     });
  50 }
  51
  52 #[bench]
  53 fn bench_push_char_two_bytes(b: &mut Bencher) {
  54     b.bytes = REPETITIONS * 2;
  55     b.iter(|| {
  56         let mut r = String::new();
  57         for _ in 0..REPETITIONS {
  58             r.push('â')
  59         }
  60     });
  61 }
  62
  63 #[bench]
  64 fn from_utf8_lossy_100_ascii(b: &mut Bencher) {
  65     let s = b"Hello there, the quick brown fox jumped over the lazy dog! \
  66               Lorem ipsum dolor sit amet, consectetur. ";
  67
  68     assert_eq!(100, s.len());
  69     b.iter(|| {
  70         let _ = String::from_utf8_lossy(s);
  71     });
  72 }
  73
  74 #[bench]
  75 fn from_utf8_lossy_100_multibyte(b: &mut Bencher) {
  76     let s = "𐌀𐌖𐌋𐌄𐌑𐌉ปรدولة الكويتทศไทย中华𐍅𐌿𐌻𐍆𐌹𐌻𐌰".as_bytes();
  77     assert_eq!(100, s.len());
  78     b.iter(|| {
  79         let _ = String::from_utf8_lossy(s);
  80     });
  81 }
  82
  83 #[bench]
  84 fn from_utf8_lossy_invalid(b: &mut Bencher) {
  85     let s = b"Hello\xC0\x80 There\xE6\x83 Goodbye";
  86     b.iter(|| {
  87         let _ = String::from_utf8_lossy(s);
  88     });
  89 }
  90
  91 #[bench]
  92 fn from_utf8_lossy_100_invalid(b: &mut Bencher) {
  93     let s = repeat(0xf5).take(100).collect::<Vec<_>>();
  94     b.iter(|| {
  95         let _ = String::from_utf8_lossy(&s);
  96     });
  97 }
  98
  99 #[bench]
 100 fn bench_exact_size_shrink_to_fit(b: &mut Bencher) {
 101     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
 102              Lorem ipsum dolor sit amet, consectetur. ";
 103     // ensure our operation produces an exact-size string before we benchmark it
 104     let mut r = String::with_capacity(s.len());
 105     r.push_str(s);
 106     assert_eq!(r.len(), r.capacity());
 107     b.iter(|| {
 108         let mut r = String::with_capacity(s.len());
 109         r.push_str(s);
 110         r.shrink_to_fit();
 111         r
 112     });
 113 }
 114
 115 #[bench]
 116 fn bench_from_str(b: &mut Bencher) {
 117     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
 118              Lorem ipsum dolor sit amet, consectetur. ";
 119     b.iter(|| String::from(s))
 120 }
 121
 122 #[bench]
 123 fn bench_from(b: &mut Bencher) {
 124     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
 125              Lorem ipsum dolor sit amet, consectetur. ";
 126     b.iter(|| String::from(s))
 127 }
 128
 129 #[bench]
 130 fn bench_to_string(b: &mut Bencher) {
 131     let s = "Hello there, the quick brown fox jumped over the lazy dog! \
 132              Lorem ipsum dolor sit amet, consectetur. ";
 133     b.iter(|| s.to_string())
 134 }