faster-chars-count
| Crates.io | faster-chars-count |
| lib.rs | faster-chars-count |
| version | 0.3.0 |
| source | src |
| created_at | 2021-03-05 13:44:51.994538 |
| updated_at | 2021-11-18 12:19:09.206719 |
| description | Library for counting length of chars faster than Chars::count() |
| homepage | |
| repository | https://github.com/aobatact/faster_chars_count |
| max_upload_size | |
| id | 364345 |
| size | 46,141 |
aobat (aobatact)
documentation
README
Library for counting length of chars faster than Chars::count()
Idea is from UTF-8のコードポイントはどうやって高速に数えるか, and UTF-8のコードポイントはどうやってもっと高速に数えるか.
usage
//before
"Hello, world!".chars().count();
//after
"Hello, world!".chars_count();
bench
repeated "a" (only 1byte utf8)
| Length | std | chars_count | chars_count(avx2) |
|---|---|---|---|
| 1 | 1.3906 ns | 3.1607 ns | 2.1750 ns |
| 10 | 4.7844 ns | 5.6093 ns | 7.2465 ns |
| 100 | 47.630 ns | 10.607 ns | 11.265 ns |
| 1000 | 475.17 ns | 67.364 ns | 17.839 ns |
| 10000 | 4.7231 us | 604.66 ns | 91.757 ns |
repeated "錆" (only 3byte utf8)
| Length | std | chars_count | chars_count(avx2) |
|---|---|---|---|
| 1 | 2.4324 ns | 4.5069 ns | 4.2662 ns |
| 10 | 13.947 ns | 10.267 ns | 11.984 ns |
| 100 | 143.74 ns | 23.935 ns | 28.758 ns |
| 1000 | 1.4210 us | 193.98 ns | 40.435 ns |
| 10000 | 1.8505 us | 270.60 ns | 14.206 us |
See performance branch for details.
future plan
sse (128bit)