Benchmark giving result of zero seconds.

main.rs

extern mod cssparser;
extern mod extra;
extern mod servo_style;

use std::io::file_reader;
use std::cell::Cell;
use std::task;
use cssparser::*;
use extra::time::precise_time_ns;

fn bench(inner: &fn()) -> u64 {
    let ns_start = precise_time_ns();
    inner();
    let ns_end = precise_time_ns();

    return ns_end - ns_start;
}

fn bench_lex_one_file(path: Path) -> Result<u64, ()> {
    let p = Cell::new(path);
    do task::try {
        let reader = file_reader(&p.take()).unwrap();
        let css = reader.read_c_str();
        do bench {
            let mut a = parse_stylesheet_rules(tokenize(css));
            for _ in a {}
        }
    }
}

fn bench_parse_one_file(path: Path) -> Result<u64, ()> {
    let p = Cell::new(path);
    do task::try {
        let reader = file_reader(&p.take()).unwrap();
        let css = reader.read_c_str();
        do bench {
            servo_style::stylesheets::parse_stylesheet(css);
        }
    }
}

fn main() {
    let base_dir = &Path("sample-data");
    let files = std::os::list_dir_path(base_dir);
    println!("name,lex,parse");

    for file in files.iter() {
        let lex_time = bench_lex_one_file(file.clone());
        let parse_time = bench_parse_one_file(file.clone());
        match (lex_time, parse_time) {
            (Ok(l), Ok(p)) =>
                println!("{},{:.4f},{:.4f}",
                                file.filename().unwrap(),
                                l as float / 1_000f,
                                p as float / 1_000f),
            _ => (),
        }
    }
}

parse_pct.txt

| name                    | parse_pct |   size |
|-------------------------+-----------+--------|
| youtube01.css           |       4.8 | 293.04 |
| facebook04.css          |      6.15 | 244.61 |
| twitter03.css           |      7.65 | 161.32 |
| yahoo04.css             |      4.45 |  154.4 |
| youtube02.css           |      4.85 | 133.97 |
| bootstrap.css           |     12.17 | 117.08 |
| wikipedia06.css         |     18.29 | 116.46 |
| amazon14.css            |      4.55 | 108.49 |
| bootstrap.min.css       |     12.96 |  95.06 |
| facebook07.css          |      4.76 |  77.38 |
| qq00.css                |       9.5 |  68.29 |
| wikipedia02.css         |      3.33 |  66.18 |
| facebook01.css          |       4.2 |  52.32 |
| facebook03.css          |      4.79 |  48.96 |
| google08.css            |      4.29 |  45.02 |
| google00.css            |       4.5 |     42 |
| facebook09.css          |      9.92 |  40.71 |
| yahoo05.css             |       9.3 |  40.11 |
| wikipedia01.css         |      6.41 |  39.18 |
| facebook00.css          |      7.03 |  33.78 |
| facebook08.css          |      8.14 |  25.32 |
| wikipedia03.css         |     11.43 |  25.08 |
| amazon13.css            |     10.78 |  22.34 |
| amazon15.css            |     14.06 |  21.88 |
| wikipedia07.css         |      29.5 |  20.56 |
| bootstrap-theme.css     |      2.18 |  16.42 |
| google03.css            |      5.09 |  16.33 |
| bootstrap-theme.min.css |      2.23 |  14.64 |
| amazon00.css            |     34.27 |  13.98 |
| amazon11.css            |       6.8 |   8.53 |
| qq04.css                |      4.93 |    8.4 |
| google07.css            |      5.95 |   7.64 |
| wikipedia00.css         |      8.42 |   7.21 |
| twitter00.css           |      5.85 |   5.76 |
| youtube00.css           |     14.99 |   4.76 |
| amazon16.css            |     39.69 |   4.41 |
| baidu00.css             |     16.53 |   3.25 |
| amazon09.css            |      9.29 |   3.19 |
| google02.css            |     11.97 |   3.05 |
| google01.css            |     19.59 |   2.76 |
| qq05.css                |      9.39 |   2.76 |
| google06.css            |     10.08 |   2.53 |
| amazon03.css            |     12.54 |   2.28 |
| amazon01.css            |     24.41 |   2.09 |
| yahoo03.css             |     16.28 |   1.96 |
| yahoo06.css             |     15.48 |   1.81 |
| google05.css            |     12.32 |   1.73 |
| amazon12.css            |     14.91 |   1.32 |
| baidu01.css             |     19.68 |   0.97 |
| amazon06.css            |     24.58 |   0.95 |
| yahoo00.css             |      23.8 |   0.95 |
| yahoo02.css             |     21.64 |   0.74 |
| facebook02.css          |     25.18 |   0.68 |
| facebook05.css          |     25.95 |   0.57 |
| amazon10.css            |     36.33 |    0.5 |
| amazon04.css            |     35.72 |   0.49 |
| facebook06.css          |     33.66 |   0.42 |
| google04.css            |     29.64 |   0.41 |
| amazon02.css            |     34.33 |   0.32 |
| qq01.css                |     34.52 |   0.31 |
| amazon08.css            |     60.88 |   0.27 |
| amazon05.css            |     49.02 |   0.22 |
| qq02.css                |     45.79 |   0.18 |
| wikipedia04.css         |     59.86 |   0.18 |
| yahoo01.css             |     48.22 |   0.18 |
| twitter01.css           |     72.03 |   0.11 |
| amazon07.css            |     60.42 |   0.11 |
| twitter02.css           |     78.07 |   0.07 |
| wikipedia05.css         |     78.68 |   0.07 |
| qq03.css                |     81.38 |   0.03 |

timings.csv