tl 0.7.8

Fast HTML parser written in pure Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

use std::{ptr, simd::*, simd::cmp::{SimdPartialEq,  SimdPartialOrd}};

use crate::simd::fallback;

/// Optimized function for finding a byte in `haystack`
pub fn find(haystack: &[u8], needle: u8) -> Option<usize> {
    #[inline(never)]
    #[cold]
    fn unlikely_find(haystack: &[u8], needle: u8) -> Option<usize> {
        fallback::find(haystack, needle)
    }

    let len = haystack.len();
    let ptr = haystack.as_ptr();
    if len < 16 {
        return unlikely_find(haystack, needle);
    }

    let mut i = 0;
    let needle16 = u8x16::splat(needle);

    while i <= len - 16 {
        let mut bytes = [0; 16];
        unsafe { ptr::copy_nonoverlapping(ptr.add(i), bytes.as_mut_ptr(), 16) };

        let bytes = u8x16::from_array(bytes);
        let eq = bytes.simd_eq(needle16).to_int();
        let num = unsafe { std::mem::transmute::<Simd<i8, 16>, u128>(eq) };
        if num != 0 {
            return Some(i + (num.trailing_zeros() >> 3) as usize);
        }

        i += 16;
    }

    fallback::find(&haystack[i..], needle).map(|x| i + x)
}

/// Optimized function for finding one of 4 bytes in `haystack`
pub fn find4(haystack: &[u8], needle: [u8; 4]) -> Option<usize> {
    #[inline(never)]
    #[cold]
    fn unlikely_find(haystack: &[u8], needle: [u8; 4]) -> Option<usize> {
        fallback::find_multi(haystack, needle)
    }

    let len = haystack.len();
    let ptr = haystack.as_ptr();
    if len < 16 {
        return unlikely_find(haystack, needle);
    }

    let mut i = 0;
    let needle16a = u8x16::splat(needle[0]);
    let needle16b = u8x16::splat(needle[1]);
    let needle16c = u8x16::splat(needle[2]);
    let needle16d = u8x16::splat(needle[3]);

    while i <= len - 16 {
        let mut bytes = [0; 16];
        unsafe { ptr::copy_nonoverlapping(ptr.add(i), bytes.as_mut_ptr(), 16) };

        let bytes = u8x16::from_array(bytes);

        let eq1 = bytes.simd_eq(needle16a);
        let eq2 = bytes.simd_eq(needle16b);
        let eq3 = bytes.simd_eq(needle16c);
        let eq4 = bytes.simd_eq(needle16d);
        let or = (eq1 | eq2 | eq3 | eq4).to_int();
        let num = unsafe { std::mem::transmute::<i8x16, u128>(or) };
        if num != 0 {
            return Some(i + (num.trailing_zeros() >> 3) as usize);
        }

        i += 16;
    }

    fallback::find_multi(&haystack[i..], needle).map(|x| i + x)
}

/// Optimized function for searching for the first non-identifier
pub fn search_non_ident(haystack: &[u8]) -> Option<usize> {
    #[inline(never)]
    #[cold]
    fn unlikely_search(haystack: &[u8]) -> Option<usize> {
        fallback::search_non_ident(haystack)
    }

    let len = haystack.len();
    let ptr = haystack.as_ptr();
    if len < 16 {
        return unlikely_search(haystack);
    }

    let mut i = 0;
    let needle_zero = u8x16::splat(b'0');
    let needle_nine = u8x16::splat(b'9');
    let needle_lc_a = u8x16::splat(b'a');
    let needle_lc_z = u8x16::splat(b'z');
    let needle_uc_a = u8x16::splat(b'A');
    let needle_uc_z = u8x16::splat(b'Z');
    let needle_minus = u8x16::splat(b'-');
    let needle_underscore = u8x16::splat(b'_');

    while i <= len - 16 {
        let mut bytes = [0; 16];
        unsafe { ptr::copy_nonoverlapping(ptr.add(i), bytes.as_mut_ptr(), 16) };

        let bytes = u8x16::from_array(bytes);

        let ge_zero = bytes.simd_ge(needle_zero);
        let le_nine = bytes.simd_le(needle_nine);
        let digit = ge_zero & le_nine;

        let ge_lc_a = bytes.simd_ge(needle_lc_a);
        let le_lc_z = bytes.simd_le(needle_lc_z);
        let lowercase = ge_lc_a & le_lc_z;

        let ge_uc_a = bytes.simd_ge(needle_uc_a);
        let le_uc_z = bytes.simd_le(needle_uc_z);
        let uppercase = ge_uc_a & le_uc_z;

        let eq_minus = bytes.simd_eq(needle_minus);
        let eq_underscore = bytes.simd_eq(needle_underscore);
        let symbol = eq_minus | eq_underscore;

        let or = !(digit | lowercase | uppercase | symbol).to_int();

        let num = unsafe { std::mem::transmute::<i8x16, u128>(or) };
        if num != 0 {
            return Some(i + (num.trailing_zeros() >> 3) as usize);
        }

        i += 16;
    }

    fallback::search_non_ident(&haystack[i..]).map(|x| i + x)
}

/// Optimized function for checking if a byte is a closing tag
#[inline]
pub fn is_closing(needle: u8) -> bool {
    (needle == b'/') | (needle == b'>')
}