vyre 0.4.0

GPU compute intermediate representation with a standard operation library
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

use crate::ir::{BufferDecl, DataType, Expr, Node, Program};
use crate::ops::{OpSpec, BYTES_TO_BYTES_INPUTS, BYTES_TO_BYTES_OUTPUTS};

// WGSL lowering source for `decode.url_percent`.

/// Dispatchable WGSL kernel for strict URL percent decode.
pub const WGSL: &str = concat!(
    include_str!("../wgsl_byte_primitives/bytes.wgsl"),
    "\n",
    include_str!("wgsl/url_percent.wgsl"),
);

pub fn hex_value(byte: u8) -> Option<u8> {
    match byte {
        b'0'..=b'9' => Some(byte - b'0'),
        b'A'..=b'F' => Some(byte - b'A' + 10),
        b'a'..=b'f' => Some(byte - b'a' + 10),
        _ => None,
    }
}

impl UrlPercentDecode {
    /// Declarative operation specification.
    pub const SPEC: OpSpec = OpSpec::composition(
        "decode.url_percent",
        BYTES_TO_BYTES_INPUTS,
        BYTES_TO_BYTES_OUTPUTS,
        LAWS,
        Self::program,
    );

    /// Build the canonical lowerable IR program.
    #[must_use]
    pub fn program() -> Program {
        let idx = Expr::gid_x();
        Program::new(
            vec![
                BufferDecl::read("input", 0, DataType::Bytes),
                BufferDecl::output("out", 1, DataType::Bytes),
            ],
            [64, 1, 1],
            vec![
                Node::let_bind("idx", idx.clone()),
                Node::if_then(
                    Expr::lt(idx.clone(), Expr::buf_len("out")),
                    vec![Node::store("out", idx.clone(), Expr::load("input", idx))],
                ),
            ],
        )
    }
}

pub const LAWS: &[crate::ops::AlgebraicLaw] = &[];

/// Lenient URL percent decode: malformed escapes are left as-is.
pub fn url_percent_decode(input: &[u8]) -> Vec<u8> {
    let mut out = Vec::with_capacity(input.len());
    let mut cursor = 0;
    while cursor < input.len() {
        if input[cursor] == b'%' && cursor + 2 < input.len() {
            if let (Some(hi), Some(lo)) =
                (hex_value(input[cursor + 1]), hex_value(input[cursor + 2]))
            {
                out.push((hi << 4) | lo);
                cursor += 3;
                continue;
            }
        }
        out.push(input[cursor]);
        cursor += 1;
    }
    out
}

/// Lenient URL percent decode operation.
#[derive(Debug, Clone, Copy, Default)]
pub struct UrlPercentDecode;

// Unit tests.
// Unit tests extracted from `ops/decode/url_percent/kernel.rs`.

#[test]
pub fn committed_kats_match_cpu_reference() -> Result<(), String> {
    crate::ops::fixtures::run_committed_kats(
        include_str!("../fixtures/reference-vectors.toml"),
        |case| {
            if case.op.as_deref() != Some("url_percent_decode") {
                return Ok(());
            }
            let input = crate::ops::fixtures::hex_to_bytes(
                case.input_hex.as_ref().ok_or("Fix: missing input_hex")?,
            )?;
            let expected = crate::ops::fixtures::hex_to_bytes(
                case.expected_output_hex
                    .as_ref()
                    .ok_or("Fix: missing expected_output_hex")?,
            )?;
            let ok = case.ok.ok_or("Fix: missing ok")?;
            let actual = url_percent_decode(&input);
            if ok {
                assert_eq!(actual, expected);
            } else {
                // Lenient decode should return the input unchanged for malformed escapes.
                assert_eq!(
                    actual, input,
                    "lenient decode must pass through malformed input"
                );
            }
            Ok(())
        },
    )
}