vrl/stdlib/
decode_base16.rs

1use crate::compiler::prelude::*;
2use nom::AsBytes;
3use std::str;
4
5fn decode_base16(value: &Value) -> Resolved {
6    match base16::decode(&value.try_bytes_utf8_lossy()?.to_string()) {
7        Ok(s) => Ok((s.as_bytes()).into()),
8        Err(_) => Err("unable to decode value to base16".into()),
9    }
10}
11
12#[derive(Clone, Copy, Debug)]
13pub struct DecodeBase16;
14
15impl Function for DecodeBase16 {
16    fn identifier(&self) -> &'static str {
17        "decode_base16"
18    }
19
20    fn usage(&self) -> &'static str {
21        "Decodes the `value` (a [Base16](https://en.wikipedia.org/wiki/Hexadecimal) string) into its original string."
22    }
23
24    fn category(&self) -> &'static str {
25        Category::Codec.as_ref()
26    }
27
28    fn internal_failure_reasons(&self) -> &'static [&'static str] {
29        &["`value` isn't a valid encoded Base16 string."]
30    }
31
32    fn return_kind(&self) -> u16 {
33        kind::BYTES
34    }
35
36    fn parameters(&self) -> &'static [Parameter] {
37        const PARAMETERS: &[Parameter] = &[Parameter::required(
38            "value",
39            kind::BYTES,
40            "The [Base16](https://en.wikipedia.org/wiki/Hexadecimal) data to decode.",
41        )];
42        PARAMETERS
43    }
44
45    fn compile(
46        &self,
47        _state: &state::TypeState,
48        _ctx: &mut FunctionCompileContext,
49        arguments: ArgumentList,
50    ) -> Compiled {
51        let value = arguments.required("value");
52
53        Ok(DecodeBase16Fn { value }.as_expr())
54    }
55
56    fn examples(&self) -> &'static [Example] {
57        &[
58            example! {
59                title: "Decode Base16 data",
60                source: r#"decode_base16!("736F6D6520737472696E672076616C7565")"#,
61                result: Ok("some string value"),
62            },
63            example! {
64                title: "Decode longer Base16 data",
65                source: r#"decode_base16!("796f752068617665207375636365737366756c6c79206465636f646564206d65")"#,
66                result: Ok("you have successfully decoded me"),
67            },
68        ]
69    }
70}
71
72#[derive(Clone, Debug)]
73struct DecodeBase16Fn {
74    value: Box<dyn Expression>,
75}
76
77impl FunctionExpression for DecodeBase16Fn {
78    fn resolve(&self, ctx: &mut Context) -> Resolved {
79        let value = self.value.resolve(ctx)?;
80
81        decode_base16(&value)
82    }
83
84    fn type_def(&self, _: &state::TypeState) -> TypeDef {
85        // Always fallible due to the possibility of decoding errors that VRL can't detect in `base16`
86        TypeDef::bytes().fallible()
87    }
88}
89
90#[cfg(test)]
91mod test {
92    use super::*;
93    use crate::value;
94
95    test_function![
96        decode_base16 => DecodeBase16;
97
98        standard {
99            args: func_args![value: value!("736F6D652B3D737472696E672F76616C7565")],
100            want: Ok(value!("some+=string/value")),
101            tdef: TypeDef::bytes().fallible(),
102        }
103    ];
104}
vrl/stdlib/decode_base16.rs

vrl/stdlib/
decode_base16.rs
