zenkey 0.3.0

Executable form of the keyspace-v2 Zenoh semantic convention: typed key grammar, origin minting, slugs, QoS profiles, registry slices
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

//! Canonical, injective slugging of foreign values into key chunks (RFC 03 §2).
//!
//! Rules:
//! - **IPs are always slugged**, even charset-legal dotted IPv4 (dotted forms
//!   are non-canonical chunks). IPv6 is canonicalized per RFC 5952 and IPv4 to
//!   minimal dotted-quad first, then `.`/`:` → `-`.
//! - Other values (unit names, filenames, config names) stay literal when
//!   already legal per the chunk charset; otherwise each excluded character is
//!   escaped losslessly as `_xNN_` (lowercase hex of the byte). Plain `-`
//!   substitution is forbidden — it is not injective.

use std::net::IpAddr;

use crate::grammar::is_valid_plain_chunk;

/// Slug an IP address (RFC 03 §2). `std`'s `Display` for `Ipv6Addr` is
/// RFC 5952-conformant (lowercase, `::` compression), so parsing + formatting
/// *is* the canonicalization.
pub fn ip_slug(ip: IpAddr) -> String {
    ip.to_string().replace(['.', ':'], "-")
}

/// Parse-and-slug a textual IP; returns `None` when the text is not an IP
/// (callers then fall back to [`chunk_slug`] for hostnames).
pub fn ip_slug_str(text: &str) -> Option<String> {
    text.parse::<IpAddr>().ok().map(ip_slug)
}

/// Slug an arbitrary value (unit name, filename, device name) into a single
/// legal chunk, losslessly (RFC 03 §2).
pub fn chunk_slug(value: &str) -> String {
    if is_valid_plain_chunk(value) {
        return value.to_string();
    }
    let mut out = String::with_capacity(value.len() + 8);
    for &b in value.as_bytes() {
        let c = b as char;
        let legal_inner =
            c.is_ascii_lowercase() || c.is_ascii_digit() || c == '.' || c == '_' || c == '-';
        if legal_inner {
            out.push(c);
        } else {
            out.push_str(&format!("_x{b:02x}_"));
        }
    }
    // The escape may leave an illegal first/last byte (e.g. leading '.') —
    // guard the boundary bytes the same lossless way.
    let bytes = out.as_bytes();
    let boundary_ok = |b: u8| b.is_ascii_lowercase() || b.is_ascii_digit();
    let fix_first = !bytes.is_empty() && !boundary_ok(bytes[0]) && bytes[0] != b'_';
    let fix_last =
        bytes.len() > 1 && !boundary_ok(bytes[bytes.len() - 1]) && bytes[bytes.len() - 1] != b'_';
    let mut fixed = String::new();
    for (i, &b) in out.as_bytes().iter().enumerate() {
        let at_first = i == 0 && fix_first;
        let at_last = i == out.len() - 1 && fix_last;
        if at_first || at_last {
            fixed.push_str(&format!("_x{b:02x}_"));
        } else {
            fixed.push(b as char);
        }
    }
    // `_xNN_` starts/ends with '_', which the charset forbids at boundaries;
    // pad with the sentinel 'e' ("escaped") on each affected side.
    let mut result = fixed;
    if result.starts_with('_') {
        result.insert(0, 'e');
    }
    if result.ends_with('_') {
        result.push('e');
    }
    result
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::collections::HashSet;

    #[test]
    fn ipv4_always_slugged() {
        assert_eq!(ip_slug_str("10.0.0.7").unwrap(), "10-0-0-7");
        assert_eq!(ip_slug_str("93.184.216.34").unwrap(), "93-184-216-34");
    }

    #[test]
    fn ipv6_rfc5952_canonical_before_slugging() {
        // Two spellings of one address MUST slug identically (RFC 03 §2).
        let a = ip_slug_str("2001:db8::1").unwrap();
        let b = ip_slug_str("2001:db8:0:0:0:0:0:1").unwrap();
        let c = ip_slug_str("2001:DB8::1").unwrap();
        assert_eq!(a, "2001-db8--1");
        assert_eq!(a, b);
        assert_eq!(a, c);
    }

    #[test]
    fn legal_values_stay_literal() {
        assert_eq!(chunk_slug("sshd.service"), "sshd.service");
        assert_eq!(chunk_slug("cam0"), "cam0");
    }

    #[test]
    fn escape_is_injective() {
        // The RFC's motivating counterexample: these MUST NOT share a chunk.
        let a = chunk_slug("foo@1.service");
        let b = chunk_slug("foo-1.service");
        assert_ne!(a, b);
        assert_eq!(a, "foo_x40_1.service");

        // Property check over a corpus of near-collisions.
        let corpus = [
            "getty@tty1.service",
            "getty-tty1.service",
            "a b",
            "a_b",
            "a-b",
            "A",
            "a",
            "Ab",
            "a.b",
            ".ab",
            "ab.",
            "café",
            "unit@.service",
        ];
        let slugs: Vec<String> = corpus.iter().map(|v| chunk_slug(v)).collect();
        let unique: HashSet<&String> = slugs.iter().collect();
        assert_eq!(unique.len(), corpus.len(), "collision in {slugs:?}");
        for s in &slugs {
            assert!(
                crate::grammar::is_valid_plain_chunk(s),
                "illegal slug {s:?}"
            );
        }
    }
}