syscall_map/
hash.rs

1/// MurmurHash3 32-bit hash function (const-compatible)
2pub const fn murmur3_32(buf: &str) -> u32 {
3    const fn pre_mix(buf: [u8; 4]) -> u32 {
4        u32::from_le_bytes(buf)
5            .wrapping_mul(0xcc9e2d51)
6            .rotate_left(15)
7            .wrapping_mul(0x1b873593)
8    }
9
10    let mut hash = 0;
11    let mut i = 0;
12    let buf = buf.as_bytes();
13
14    while i < buf.len() / 4 {
15        let buf = [buf[i * 4], buf[i * 4 + 1], buf[i * 4 + 2], buf[i * 4 + 3]];
16        hash ^= pre_mix(buf);
17        hash = hash.rotate_left(13);
18        hash = hash.wrapping_mul(5).wrapping_add(0xe6546b64);
19
20        i += 1;
21    }
22
23    match buf.len() % 4 {
24        0 => {}
25        1 => {
26            hash = hash ^ pre_mix([buf[i * 4], 0, 0, 0]);
27        }
28        2 => {
29            hash = hash ^ pre_mix([buf[i * 4], buf[i * 4 + 1], 0, 0]);
30        }
31        3 => {
32            hash = hash ^ pre_mix([buf[i * 4], buf[i * 4 + 1], buf[i * 4 + 2], 0]);
33        }
34        _ => { /* unreachable!() */ }
35    }
36
37    hash = hash ^ buf.len() as u32;
38    hash = hash ^ (hash.wrapping_shr(16));
39    hash = hash.wrapping_mul(0x85ebca6b);
40    hash = hash ^ (hash.wrapping_shr(13));
41    hash = hash.wrapping_mul(0xc2b2ae35);
42    hash = hash ^ (hash.wrapping_shr(16));
43
44    hash
45}
46
47#[cfg(test)]
48mod tests {
49    use super::*;
50
51    #[test]
52    fn test_murmur3_hash() {
53        // Test hash function is deterministic
54        assert_eq!(murmur3_32("abort"), murmur3_32("abort"));
55        assert_ne!(murmur3_32("abort"), murmur3_32("sol_log_"));
56    }
57
58    #[test]
59    fn test_murmur3_known_values() {
60        // Test some known hash values to ensure consistency
61        const ABORT_HASH: u32 = murmur3_32("abort");
62        const SOL_LOG_HASH: u32 = murmur3_32("sol_log_");
63
64        // These should remain constant across runs
65        assert_eq!(murmur3_32("abort"), ABORT_HASH);
66        assert_eq!(murmur3_32("sol_log_"), SOL_LOG_HASH);
67    }
68}
syscall_map/hash.rs

syscall_map/
hash.rs
