Repo of no-std crates for my personal embedded projects
feat: FNV hasher crate
authored by
Sachymetsu
and committed by
Tangled
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70fade2f
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.tangled/workflows/test.yml
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.tangled/workflows/test.yml
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Cargo.lock
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Cargo.lock
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Cargo.toml
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Cargo.toml
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sachy-fnv/Cargo.toml
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sachy-fnv/Cargo.toml
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sachy-fnv/src/lib.rs
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sachy-fnv/src/lib.rs
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//! This crate provides a `const` FNV32 hasher for the purpose of supporting the ESPHome/Home Assistant protocol where required.
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//!
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//! ```
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//! use sachy_fnv::fnv32_hash;
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//!
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//! let hash = fnv32_hash("water_pump_1");
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//!
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//! assert_eq!(hash, 3557162331);
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//! ```
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#![no_std]
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const FNV_OFFSET_BASIS_32: u32 = 0x811c9dc5;
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const FNV_PRIME_32: u32 = 0x01000193;
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/// `const` FNV32 hasher. Takes a `&str` and returns a `u32` hash.
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pub const fn fnv32_hash(str: &str) -> u32 {
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let bytes = str.as_bytes();
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let mut hash = FNV_OFFSET_BASIS_32;
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let mut i = 0;
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let len = bytes.len();
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while i < len {
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hash = hash.wrapping_mul(FNV_PRIME_32);
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hash ^= bytes[i] as u32;
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i += 1;
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}
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hash
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn it_works() {
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let result = fnv32_hash("water_pump_1");
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assert_eq!(result, 3557162331);
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let result = fnv32_hash("pump_1_duration");
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assert_eq!(result, 931766070);
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}
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}