fnv.nx

RETIRED 2026-07-30 -- moved here from runtime/fnv.nx. PRESERVED VERBATIM BELOW, NOT DELETED (rule 13). WHY IT WAS RETIRED: it defined `fnv1a`, `fnv1a_init`, `fnv1a_update` and `fnv1a_cstr` -- THE EXACT FOUR SYMBOLS the canonical runtime/nx_fnv.nx defines -- with a byte-identical algorithm and identical constants. The ONLY difference was `import "syscalls.nx"` vs `import "nx_syscalls.nx"`. TWO FILES CLAIMING TO BE THE CANONICAL HASH IS WORSE THAN NONE: nx_fnv.nx's own header carries the cardinal law "All other primitives needing FNV-1a MUST import nx_fnv.nx ... never re-implement a hash inline" -- but that law names a target that was AMBIGUOUS, and any organ importing both would collide symbol-for-symbol. MEASURED BEFORE RETIRING (complete scan of buildroot, not a partial one): runtime/fnv.nx 2577 B -- 0 importers runtime/nx_fnv.nx 3067 B -- 7 importers <- canonical, keeps the name the law points at A sovereign nx_shelltool scan returned 0 matches too, but reported PARTIAL (budget-exceeded at 15315 of ~19940 files) -- and ZERO ON A PARTIAL SCAN IS NOT PROOF OF ABSENCE, so the count above is from a complete scan. The tool was right to say so; the reading would have been wrong to trust. TO RESURRECT: copy this file back to runtime/fnv.nx and change the import to nx_syscalls.nx -- but do not, because nx_fnv.nx already is this, and re-adding it re-creates the ambiguity. license_tier: ORIGINAL No hw writes (Rule 26). ---------------- ORIGINAL CONTENT, VERBATIM ---------------- fnv.nx -- FNV-1a non-cryptographic hash (Fowler-Noll-Vo). 64-bit FNV-1a. Used for: hash table keying, file fingerprinting, Bloom filter mixing, deduplication. NOT for security -- an attacker who controls input can construct collisions. For cryptographic hashing use sha256 / sha512 / sha3. Algorithm (Fowler-Noll-Vo 1991; rfc draft-eastlake-fnv): hash = FNV_OFFSET_BASIS for each byte b in input: hash = hash XOR b hash = hash * FNV_PRIME FNV-1a (xor-then-multiply) has better avalanche than plain FNV-1 (multiply-then-xor) so we implement 1a.