murmur3.nx

murmur3.nx -- MurmurHash3 (Austin Appleby 2008/2011). Fast non-cryptographic hash. Distributes well across the output range, fast (4-byte chunks), suitable for hash tables when adversarial inputs aren't a concern (otherwise use siphash.nx). Used by: ClickHouse, Cassandra, Hadoop, Lucene, RocksDB secondary indices, Bloom filters, sketch data structures. We ship only the 32-bit variant (MurmurHash3_x86_32) because it's the most widely deployed. 64-bit and 128-bit variants exist (x86_128, x64_128) and produce different output. Invariants: MM1 Pure function: hash(seed, bytes) is deterministic; no global state, no random. MM2 Output is exactly 32 bits packed into i64's low half. MM3 NOT cryptographically secure. An attacker can craft keys that collide; never use as a MAC or to defend against algorithmic-complexity attacks on hash tables in adversarial contexts.