ChargeHash

ChargeHash (as a proprietary, source-available product of Eightomic) is the fast constrained hash (non-cryptographic) that has "one-at-a-time" (OAAT) byte copying with a single byte hashed in each loop iteration, excellent non-cryptographic output quality (passed 32-bit SMHasher3 --extra tests), excellent non-cryptographic security properties (light resistance against both HashDoS and length-extension attacks), low-footprint implementation (efficient memory usage and small code size), no division/modulus/multiplication operators and ultra-fast speed (relative to the aforementioned constraints).

ChargeHash is implemented in C (requiring the stdint.h header to define unsigned integral types for both an 8-bit uint8_t and a 32-bit uint32_t).

chargehash.c

The chargehash function uses a uint32_t seed integer to hash a key array of key_length uint8_t integers and return a uint32_t digest.

Each of the following results log the fastest process execution speed (in milliseconds) among several repetitions of a speed benchmark (with gcc -O0 from an AMD A4-9120C) that hashes 1 million key_length pseudorandom keys in a blocking #pragma GCC unroll 0 loop.

key_length   Elapsed        Elapsed
             (chargehash)   (goodoaat)

1            35ms           49ms
2            48ms           58ms
3            51ms           71ms
4            59ms           84ms
5            66ms           96ms
6            76ms           110ms
7            81ms           123ms
8            88ms           135ms
12           109ms          188ms
16           146ms          238ms
32           254ms          447ms
64           484ms          850ms
128          862ms          1780ms
256          1668ms         3378ms