about

collection of lightweight implementations of the non-cryptographic hash algorithms, with compile-time variants for each. list of the implemented algorithms:

• CRC 32
• DJB2 32
• DJB2A 32
• FNV1A 32/64
• MURMUR2 32/64
• MURMUR2A 32
• MURMUR3 32

usage

all hash implementations have a uniform appearance, so the example usage also remains same for the all of them.

to generate hash of the byte buffer:

CRC32_t uHash = CRC32::Hash(pBuffer, nBufferSize);

// custom basis
CRC32_t uBasisHash = CRC32::Hash(pBuffer, nBufferSize, 0xFFFFFFFF);

to generate hash of string:

CRC32_t uHash = CRC32::Hash(pBuffer, nBufferSize);

// custom basis
CRC32_t uBasisHash = CRC32::Hash(pBuffer, nBufferSize, 0xFFFFFFFF);

to generate hash of string, guaranteed at compile-time:

CRC32_t uHash = CRC32::HashConst("example");

// custom basis
CRC32_t uBasisHash = CRC32::HashConst("example", 0xFFFFFFFF);

every hash's constant can be overwritten with appropriate definitions:

hash	definition
CRC 32	Q_HASH_CRC32_POLY
DJB2	Q_HASH_DJB2_BASIS
DJB2A	Q_HASH_DJB2A_BASIS
FNV1A	Q_HASH_FNV1A_BASIS, Q_HASH_FNV1A_PRIME
FNV1A 64	Q_HASH_FNV1A_64_BASIS, Q_HASH_FNV1A_64_PRIME
MURMUR2	Q_HASH_MURMUR2_MODULO
MURMUR2 64	Q_HASH_MURMUR2_64_MODULO
MURMUR2A	Q_HASH_MURMUR2A_MODULO
MURMUR3	Q_HASH_MURMUR3_FIRST, Q_HASH_MURMUR3_SECOND, Q_HASH_MURMUR3_THIRD, Q_HASH_MURMUR3_AVALANCHE_FIRST, Q_HASH_MURMUR3_AVALANCHE_SECOND

other options available for various algorithms:

hash	definition	note
CRC 32	Q_HASH_CRC32_NO_LUT	do not use lookup table for the hash calculation, saves ~1KB of the binary size

further information

has opt-in integration with the common and crt libraries. you can read about installation, contributing and look for other general information on the q-tee main page.