c_cpp 16位哈希

Posted 2021-05-14

/*
 * hash_16
 *   DESCRIPTION: Produces a 16-bit hash of the input given the length.
 *                Currently uses Bernstein-like hash; we may want to consider
 *                another hashing algorithm later if we need to.
 *   INPUTS: unsigned char* input - bytestring to be hashed
 *           int length - number of bytes to read from input
 *   OUTPUTS: 16-bit hash of the input
 */
uint16_t hash16(uint8_t* input, int length) {
    uint16_t hash = 5381;   // seed for Bernstein hash
    int i;
    // Hash over all bytes in input
    for(i = 0; i < length; i++) {
        hash = ((hash << 5) + hash) + *input++;
    }
    return hash;
}