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mirror of https://github.com/janet-lang/janet synced 2025-01-10 23:50:26 +00:00

Add an extra has mix round to string hashes.

This should improve hashing quality of strings.
This commit is contained in:
Calvin Rose 2024-11-17 11:31:12 -06:00
parent bafa6bfff0
commit 5d1bd8a932

View File

@ -117,14 +117,20 @@ const char *const janet_status_names[16] = {
"alive"
};
uint32_t janet_hash_mix(uint32_t input, uint32_t more) {
uint32_t mix1 = (more + 0x9e3779b9 + (input << 6) + (input >> 2));
return input ^ (0x9e3779b9 + (mix1 << 6) + (mix1 >> 2));
}
#ifndef JANET_PRF
int32_t janet_string_calchash(const uint8_t *str, int32_t len) {
if (NULL == str) return 5381;
if (NULL == str || len == 0) return 5381;
const uint8_t *end = str + len;
uint32_t hash = 5381;
while (str < end)
hash = (hash << 5) + hash + *str++;
hash = janet_hash_mix(hash, (uint32_t) len);
return (int32_t) hash;
}
@ -240,11 +246,6 @@ int32_t janet_string_calchash(const uint8_t *str, int32_t len) {
#endif
uint32_t janet_hash_mix(uint32_t input, uint32_t more) {
uint32_t mix1 = (more + 0x9e3779b9 + (input << 6) + (input >> 2));
return input ^ (0x9e3779b9 + (mix1 << 6) + (mix1 >> 2));
}
/* Computes hash of an array of values */
int32_t janet_array_calchash(const Janet *array, int32_t len) {
const Janet *end = array + len;