Mirrors/the-algorithm
2
0
Fork 0
mirror of https://github.com/twitter/the-algorithm.git synced 2024-12-22 02:01:51 +01:00
Code Issues Packages Projects Releases Wiki Activity

Update utilities.h

Browse Source 
Fix and optimize mixDiscreteIdAndValue() and mixStringIdAndValue() functions
This commit is contained in:
Leon Banik 2023-04-01 17:57:31 +02:00 committed by GitHub
parent ec83d01dca
commit ca2cc4c12f
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 17 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
twml/libtwml/include/twml/utilities.h
View File

@ -1,18 +1,21 @@
#pragma once
#ifdef __cplusplus
#include <cstdint>
#include <cstring>
namespace twml {
inline int64_t mixDiscreteIdAndValue(int64_t key, int64_t value) {
key ^= ((17LL + value) * 2654435761LL);
return key;
}
inline int64_t mixDiscreteIdAndValue(int64_t key, int64_t value) {
key ^= ((17LL + value) * 2654435761LL);
return key;
}
inline int64_t mixStringIdAndValue(int64_t key, int32_t str_len, const uint8_t *str) {
int32_t hash = 0;
for (int32_t i = 0; i < str_len; i++) {
hash = (31 * hash) + (int32_t)str[i];
}
return key ^ hash;
}
}
#endif
inline int64_t mixStringIdAndValue(int64_t key, int32_t str_len, const uint8_t* str) {
const uint8_t* end = str + str_len;
while (str != end) {
key = (key * 31) + *str++;
}
return key;
}
} // namespace twml