python - 128 bit Integer hash function -

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looking string integer hash function values in range of mysql bigint unsigned datatype (0 <= n <= 18446744073709551615). converting md5/sha1 integer base of 16 not fit requirement.

java uses rolling hash should work you

from java.lang.string :

public int hashcode() {     int h = hash;     if (h == 0 && count > 0) {         int off = offset;         char val[] = value;         int len = count;          (int = 0; < len; i++) {             h = 31*h + val[off++];         }         hash = h;     }     return h; }

the idea calculate hash :

s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

to deal overflow, can add step hash checked against 18446744073709551615 , if larger take mod of hash , 18446744073709551615.


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