sstrhash.c

#include "sstrhash.h"

#include <stdint.h>
#include <string.h>

#define mix(a,b,c) \
{ \
  a -= b; a -= c; a ^= (c>>13); \
  b -= c; b -= a; b ^= (a<<8); \
  c -= a; c -= b; c ^= (b>>13); \
  a -= b; a -= c; a ^= (c>>12);  \
  b -= c; b -= a; b ^= (a<<16); \
  c -= a; c -= b; c ^= (b>>5); \
  a -= b; a -= c; a ^= (c>>3);  \
  b -= c; b -= a; b ^= (a<<10); \
  c -= a; c -= b; c ^= (b>>15); \
}

static uint32_t hash(uint8_t *k, uint32_t length, uint32_t initval)
{
   register uint32_t a,b,c,len;

   /* Set up the internal state */
   len = length;
   a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */
   c = initval;         /* the previous hash value */

   /*---------------------------------------- handle most of the key */
   while (len >= 12)
   {
      a += (k[0] +((uint32_t)k[1]<<8) +((uint32_t)k[2]<<16) +((uint32_t)k[3]<<24));
      b += (k[4] +((uint32_t)k[5]<<8) +((uint32_t)k[6]<<16) +((uint32_t)k[7]<<24));
      c += (k[8] +((uint32_t)k[9]<<8) +((uint32_t)k[10]<<16)+((uint32_t)k[11]<<24));
      mix(a,b,c);
      k += 12; len -= 12;
   }

   /*------------------------------------- handle the last 11 bytes */
   c += length;
   switch(len)              /* all the case statements fall through */
   {
   case 11: c+=((uint32_t)k[10]<<24);
   case 10: c+=((uint32_t)k[9]<<16);
   case 9 : c+=((uint32_t)k[8]<<8);
      /* the first byte of c is reserved for the length */
   case 8 : b+=((uint32_t)k[7]<<24);
   case 7 : b+=((uint32_t)k[6]<<16);
   case 6 : b+=((uint32_t)k[5]<<8);
   case 5 : b+=k[4];
   case 4 : a+=((uint32_t)k[3]<<24);
   case 3 : a+=((uint32_t)k[2]<<16);
   case 2 : a+=((uint32_t)k[1]<<8);
   case 1 : a+=k[0];
     /* case 0: nothing left to add */
   }
   mix(a,b,c);
   /*-------------------------------------------- report the result */
   return c;
}

#undef mix

uint32_t hashfunc(uint8_t *key){
    return hash(key, strlen(key), 0);
}

uint32_t SStrHash2(uint8_t *key){
    uint8_t buff[0x400];
    uint32_t len=0;
    while(*key){
        if(*key <'a' || *key>'z'){
            if(*key == '/'){
                buff[len] = '\\';
            }else{
                buff[len] = *key;
            }
        }else{
            buff[len] = *key - 0x20;
        }
        key++;
        len++;
    }
    return hash(buff, len, 0);
}