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gluon-web: template_lmo: clean up sfh_hash()

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This commit is contained in:
Matthias Schiffer 2018-02-22 14:06:12 +01:00
parent 9e8a6ec2b5
commit f957593f26
No known key found for this signature in database
GPG Key ID: 16EF3F64CB201D9C
2 changed files with 21 additions and 31 deletions
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45
package/gluon-web/src/template_lmo.c
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@ -22,40 +22,37 @@
* Hash function from http://www.azillionmonkeys.com/qed/hash.html
* Copyright (C) 2004-2008 by Paul Hsieh
*/
static inline uint16_t get_le16(const uint8_t *d) {
return (((uint16_t)d[1]) << 8) | d[0];
}
static uint32_t sfh_hash(const char *data, int len)
static uint32_t sfh_hash(const uint8_t *data, int len)
{
uint32_t hash = len, tmp;
int rem;
if (len <= 0 || data == NULL) return 0;
rem = len & 3;
len >>= 2;
/* Main loop */
for (;len > 0; len--) {
hash += sfh_get16(data);
tmp = (sfh_get16(data+2) << 11) ^ hash;
for (; len > 3; len -= 4) {
hash += get_le16(data);
tmp = (get_le16(data+2) << 11) ^ hash;
hash = (hash << 16) ^ tmp;
data += 2*sizeof(uint16_t);
data += 4;
hash += hash >> 11;
}
/* Handle end cases */
switch (rem) {
case 3: hash += sfh_get16(data);
hash ^= hash << 16;
hash ^= data[sizeof(uint16_t)] << 18;
hash += hash >> 11;
break;
case 2: hash += sfh_get16(data);
hash ^= hash << 11;
hash += hash >> 17;
break;
case 1: hash += *data;
hash ^= hash << 10;
hash += hash >> 1;
switch (len) {
case 3: hash += get_le16(data);
hash ^= hash << 16;
hash ^= data[2] << 18;
hash += hash >> 11;
break;
case 2: hash += get_le16(data);
hash ^= hash << 11;
hash += hash >> 17;
break;
case 1: hash += *data;
hash ^= hash << 10;
hash += hash >> 1;
}
/* Force "avalanching" of final 127 bits */

7
package/gluon-web/src/template_lmo.h
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@ -34,13 +34,6 @@
#include <ctype.h>
#include <limits.h>
#if (defined(__GNUC__) && defined(__i386__))
#define sfh_get16(d) (*((const uint16_t *) (d)))
#else
#define sfh_get16(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
+(uint32_t)(((const uint8_t *)(d))[0]) )
#endif
struct lmo_entry {
uint32_t key_id;