mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 05:02:12 +00:00
df561f6688
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
132 lines
2.9 KiB
C
132 lines
2.9 KiB
C
|
|
#include <linux/ceph/types.h>
|
|
#include <linux/module.h>
|
|
|
|
/*
|
|
* Robert Jenkin's hash function.
|
|
* https://burtleburtle.net/bob/hash/evahash.html
|
|
* This is in the public domain.
|
|
*/
|
|
#define mix(a, b, c) \
|
|
do { \
|
|
a = a - b; a = a - c; a = a ^ (c >> 13); \
|
|
b = b - c; b = b - a; b = b ^ (a << 8); \
|
|
c = c - a; c = c - b; c = c ^ (b >> 13); \
|
|
a = a - b; a = a - c; a = a ^ (c >> 12); \
|
|
b = b - c; b = b - a; b = b ^ (a << 16); \
|
|
c = c - a; c = c - b; c = c ^ (b >> 5); \
|
|
a = a - b; a = a - c; a = a ^ (c >> 3); \
|
|
b = b - c; b = b - a; b = b ^ (a << 10); \
|
|
c = c - a; c = c - b; c = c ^ (b >> 15); \
|
|
} while (0)
|
|
|
|
unsigned int ceph_str_hash_rjenkins(const char *str, unsigned int length)
|
|
{
|
|
const unsigned char *k = (const unsigned char *)str;
|
|
__u32 a, b, c; /* the internal state */
|
|
__u32 len; /* how many key bytes still need mixing */
|
|
|
|
/* Set up the internal state */
|
|
len = length;
|
|
a = 0x9e3779b9; /* the golden ratio; an arbitrary value */
|
|
b = a;
|
|
c = 0; /* variable initialization of internal state */
|
|
|
|
/* handle most of the key */
|
|
while (len >= 12) {
|
|
a = a + (k[0] + ((__u32)k[1] << 8) + ((__u32)k[2] << 16) +
|
|
((__u32)k[3] << 24));
|
|
b = b + (k[4] + ((__u32)k[5] << 8) + ((__u32)k[6] << 16) +
|
|
((__u32)k[7] << 24));
|
|
c = c + (k[8] + ((__u32)k[9] << 8) + ((__u32)k[10] << 16) +
|
|
((__u32)k[11] << 24));
|
|
mix(a, b, c);
|
|
k = k + 12;
|
|
len = len - 12;
|
|
}
|
|
|
|
/* handle the last 11 bytes */
|
|
c = c + length;
|
|
switch (len) {
|
|
case 11:
|
|
c = c + ((__u32)k[10] << 24);
|
|
fallthrough;
|
|
case 10:
|
|
c = c + ((__u32)k[9] << 16);
|
|
fallthrough;
|
|
case 9:
|
|
c = c + ((__u32)k[8] << 8);
|
|
/* the first byte of c is reserved for the length */
|
|
fallthrough;
|
|
case 8:
|
|
b = b + ((__u32)k[7] << 24);
|
|
fallthrough;
|
|
case 7:
|
|
b = b + ((__u32)k[6] << 16);
|
|
fallthrough;
|
|
case 6:
|
|
b = b + ((__u32)k[5] << 8);
|
|
fallthrough;
|
|
case 5:
|
|
b = b + k[4];
|
|
fallthrough;
|
|
case 4:
|
|
a = a + ((__u32)k[3] << 24);
|
|
fallthrough;
|
|
case 3:
|
|
a = a + ((__u32)k[2] << 16);
|
|
fallthrough;
|
|
case 2:
|
|
a = a + ((__u32)k[1] << 8);
|
|
fallthrough;
|
|
case 1:
|
|
a = a + k[0];
|
|
/* case 0: nothing left to add */
|
|
}
|
|
mix(a, b, c);
|
|
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* linux dcache hash
|
|
*/
|
|
unsigned int ceph_str_hash_linux(const char *str, unsigned int length)
|
|
{
|
|
unsigned long hash = 0;
|
|
unsigned char c;
|
|
|
|
while (length--) {
|
|
c = *str++;
|
|
hash = (hash + (c << 4) + (c >> 4)) * 11;
|
|
}
|
|
return hash;
|
|
}
|
|
|
|
|
|
unsigned int ceph_str_hash(int type, const char *s, unsigned int len)
|
|
{
|
|
switch (type) {
|
|
case CEPH_STR_HASH_LINUX:
|
|
return ceph_str_hash_linux(s, len);
|
|
case CEPH_STR_HASH_RJENKINS:
|
|
return ceph_str_hash_rjenkins(s, len);
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(ceph_str_hash);
|
|
|
|
const char *ceph_str_hash_name(int type)
|
|
{
|
|
switch (type) {
|
|
case CEPH_STR_HASH_LINUX:
|
|
return "linux";
|
|
case CEPH_STR_HASH_RJENKINS:
|
|
return "rjenkins";
|
|
default:
|
|
return "unknown";
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(ceph_str_hash_name);
|