1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <string.h>
#include "hash-funcs.h"
#include "path-util.h"
void string_hash_func(const char *p, struct siphash *state) {
siphash24_compress(p, strlen(p) + 1, state);
}
DEFINE_HASH_OPS(string_hash_ops, char, string_hash_func, string_compare_func);
void path_hash_func(const char *q, struct siphash *state) {
size_t n;
assert(q);
assert(state);
/* Calculates a hash for a path in a way this duplicate inner slashes don't make a differences, and also
* whether there's a trailing slash or not. This fits well with the semantics of path_compare(), which does
* similar checks and also doesn't care for trailing slashes. Note that relative and absolute paths (i.e. those
* which begin in a slash or not) will hash differently though. */
n = strspn(q, "/");
if (n > 0) { /* Eat up initial slashes, and add one "/" to the hash for all of them */
siphash24_compress(q, 1, state);
q += n;
}
for (;;) {
/* Determine length of next component */
n = strcspn(q, "/");
if (n == 0) /* Reached the end? */
break;
/* Add this component to the hash and skip over it */
siphash24_compress(q, n, state);
q += n;
/* How many slashes follow this component? */
n = strspn(q, "/");
if (q[n] == 0) /* Is this a trailing slash? If so, we are at the end, and don't care about the slashes anymore */
break;
/* We are not add the end yet. Hash exactly one slash for all of the ones we just encountered. */
siphash24_compress(q, 1, state);
q += n;
}
}
int path_compare_func(const char *a, const char *b) {
return path_compare(a, b);
}
DEFINE_HASH_OPS(path_hash_ops, char, path_hash_func, path_compare_func);
void trivial_hash_func(const void *p, struct siphash *state) {
siphash24_compress(&p, sizeof(p), state);
}
int trivial_compare_func(const void *a, const void *b) {
return CMP(a, b);
}
const struct hash_ops trivial_hash_ops = {
.hash = trivial_hash_func,
.compare = trivial_compare_func,
};
void uint64_hash_func(const uint64_t *p, struct siphash *state) {
siphash24_compress(p, sizeof(uint64_t), state);
}
int uint64_compare_func(const uint64_t *a, const uint64_t *b) {
return CMP(*a, *b);
}
DEFINE_HASH_OPS(uint64_hash_ops, uint64_t, uint64_hash_func, uint64_compare_func);
#if SIZEOF_DEV_T != 8
void devt_hash_func(const dev_t *p, struct siphash *state) {
siphash24_compress(p, sizeof(dev_t), state);
}
int devt_compare_func(const dev_t *a, const dev_t *b) {
return CMP(*a, *b);
}
DEFINE_HASH_OPS(devt_hash_ops, dev_t, devt_hash_func, devt_compare_func);
#endif
|
