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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
/* the Music Player Daemon (MPD)
* Copyright (C) 2008 Max Kellermann <max@duempel.org>
* This project's homepage is: http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "strset.h"
#include "utils.h"
#include "os_compat.h"
#define NUM_SLOTS 16384
struct strset_slot {
struct strset_slot *next;
const char *value;
};
struct strset {
unsigned size;
struct strset_slot *current_slot;
unsigned next_slot;
struct strset_slot slots[NUM_SLOTS];
};
static unsigned calc_hash(const char *p) {
unsigned hash = 5381;
assert(p != NULL);
while (*p != 0)
hash = (hash << 5) + hash + *p++;
return hash;
}
mpd_malloc struct strset *strset_new(void)
{
struct strset *set = xcalloc(1, sizeof(*set));
return set;
}
void strset_free(struct strset *set)
{
unsigned i;
for (i = 0; i < NUM_SLOTS; ++i) {
struct strset_slot *slot = set->slots[i].next, *next;
while (slot != NULL) {
next = slot->next;
free(slot);
slot = next;
}
}
free(set);
}
void strset_add(struct strset *set, const char *value)
{
struct strset_slot *base_slot
= &set->slots[calc_hash(value) % NUM_SLOTS];
struct strset_slot *slot = base_slot;
if (base_slot->value == NULL) {
/* empty slot - put into base_slot */
assert(base_slot->next == NULL);
base_slot->value = value;
++set->size;
return;
}
for (slot = base_slot; slot != NULL; slot = slot->next)
if (strcmp(slot->value, value) == 0)
/* found it - do nothing */
return;
/* insert it into the slot chain */
slot = xmalloc(sizeof(*slot));
slot->next = base_slot->next;
slot->value = value;
base_slot->next = slot;
++set->size;
}
int strset_get(const struct strset *set, const char *value)
{
const struct strset_slot *slot = &set->slots[calc_hash(value)];
if (slot->value == NULL)
return 0;
for (slot = slot->next; slot != NULL; slot = slot->next)
if (strcmp(slot->value, value) == 0)
/* found it - do nothing */
return 1;
return 0;
}
unsigned strset_size(const struct strset *set)
{
return set->size;
}
void strset_rewind(struct strset *set)
{
set->current_slot = NULL;
set->next_slot = 0;
}
const char *strset_next(struct strset *set)
{
if (set->current_slot != NULL && set->current_slot->next != NULL) {
set->current_slot = set->current_slot->next;
return set->current_slot->value;
}
while (set->next_slot < NUM_SLOTS &&
set->slots[set->next_slot].value == NULL)
++set->next_slot;
if (set->next_slot >= NUM_SLOTS)
return NULL;
set->current_slot = &set->slots[set->next_slot++];
return set->current_slot->value;
}
|
