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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "debug.h"
/*
Dictionary based on code by Morten Eriksen <mortene@sim.no>.
*/
#include "dict.h"
struct dict_entry {
unsigned int hash;
void * key;
void * value;
struct dict_entry * next;
};
/* #define DICTTABLESIZE 97 */
#define DICTTABLESIZE 997 /* Semi-randomly selected prime number. */
/* #define DICTTABLESIZE 9973 */
/* #define DICTTABLESIZE 99991 */
/* #define DICTTABLESIZE 999983 */
struct dict {
struct dict_entry * buckets[DICTTABLESIZE];
unsigned int (*key2hash)(void *);
int (*key_cmp)(void *, void *);
};
struct dict *
dict_init(unsigned int (*key2hash)(void *), int (*key_cmp)(void *, void *)) {
struct dict * d;
int i;
d = malloc(sizeof(struct dict));
if (!d) {
perror("malloc()");
exit(1);
}
for (i = 0; i < DICTTABLESIZE; i++) { /* better use memset()? */
d->buckets[i] = NULL;
}
d->key2hash = key2hash;
d->key_cmp = key_cmp;
return d;
}
void
dict_clear(struct dict * d) {
int i;
struct dict_entry * entry, * nextentry;
assert(d);
for (i = 0; i < DICTTABLESIZE; i++) {
for (entry = d->buckets[i]; entry != NULL; entry = nextentry) {
nextentry = entry->next;
free(entry);
}
d->buckets[i] = NULL;
}
free(d);
}
int
dict_enter(struct dict * d, void * key, void * value) {
struct dict_entry * entry, * newentry;
unsigned int hash = d->key2hash(key);
unsigned int bucketpos = hash % DICTTABLESIZE;
assert(d);
newentry = malloc(sizeof(struct dict_entry));
if (!newentry) {
perror("malloc");
exit(1);
}
newentry->hash = hash;
newentry->key = key;
newentry->value = value;
newentry->next = NULL;
entry = d->buckets[bucketpos];
while (entry && entry->next) entry = entry->next;
if (entry) entry->next = newentry;
else d->buckets[bucketpos] = newentry;
debug(3, "new dict entry at %p[%d]: (%p,%p)\n", d, bucketpos, key, value);
return 0;
}
void *
dict_find_entry(struct dict * d, void * key) {
unsigned int hash = d->key2hash(key);
unsigned int bucketpos = hash % DICTTABLESIZE;
struct dict_entry * entry;
assert(d);
for (entry = d->buckets[bucketpos]; entry; entry = entry->next) {
if (hash != entry->hash) {
continue;
}
if (!d->key_cmp(key, entry->key)) {
break;
}
}
return entry ? entry->value : NULL;
}
void
dict_apply_to_all(struct dict * d, void (*func)(void *key, void *value, void *data), void *data) {
int i;
if (!d) {
return;
}
for (i = 0; i < DICTTABLESIZE; i++) {
struct dict_entry * entry = d->buckets[i];
while (entry) {
func(entry->key, entry->value, data);
entry = entry->next;
}
}
}
/*****************************************************************************/
unsigned int
dict_key2hash_string(void * key) {
const char * s = (const char *)key;
unsigned int total = 0, shift = 0;
assert(key);
while (*s) {
total = total ^ ((*s) << shift);
shift += 5;
if (shift > 24) shift -= 24;
s++;
}
return total;
}
int
dict_key_cmp_string(void * key1, void * key2) {
assert(key1);
assert(key2);
return strcmp((const char *)key1, (const char *)key2);
}
unsigned int
dict_key2hash_int(void * key) {
return (unsigned long)key;
}
int
dict_key_cmp_int(void * key1, void * key2) {
return key1 - key2;
}
|
