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
|
// Copyright © Tavian Barnes <tavianator@tavianator.com>
// SPDX-License-Identifier: 0BSD
#ifndef BFS_TRIE_H
#define BFS_TRIE_H
#include "alloc.h"
#include "list.h"
#include <stddef.h>
#include <stdint.h>
/**
* A leaf of a trie.
*/
struct trie_leaf {
/** An arbitrary value associated with this leaf. */
void *value;
/** The length of the key in bytes. */
size_t length;
/** The key itself, stored inline. */
char key[];
};
/**
* A trie that holds a set of fixed- or variable-length strings.
*/
struct trie {
/** Pointer to the root node/leaf. */
uintptr_t root;
/** Node allocator. */
struct varena nodes;
/** Leaf allocator. */
struct varena leaves;
};
/**
* Initialize an empty trie.
*/
void trie_init(struct trie *trie);
/**
* Find the leaf for a string key.
*
* @trie
* The trie to search.
* @key
* The key to look up.
* @return
* The found leaf, or NULL if the key is not present.
*/
struct trie_leaf *trie_find_str(const struct trie *trie, const char *key);
/**
* Find the leaf for a fixed-size key.
*
* @trie
* The trie to search.
* @key
* The key to look up.
* @length
* The length of the key in bytes.
* @return
* The found leaf, or NULL if the key is not present.
*/
struct trie_leaf *trie_find_mem(const struct trie *trie, const void *key, size_t length);
/**
* Find the shortest leaf that starts with a given key.
*
* @trie
* The trie to search.
* @key
* The key to look up.
* @return
* A leaf that starts with the given key, or NULL.
*/
struct trie_leaf *trie_find_postfix(const struct trie *trie, const char *key);
/**
* Find the leaf that is the longest prefix of the given key.
*
* @trie
* The trie to search.
* @key
* The key to look up.
* @return
* The longest prefix match for the given key, or NULL.
*/
struct trie_leaf *trie_find_prefix(const struct trie *trie, const char *key);
/**
* Insert a string key into the trie.
*
* @trie
* The trie to modify.
* @key
* The key to insert.
* @return
* The inserted leaf, or NULL on failure.
*/
struct trie_leaf *trie_insert_str(struct trie *trie, const char *key);
/**
* Insert a fixed-size key into the trie.
*
* @trie
* The trie to modify.
* @key
* The key to insert.
* @length
* The length of the key in bytes.
* @return
* The inserted leaf, or NULL on failure.
*/
struct trie_leaf *trie_insert_mem(struct trie *trie, const void *key, size_t length);
/**
* Remove a leaf from a trie.
*
* @trie
* The trie to modify.
* @leaf
* The leaf to remove.
*/
void trie_remove(struct trie *trie, struct trie_leaf *leaf);
/**
* Remove all leaves from a trie.
*/
void trie_clear(struct trie *trie);
/**
* Destroy a trie and its contents.
*/
void trie_destroy(struct trie *trie);
/**
* Iterate over the leaves of a trie.
*/
#define for_trie(leaf, trie) \
for_varena (struct trie_leaf, leaf, &(trie)->leaves)
#endif // BFS_TRIE_H
|
