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
|
/*
* Copyright (C) 2017-2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/* Memory allocation function prototypes. */
typedef void* (*knot_mm_alloc_t)(void* ctx, size_t len);
typedef void (*knot_mm_free_t)(void* p);
/*! \brief Memory allocation context. */
typedef struct knot_mm {
void* ctx; /* \note Must be first */
knot_mm_alloc_t alloc;
knot_mm_free_t free;
} knot_mm_t;
/*!
* \brief Native API of QP-tries:
*
* - keys are uint8_t strings, not necessarily zero-terminated,
* the structure copies the contents of the passed keys
* - values are void* pointers, typically you get an ephemeral pointer to it
* - key lengths are limited by 2^32-1 ATM
*/
/*! \brief Element value. */
typedef void* trie_val_t;
/*! \brief Opaque structure holding a QP-trie. */
typedef struct trie trie_t;
/*! \brief Opaque type for holding a QP-trie iterator. */
typedef struct trie_it trie_it_t;
/*! \brief Create a trie instance. Pass NULL to use malloc+free. */
trie_t* trie_create(knot_mm_t* mm);
/*! \brief Free a trie instance. */
void trie_free(trie_t* tbl);
/*! \brief Clear a trie instance (make it empty). */
void trie_clear(trie_t* tbl);
/*! \brief Return the number of keys in the trie. */
size_t trie_weight(const trie_t* tbl);
/*! \brief Search the trie, returning NULL on failure. */
trie_val_t* trie_get_try(trie_t* tbl, const uint8_t* key, uint32_t len);
/*!
* \brief Return pointer to the minimum. Optionally with key and its length. */
trie_val_t* trie_get_first(trie_t* tbl, uint8_t** key, uint32_t* len);
/*! \brief Search the trie, inserting NULL trie_val_t on failure. */
trie_val_t* trie_get_ins(trie_t* tbl, const uint8_t* key, uint32_t len);
/*!
* \brief Search for less-or-equal element.
*
* \param tbl Trie.
* \param key Searched key.
* \param len Key length.
* \param val Must be valid; it will be set to NULL if not found or errored.
* \return KNOT_EOK for exact match, 1 for previous, KNOT_ENOENT for not-found,
* or KNOT_E*.
*/
int trie_get_leq(trie_t* tbl, const uint8_t* key, uint32_t len, trie_val_t** val);
/*!
* \brief Apply a function to every trie_val_t, in order.
*
* \param d Parameter passed as the second argument to f().
* \return First nonzero from f() or zero (i.e. KNOT_EOK).
*/
int trie_apply(trie_t* tbl, int (*f)(trie_val_t*, void*), void* d);
/*! \brief Create a new iterator pointing to the first element (if any). */
trie_it_t* trie_it_begin(trie_t* tbl);
/*!
* \brief Advance the iterator to the next element.
*
* Iteration is in ascending lexicographical order.
* In particular, the empty string would be considered as the very first.
*
* \note You may not use this function if the trie's key-set has been modified
* during the lifetime of the iterator (modifying values only is OK).
*/
void trie_it_next(trie_it_t* it);
/*! \brief Test if the iterator has gone past the last element. */
bool trie_it_finished(trie_it_t* it);
/*! \brief Free any resources of the iterator. It's OK to call it on NULL. */
void trie_it_free(trie_it_t* it);
/*!
* \brief Return pointer to the key of the current element.
*
* \note The optional len is uint32_t internally but size_t is better for our usage,
* as it is without an additional type conversion.
*/
const uint8_t* trie_it_key(trie_it_t* it, size_t* len);
/*! \brief Return pointer to the value of the current element (writable). */
trie_val_t* trie_it_val(trie_it_t* it);
|
