| blob | 03cc46fc5836c8003e2c1e325c13a5ec6df5db47 |
1 /* Licensed under LGPLv2+ - see LICENSE file for details */
2 #ifndef CCAN_HTABLE_TYPE_H
3 #define CCAN_HTABLE_TYPE_H
4 #include <ccan/htable/htable.h>
7 /**
8 * HTABLE_DEFINE_TYPE - create a set of htable ops for a type
9 * @type: a type whose pointers will be values in the hash.
10 * @keyof: a function/macro to extract a key: <keytype> @keyof(const type *elem)
11 * @hashfn: a hash function for a @key: size_t @hashfn(const <keytype> *)
12 * @eqfn: an equality function keys: bool @eqfn(const type *, const <keytype> *)
13 * @prefix: a prefix for all the functions to define (of form <name>_*)
14 *
15 * NULL values may not be placed into the hash table.
16 *
17 * This defines the type hashtable type and an iterator type:
18 * struct <name>;
19 * struct <name>_iter;
20 *
21 * It also defines initialization and freeing functions:
22 * void <name>_init(struct <name> *);
23 * void <name>_clear(struct <name> *);
24 *
25 * Add function only fails if we run out of memory:
26 * bool <name>_add(struct <name> *ht, const <type> *e);
27 *
28 * Delete and delete-by key return true if it was in the set:
29 * bool <name>_del(struct <name> *ht, const <type> *e);
30 * bool <name>_delkey(struct <name> *ht, const <keytype> *k);
31 *
32 * Find function return the matching element, or NULL:
33 * type *<name>_get(const struct @name *ht, const <keytype> *k);
34 *
35 * Iteration over hashtable is also supported:
36 * type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
37 * type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
38 *
39 * It's currently safe to iterate over a changing hashtable, but you might
40 * miss an element. Iteration isn't very efficient, either.
41 *
42 * You can use HTABLE_INITIALIZER like so:
43 * struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
44 */
45 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name) \
46 struct name { struct htable raw; }; \
47 struct name##_iter { struct htable_iter i; }; \
48 static inline size_t name##_hash(const void *elem, void *priv) \
49 { \
50 return hashfn(keyof((const type *)elem)); \
51 } \
52 static inline void name##_init(struct name *ht) \
53 { \
54 htable_init(&ht->raw, name##_hash, NULL); \
55 } \
56 static inline void name##_clear(struct name *ht) \
57 { \
58 htable_clear(&ht->raw); \
59 } \
60 static inline bool name##_add(struct name *ht, const type *elem) \
61 { \
62 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
63 } \
64 static inline bool name##_del(struct name *ht, const type *elem) \
65 { \
66 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
67 } \
68 static inline type *name##_get(const struct name *ht, \
69 const HTABLE_KTYPE(keyof) k) \
70 { \
72 (void)sizeof(eqfn((const type *)NULL, \
73 keyof((const type *)NULL))); \
74 return htable_get(&ht->raw, \
75 hashfn(k), \
76 (bool (*)(const void *, void *))(eqfn), \
77 k); \
78 } \
79 static inline bool name##_delkey(struct name *ht, \
80 const HTABLE_KTYPE(keyof) k) \
81 { \
82 type *elem = name##_get(ht, k); \
83 if (elem) \
84 return name##_del(ht, elem); \
85 return false; \
86 } \
87 static inline type *name##_first(const struct name *ht, \
88 struct name##_iter *iter) \
89 { \
90 return htable_first(&ht->raw, &iter->i); \
91 } \
92 static inline type *name##_next(const struct name *ht, \
93 struct name##_iter *iter) \
94 { \
95 return htable_next(&ht->raw, &iter->i); \
96 }
98 #if HAVE_TYPEOF
99 #define HTABLE_KTYPE(keyof) typeof(keyof(NULL))
100 #else
101 #define HTABLE_KTYPE(keyof) void *
102 #endif