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>
5 #include <ccan/compiler/compiler.h>
9 * HTABLE_DEFINE_TYPE - create a set of htable ops for a type
10 * @type: a type whose pointers will be values in the hash.
11 * @keyof: a function/macro to extract a key: <keytype> @keyof(const type *elem)
12 * @hashfn: a hash function for a @key: size_t @hashfn(const <keytype> *)
13 * @eqfn: an equality function keys: bool @eqfn(const type *, const <keytype> *)
14 * @prefix: a prefix for all the functions to define (of form <name>_*)
16 * NULL values may not be placed into the hash table.
18 * This defines the type hashtable type and an iterator type:
22 * It also defines initialization and freeing functions:
23 * void <name>_init(struct <name> *);
24 * void <name>_init_sized(struct <name> *, size_t);
25 * void <name>_clear(struct <name> *);
27 * Add function only fails if we run out of memory:
28 * bool <name>_add(struct <name> *ht, const <type> *e);
30 * Delete and delete-by key return true if it was in the set:
31 * bool <name>_del(struct <name> *ht, const <type> *e);
32 * bool <name>_delkey(struct <name> *ht, const <keytype> *k);
34 * Find function return the matching element, or NULL:
35 * type *<name>_get(const struct @name *ht, const <keytype> *k);
37 * Iteration over hashtable is also supported:
38 * type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
39 * type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
41 * It's currently safe to iterate over a changing hashtable, but you might
42 * miss an element. Iteration isn't very efficient, either.
44 * You can use HTABLE_INITIALIZER like so:
45 * struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
47 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name) \
48 struct name { struct htable raw; }; \
49 struct name##_iter { struct htable_iter i; }; \
50 static inline size_t name##_hash(const void *elem, void *priv) \
52 return hashfn(keyof((const type *)elem)); \
54 static inline UNNEEDED void name##_init(struct name *ht) \
56 htable_init(&ht->raw, name##_hash, NULL); \
58 static inline UNNEEDED void name##_init_sized(struct name *ht, \
61 htable_init_sized(&ht->raw, name##_hash, NULL, s); \
63 static inline UNNEEDED void name##_clear(struct name *ht) \
65 htable_clear(&ht->raw); \
67 static inline bool name##_add(struct name *ht, const type *elem) \
69 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
71 static inline UNNEEDED bool name##_del(struct name *ht, \
74 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
76 static inline UNNEEDED type *name##_get(const struct name *ht, \
77 const HTABLE_KTYPE(keyof) k) \
79 /* Typecheck for eqfn */ \
80 (void)sizeof(eqfn((const type *)NULL, \
81 keyof((const type *)NULL))); \
82 return htable_get(&ht->raw, \
84 (bool (*)(const void *, void *))(eqfn), \
87 static inline UNNEEDED bool name##_delkey(struct name *ht, \
88 const HTABLE_KTYPE(keyof) k) \
90 type *elem = name##_get(ht, k); \
92 return name##_del(ht, elem); \
95 static inline UNNEEDED type *name##_first(const struct name *ht, \
96 struct name##_iter *iter) \
98 return htable_first(&ht->raw, &iter->i); \
100 static inline UNNEEDED type *name##_next(const struct name *ht, \
101 struct name##_iter *iter) \
103 return htable_next(&ht->raw, &iter->i); \
107 #define HTABLE_KTYPE(keyof) typeof(keyof(NULL))
109 #define HTABLE_KTYPE(keyof) void *
111 #endif /* CCAN_HTABLE_TYPE_H */