git.ozlabs.org Git - ccan/blob - ccan/htable/htable_type.h

   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>
   6 #include "config.h"
   7
   8 /**
   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>_*)
  15  *
  16  * NULL values may not be placed into the hash table.
  17  *
  18  * This defines the type hashtable type and an iterator type:
  19  *      struct <name>;
  20  *      struct <name>_iter;
  21  *
  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> *);
  26  *
  27  * Add function only fails if we run out of memory:
  28  *      bool <name>_add(struct <name> *ht, const <type> *e);
  29  *
  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);
  33  *
  34  * Find and return the (first) matching element, or NULL:
  35  *      type *<name>_get(const struct @name *ht, const <keytype> *k);
  36  *
  37  * Find and return all matching elements, or NULL:
  38  *      type *<name>_getfirst(const struct @name *ht, const <keytype> *k,
  39  *                            struct <name>_iter *i);
  40  *      type *<name>_getnext(const struct @name *ht, const <keytype> *k,
  41  *                           struct <name>_iter *i);
  42  *
  43  * Iteration over hashtable is also supported:
  44  *      type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
  45  *      type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
  46  *      type *<name>_prev(const struct <name> *ht, struct <name>_iter *i);
  47  *
  48  * It's currently safe to iterate over a changing hashtable, but you might
  49  * miss an element.  Iteration isn't very efficient, either.
  50  *
  51  * You can use HTABLE_INITIALIZER like so:
  52  *      struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
  53  */
  54 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)             \
  55         struct name { struct htable raw; };                             \
  56         struct name##_iter { struct htable_iter i; };                   \
  57         static inline size_t name##_hash(const void *elem, void *priv)  \
  58         {                                                               \
  59                 (void)priv;                                             \
  60                 return hashfn(keyof((const type *)elem));               \
  61         }                                                               \
  62         static inline UNNEEDED void name##_init(struct name *ht)        \
  63         {                                                               \
  64                 htable_init(&ht->raw, name##_hash, NULL);               \
  65         }                                                               \
  66         static inline UNNEEDED void name##_init_sized(struct name *ht,  \
  67                                                       size_t s)         \
  68         {                                                               \
  69                 htable_init_sized(&ht->raw, name##_hash, NULL, s);      \
  70         }                                                               \
  71         static inline UNNEEDED void name##_clear(struct name *ht)       \
  72         {                                                               \
  73                 htable_clear(&ht->raw);                                 \
  74         }                                                               \
  75         static inline bool name##_add(struct name *ht, const type *elem) \
  76         {                                                               \
  77                 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
  78         }                                                               \
  79         static inline UNNEEDED bool name##_del(struct name *ht,         \
  80                                                const type *elem)        \
  81         {                                                               \
  82                 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
  83         }                                                               \
  84         static inline UNNEEDED type *name##_get(const struct name *ht,  \
  85                                        const HTABLE_KTYPE(keyof, type) k) \
  86         {                                                               \
  87                 /* Typecheck for eqfn */                                \
  88                 (void)sizeof(eqfn((const type *)NULL,                   \
  89                                   keyof((const type *)NULL)));          \
  90                 return htable_get(&ht->raw,                             \
  91                                   hashfn(k),                            \
  92                                   (bool (*)(const void *, void *))(eqfn), \
  93                                   k);                                   \
  94         }                                                               \
  95         static inline UNNEEDED type *name##_getmatch_(const struct name *ht, \
  96                                          const HTABLE_KTYPE(keyof, type) k, \
  97                                          size_t h,                      \
  98                                          type *v,                       \
  99                                          struct name##_iter *iter)      \
 100         {                                                               \
 101                 while (v) {                                             \
 102                         if (eqfn(v, k))                                 \
 103                                 break;                                  \
 104                         v = htable_nextval(&ht->raw, &iter->i, h);      \
 105                 }                                                       \
 106                 return v;                                               \
 107         }                                                               \
 108         static inline UNNEEDED type *name##_getfirst(const struct name *ht, \
 109                                          const HTABLE_KTYPE(keyof, type) k, \
 110                                          struct name##_iter *iter)      \
 111         {                                                               \
 112                 size_t h = hashfn(k);                                   \
 113                 type *v = htable_firstval(&ht->raw, &iter->i, h);       \
 114                 return name##_getmatch_(ht, k, h, v, iter);                     \
 115         }                                                               \
 116         static inline UNNEEDED type *name##_getnext(const struct name *ht, \
 117                                          const HTABLE_KTYPE(keyof, type) k, \
 118                                          struct name##_iter *iter)      \
 119         {                                                               \
 120                 size_t h = hashfn(k);                                   \
 121                 type *v = htable_nextval(&ht->raw, &iter->i, h);        \
 122                 return name##_getmatch_(ht, k, h, v, iter);             \
 123         }                                                               \
 124         static inline UNNEEDED bool name##_delkey(struct name *ht,      \
 125                                          const HTABLE_KTYPE(keyof, type) k) \
 126         {                                                               \
 127                 type *elem = name##_get(ht, k);                         \
 128                 if (elem)                                               \
 129                         return name##_del(ht, elem);                    \
 130                 return false;                                           \
 131         }                                                               \
 132         static inline UNNEEDED type *name##_first(const struct name *ht, \
 133                                          struct name##_iter *iter)      \
 134         {                                                               \
 135                 return htable_first(&ht->raw, &iter->i);                \
 136         }                                                               \
 137         static inline UNNEEDED type *name##_next(const struct name *ht, \
 138                                         struct name##_iter *iter)       \
 139         {                                                               \
 140                 return htable_next(&ht->raw, &iter->i);                 \
 141         }                                                               \
 142         static inline UNNEEDED type *name##_prev(const struct name *ht, \
 143                                         struct name##_iter *iter)       \
 144         {                                                               \
 145                 return htable_prev(&ht->raw, &iter->i);                 \
 146         }
 147
 148 #if HAVE_TYPEOF
 149 #define HTABLE_KTYPE(keyof, type) typeof(keyof((const type *)NULL))
 150 #else
 151 #define HTABLE_KTYPE(keyof, type) void *
 152 #endif
 153 #endif /* CCAN_HTABLE_TYPE_H */