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  *
  47  * It's currently safe to iterate over a changing hashtable, but you might
  48  * miss an element.  Iteration isn't very efficient, either.
  49  *
  50  * You can use HTABLE_INITIALIZER like so:
  51  *      struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
  52  */
  53 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)             \
  54         struct name { struct htable raw; };                             \
  55         struct name##_iter { struct htable_iter i; };                   \
  56         static inline size_t name##_hash(const void *elem, void *priv)  \
  57         {                                                               \
  58                 (void)priv;                                             \
  59                 return hashfn(keyof((const type *)elem));               \
  60         }                                                               \
  61         static inline UNNEEDED void name##_init(struct name *ht)        \
  62         {                                                               \
  63                 htable_init(&ht->raw, name##_hash, NULL);               \
  64         }                                                               \
  65         static inline UNNEEDED void name##_init_sized(struct name *ht,  \
  66                                                       size_t s)         \
  67         {                                                               \
  68                 htable_init_sized(&ht->raw, name##_hash, NULL, s);      \
  69         }                                                               \
  70         static inline UNNEEDED void name##_clear(struct name *ht)       \
  71         {                                                               \
  72                 htable_clear(&ht->raw);                                 \
  73         }                                                               \
  74         static inline bool name##_add(struct name *ht, const type *elem) \
  75         {                                                               \
  76                 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
  77         }                                                               \
  78         static inline UNNEEDED bool name##_del(struct name *ht,         \
  79                                                const type *elem)        \
  80         {                                                               \
  81                 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
  82         }                                                               \
  83         static inline UNNEEDED type *name##_get(const struct name *ht,  \
  84                                        const HTABLE_KTYPE(keyof) k)     \
  85         {                                                               \
  86                 /* Typecheck for eqfn */                                \
  87                 (void)sizeof(eqfn((const type *)NULL,                   \
  88                                   keyof((const type *)NULL)));          \
  89                 return htable_get(&ht->raw,                             \
  90                                   hashfn(k),                            \
  91                                   (bool (*)(const void *, void *))(eqfn), \
  92                                   k);                                   \
  93         }                                                               \
  94         static inline UNNEEDED type *name##_getmatch_(const struct name *ht, \
  95                                          const HTABLE_KTYPE(keyof) k,   \
  96                                          size_t h,                      \
  97                                          type *v,                       \
  98                                          struct name##_iter *iter)      \
  99         {                                                               \
 100                 while (v) {                                             \
 101                         if (eqfn(v, k))                                 \
 102                                 break;                                  \
 103                         v = htable_nextval(&ht->raw, &iter->i, h);      \
 104                 }                                                       \
 105                 return v;                                               \
 106         }                                                               \
 107         static inline UNNEEDED type *name##_getfirst(const struct name *ht, \
 108                                          const HTABLE_KTYPE(keyof) k,   \
 109                                          struct name##_iter *iter)      \
 110         {                                                               \
 111                 size_t h = hashfn(k);                                   \
 112                 type *v = htable_firstval(&ht->raw, &iter->i, h);       \
 113                 return name##_getmatch_(ht, k, h, v, iter);                     \
 114         }                                                               \
 115         static inline UNNEEDED type *name##_getnext(const struct name *ht, \
 116                                          const HTABLE_KTYPE(keyof) k,   \
 117                                          struct name##_iter *iter)      \
 118         {                                                               \
 119                 size_t h = hashfn(k);                                   \
 120                 type *v = htable_nextval(&ht->raw, &iter->i, h);        \
 121                 return name##_getmatch_(ht, k, h, v, iter);             \
 122         }                                                               \
 123         static inline UNNEEDED bool name##_delkey(struct name *ht,      \
 124                                          const HTABLE_KTYPE(keyof) k)   \
 125         {                                                               \
 126                 type *elem = name##_get(ht, k);                         \
 127                 if (elem)                                               \
 128                         return name##_del(ht, elem);                    \
 129                 return false;                                           \
 130         }                                                               \
 131         static inline UNNEEDED type *name##_first(const struct name *ht, \
 132                                          struct name##_iter *iter)      \
 133         {                                                               \
 134                 return htable_first(&ht->raw, &iter->i);                \
 135         }                                                               \
 136         static inline UNNEEDED type *name##_next(const struct name *ht, \
 137                                         struct name##_iter *iter)       \
 138         {                                                               \
 139                 return htable_next(&ht->raw, &iter->i);                 \
 140         }
 141
 142 #if HAVE_TYPEOF
 143 #define HTABLE_KTYPE(keyof) typeof(keyof(NULL))
 144 #else
 145 #define HTABLE_KTYPE(keyof) void *
 146 #endif
 147 #endif /* CCAN_HTABLE_TYPE_H */