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  *      bool <name>_init_sized(struct <name> *, size_t);
  25  *      void <name>_clear(struct <name> *);
  26  *      bool <name>_copy(struct <name> *dst, const struct <name> *src);
  27  *
  28  * Add function only fails if we run out of memory:
  29  *      bool <name>_add(struct <name> *ht, const <type> *e);
  30  *
  31  * Delete and delete-by key return true if it was in the set:
  32  *      bool <name>_del(struct <name> *ht, const <type> *e);
  33  *      bool <name>_delkey(struct <name> *ht, const <keytype> *k);
  34  *
  35  * Find and return the (first) matching element, or NULL:
  36  *      type *<name>_get(const struct @name *ht, const <keytype> *k);
  37  *
  38  * Find and return all matching elements, or NULL:
  39  *      type *<name>_getfirst(const struct @name *ht, const <keytype> *k,
  40  *                            struct <name>_iter *i);
  41  *      type *<name>_getnext(const struct @name *ht, const <keytype> *k,
  42  *                           struct <name>_iter *i);
  43  *
  44  * Iteration over hashtable is also supported:
  45  *      type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
  46  *      type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
  47  *      type *<name>_prev(const struct <name> *ht, struct <name>_iter *i);
  48  *
  49  * It's currently safe to iterate over a changing hashtable, but you might
  50  * miss an element.  Iteration isn't very efficient, either.
  51  *
  52  * You can use HTABLE_INITIALIZER like so:
  53  *      struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
  54  */
  55 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)             \
  56         struct name { struct htable raw; };                             \
  57         struct name##_iter { struct htable_iter i; };                   \
  58         static inline size_t name##_hash(const void *elem, void *priv)  \
  59         {                                                               \
  60                 (void)priv;                                             \
  61                 return hashfn(keyof((const type *)elem));               \
  62         }                                                               \
  63         static inline UNNEEDED void name##_init(struct name *ht)        \
  64         {                                                               \
  65                 htable_init(&ht->raw, name##_hash, NULL);               \
  66         }                                                               \
  67         static inline UNNEEDED bool name##_init_sized(struct name *ht,  \
  68                                                       size_t s)         \
  69         {                                                               \
  70                 return htable_init_sized(&ht->raw, name##_hash, NULL, s); \
  71         }                                                               \
  72         static inline UNNEEDED void name##_clear(struct name *ht)       \
  73         {                                                               \
  74                 htable_clear(&ht->raw);                                 \
  75         }                                                               \
  76         static inline UNNEEDED bool name##_copy(struct name *dst,       \
  77                                                 const struct name *src) \
  78         {                                                               \
  79                 return htable_copy(&dst->raw, &src->raw);               \
  80         }                                                               \
  81         static inline bool name##_add(struct name *ht, const type *elem) \
  82         {                                                               \
  83                 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
  84         }                                                               \
  85         static inline UNNEEDED bool name##_del(struct name *ht,         \
  86                                                const type *elem)        \
  87         {                                                               \
  88                 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
  89         }                                                               \
  90         static inline UNNEEDED type *name##_get(const struct name *ht,  \
  91                                        const HTABLE_KTYPE(keyof, type) k) \
  92         {                                                               \
  93                 /* Typecheck for eqfn */                                \
  94                 (void)sizeof(eqfn((const type *)NULL,                   \
  95                                   keyof((const type *)NULL)));          \
  96                 return htable_get(&ht->raw,                             \
  97                                   hashfn(k),                            \
  98                                   (bool (*)(const void *, void *))(eqfn), \
  99                                   k);                                   \
 100         }                                                               \
 101         static inline UNNEEDED type *name##_getmatch_(const struct name *ht, \
 102                                          const HTABLE_KTYPE(keyof, type) k, \
 103                                          size_t h,                      \
 104                                          type *v,                       \
 105                                          struct name##_iter *iter)      \
 106         {                                                               \
 107                 while (v) {                                             \
 108                         if (eqfn(v, k))                                 \
 109                                 break;                                  \
 110                         v = htable_nextval(&ht->raw, &iter->i, h);      \
 111                 }                                                       \
 112                 return v;                                               \
 113         }                                                               \
 114         static inline UNNEEDED type *name##_getfirst(const struct name *ht, \
 115                                          const HTABLE_KTYPE(keyof, type) k, \
 116                                          struct name##_iter *iter)      \
 117         {                                                               \
 118                 size_t h = hashfn(k);                                   \
 119                 type *v = htable_firstval(&ht->raw, &iter->i, h);       \
 120                 return name##_getmatch_(ht, k, h, v, iter);                     \
 121         }                                                               \
 122         static inline UNNEEDED type *name##_getnext(const struct name *ht, \
 123                                          const HTABLE_KTYPE(keyof, type) k, \
 124                                          struct name##_iter *iter)      \
 125         {                                                               \
 126                 size_t h = hashfn(k);                                   \
 127                 type *v = htable_nextval(&ht->raw, &iter->i, h);        \
 128                 return name##_getmatch_(ht, k, h, v, iter);             \
 129         }                                                               \
 130         static inline UNNEEDED bool name##_delkey(struct name *ht,      \
 131                                          const HTABLE_KTYPE(keyof, type) k) \
 132         {                                                               \
 133                 type *elem = name##_get(ht, k);                         \
 134                 if (elem)                                               \
 135                         return name##_del(ht, elem);                    \
 136                 return false;                                           \
 137         }                                                               \
 138         static inline UNNEEDED type *name##_first(const struct name *ht, \
 139                                          struct name##_iter *iter)      \
 140         {                                                               \
 141                 return htable_first(&ht->raw, &iter->i);                \
 142         }                                                               \
 143         static inline UNNEEDED type *name##_next(const struct name *ht, \
 144                                         struct name##_iter *iter)       \
 145         {                                                               \
 146                 return htable_next(&ht->raw, &iter->i);                 \
 147         }                                                               \
 148         static inline UNNEEDED type *name##_prev(const struct name *ht, \
 149                                         struct name##_iter *iter)       \
 150         {                                                               \
 151                 return htable_prev(&ht->raw, &iter->i);                 \
 152         }
 153
 154 #if HAVE_TYPEOF
 155 #define HTABLE_KTYPE(keyof, type) typeof(keyof((const type *)NULL))
 156 #else
 157 #define HTABLE_KTYPE(keyof, type) void *
 158 #endif
 159 #endif /* CCAN_HTABLE_TYPE_H */