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  * Count entries:
  29  *      size_t <name>_count(const struct <name> *ht);
  30  *
  31  * Add function only fails if we run out of memory:
  32  *      bool <name>_add(struct <name> *ht, const <type> *e);
  33  *
  34  * Delete and delete-by key return true if it was in the set:
  35  *      bool <name>_del(struct <name> *ht, const <type> *e);
  36  *      bool <name>_delkey(struct <name> *ht, const <keytype> *k);
  37  *
  38  * Find and return the (first) matching element, or NULL:
  39  *      type *<name>_get(const struct @name *ht, const <keytype> *k);
  40  *
  41  * Find and return all matching elements, or NULL:
  42  *      type *<name>_getfirst(const struct @name *ht, const <keytype> *k,
  43  *                            struct <name>_iter *i);
  44  *      type *<name>_getnext(const struct @name *ht, const <keytype> *k,
  45  *                           struct <name>_iter *i);
  46  *
  47  * Iteration over hashtable is also supported:
  48  *      type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
  49  *      type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
  50  *      type *<name>_prev(const struct <name> *ht, struct <name>_iter *i);
  51  *
  52  * It's currently safe to iterate over a changing hashtable, but you might
  53  * miss an element.  Iteration isn't very efficient, either.
  54  *
  55  * You can use HTABLE_INITIALIZER like so:
  56  *      struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
  57  */
  58 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)             \
  59         struct name { struct htable raw; };                             \
  60         struct name##_iter { struct htable_iter i; };                   \
  61         static inline size_t name##_hash(const void *elem, void *priv)  \
  62         {                                                               \
  63                 (void)priv;                                             \
  64                 return hashfn(keyof((const type *)elem));               \
  65         }                                                               \
  66         static inline UNNEEDED void name##_init(struct name *ht)        \
  67         {                                                               \
  68                 htable_init(&ht->raw, name##_hash, NULL);               \
  69         }                                                               \
  70         static inline UNNEEDED bool name##_init_sized(struct name *ht,  \
  71                                                       size_t s)         \
  72         {                                                               \
  73                 return htable_init_sized(&ht->raw, name##_hash, NULL, s); \
  74         }                                                               \
  75         static inline UNNEEDED size_t name##_count(const struct name *ht) \
  76         {                                                               \
  77                 return htable_count(&ht->raw);                          \
  78         }                                                               \
  79         static inline UNNEEDED void name##_clear(struct name *ht)       \
  80         {                                                               \
  81                 htable_clear(&ht->raw);                                 \
  82         }                                                               \
  83         static inline UNNEEDED bool name##_copy(struct name *dst,       \
  84                                                 const struct name *src) \
  85         {                                                               \
  86                 return htable_copy(&dst->raw, &src->raw);               \
  87         }                                                               \
  88         static inline bool name##_add(struct name *ht, const type *elem) \
  89         {                                                               \
  90                 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
  91         }                                                               \
  92         static inline UNNEEDED bool name##_del(struct name *ht,         \
  93                                                const type *elem)        \
  94         {                                                               \
  95                 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
  96         }                                                               \
  97         static inline UNNEEDED type *name##_get(const struct name *ht,  \
  98                                        const HTABLE_KTYPE(keyof, type) k) \
  99         {                                                               \
 100                 struct htable_iter i;                                   \
 101                 size_t h = hashfn(k);                                   \
 102                 void *c;                                                \
 103                                                                         \
 104                 for (c = htable_firstval(&ht->raw,&i,h);                \
 105                      c;                                                 \
 106                      c = htable_nextval(&ht->raw,&i,h)) {               \
 107                         if (eqfn(c, k))                                 \
 108                                 return c;                               \
 109                 }                                                       \
 110                 return NULL;                                            \
 111         }                                                               \
 112         static inline UNNEEDED type *name##_getmatch_(const struct name *ht, \
 113                                          const HTABLE_KTYPE(keyof, type) k, \
 114                                          size_t h,                      \
 115                                          type *v,                       \
 116                                          struct name##_iter *iter)      \
 117         {                                                               \
 118                 while (v) {                                             \
 119                         if (eqfn(v, k))                                 \
 120                                 break;                                  \
 121                         v = htable_nextval(&ht->raw, &iter->i, h);      \
 122                 }                                                       \
 123                 return v;                                               \
 124         }                                                               \
 125         static inline UNNEEDED type *name##_getfirst(const struct name *ht, \
 126                                          const HTABLE_KTYPE(keyof, type) k, \
 127                                          struct name##_iter *iter)      \
 128         {                                                               \
 129                 size_t h = hashfn(k);                                   \
 130                 type *v = htable_firstval(&ht->raw, &iter->i, h);       \
 131                 return name##_getmatch_(ht, k, h, v, iter);                     \
 132         }                                                               \
 133         static inline UNNEEDED type *name##_getnext(const struct name *ht, \
 134                                          const HTABLE_KTYPE(keyof, type) k, \
 135                                          struct name##_iter *iter)      \
 136         {                                                               \
 137                 size_t h = hashfn(k);                                   \
 138                 type *v = htable_nextval(&ht->raw, &iter->i, h);        \
 139                 return name##_getmatch_(ht, k, h, v, iter);             \
 140         }                                                               \
 141         static inline UNNEEDED bool name##_delkey(struct name *ht,      \
 142                                          const HTABLE_KTYPE(keyof, type) k) \
 143         {                                                               \
 144                 type *elem = name##_get(ht, k);                         \
 145                 if (elem)                                               \
 146                         return name##_del(ht, elem);                    \
 147                 return false;                                           \
 148         }                                                               \
 149         static inline UNNEEDED type *name##_first(const struct name *ht, \
 150                                          struct name##_iter *iter)      \
 151         {                                                               \
 152                 return htable_first(&ht->raw, &iter->i);                \
 153         }                                                               \
 154         static inline UNNEEDED type *name##_next(const struct name *ht, \
 155                                         struct name##_iter *iter)       \
 156         {                                                               \
 157                 return htable_next(&ht->raw, &iter->i);                 \
 158         }                                                               \
 159         static inline UNNEEDED type *name##_prev(const struct name *ht, \
 160                                         struct name##_iter *iter)       \
 161         {                                                               \
 162                 return htable_prev(&ht->raw, &iter->i);                 \
 163         }
 164
 165 #if HAVE_TYPEOF
 166 #define HTABLE_KTYPE(keyof, type) typeof(keyof((const type *)NULL))
 167 #else
 168 /* Assumes keys are a pointer: if not, override. */
 169 #ifndef HTABLE_KTYPE
 170 #define HTABLE_KTYPE(keyof, type) void *
 171 #endif
 172 #endif
 173 #endif /* CCAN_HTABLE_TYPE_H */