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  * Delete by iterator:
  39  *      bool <name>_delval(struct <name> *ht, struct <name>_iter *i);
  40  *
  41  * Find and return the (first) matching element, or NULL:
  42  *      type *<name>_get(const struct @name *ht, const <keytype> *k);
  43  *
  44  * Find and return all matching elements, or NULL:
  45  *      type *<name>_getfirst(const struct @name *ht, const <keytype> *k,
  46  *                            struct <name>_iter *i);
  47  *      type *<name>_getnext(const struct @name *ht, const <keytype> *k,
  48  *                           struct <name>_iter *i);
  49  *
  50  * Iteration over hashtable is also supported:
  51  *      type *<name>_first(const struct <name> *ht, struct <name>_iter *i);
  52  *      type *<name>_next(const struct <name> *ht, struct <name>_iter *i);
  53  *      type *<name>_prev(const struct <name> *ht, struct <name>_iter *i);
  54  *      type *<name>_pick(const struct <name> *ht, size_t seed,
  55  *                        struct <name>_iter *i);
  56  * It's currently safe to iterate over a changing hashtable, but you might
  57  * miss an element.  Iteration isn't very efficient, either.
  58  *
  59  * You can use HTABLE_INITIALIZER like so:
  60  *      struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };
  61  */
  62 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)             \
  63         struct name { struct htable raw; };                             \
  64         struct name##_iter { struct htable_iter i; };                   \
  65         static inline size_t name##_hash(const void *elem, void *priv)  \
  66         {                                                               \
  67                 (void)priv;                                             \
  68                 return hashfn(keyof((const type *)elem));               \
  69         }                                                               \
  70         static inline UNNEEDED void name##_init(struct name *ht)        \
  71         {                                                               \
  72                 htable_init(&ht->raw, name##_hash, NULL);               \
  73         }                                                               \
  74         static inline UNNEEDED bool name##_init_sized(struct name *ht,  \
  75                                                       size_t s)         \
  76         {                                                               \
  77                 return htable_init_sized(&ht->raw, name##_hash, NULL, s); \
  78         }                                                               \
  79         static inline UNNEEDED size_t name##_count(const struct name *ht) \
  80         {                                                               \
  81                 return htable_count(&ht->raw);                          \
  82         }                                                               \
  83         static inline UNNEEDED void name##_clear(struct name *ht)       \
  84         {                                                               \
  85                 htable_clear(&ht->raw);                                 \
  86         }                                                               \
  87         static inline UNNEEDED bool name##_copy(struct name *dst,       \
  88                                                 const struct name *src) \
  89         {                                                               \
  90                 return htable_copy(&dst->raw, &src->raw);               \
  91         }                                                               \
  92         static inline bool name##_add(struct name *ht, const type *elem) \
  93         {                                                               \
  94                 return htable_add(&ht->raw, hashfn(keyof(elem)), elem); \
  95         }                                                               \
  96         static inline UNNEEDED bool name##_del(struct name *ht,         \
  97                                                const type *elem)        \
  98         {                                                               \
  99                 return htable_del(&ht->raw, hashfn(keyof(elem)), elem); \
 100         }                                                               \
 101         static inline UNNEEDED type *name##_get(const struct name *ht,  \
 102                                        const HTABLE_KTYPE(keyof, type) k) \
 103         {                                                               \
 104                 struct htable_iter i;                                   \
 105                 size_t h = hashfn(k);                                   \
 106                 void *c;                                                \
 107                                                                         \
 108                 for (c = htable_firstval(&ht->raw,&i,h);                \
 109                      c;                                                 \
 110                      c = htable_nextval(&ht->raw,&i,h)) {               \
 111                         if (eqfn(c, k))                                 \
 112                                 return c;                               \
 113                 }                                                       \
 114                 return NULL;                                            \
 115         }                                                               \
 116         static inline UNNEEDED type *name##_getmatch_(const struct name *ht, \
 117                                          const HTABLE_KTYPE(keyof, type) k, \
 118                                          size_t h,                      \
 119                                          type *v,                       \
 120                                          struct name##_iter *iter)      \
 121         {                                                               \
 122                 while (v) {                                             \
 123                         if (eqfn(v, k))                                 \
 124                                 break;                                  \
 125                         v = htable_nextval(&ht->raw, &iter->i, h);      \
 126                 }                                                       \
 127                 return v;                                               \
 128         }                                                               \
 129         static inline UNNEEDED type *name##_getfirst(const struct name *ht, \
 130                                          const HTABLE_KTYPE(keyof, type) k, \
 131                                          struct name##_iter *iter)      \
 132         {                                                               \
 133                 size_t h = hashfn(k);                                   \
 134                 type *v = htable_firstval(&ht->raw, &iter->i, h);       \
 135                 return name##_getmatch_(ht, k, h, v, iter);                     \
 136         }                                                               \
 137         static inline UNNEEDED type *name##_getnext(const struct name *ht, \
 138                                          const HTABLE_KTYPE(keyof, type) k, \
 139                                          struct name##_iter *iter)      \
 140         {                                                               \
 141                 size_t h = hashfn(k);                                   \
 142                 type *v = htable_nextval(&ht->raw, &iter->i, h);        \
 143                 return name##_getmatch_(ht, k, h, v, iter);             \
 144         }                                                               \
 145         static inline UNNEEDED bool name##_delkey(struct name *ht,      \
 146                                          const HTABLE_KTYPE(keyof, type) k) \
 147         {                                                               \
 148                 type *elem = name##_get(ht, k);                         \
 149                 if (elem)                                               \
 150                         return name##_del(ht, elem);                    \
 151                 return false;                                           \
 152         }                                                               \
 153         static inline UNNEEDED void name##_delval(struct name *ht,      \
 154                                                   struct name##_iter *iter) \
 155         {                                                               \
 156                 htable_delval(&ht->raw, &iter->i);                      \
 157         }                                                               \
 158         static inline UNNEEDED type *name##_pick(const struct name *ht, \
 159                                                 size_t seed,            \
 160                                                 struct name##_iter *iter) \
 161         {                                                               \
 162                 /* Note &iter->i == NULL iff iter is NULL */            \
 163                 return htable_pick(&ht->raw, seed, &iter->i);                   \
 164         }                                                               \
 165         static inline UNNEEDED type *name##_first(const struct name *ht, \
 166                                          struct name##_iter *iter)      \
 167         {                                                               \
 168                 return htable_first(&ht->raw, &iter->i);                \
 169         }                                                               \
 170         static inline UNNEEDED type *name##_next(const struct name *ht, \
 171                                         struct name##_iter *iter)       \
 172         {                                                               \
 173                 return htable_next(&ht->raw, &iter->i);                 \
 174         }                                                               \
 175         static inline UNNEEDED type *name##_prev(const struct name *ht, \
 176                                         struct name##_iter *iter)       \
 177         {                                                               \
 178                 return htable_prev(&ht->raw, &iter->i);                 \
 179         }
 180
 181 #if HAVE_TYPEOF
 182 #define HTABLE_KTYPE(keyof, type) typeof(keyof((const type *)NULL))
 183 #else
 184 /* Assumes keys are a pointer: if not, override. */
 185 #ifndef HTABLE_KTYPE
 186 #define HTABLE_KTYPE(keyof, type) void *
 187 #endif
 188 #endif
 189 #endif /* CCAN_HTABLE_TYPE_H */