htable: first implementation

[ccan] / ccan / htable / htable_type.h

diff --git a/ccan/htable/htable_type.h b/ccan/htable/htable_type.h
new file mode 100644 (file)
index 0000000..6fe05e2
--- /dev/null
+++ b/ccan/htable/htable_type.h
@@ -0,0 +1,97 @@
+#ifndef CCAN_HTABLE_TYPE_H
+#define CCAN_HTABLE_TYPE_H
+#include <ccan/htable/htable.h>
+#include "config.h"
+
+/**
+ * HTABLE_DEFINE_TYPE - create a set of htable ops for a type
+ * @type: a type whose pointers will be values in the hash.
+ * @keyof: a function/macro to extract a key from a @type element.
+ * @hashfn: a hash function for a @key
+ * @cmpfn: a comparison function for two keyof()s.
+ * @name: a name for all the functions to define (of form htable_<name>_*)
+ *
+ * NULL values may not be placed into the hash table.
+ *
+ * The following wrapper functions are defined; each one is a
+ * simplified version of the htable.h equivalent:
+ *
+ *     // Creating and freeing.
+ *     struct htable_@name *htable_@name_new(void);
+ *     void htable_@name_free(const struct htable_@name *ht);
+ *
+ *     // Add, delete and find.
+ *     bool htable_@name_add(struct htable_@name *ht, const type *e);
+ *     bool htable_@name_del(struct htable_@name *ht, const type *e);
+ *     bool htable_@name_delkey(struct htable_@name *ht, const ktype *k);
+ *     type *htable_@name_get(const struct htable_@name *ht, const ktype *k);
+ *
+ *     // Iteration.
+ *     struct htable_@name_iter;
+ *     type *htable_@name_first(const struct htable_@name *ht,
+ *                              struct htable_@name_iter *i);
+ *     type *htable_@name_next(const struct htable_@name *ht,
+ *                             struct htable_@name_iter *i);
+ */
+#define HTABLE_DEFINE_TYPE(type, keyof, hashfn, cmpfn, name)           \
+struct htable_##name;                                                  \
+struct htable_##name##_iter { struct htable_iter i; };                 \
+static inline size_t htable_##name##_hash(const void *elem, void *priv)        \
+{                                                                      \
+       return hashfn(keyof((const type *)elem));                       \
+}                                                                      \
+static inline struct htable_##name *htable_##name##_new(void)          \
+{                                                                      \
+       return (struct htable_##name *)htable_new(htable_##name##_hash, \
+                                                 NULL);                \
+}                                                                      \
+static inline void htable_##name##_free(const struct htable_##name *ht)        \
+{                                                                      \
+       htable_free((const struct htable *)ht);                         \
+}                                                                      \
+static inline bool htable_##name##_add(struct htable_##name *ht,       \
+                                      const type *elem)                \
+{                                                                      \
+       return htable_add((struct htable *)ht, hashfn(keyof(elem)), elem); \
+}                                                                      \
+static inline bool htable_##name##_del(const struct htable_##name *ht, \
+                                      const type *elem)                \
+{                                                                      \
+       return htable_del((struct htable *)ht, hashfn(keyof(elem)), elem); \
+}                                                                      \
+static inline type *htable_##name##_get(const struct htable_##name *ht,        \
+                                       const HTABLE_KTYPE(keyof) k)    \
+{                                                                      \
+       /* Typecheck for cmpfn */                                       \
+       (void)sizeof(cmpfn(keyof((const type *)NULL),                   \
+                          keyof((const type *)NULL)));                 \
+       return (type *)htable_get((const struct htable *)ht,            \
+                                 hashfn(k),                            \
+                                 (bool (*)(const void *, void *))(cmpfn), \
+                                 k);                                   \
+}                                                                      \
+static inline bool htable_##name##_delkey(struct htable_##name *ht,    \
+                                         const HTABLE_KTYPE(keyof) k) \
+{                                                                      \
+       type *elem = htable_##name##_get(ht, k);                        \
+       if (elem)                                                       \
+               return htable_##name##_del(ht, elem);                   \
+       return false;                                                   \
+}                                                                      \
+static inline type *htable_##name##_first(const struct htable_##name *ht, \
+                                         struct htable_##name##_iter *iter) \
+{                                                                      \
+       return htable_first((const struct htable *)ht, &iter->i);       \
+}                                                                      \
+static inline type *htable_##name##_next(const struct htable_##name *ht, \
+                                        struct htable_##name##_iter *iter) \
+{                                                                      \
+       return htable_next((const struct htable *)ht, &iter->i);        \
+}
+
+#if HAVE_TYPEOF
+#define HTABLE_KTYPE(keyof) typeof(keyof(NULL))
+#else
+#define HTABLE_KTYPE(keyof) void *
+#endif
+#endif /* CCAN_HTABLE_TYPE_H */