htable: HTABLE_INITIALIZER() for static initialization.

Unfortunately it's a bit of a pain to use for typed hashtables, but it
works.

diff --git a/ccan/htable/htable.c b/ccan/htable/htable.c
index f3e529211d5b2456bad5165d3baa848de4314d3d..0a01ead8978ad4c4e914a37dbe029c2ef1219004 100644 (file)
--- a/ccan/htable/htable.c
+++ b/ccan/htable/htable.c
@@ -45,18 +45,10 @@ static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
 void htable_init(struct htable *ht,
                 size_t (*rehash)(const void *elem, void *priv), void *priv)
 {
 void htable_init(struct htable *ht,
                 size_t (*rehash)(const void *elem, void *priv), void *priv)
 {

-       ht->bits = 0;
+       struct htable empty = HTABLE_INITIALIZER(empty, NULL, NULL);
+       *ht = empty;

        ht->rehash = rehash;
        ht->priv = priv;
        ht->rehash = rehash;
        ht->priv = priv;

-       ht->elems = 0;
-       ht->deleted = 0;
-       ht->max = 0;
-       ht->max_with_deleted = 0;
-       /* This guarantees we enter update_common first add. */
-       ht->common_mask = -1;
-       ht->common_bits = 0;
-       ht->perfect_bit = 0;
-       /* Dummy table until first insert. */

        ht->table = &ht->perfect_bit;
 }
 
        ht->table = &ht->perfect_bit;
 }
 

diff --git a/ccan/htable/htable.h b/ccan/htable/htable.h
index b3962ac050251747706c3de25259b781e3b026ca..ed668e7405ed84e819cec49b85f8186b85287933 100644 (file)
--- a/ccan/htable/htable.h
+++ b/ccan/htable/htable.h
@@ -24,7 +24,26 @@ struct htable {
 };
 
 /**
 };
 
 /**

- * htable_init - initialize an empty hash tree.
+ * HTABLE_INITIALIZER - static initialization for a hash table.
+ * @name: name of this htable.
+ * @rehash: hash function to use for rehashing.
+ * @priv: private argument to @rehash function.
+ *
+ * This is useful for setting up static and global hash tables.
+ *
+ * Example:
+ *     // For simplicity's sake, say hash value is contents of elem.
+ *     static size_t rehash(const void *elem, void *unused)
+ *     {
+ *             return *(size_t *)elem;
+ *     }
+ *     static struct htable ht = HTABLE_INITIALIZER(ht, rehash, NULL);
+ */
+#define HTABLE_INITIALIZER(name, rehash, priv)                         \
+       { rehash, priv, 0, 0, 0, 0, 0, -1, 0, 0, &name.perfect_bit }
+
+/**
+ * htable_init - initialize an empty hash table.

  * @ht: the hash table to initialize
  * @rehash: hash function to use for rehashing.
  * @priv: private argument to @rehash function.
  * @ht: the hash table to initialize
  * @rehash: hash function to use for rehashing.
  * @priv: private argument to @rehash function.


@@ -33,7 +52,7 @@ void htable_init(struct htable *ht,
                 size_t (*rehash)(const void *elem, void *priv), void *priv);
 
 /**
                 size_t (*rehash)(const void *elem, void *priv), void *priv);
 
 /**

- * htable_clear - empty a hash tree.
+ * htable_clear - empty a hash table.

  * @ht: the hash table to clear
  *
  * This doesn't do anything to any pointers left in it.
  * @ht: the hash table to clear
  *
  * This doesn't do anything to any pointers left in it.


@@ -48,7 +67,7 @@ void htable_clear(struct htable *ht);
 size_t htable_rehash(const void *elem);
 
 /**
 size_t htable_rehash(const void *elem);
 
 /**

- * htable_add - add a pointer into a hash tree.
+ * htable_add - add a pointer into a hash table.

  * @ht: the htable
  * @hash: the hash value of the object
  * @p: the non-NULL pointer
  * @ht: the htable
  * @hash: the hash value of the object
  * @p: the non-NULL pointer


@@ -59,7 +78,7 @@ size_t htable_rehash(const void *elem);
 bool htable_add(struct htable *ht, size_t hash, const void *p);
 
 /**
 bool htable_add(struct htable *ht, size_t hash, const void *p);
 
 /**

- * htable_del - remove a pointer from a hash tree
+ * htable_del - remove a pointer from a hash table

  * @ht: the htable
  * @hash: the hash value of the object
  * @p: the pointer
  * @ht: the htable
  * @hash: the hash value of the object
  * @p: the pointer


@@ -145,7 +164,7 @@ void *htable_first(const struct htable *htable, struct htable_iter *i);
 void *htable_next(const struct htable *htable, struct htable_iter *i);
 
 /**
 void *htable_next(const struct htable *htable, struct htable_iter *i);
 
 /**

- * htable_delval - remove an iterated pointer from a hash tree
+ * htable_delval - remove an iterated pointer from a hash table

  * @ht: the htable
  * @i: the htable_iter
  *
  * @ht: the htable
  * @i: the htable_iter
  *

diff --git a/ccan/htable/htable_type.h b/ccan/htable/htable_type.h
index 3b555cde4aaadd183d6e196ac50986d11fdc58d7..03cc46fc5836c8003e2c1e325c13a5ec6df5db47 100644 (file)
--- a/ccan/htable/htable_type.h
+++ b/ccan/htable/htable_type.h
@@ -38,6 +38,9 @@
  *
  * It's currently safe to iterate over a changing hashtable, but you might
  * miss an element.  Iteration isn't very efficient, either.
  *
  * It's currently safe to iterate over a changing hashtable, but you might
  * miss an element.  Iteration isn't very efficient, either.

+ *
+ * You can use HTABLE_INITIALIZER like so:
+ *     struct <name> ht = { HTABLE_INITIALIZER(ht.raw, <name>_hash, NULL) };

  */
 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)            \
        struct name { struct htable raw; };                             \
  */
 #define HTABLE_DEFINE_TYPE(type, keyof, hashfn, eqfn, name)            \
        struct name { struct htable raw; };                             \