htable: add htable_count().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/htable/htable.h

@@ -75,6 +75,15 @@ bool htable_init_sized(struct htable *ht,
 		       size_t (*rehash)(const void *elem, void *priv),
 		       void *priv, size_t size);
 
+/**
+ * htable_count - count number of entries in a hash table.
+ * @ht: the hash table
+ */
+static inline size_t htable_count(const struct htable *ht)
+{
+	return ht->elems;
+}
+
 /**
  * htable_clear - empty a hash table.
  * @ht: the hash table to clear

ccan/htable/htable_type.h

@@ -25,6 +25,9 @@
  *	void <name>_clear(struct <name> *);
  *	bool <name>_copy(struct <name> *dst, const struct <name> *src);
  *
+ * Count entries:
+ *	size_t <name>_count(const struct <name> *ht);
+ *
  * Add function only fails if we run out of memory:
  *	bool <name>_add(struct <name> *ht, const <type> *e);
  *
@@ -69,6 +72,10 @@
 	{								\
 		return htable_init_sized(&ht->raw, name##_hash, NULL, s); \
 	}								\
+	static inline UNNEEDED size_t name##_count(const struct name *ht) \
+	{								\
+		return htable_count(&ht->raw);				\
+	}								\
 	static inline UNNEEDED void name##_clear(struct name *ht)	\
 	{								\
 		htable_clear(&ht->raw);					\

ccan/htable/test/run-type.c

@@ -65,7 +65,7 @@ static void find_vals(const struct htable_obj *ht,
 			return;
 		}
 	}
-	pass("Found %u numbers in hash", i);
+	ok1(htable_obj_count(ht) == i);
 }
 
 static void del_vals(struct htable_obj *ht,
@@ -116,12 +116,13 @@ int main(void)
 	void *p;
 	struct htable_obj_iter iter;
 
-	plan_tests(29);
+	plan_tests(32);
 	for (i = 0; i < NUM_VALS; i++)
 		val[i].key = i;
 	dne = i;
 
 	htable_obj_init(&ht);
+	ok1(htable_obj_count(&ht) == 0);
 	ok1(ht_max(&ht.raw) == 0);
 	ok1(ht.raw.bits == 0);
 
@@ -205,6 +206,8 @@ int main(void)
 	}
 
 	htable_obj_clear(&ht);
+	ok1(htable_obj_count(&ht) == 0);
 	htable_obj_clear(&ht2);
+	ok1(htable_obj_count(&ht2) == 0);
 	return exit_status();
 }

ccan/htable/test/run.c

@@ -67,7 +67,7 @@ static void find_vals(struct htable *ht,
 			return;
 		}
 	}
-	pass("Found %llu numbers in hash", (long long)i);
+	ok1(htable_count(ht) == i);
 }
 
 static void del_vals(struct htable *ht,
@@ -105,12 +105,13 @@ int main(void)
 	void *p;
 	struct htable_iter iter;
 
-	plan_tests(36);
+	plan_tests(38);
 	for (i = 0; i < NUM_VALS; i++)
 		val[i] = i;
 	dne = i;
 
 	htable_init(&ht, hash, NULL);
+	ok1(htable_count(&ht) == 0);
 	ok1(ht_max(&ht) == 0);
 	ok1(ht.bits == 0);
 
@@ -208,5 +209,7 @@ int main(void)
 	ok1(ht_max(&ht) >= 1025);
 	htable_clear(&ht);
 
+	ok1(htable_count(&ht) == 0);
+
 	return exit_status();
 }