Addition of hashtable iterator

User print routine

rejig of show users to show dbusers and a new show users command in the debugcli

core/adminusers.c

@@ -185,3 +185,14 @@ admin_test_user(char *user)
 		return 0;
 	return users_fetch(users, user) != NULL;
 }
+
+/**
+ * Print the statistics and user names of the administration users
+ *
+ * @param dcb	A DCB to send the output to
+ */
+void
+dcb_PrintAdminUsers(DCB *dcb)
+{
+	dcb_usersPrint(dcb, users);
+}

core/hashtable.c

@@ -51,6 +51,7 @@
  *
  * Date		Who		Description
  * 23/06/13	Mark Riddoch	Initial implementation
+ * 23/07/13	Mark Riddoch	Addition of hashtable iterator
  *
  * @endverbatim
  */
@@ -437,3 +438,68 @@ hashtable_write_unlock(HASHTABLE *table)
 {
 	atomic_add(&table->writelock, -1);
 }
+
+/**
+ * Create an iterator on a hash table
+ *
+ * @param table		The table to ceate an iterator on
+ * @return	An iterator to use in future calls
+ */
+HASHITERATOR *
+hashtable_iterator(HASHTABLE *table)
+{
+HASHITERATOR	*rval;
+
+	if ((rval = (HASHITERATOR *)malloc(sizeof(HASHITERATOR))) != NULL)
+	{
+		rval->table = table;
+		rval->chain = 0;
+		rval->depth = -1;
+	}
+	return rval;
+}
+
+/**
+ * Return the next key for a hashtable iterator
+ *
+ * @param iter	The hashtable iterator
+ * @return	The next key value or NULL
+ */
+void *
+hashtable_next(HASHITERATOR *iter)
+{
+int		i;
+HASHENTRIES	*entries;
+
+	iter->depth++;
+	while (iter->chain < iter->table->hashsize)
+	{
+		if ((entries = iter->table->entries[iter->chain]) != NULL)
+		{
+			i = 0;
+			hashtable_read_lock(iter->table);
+			while (entries && i < iter->depth)
+			{
+				entries = entries->next;
+				i++;
+			}
+			hashtable_read_unlock(iter->table);
+			if (entries)
+				return entries->key;
+		}
+		iter->depth = 0;
+		iter->chain++;
+	}
+	return NULL;
+}
+
+/**
+ * Free a hashtable iterator
+ *
+ * @param iter	The iterator to free
+ */
+void
+hashtable_iterator_free(HASHITERATOR *iter)
+{
+	free(iter);
+}

core/users.c

@@ -170,6 +170,20 @@ usersPrint(USERS *users)
 void
 dcb_usersPrint(DCB *dcb, USERS *users)
 {
+HASHITERATOR	*iter;
+char		*sep, *user;
+
 	dcb_printf(dcb, "Users table data\n");
 	dcb_hashtable_stats(dcb, users->data);
+	if ((iter = hashtable_iterator(users->data)) != NULL)
+	{
+		dcb_printf(dcb, "User names: ");
+		sep = "";
+		while ((user = hashtable_next(iter)) != NULL)
+		{
+			dcb_printf(dcb, "%s%s", sep, user);
+			sep = ", ";
+		}
+		dcb_printf(dcb, "\n");
+	}
 }

include/adminusers.h

@@ -34,5 +34,7 @@
 extern int	admin_verify(char *, char *);
 extern char	*admin_add_user(char *, char *);
 extern int	admin_test_user(char *);
+extern void	dcb_PrintAdminUsers(DCB *dcb);
+
 
 #endif

include/hashtable.h

@@ -27,6 +27,7 @@
  *
  * Date		Who		Description
  * 23/06/13	Mark Riddoch	Initial implementation
+ * 23/07/13	Mark Riddoch	Addition of iterator mechanism
  *
  * @endverbatim
  */
@@ -46,6 +47,17 @@ typedef struct hashentry {
 	struct	hashentry	*next;	/**< The overflow chain */
 } HASHENTRIES;
 
+/**
+ * HASHTABLE iterator - used to walk the hashtable in a thread safe
+ * way
+ */
+typedef struct hashiterator {
+	struct hashtable
+			*table;		/**< The hashtable the iterator refers to */
+	int		chain;		/**< The current chain we are walking */
+	int		depth;		/**< The current depth down the chain */
+} HASHITERATOR;
+
 /**
  * The type definition for the memory allocation functions
  */
@@ -80,4 +92,9 @@ extern void		*hashtable_fetch(HASHTABLE *, void *);
 				/**< Fetch the data for a given key */
 extern void		hashtable_stats(HASHTABLE *);			/**< Print statisitics */
 extern void		dcb_hashtable_stats(DCB *, HASHTABLE *);	/**< Print statisitics */
+extern HASHITERATOR	*hashtable_iterator(HASHTABLE *);
+				/**< Allocate an iterator on the hashtable */
+extern void		*hashtable_next(HASHITERATOR *);
+				/**< Return the key of the hash table iterator */
+extern void		hashtable_iterator_free(HASHITERATOR *);
 #endif

modules/routing/debugcmd.c

@@ -75,6 +75,7 @@ struct subcommand {
 	int	arg_types[3];
 };
 
+static	void	telnetdShowUsers(DCB *);
 /**
  * The subcommands of the show command
  */
@@ -97,7 +98,9 @@ struct subcommand showoptions[] = {
 				{ARG_TYPE_ADDRESS, 0, 0} },
 	{ "epoll",	0, dprintPollStats,	"Show the poll statistics",
 				{0, 0, 0} },
-	{ "users",	1, dcb_usersPrint,	"Show statistics for a users table",
+	{ "dbusers",	1, dcb_usersPrint,	"Show statistics and user names for a service's user table",
+				{ARG_TYPE_ADDRESS, 0, 0} },
+	{ "users",	0, telnetdShowUsers,	"Show statistics and user names for the debug interface",
 				{ARG_TYPE_ADDRESS, 0, 0} },
 	{ NULL,		0, NULL,		NULL,
 				{0, 0, 0} }
@@ -503,3 +506,15 @@ char	*err;
 	else
 		dcb_printf(dcb, "Failed to add new user. %s\n", err);
 }
+
+/**
+ * Print the adminsitration users
+ *
+ * @param dcb	The DCB to print the user data to
+ */
+static void
+telnetdShowUsers(DCB *dcb)
+{
+	dcb_printf(dcb, "Administration interface users:\n");
+	dcb_PrintAdminUsers(dcb);
+}