libnm: avoid unnecessary copies accessing NMIPRoute's attributes

We want to support large number of routes. Reduce the number
of copies, by adding internal accessor functions.

Also, work around a complaint from coverity:

  46. NetworkManager-1.9.2/libnm-core/nm-utils.c:1987:
  dereference: Dereferencing a null pointer "names".

clients/cli/common.c

@@ -42,7 +42,7 @@
 static char **
 _ip_config_get_routes (NMIPConfig *cfg)
 {
-	gs_unref_hashtable GHashTable *hash = g_hash_table_new (nm_str_hash, g_str_equal);
+	gs_unref_hashtable GHashTable *hash = NULL;
 	GPtrArray *ptr_array;
 	char **arr;
 	guint i;
@@ -55,10 +55,10 @@ _ip_config_get_routes (NMIPConfig *cfg)
 	for (i = 0; i < ptr_array->len; i++) {
 		NMIPRoute *route = g_ptr_array_index (ptr_array, i);
 		gs_strfreev char **names = NULL;
-		gs_free char *attributes = NULL;
 		gsize j;
 		GString *str;
 		guint64 metric;
+		gs_free char *attributes = NULL;
 
 		str = g_string_new (NULL);
 		g_string_append_printf (str,
@@ -76,13 +76,20 @@ _ip_config_get_routes (NMIPConfig *cfg)
 		}
 
 		names = nm_ip_route_get_attribute_names (route);
-		g_hash_table_remove_all (hash);
+		if (names[0]) {
-		for (j = 0; names && names[j]; j++)
+			if (!hash)
-			g_hash_table_insert (hash, names[j], nm_ip_route_get_attribute (route, names[j]));
+				hash = g_hash_table_new (nm_str_hash, g_str_equal);
-		attributes = nm_utils_format_variant_attributes (hash, ',', '=');
+			else
-		if (attributes) {
+				g_hash_table_remove_all (hash);
-			g_string_append (str, ", ");
+
-			g_string_append (str, attributes);
+			for (j = 0; names[j]; j++)
+				g_hash_table_insert (hash, names[j], nm_ip_route_get_attribute (route, names[j]));
+
+			attributes = nm_utils_format_variant_attributes (hash, ',', '=');
+			if (attributes) {
+				g_string_append (str, ", ");
+				g_string_append (str, attributes);
+			}
 		}
 
 		arr[i] = g_string_free (str, FALSE);

libnm-core/nm-core-internal.h

@@ -199,6 +199,8 @@ GHashTable *_nm_utils_copy_strdict (GHashTable *strdict);
 typedef gpointer (*NMUtilsCopyFunc) (gpointer);
 
 gboolean _nm_ip_route_attribute_validate_all (const NMIPRoute *route);
+const char **_nm_ip_route_get_attribute_names (const NMIPRoute *route, gboolean sorted, guint *out_length);
+GHashTable *_nm_ip_route_get_attributes_direct (NMIPRoute *route);
 
 static inline void
 _nm_auto_ip_route_unref (NMIPRoute **v)

libnm-core/nm-keyfile-writer.c

@@ -193,14 +193,9 @@ write_ip_values (GKeyFile *file,
 
 		if (is_route) {
 			gs_free char *attributes = NULL;
-			gs_strfreev char **names = NULL;
+			GHashTable *hash;
-			gs_unref_hashtable GHashTable *hash = g_hash_table_new (g_str_hash, g_str_equal);
-			int j;
-
-			names = nm_ip_route_get_attribute_names (array->pdata[i]);
-			for (j = 0; names && names[j]; j++)
-				g_hash_table_insert (hash, names[j], nm_ip_route_get_attribute (array->pdata[i], names[j]));
 
+			hash = _nm_ip_route_get_attributes_direct (array->pdata[i]);
 			attributes = nm_utils_format_variant_attributes (hash, ',', '=');
 			if (attributes) {
 				g_strlcat (key_name, "_options", sizeof (key_name));

libnm-core/nm-setting-ip-config.c

@@ -1112,6 +1112,54 @@ nm_ip_route_set_metric (NMIPRoute *route,
 	route->metric = metric;
 }
 
+GHashTable *
+_nm_ip_route_get_attributes_direct (NMIPRoute *route)
+{
+	nm_assert (route);
+
+	return route->attributes;
+}
+
+/**
+ * _nm_ip_route_get_attribute_names:
+ * @route: the #NMIPRoute
+ * @sorted: whether to sort the names. Otherwise, their order is
+ *   undefined and unstable.
+ * @out_length: (allow-none): (out): the number of elements
+ *
+ * Gets an array of attribute names defined on @route.
+ *
+ * Returns: (array length=out_length) (transfer container): a %NULL-terminated array
+ *   of attribute names or %NULL if there are no attributes. The order of the returned
+ *   names is undefined.
+ **/
+const char **
+_nm_ip_route_get_attribute_names (const NMIPRoute *route, gboolean sorted, guint *out_length)
+{
+	const char **names;
+	guint length;
+
+	g_return_val_if_fail (route != NULL, NULL);
+
+	if (   !route->attributes
+	    || !g_hash_table_size (route->attributes)) {
+		NM_SET_OUT (out_length, 0);
+		return NULL;
+	}
+
+	names = (const char **) g_hash_table_get_keys_as_array (route->attributes, &length);
+	if (   sorted
+	    && length > 1) {
+		g_qsort_with_data (names,
+		                   length,
+		                   sizeof (char *),
+		                   nm_strcmp_p_with_data,
+		                   NULL);
+	}
+	NM_SET_OUT (out_length, length);
+	return names;
+}
+
 /**
  * nm_ip_route_get_attribute_names:
  * @route: the #NMIPRoute
@@ -1123,23 +1171,21 @@ nm_ip_route_set_metric (NMIPRoute *route,
 char **
 nm_ip_route_get_attribute_names (NMIPRoute *route)
 {
-	GHashTableIter iter;
+	char **names;
-	const char *key;
+	guint i, len;
-	GPtrArray *names;
 
 	g_return_val_if_fail (route != NULL, NULL);
 
-	names = g_ptr_array_new ();
+	names = (char **) _nm_ip_route_get_attribute_names (route, TRUE, &len);
+	if (!names)
+		return g_new0 (char *, 1);
 
-	if (route->attributes) {
+	nm_assert (len > 0 && names && names[len] == NULL);
-		g_hash_table_iter_init (&iter, route->attributes);
+	for (i = 0; i < len; i++) {
-		while (g_hash_table_iter_next (&iter, (gpointer *) &key, NULL))
+		nm_assert (names[i]);
-			g_ptr_array_add (names, g_strdup (key));
+		names[i] = g_strdup (names[i]);
 	}
-	g_ptr_array_sort (names, nm_strcmp_p);
+	return names;
-	g_ptr_array_add (names, NULL);
-
-	return (char **) g_ptr_array_free (names, FALSE);
 }
 
 /**

libnm-core/nm-utils.c

@@ -1962,8 +1962,8 @@ nm_utils_ip_routes_to_variant (GPtrArray *routes)
 		for (i = 0; i < routes->len; i++) {
 			NMIPRoute *route = routes->pdata[i];
 			GVariantBuilder route_builder;
-			char **names;
+			gs_free const char **names = NULL;
-			int n;
+			guint j, len;
 
 			g_variant_builder_init (&route_builder, G_VARIANT_TYPE ("a{sv}"));
 			g_variant_builder_add (&route_builder, "{sv}",
@@ -1983,13 +1983,12 @@ nm_utils_ip_routes_to_variant (GPtrArray *routes)
 				                       g_variant_new_uint32 ((guint32) nm_ip_route_get_metric (route)));
 			}
 
-			names = nm_ip_route_get_attribute_names (route);
+			names = _nm_ip_route_get_attribute_names (route, TRUE, &len);
-			for (n = 0; names[n]; n++) {
+			for (j = 0; j < len; j++) {
 				g_variant_builder_add (&route_builder, "{sv}",
-				                       names[n],
+				                       names[j],
-				                       nm_ip_route_get_attribute (route, names[n]));
+				                       nm_ip_route_get_attribute (route, names[j]));
 			}
-			g_strfreev (names);
 
 			g_variant_builder_add (&builder, "a{sv}", &route_builder);
 		}

src/settings/plugins/ifcfg-rh/nms-ifcfg-rh-writer.c

@@ -1867,18 +1867,18 @@ write_connection_setting (NMSettingConnection *s_con, shvarFile *ifcfg)
 static char *
 get_route_attributes_string (NMIPRoute *route, int family)
 {
-	gs_strfreev char **names = NULL;
+	gs_free const char **names = NULL;
 	GVariant *attr, *lock;
 	GString *str;
-	int i;
+	guint i, len;
 
-	names = nm_ip_route_get_attribute_names (route);
+	names = _nm_ip_route_get_attribute_names (route, TRUE, &len);
-	if (!names || !names[0])
+	if (!len)
 		return NULL;
 
 	str = g_string_new ("");
 
-	for (i = 0; names[i]; i++) {
+	for (i = 0; i < len; i++) {
 		attr = nm_ip_route_get_attribute (route, names[i]);
 
 		if (!nm_ip_route_attribute_validate (names[i], attr, family, NULL, NULL))