values: add bt_value_map_extend()

[babeltrace.git] / lib / values.c

diff --git a/lib/values.c b/lib/values.c
index bd217bf61ce5fa8f1cc6ad577ae3cb0f2ad96d3a..cea4b10bdc2e3e7b99be948b9dde0618b4392841 100644 (file)
--- a/lib/values.c
+++ b/lib/values.c
@@ -1168,6 +1168,81 @@ end:
        return ret;
 }
 
+struct extend_map_element_data {
+       struct bt_value *extended_obj;
+       bool got_error;
+};
+
+static
+bool extend_map_element(const char *key,
+               struct bt_value *extension_obj_elem, void *data)
+{
+       bool ret = true;
+
+       struct extend_map_element_data *extend_data = data;
+
+       /* Copy object which is to replace the current one */
+       struct bt_value *extension_obj_elem_copy =
+               bt_value_copy(extension_obj_elem);
+
+       /* Replace in extended object */
+       if (bt_value_map_insert(extend_data->extended_obj, key,
+                       extension_obj_elem_copy)) {
+               goto error;
+       }
+
+       goto end;
+
+error:
+       ret = false;
+       extend_data->got_error = true;
+
+end:
+       BT_PUT(extension_obj_elem_copy);
+
+       return ret;
+}
+
+struct bt_value *bt_value_map_extend(struct bt_value *base_map_obj,
+               struct bt_value *extension_obj)
+{
+       struct bt_value *extended_obj = NULL;
+       struct extend_map_element_data extend_data = { 0 };
+
+       if (!bt_value_is_map(base_map_obj) || !bt_value_is_map(extension_obj)) {
+               goto error;
+       }
+
+       /* Create copy of base map object to start with */
+       extended_obj = bt_value_copy(base_map_obj);
+       if (!extended_obj) {
+               goto error;
+       }
+
+       /*
+        * For each key in the extension map object, replace this key
+        * in the copied map object.
+        */
+       extend_data.extended_obj = extended_obj;
+
+       if (bt_value_map_foreach(extension_obj, extend_map_element,
+                       &extend_data)) {
+               goto error;
+       }
+
+       if (extend_data.got_error) {
+               goto error;
+       }
+
+       goto end;
+
+error:
+       BT_PUT(extended_obj);
+
+end:
+       return extended_obj;
+}
+
 struct bt_value *bt_value_copy(const struct bt_value *object)
 {
        struct bt_value *copy_obj = NULL;