/*
- * update_image.c - Update a WIM image.
+ * update_image.c - see description below
*/
/*
* along with this file; if not, see http://www.gnu.org/licenses/.
*/
+/*
+ * This file contains the implementation of wimlib_update_image(), which is one
+ * of the two ways by which library users can make changes to a WIM image. (The
+ * other way is by mounting an image read-write.) wimlib_update_image() is also
+ * used in the implementation of wimlib_add_image(), since "create a WIM image
+ * from this directory tree" is equivalent to "create an empty WIM image, then
+ * update it to add this directory tree as the root".
+ *
+ * wimlib_update_image() processes a list of commands passed to it. Currently,
+ * the following types of commands are supported:
+ *
+ * - Add a directory tree from an external source (filesystem or NTFS volume).
+ * This can be used to add new files or to replace existing files.
+ * - Delete a file or directory tree.
+ * - Rename a file or directory tree.
+ *
+ * Not supported are creating links to existing files or changing metadata of
+ * existing files.
+ *
+ * wimlib_update_image() is atomic. If it cannot complete successfully, then
+ * all changes are rolled back and the WIMStruct is left unchanged. Rollback is
+ * implemented by breaking the commands into primitive operations such as "link
+ * this dentry tree here" which can be undone by doing the opposite operations
+ * in reverse order.
+ */
+
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
+#include "wimlib/assert.h"
#include "wimlib/capture.h"
#include "wimlib/dentry.h"
#include "wimlib/encoding.h"