X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fupdate_image.c;h=65389e156cc227464c82d6df0cc0b7ad3e08cab7;hb=0a97ffa6074b6b69b9982d83b398145c5ac860ab;hp=fc149f0a415cd6e5771783634abc91dab89b9200;hpb=4c73e29d8d74a4e969782d2d40e209337414034c;p=wimlib

diff --git a/src/update_image.c b/src/update_image.c
index fc149f0a..65389e15 100644
--- a/src/update_image.c
+++ b/src/update_image.c
@@ -1,5 +1,5 @@
 /*
- * update_image.c - Update a WIM image.
+ * update_image.c - see description below
  */
 
 /*
@@ -19,10 +19,37 @@
  * 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"
@@ -765,7 +792,7 @@ execute_add_command(struct update_command_journal *j,
 	tchar *fs_source_path;
 	tchar *wim_target_path;
 	const tchar *config_file;
-	struct add_image_params params;
+	struct capture_params params;
 	struct capture_config config;
 	capture_tree_t capture_tree = platform_default_capture_tree;
 #ifdef WITH_NTFS_3G