*
* o Ask the filesystem for files and directories within 'path'
* (via scandir and stored in fs_entries)
- * o Ask the database for files and directories within 'path'
- * (db_files and db_subdirs)
*
* o Pass 1: For each directory in fs_entries, recursively call into
* this same function.
*
- * o Pass 2: If 'fs_mtime' > 'db_mtime', then walk fs_entries
- * simultaneously with db_files and db_subdirs. Look for one of
- * three interesting cases:
+ * o Compare fs_mtime to db_mtime. If they are equivalent, terminate
+ * the algorithm at this point, (this directory has not been
+ * updated in the filesystem since the last database scan of PASS
+ * 2).
+ *
+ * o Ask the database for files and directories within 'path'
+ * (db_files and db_subdirs)
+ *
+ * o Pass 2: Walk fs_entries simultaneously with db_files and
+ * db_subdirs. Look for one of three interesting cases:
*
* 1. Regular file in fs_entries and not in db_files
* This is a new file to add_message into the database.
if (fs_mtime == db_mtime)
goto DONE;
+ /* new_directory means a directory that the database has never
+ * seen before. In that case, we can simply leave db_files and
+ * db_subdirs NULL. */
if (!new_directory) {
db_files = notmuch_directory_get_child_files (directory);
db_subdirs = notmuch_directory_get_child_directories (directory);