[PATCH] new: read db_files and db_subdirs if mtime changed

[Karel Zak <kzak@redhat.com>]

The db_files and db_subdirs are unnecessary for unchanged directories.

maildir with 10000 e-mails:

old version:
	$ time ./notmuch new
	No new mail.

	real    0m0.053s
	user    0m0.028s
	sys     0m0.026s

new version:
	$ time ./notmuch new
	No new mail.

	real    0m0.032s
	user    0m0.009s
	sys     0m0.023s

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 notmuch-new.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/notmuch-new.c b/notmuch-new.c
index 941f9d6..31d4553 100644
--- a/notmuch-new.c
+++ b/notmuch-new.c
@@ -247,15 +247,7 @@ add_files_recursive (notmuch_database_t *notmuch,
     directory = notmuch_database_get_directory (notmuch, path);
     db_mtime = notmuch_directory_get_mtime (directory);
 
-    if (db_mtime == 0) {
-	new_directory = TRUE;
-	db_files = NULL;
-	db_subdirs = NULL;
-    } else {
-	new_directory = FALSE;
-	db_files = notmuch_directory_get_child_files (directory);
-	db_subdirs = notmuch_directory_get_child_directories (directory);
-    }
+    new_directory = db_mtime ? FALSE : TRUE;
 
     /* If the database knows about this directory, then we sort based
      * on strcmp to match the database sorting. Otherwise, we can do
@@ -328,6 +320,11 @@ add_files_recursive (notmuch_database_t *notmuch,
     if (fs_mtime == db_mtime)
 	goto DONE;
 
+    if (!new_directory) {
+	db_files = notmuch_directory_get_child_files (directory);
+	db_subdirs = notmuch_directory_get_child_directories (directory);
+    }
+
     /* Pass 2: Scan for new files, removed files, and removed directories. */
     for (i = 0; i < num_fs_entries; i++)
     {
-- 
1.7.3.4