From b0006b6ea2357572637b0c7946dfd074cfe18178 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Fri, 4 Feb 2011 22:44:31 +0100 Subject: [PATCH] new: read db_files and db_subdirs only if mtime changed 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 Reviewed-by: Austin Clements Looks good (faster than, but provably equivalent to the original code! notmuch_directory_get_child_* are side-effect free, db_files/db_subdirs aren't used between where they were set in the old code and where they are set in the new code, and db_files/db_subdirs are initialized to NULL when declared). Another timing data point: Old code: ./notmuch new 0.77s user 0.28s system 99% cpu 1.051 total New code: ./notmuch new 0.09s user 0.27s system 98% cpu 0.368 total --- notmuch-new.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/notmuch-new.c b/notmuch-new.c index 941f9d61..31d45532 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++) { -- 2.45.2