Re: [PATCH v2] Improve performance of git status --ignored
From: Junio C Hamano <hidden>
Date: 2017-09-19 03:27:25
Jameson Miller [off-list ref] writes:
Improve the performance of the directory listing logic when it wants to list non-empty ignored directories. In order to show non-empty ignored directories, the existing logic will recursively iterate through all contents of an ignored directory. This change introduces the optimization to stop iterating through the contents once it finds the first file.
Wow, such an obviously correct optimization. Very nicely explained, too.
This can have a significant improvement in 'git status --ignored' performance in repositories with a large number of files in ignored directories. For an example of the performance difference on an example repository with 196,000 files in 400 ignored directories: | Command | Time (s) | | -------------------------- | --------- | | git status | 1.2 | | git status --ignored (old) | 3.9 | | git status --ignored (new) | 1.4 | Signed-off-by: Jameson Miller <redacted> ---
I wish all the contributions I have to accept are as nicely done as this one ;-) Thanks.
quoted hunk
dir.c | 47 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 6 deletions(-)diff --git a/dir.c b/dir.c index 1c55dc3..1d17b80 100644 --- a/dir.c +++ b/dir.c@@ -49,7 +49,7 @@ struct cached_dir { static enum path_treatment read_directory_recursive(struct dir_struct *dir, struct index_state *istate, const char *path, int len, struct untracked_cache_dir *untracked, - int check_only, const struct pathspec *pathspec); + int check_only, int stop_at_first_file, const struct pathspec *pathspec);
We might want to make check_only and stop_at_first_file into a single "unsigned flags" used as a collection of bits, but we can wait until we start feeling the urge to add the third boolean parameter to this function (at which point I'd probably demand a preliminary clean-up to merge these two into a single flags word before adding the third one as a new bit in that word).
quoted hunk
@@ -1404,8 +1404,13 @@ static enum path_treatment treat_directory(struct dir_struct *dir, untracked = lookup_untracked(dir->untracked, untracked, dirname + baselen, len - baselen); + + /* + * If this is an excluded directory, then we only need to check if + * the directory contains any files. + */ return read_directory_recursive(dir, istate, dirname, len, - untracked, 1, pathspec); + untracked, 1, exclude, pathspec);
Nicely explained in the in-code comment. I'd assume that you want your microsoft e-mail address used on the signed-off-by line appear as the author, so I'll tweak this a bit to make it so (otherwise, your 81@gmail.com would become the author). Thanks.