From: Phillip Wood <phillip.wood123@gmail.com>
Date: Tue, 10 May 2022 13:10:07 GMT
Subject: Re: [PATCH v2 15/15] entry.c: use dir-iterator to avoid explicit dir traversal
Message-ID: <091db194-2e6e-8c15-2e84-5f873fd08b55@gmail.com>
In-Reply-To: <20220509175159.2948802-16-kioplato@gmail.com>

Hi Plato

On 09/05/2022 18:51, Plato Kiorpelidis wrote:
> Replace usage of opendir/readdir/closedir API to traverse directories
> recursively, at remove_subtree() function, by the dir-iterator API. This
> simplifies the code and avoids recursive calls to remove_subtree().

Thanks for adding this conversion, it is nice to see the post-order 
traversal being used and the end result is an improvement on the original.

Best Wishes

Phillip

> Signed-off-by: Plato Kiorpelidis <kioplato@gmail.com>
> ---
>   entry.c | 38 +++++++++++++++++++-------------------
>   1 file changed, 19 insertions(+), 19 deletions(-)
> 
> diff --git a/entry.c b/entry.c
> index 1c9df62b30..46ef145f97 100644
> --- a/entry.c
> +++ b/entry.c
> @@ -8,6 +8,8 @@
>   #include "fsmonitor.h"
>   #include "entry.h"
>   #include "parallel-checkout.h"
> +#include "iterator.h"
> +#include "dir-iterator.h"
>   
>   static void create_directories(const char *path, int path_len,
>   			       const struct checkout *state)
> @@ -52,26 +54,24 @@ static void create_directories(const char *path, int path_len,
>   
>   static void remove_subtree(struct strbuf *path)
>   {
> -	DIR *dir = opendir(path->buf);
> -	struct dirent *de;
> -	int origlen = path->len;
> -
> -	if (!dir)
> -		die_errno("cannot opendir '%s'", path->buf);
> -	while ((de = readdir_skip_dot_and_dotdot(dir)) != NULL) {
> -		struct stat st;
> -
> -		strbuf_addch(path, '/');
> -		strbuf_addstr(path, de->d_name);
> -		if (lstat(path->buf, &st))
> -			die_errno("cannot lstat '%s'", path->buf);
> -		if (S_ISDIR(st.st_mode))
> -			remove_subtree(path);
> -		else if (unlink(path->buf))
> -			die_errno("cannot unlink '%s'", path->buf);
> -		strbuf_setlen(path, origlen);
> +	unsigned int flags = DIR_ITERATOR_DIRS_AFTER;
> +	struct dir_iterator *iter = NULL;
> +	int ok;
> +
> +	if (!(iter = dir_iterator_begin(path->buf, flags)))
> +		die_errno("cannot open directory '%s'", path->buf);
> +
> +	while ((ok = dir_iterator_advance(iter)) == ITER_OK) {
> +		if (S_ISDIR(iter->st.st_mode) && rmdir(iter->path.buf))
> +			die_errno("cannot rmdir '%s'", iter->path.buf);
> +
> +		if (!S_ISDIR(iter->st.st_mode) && unlink(iter->path.buf))
> +			die_errno("cannot unlink '%s'", iter->path.buf);
>   	}
> -	closedir(dir);
> +
> +	if (ok != ITER_DONE)
> +		die_errno("failed to iterate over directory '%s'", path->buf);
> +
>   	if (rmdir(path->buf))
>   		die_errno("cannot rmdir '%s'", path->buf);
>   }