On Tue, Feb 26 2019, Duy Nguyen wrote:

On Tue, Feb 26, 2019 at 12:18 PM Matheus Tavares
[off-list ref] wrote:

quoted

Replace usage of opendir/readdir/closedir API to traverse directories
recursively, at copy_or_link_directory function, by the dir-iterator
API. This simplifies the code and avoid recursive calls to
copy_or_link_directory.

This process also makes copy_or_link_directory call die() in case of an
error on readdir or stat, inside dir_iterator_advance. Previously it
would just print a warning for errors on stat and ignore errors on
readdir, which isn't nice because a local git clone would end up
successfully even though the .git/objects copy didn't fully succeeded.

Signed-off-by: Matheus Tavares <redacted>
---
I can also make the change described in the last paragraph in a separate
patch before this one, but I would have to undo it in this patch because
dir-iterator already implements it. So, IMHO, it would be just noise
and not worthy.

 builtin/clone.c | 45 +++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/builtin/clone.c b/builtin/clone.c
index fd580fa98d..b23ba64c94 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c

@@ -23,6 +23,8 @@
 #include "transport.h"
 #include "strbuf.h"
 #include "dir.h"
+#include "dir-iterator.h"
+#include "iterator.h"
 #include "sigchain.h"
 #include "branch.h"
 #include "remote.h"

@@ -411,42 +413,37 @@ static void mkdir_if_missing(const char *pathname, mode_t mode)
 }

 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
-                                  const char *src_repo, int src_baselen)
+                                  const char *src_repo)
 {
-       struct dirent *de;
-       struct stat buf;
        int src_len, dest_len;
-       DIR *dir;
-
-       dir = opendir(src->buf);
-       if (!dir)
-               die_errno(_("failed to open '%s'"), src->buf);
+       struct dir_iterator *iter;
+       int iter_status;
+       struct stat st;
+       unsigned flags;

        mkdir_if_missing(dest->buf, 0777);

+       flags = DIR_ITERATOR_PEDANTIC | DIR_ITERATOR_FOLLOW_SYMLINKS;
+       iter = dir_iterator_begin(src->buf, flags);
+
        strbuf_addch(src, '/');
        src_len = src->len;
        strbuf_addch(dest, '/');
        dest_len = dest->len;

-       while ((de = readdir(dir)) != NULL) {
+       while ((iter_status = dir_iterator_advance(iter)) == ITER_OK) {
                strbuf_setlen(src, src_len);
-               strbuf_addstr(src, de->d_name);
+               strbuf_addstr(src, iter->relative_path);
                strbuf_setlen(dest, dest_len);
-               strbuf_addstr(dest, de->d_name);
-               if (stat(src->buf, &buf)) {
-                       warning (_("failed to stat %s\n"), src->buf);
-                       continue;
-               }
-               if (S_ISDIR(buf.st_mode)) {
-                       if (!is_dot_or_dotdot(de->d_name))
-                               copy_or_link_directory(src, dest,
-                                                      src_repo, src_baselen);
+               strbuf_addstr(dest, iter->relative_path);
+
+               if (S_ISDIR(iter->st.st_mode)) {
+                       mkdir_if_missing(dest->buf, 0777);

I wonder if this mkdir_if_missing is sufficient. What if you have to
create multiple directories?

Let's say the first advance, we hit "a". The the second advance we hit
directory "b/b/b/b", we would need to mkdir recursively and something
like safe_create_leading_directories() would be a better fit.

I'm not sure if it can happen though. I haven't re-read dir-iterator
code carefully.

This part isn't a problem. It iterates one level at a time. So given a
structure like a/b/c/d/e/f/g/h/i/j/k/some-l you'll find that if you
instrument the loop in clone.c you get:

    dir = a
    dir = a/b
    dir = a/b/c
    dir = a/b/c/d
    dir = a/b/c/d/e
    dir = a/b/c/d/e/f
    dir = a/b/c/d/e/f/g
    dir = a/b/c/d/e/f/g/h
    dir = a/b/c/d/e/f/g/h/i
    dir = a/b/c/d/e/f/g/h/i/j
    dir = a/b/c/d/e/f/g/h/i/j/k
    dir = a/b/c/d/e/f/g/h/i/j/k/some-l

So it's like the old implementation in that way. It readdir()'s and
walks directories one level at a time.