On Sun, Nov 15, 2020 at 4:00 PM Alexander Lakhin <exclusion@gmail.com> wrote:
As I've found out, readdir() replacement for Windows in fact gets all the needed information (correct file size, attributes...) in WIN32_FIND_DATA, but it just leaves it inside and returns only fields of the dirent structure. So pg_ls_dir_files() (that calls ReadDir()/readdir()) needs to get this information again, that leads to opening a file on Windows. I think it can be done more effectively by adding a new function ReadDirExtendedInfo(), that will additionally accept a pointer to "struct dirent_extra" with fields {valid (indicating that the structure is filled), attributes, file size, mtime}. Maybe the advanced function could also invoke stat() inside (not on Windows).
As to patch I proposed before, I think it's still needed to fully support the following usage pattern: stat(); if (no_error) { do_something(); } else if (file_not_found) { do_something_else(); } else { error(); }
We are currently missing a WIN32 lstat() port. I was thinking about proposing a patch to implement it using GetFileAttributesEx(). That might work as fall back to the CreateFile() if the file attribute is not a FILE_ATTRIBUTE_REPARSE_POINT.
Anyhow, I do not think any retry logic should be in the stat() function, but in the caller.
