Troy Hinckley <troyhinck...@gmail.com> writes:
Hi Troy,
> Copying files when both the source and destination are on the same
> remote host is fast because tramp does a direct copy in
> tramp-do-copy-or-rename-file-directly. However there is no such
> support when copying a directory. When copying directories on a remote
> host via dired it takes a very long time, A directory that takes 100ms
> to copy via remote shell takes tramp almost a full minute. It looks
> like there is only support for direct copying files, not directories.
> Why is that? It seems like an easy performance win, but I don’t know
> if there is more complexity to it.
There might be some edge cases where it is problematic, but we'll see it
only when reported by users. I gave it a try, and I have enhanced
tramp-sh-handle-copy-directory accordingly. It passes the checks in
tramp-tests.el, which is a good sign.
Would you like to test it? I've appended the patch, it applies on top of
Tramp 2.7.1.
> -Troy Hinckley
Best regards, Michael.
diff --git a/lisp/tramp-sh.el b/lisp/tramp-sh.el
index 8fde854a..190a6aa9 100644
--- a/lisp/tramp-sh.el
+++ b/lisp/tramp-sh.el
@@ -2023,49 +2023,56 @@ ID-FORMAT valid values are `string' and `integer'."
(t2 (tramp-tramp-file-p newname))
target)
(with-parsed-tramp-file-name (if t1 dirname newname) nil
- (unless (file-exists-p dirname)
- (tramp-error v 'file-missing dirname))
-
- ;; `copy-directory-create-symlink' exists since Emacs 28.1.
- (if (and (bound-and-true-p copy-directory-create-symlink)
- (setq target (file-symlink-p dirname))
- (tramp-equal-remote dirname newname))
- (make-symbolic-link
- target
- (if (directory-name-p newname)
- (concat newname (file-name-nondirectory dirname)) newname)
- t)
-
- (if (and (not copy-contents)
- (tramp-get-method-parameter v 'tramp-copy-recursive)
- ;; When DIRNAME and NEWNAME are remote, they must
- ;; have the same method.
- (or (null t1) (null t2)
- (string-equal
- (tramp-file-name-method
- (tramp-dissect-file-name dirname))
- (tramp-file-name-method
- (tramp-dissect-file-name newname)))))
- ;; scp or rsync DTRT.
- (progn
- (when (and (file-directory-p newname)
- (not (directory-name-p newname)))
- (tramp-error v 'file-already-exists newname))
- (setq dirname (directory-file-name (expand-file-name dirname))
- newname (directory-file-name (expand-file-name newname)))
- (when (and (file-directory-p newname)
- (not (string-equal (file-name-nondirectory dirname)
- (file-name-nondirectory newname))))
- (setq newname
- (expand-file-name
- (file-name-nondirectory dirname) newname)))
- (unless (file-directory-p (file-name-directory newname))
- (make-directory (file-name-directory newname) parents))
- (tramp-do-copy-or-rename-file-out-of-band
- 'copy dirname newname 'ok-if-already-exists keep-date))
-
- ;; We must do it file-wise.
- (tramp-run-real-handler
+ (cond
+ ;; `copy-directory-create-symlink' exists since Emacs 28.1.
+ ((and (bound-and-true-p copy-directory-create-symlink)
+ (setq target (file-symlink-p dirname))
+ (tramp-equal-remote dirname newname))
+ (make-symbolic-link
+ target
+ (if (directory-name-p newname)
+ (concat newname (file-name-nondirectory dirname)) newname)
+ t))
+
+ ;; Shortcut: if method, host, user are the same for both
+ ;; files, we invoke `cp' on the remote host directly.
+ ((and (not copy-contents)
+ (tramp-equal-remote dirname newname))
+ (when (and (file-directory-p newname)
+ (not (directory-name-p newname)))
+ (tramp-error v 'file-already-exists newname))
+ (setq dirname (directory-file-name (expand-file-name dirname))
+ newname (directory-file-name (expand-file-name newname)))
+ (tramp-do-copy-or-rename-file-directly
+ 'copy dirname newname
+ 'ok-if-already-exists keep-date 'preserve-uid-gid))
+
+ ;; scp or rsync DTRT.
+ ((and (not copy-contents)
+ (tramp-get-method-parameter v 'tramp-copy-recursive)
+ ;; When DIRNAME and NEWNAME are remote, they must have
+ ;; the same method.
+ (or (null t1) (null t2)
+ (string-equal
+ (tramp-file-name-method (tramp-dissect-file-name dirname))
+ (tramp-file-name-method (tramp-dissect-file-name newname)))))
+ (when (and (file-directory-p newname)
+ (not (directory-name-p newname)))
+ (tramp-error v 'file-already-exists newname))
+ (setq dirname (directory-file-name (expand-file-name dirname))
+ newname (directory-file-name (expand-file-name newname)))
+ (when (and (file-directory-p newname)
+ (not (string-equal (file-name-nondirectory dirname)
+ (file-name-nondirectory newname))))
+ (setq newname
+ (expand-file-name (file-name-nondirectory dirname) newname)))
+ (unless (file-directory-p (file-name-directory newname))
+ (make-directory (file-name-directory newname) parents))
+ (tramp-do-copy-or-rename-file-out-of-band
+ 'copy dirname newname 'ok-if-already-exists keep-date))
+
+ ;; We must do it file-wise.
+ (t (tramp-run-real-handler
#'copy-directory
(list dirname newname keep-date parents copy-contents))))
