From 7769cad1e396c1ab68d2e6c35fc1846003b4639d Mon Sep 17 00:00:00 2001
From: Tino Calancha <tino.calancha@gmail.com>
Date: Fri, 4 Sep 2020 06:09:23 +0200
Subject: [PATCH] wdired-do-renames: Speed up for long Emacs sessions

`dired-rename-file' calls unconditionally `dired-rename-subdir'.
The second function performs performs a loop on all the Emacs
buffers; this step is only needed if FILE is a directory (bug#32899).

In a long lived Emacs session, this can make a difference
when renaming a bunch of files with `wdired'.
For instance, in my 40 days old Emacs session, with ~ 700 buffers,
this patch increases the speed to rename 2000 files a factor ~ 15.

* lisp/dired-aux.el (dired-rename-file): Call `dired-rename-subdir'
iif FILE is a directory.  Add docstring.
(dired-rename-subdir, dired-remove-entry)
(dired-remove-file): Add docstring.

(dired-remove-entry): Move definition into `dired.el'.

* lisp/wdired.el (wdired-do-renames): Use a progress-reporter.

* lisp/dired.el (dired-delete-entry):
Use `dired-remove-entry'.  Add docstring.

(dired-buffers-for-dir, dired-fun-in-all-buffers):
Change comment into docstring.
(dired-fun-in-all-buffers): Prefer `when' and `push' here.
---
 lisp/dired-aux.el | 13 ++++++-------
 lisp/dired.el     | 30 ++++++++++++++++++++----------
 lisp/wdired.el    | 12 ++++++++----
 3 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index ab13b3e26ea..eeb06beafd3 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -1549,17 +1549,13 @@ files matching `dired-omit-regexp'."
 
 ;;;###autoload
 (defun dired-remove-file (file)
+  "Remove entry FILE on each dired buffer.
+Note this doesn't delete FILE in the file system.
+See `dired-delete-file' in case you wish that."
   (dired-fun-in-all-buffers
    (file-name-directory file) (file-name-nondirectory file)
    #'dired-remove-entry file))
 
-(defun dired-remove-entry (file)
-  (save-excursion
-    (and (dired-goto-file file)
-	 (let (buffer-read-only)
-	   (delete-region (progn (beginning-of-line) (point))
-			  (line-beginning-position 2))))))
-
 ;;;###autoload
 (defun dired-relist-file (file)
   "Create or update the line for FILE in all Dired buffers it would belong in."
@@ -1676,6 +1672,9 @@ rename them using `vc-rename-file'."
 
 ;;;###autoload
 (defun dired-rename-file (file newname ok-if-already-exists)
+  "Rename FILE to NEWNAME.
+Signal a `file-already-exists' error if a file NEWNAME already exists
+unless OK-IF-ALREADY-EXISTS is non-nil."
   (dired-handle-overwrite newname)
   (dired-maybe-create-dirs (file-name-directory newname))
   (if (and dired-vc-rename-file
diff --git a/lisp/dired.el b/lisp/dired.el
index d122869a5e3..e4bc4decf84 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2908,12 +2908,12 @@ You can then feed the file name(s) to other commands with \\[yank]."
 ;; Keeping Dired buffers in sync with the filesystem and with each other
 
 (defun dired-buffers-for-dir (dir &optional file)
-;; Return a list of buffers for DIR (top level or in-situ subdir).
-;; If FILE is non-nil, include only those whose wildcard pattern (if any)
-;; matches FILE.
-;; The list is in reverse order of buffer creation, most recent last.
-;; As a side effect, killed dired buffers for DIR are removed from
-;; dired-buffers.
+  "Return a list of buffers for DIR (top level or in-situ subdir).
+If FILE is non-nil, include only those whose wildcard pattern (if any)
+matches FILE.
+The list is in reverse order of buffer creation, most recent last.
+As a side effect, killed dired buffers for DIR are removed from
+dired-buffers."
   (setq dir (file-name-as-directory dir))
   (let (result buf)
     (dolist (elt dired-buffers)
@@ -3462,18 +3462,28 @@ Return list of buffers where FUN succeeded (i.e., returned non-nil)."
   (let (success-list)
     (dolist (buf (dired-buffers-for-dir (expand-file-name directory) file))
       (with-current-buffer buf
-	(if (apply fun args)
-	    (push buf success-list))))
+	(when (apply fun args)
+	  (push (buffer-name buf) success-list))))
     ;; FIXME: AFAICT, this return value is not used by any of the callers!
     success-list))
 
 ;; Delete the entry for FILE from
-(defun dired-delete-entry (file)
+(defun dired-remove-entry (file)
+  "Remove entry FILE in the current dired buffer.
+Note this doesn't delete FILE in the file system.
+See `dired-delete-file' in case you wish that."
   (save-excursion
     (and (dired-goto-file file)
 	 (let ((inhibit-read-only t))
 	   (delete-region (progn (beginning-of-line) (point))
-			  (save-excursion (forward-line 1) (point))))))
+			  (line-beginning-position 2))))))
+
+(defun dired-delete-entry (file)
+  "Remove entry FILE in the current dired buffer.
+Like `dired-remove-entry' followed by `dired-clean-up-after-deletion'.
+Note this doesn't delete FILE in the file system.
+See `dired-delete-file' in case you wish that."
+  (dired-remove-entry file)
   (dired-clean-up-after-deletion file))
 
 (defvar dired-clean-up-buffers-too)
diff --git a/lisp/wdired.el b/lisp/wdired.el
index b98becfafe7..6defbf8bc86 100644
--- a/lisp/wdired.el
+++ b/lisp/wdired.el
@@ -461,10 +461,12 @@ non-nil means return old filename."
 
 (defun wdired-do-renames (renames)
   "Perform RENAMES in parallel."
-  (let ((residue ())
-        (progress nil)
-        (errors 0)
-        (overwrite (or (not wdired-confirm-overwrite) 1)))
+  (let* ((residue ())
+         (progress nil)
+         (errors 0)
+         (total (1- (length renames)))
+         (prep (make-progress-reporter "Renaming" 0 total))
+         (overwrite (or (not wdired-confirm-overwrite) 1)))
     (while (or renames
                ;; We've done one round through the renames, we have found
                ;; some residue, but we also made some progress, so maybe
@@ -472,6 +474,7 @@ non-nil means return old filename."
                (prog1 (setq renames residue)
                  (setq progress nil)
                  (setq residue nil)))
+      (progress-reporter-update prep (- total (length renames)))
       (let* ((rename (pop renames))
              (file-new (cdr rename)))
         (cond
@@ -519,6 +522,7 @@ non-nil means return old filename."
                  (dired-log "Rename `%s' to `%s' failed:\n%s\n"
                             file-ori file-new
                             err)))))))))
+    (progress-reporter-done prep)
     errors))
 
 (defun wdired-create-parentdirs (file-new)
-- 
2.39.5