How to quickly revert the buffer?

Question

revert-buffer is often slower than closing an opening the same file.

I've noticed - for example, I can undo to the state of the file before reverting.

While this might be useful in some cases, I would like to clear undo history and load the file as if I'd just opened emacs.

Some possible solutions:

Fast Revert

Disable undo.
Clear undo history, jump list ... etc.
Clear the buffer.
Load the data from the file into the buffer.
Re-enable undo.

Fake Revert

Store the scroll & cursor position.
Close the buffer.
Open the buffer.
Restore the scroll & cursor position.

While I could write this, it seems like there may be a more elegant solution then writing my own fast-revert-buffer function.

Does Emacs provide a way to do this already?

Not an answer to your question, but in terms of `undo`, the previous history would be irrelevant -- as such, the undo history would be completely reset to zero / nil upon a revert. — lawlist, Oct 17 '19 at 06:30
Just a question: does using `global-auto-revert-mode` with `auto-revert-interval` set to a small value (I set it at `1`) help? — Manuel Uberti, Oct 17 '19 at 09:21
@lawlist the undo history is kept (using emacs undo - no wrappers) — ideasman42, Oct 17 '19 at 23:52

score 2 · Answer 1 · answered Oct 18 '19 at 10:41

2

The revert-buffer function takes a few parameters which I think make the reload faster. I've got this bound to a keyboard shortcut for reloading the current buffer, it feels as fast as when you first open the file:

(defun reload-file-preserve-point ()
  (interactive)
  (when (or (not (buffer-modified-p))
            (y-or-n-p "Reverting will discard changes. Proceed?"))
    (save-excursion
      (revert-buffer t t t))
    (setq buffer-undo-list nil)
    (message "Buffer reverted")))

answered Oct 18 '19 at 10:41

saintamh

56
3

5

Welcome to emacs.SE and thank you for your answer! Maybe you could briefly describe what the args do that make the revert faster (this is something I immediately think I want to know when I read the answer). – JeanPierre Oct 18 '19 at 11:25

How to quickly revert the buffer?

1 Answers1