From unknown Sat Aug 09 01:08:22 2025 X-Loop: don@donarmstrong.com Subject: bug#861: Strange interaction of cursor movement and post-command-hook? Reply-To: rms@gnu.org, 861@debbugs.gnu.org Resent-From: "Richard M. Stallman" Resent-To: bug-submit-list@lists.donarmstrong.com Resent-CC: Emacs Bugs Resent-Date: Tue, 02 Sep 2008 01:20:04 +0000 Resent-Message-ID: Resent-Sender: don@donarmstrong.com X-Emacs-PR-Message: report 861 X-Emacs-PR-Package: emacs X-Emacs-PR-Keywords: Received: via spool by submit@emacsbugs.donarmstrong.com id=B.12203178421903 (code B ref -1); Tue, 02 Sep 2008 01:20:04 +0000 X-Spam-Checker-Version: SpamAssassin 3.2.3-bugs.debian.org_2005_01_02 (2007-08-08) on rzlab.ucr.edu X-Spam-Level: X-Spam-Status: No, score=-8.1 required=4.0 tests=AWL,BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.2.3-bugs.debian.org_2005_01_02 Received: (at submit) by emacsbugs.donarmstrong.com; 2 Sep 2008 01:10:42 +0000 Received: from fencepost.gnu.org (fencepost.gnu.org [140.186.70.10]) by rzlab.ucr.edu (8.13.8/8.13.8/Debian-3) with ESMTP id m821Ac0p001896 for ; Mon, 1 Sep 2008 18:10:40 -0700 Received: from rms by fencepost.gnu.org with local (Exim 4.67) (envelope-from ) id 1KaKOE-0004YV-2B; Mon, 01 Sep 2008 21:09:02 -0400 Content-Type: text/plain; charset=ISO-8859-15 From: "Richard M. Stallman" To: David Kastrup CC: emacs-pretest-bug@gnu.org In-reply-to: (message from David Kastrup on 04 Jan 2003 22:02:56 +0100) References: Message-Id: Date: Mon, 01 Sep 2008 21:09:02 -0400 Internally, the two strings share most of their state. The total amount of memory used is (roughly speaking) the memory for saved_undo_point plus the memory for just the string "foobar". That is what I figured. What I am worried about is the "roughly". There can be a lot of undo data, which is why there are special features to control how much is saved. So the efficiency of storing it is very important. Note also that undo data covers more than just buffer contents. (In reality, it's a little bit fancier than what is described above in order to put an upper bound on the amount of fragmentation of strings in memory.) Those measures, which are clearly necessary, could impact the efficiency of storing hundreds of past snapshots. This might cause the amount of duplicated buffer text to increase, even drastically. Or it might not. Making this change to the buffer representation would not _require_ changing the undo data structure and mechanism. That one area of the C code is fairly modular and independent of buffer internals. It might hardly need any change. Other areas could take more work. From debbugs-submit-bounces@debbugs.gnu.org Wed Jan 20 18:59:32 2010 Received: (at control) by debbugs.gnu.org; 20 Jan 2010 23:59:32 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NXkSR-0000SZ-OX for submit@debbugs.gnu.org; Wed, 20 Jan 2010 18:59:32 -0500 Received: from fencepost.gnu.org ([140.186.70.10]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NXkS8-0000SB-Dk for control@debbugs.gnu.org; Wed, 20 Jan 2010 18:59:29 -0500 Received: from rgm by fencepost.gnu.org with local (Exim 4.69) (envelope-from ) id 1NXkS4-0005RT-47; Wed, 20 Jan 2010 18:59:08 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <19287.39115.977758.186888@gargle.gargle.HOWL> Date: Wed, 20 Jan 2010 18:59:07 -0500 From: Glenn Morris To: control Subject: control X-Attribution: GM X-Mailer: VM (www.wonderworks.com/vm), GNU Emacs (www.gnu.org/software/emacs) X-Hue: green X-Ran: k0b69l@N'=(cOu9.=G$@*jaBb|PuRB$pk@v,mJ29L]v{A6le@He8K%OQTwcv3K5X7lURf^ X-Debbugs-No-Ack: yes X-Spam-Score: -3.4 (---) X-Debbugs-Envelope-To: control X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -3.4 (---) close 861