;; this option can also be configured to inhibit so-long entirely in this
;; scenario, or to not treat a file-local mode as a special case at all.
+;; * Buffers which are not displayed in a window
+;; ---------------------------------------------
+;; When a file with long lines is visited and the buffer is not displayed right
+;; away, it may be that it is not intended to be displayed at all, and that it
+;; has instead been visited for behind-the-scenes processing by some library.
+;; Invisible buffers are less likely to cause performance issues, and it also
+;; might be surprising to the other library if such a buffer were manipulated by
+;; `so-long' (which might in turn lead to confusing errors for the user); so in
+;; these situations the `so-long-invisible-buffer-function' value is called
+;; instead. By default this arranges for `so-long' to be invoked on the buffer
+;; if and when it is displayed, but not otherwise.
+;;
+;; This 'deferred call' is actually the most common scenario -- even when a
+;; visited file is displayed "right away", it is normal for the buffer to be
+;; invisible when `global-so-long-mode' processes it, and the gap between
+;; "arranging to call" and "calling" `so-long' is simply extremely brief.
+
;; * Inhibiting and disabling minor modes
;; --------------------------------------
;; Certain minor modes cause significant performance issues in the presence of
;; - New user option `so-long-variable-overrides'.
;; - New user option `so-long-skip-leading-comments'.
;; - New user option `so-long-file-local-mode-function'.
+;; - New user option `so-long-invisible-buffer-function'.
;; - New user option `so-long-predicate'.
;; - New variable and function `so-long-function'.
;; - New variable and function `so-long-revert-function'.
:package-version '(so-long . "1.0")
:group 'so-long)
+(defcustom so-long-invisible-buffer-function #'so-long-deferred
+ "Function called in place of `so-long' when the buffer is not displayed.
+
+This affects the behaviour of `global-so-long-mode'.
+
+We treat invisible buffers differently from displayed buffers because, in
+cases where a library is using a buffer for behind-the-scenes processing,
+it might be surprising if that buffer were unexpectedly manipulated by
+`so-long' (which might in turn lead to confusing errors for the user).
+Invisible buffers are less likely to cause performance issues related to
+long lines, so this differentiation is generally satisfactory.
+
+The default value `so-long-deferred' prevents `global-so-long-mode' from
+triggering `so-long' for any given buffer until such time as the buffer is
+displayed in a window.
+
+\(Note that buffers are normally invisible at this point -- when `find-file'
+is used, the buffer is not displayed in a window until a short time after
+`global-so-long-mode' has seen it.)
+
+The value nil or `so-long' means that `so-long' will be called directly; in
+which case it may be problematic for `so-long-variable-overrides' to enable
+`buffer-read-only', or for `so-long-action' to be set to `so-long-mode'.
+This is because the buffer may not be intended to be displayed at all, and
+the mentioned options might interfere with some intended processing."
+ :type '(radio (const so-long-deferred)
+ (const :tag "nil: Call so-long as normal" nil)
+ (function :tag "Custom function"))
+ :package-version '(so-long . "1.0")
+ :group 'so-long)
+
(defcustom so-long-predicate 'so-long-detected-long-line-p
"Function, called after `set-auto-mode' to decide whether action is needed.
(or (eq so-long-target-modes t)
(apply #'derived-mode-p so-long-target-modes))
(setq so-long-detected-p (funcall so-long-predicate))
- (so-long)))
+ ;; `so-long' should be called; but only if and when the buffer is
+ ;; displayed in a window. Long lines in invisible buffers are generally
+ ;; not problematic, whereas it might cause problems if an invisible
+ ;; buffer being used for behind-the-scenes processing is manipulated
+ ;; unexpectedly. The default `so-long-invisible-buffer-function' value
+ ;; is `so-long-deferred', which arranges to call `so-long' as soon as
+ ;; the buffer is displayed.
+ (if (or (get-buffer-window (current-buffer) t)
+ (not so-long-invisible-buffer-function))
+ (so-long)
+ (funcall so-long-invisible-buffer-function))))
(defun so-long--hack-one-local-variable (orig-fun var val)
;; Advice, enabled with:
;; VAR is not the 'mode' pseudo-variable.
(funcall orig-fun var val)))
+(defun so-long-deferred ()
+ "Arrange to call `so-long' if the current buffer is displayed in a window."
+ ;; The first time that a window-configuration change results in the buffer
+ ;; being displayed in a window, `so-long' will be called (with the window
+ ;; selected and the buffer set as current). Because `so-long' removes this
+ ;; buffer-local hook value, it triggers once at most.
+ (add-hook 'window-configuration-change-hook #'so-long nil :local))
+
;;;###autoload
(defun so-long (&optional action)
"Invoke `so-long-action' and run `so-long-hook'.
(completing-read "Action (none): "
(mapcar #'car so-long-action-alist)
nil :require-match)))))
+ ;; Ensure that `so-long-deferred' only triggers `so-long' once (at most).
+ (remove-hook 'window-configuration-change-hook #'so-long :local)
(unless so-long--calling
(let ((so-long--calling t))
(so-long--ensure-enabled)
(defun so-long-unload-function ()
"Handler for `unload-feature'."
(global-so-long-mode 0)
+ ;; Remove buffer-local `window-configuration-change-hook' values set by
+ ;; `so-long-deferred'.
+ (dolist (buf (buffer-list))
+ (with-current-buffer buf
+ (remove-hook 'window-configuration-change-hook #'so-long :local)))
+ ;; Return nil. Refer to `unload-feature'.
nil)
\f
;; (We could consistently use the latter, but the mixture of approaches
;; means that we're testing more things.)
-;; Running the tests with "make lisp/so-long-tests" is like:
+;; Running manually:
;;
-;; HOME=/nonexistent EMACSLOADPATH= LC_ALL=C \
-;; EMACS_TEST_DIRECTORY=/home/phil/emacs/trunk/repository/test \
+;; for test in lisp/so-long-tests/*-tests.el; do make ${test%.el}; done \
+;; 2>&1 | egrep -v '^(Loading|Source file|make|Changed to so-long-mode)'
+;;
+;; Which is equivalent to:
+;;
+;; for test in lisp/so-long-tests/*-tests.el; do \
+;; HOME=/nonexistent EMACSLOADPATH= LC_ALL=C EMACS_TEST_DIRECTORY=. \
;; "../src/emacs" --no-init-file --no-site-file --no-site-lisp \
-;; -L ":." -l ert -l lisp/so-long-tests.el --batch --eval \
-;; '(ert-run-tests-batch-and-exit (quote (not (tag :unstable))))'
+;; -L ":." -l ert -l "$test" --batch --eval \
+;; '(ert-run-tests-batch-and-exit (quote (not (tag :unstable))))'; \
+;; done 2>&1 | egrep -v '^(Loading|Source file|Changed to so-long-mode)'
;;
;; See also `ert-run-tests-batch-and-exit'.
(ert-deftest so-long-tests-threshold-under ()
"Under line length threshold."
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1- so-long-threshold) ?x))
(normal-mode)
(ert-deftest so-long-tests-threshold-at ()
"At line length threshold."
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1- so-long-threshold) ?x))
(normal-mode)
(ert-deftest so-long-tests-threshold-over ()
"Over line length threshold."
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(normal-mode)
(so-long-tests-remember)
"Skip leading shebang, whitespace, and comments."
;; Long comment, no newline.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1+ so-long-threshold) ?\;))
(normal-mode)
(should (eq major-mode 'emacs-lisp-mode)))
;; Long comment, with newline.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1+ so-long-threshold) ?\;))
(insert "\n")
(should (eq major-mode 'emacs-lisp-mode)))
;; Long comment, with short text following.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1+ so-long-threshold) ?\;))
(insert "\n")
(should (eq major-mode 'emacs-lisp-mode)))
;; Long comment, with long text following.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1+ so-long-threshold) ?\;))
(insert "\n")
(ert-deftest so-long-tests-max-lines ()
"Give up after `so-long-max-lines'."
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
;; Insert exactly `so-long-max-lines' non-comment lines, followed
;; by a long line.
(normal-mode)
(should (eq major-mode 'so-long-mode))))))
+(ert-deftest so-long-tests-invisible-buffer-function ()
+ "Call `so-long-invisible-buffer-function' in invisible buffers."
+ ;; Visible buffer.
+ (with-temp-buffer
+ (display-buffer (current-buffer))
+ (insert "#!emacs\n")
+ (normal-mode)
+ (so-long-tests-remember)
+ (insert (make-string (1+ so-long-threshold) ?x))
+ (normal-mode)
+ (so-long-tests-assert-and-revert 'so-long-mode))
+ ;; Invisible buffer.
+ (with-temp-buffer
+ (insert "#!emacs\n")
+ (normal-mode)
+ (so-long-tests-remember)
+ (insert (make-string (1+ so-long-threshold) ?x))
+ (normal-mode)
+ (should (eq major-mode 'emacs-lisp-mode))
+ (should (eq nil (get-buffer-window)))
+ ;; Displaying the buffer should invoke `so-long'.
+ (display-buffer (current-buffer))
+ (should (window-live-p (get-buffer-window)))
+ (unless (version< emacs-version "27")
+ ;; From Emacs 27 the `display-buffer' call is insufficient.
+ ;; The various 'window change functions' are now invoked by the
+ ;; redisplay, and redisplay does nothing at all in batch mode,
+ ;; so we cannot test under this revised behaviour. Refer to:
+ ;; https://lists.gnu.org/archive/html/emacs-devel/2019-10/msg00971.html
+ ;; For interactive (non-batch) test runs, calling `redisplay'
+ ;; does do the trick; so do that first.
+ (redisplay)
+ (when noninteractive
+ ;; In batch mode we need to cheat, and just pretend that
+ ;; `redisplay' triggered `window-configuration-change-hook'.
+ ;; This means the test is not as useful, but it still covers
+ ;; part of the process, and so it's better than nothing.
+ ;;
+ ;; Also test `so-long--active', in case a future version of
+ ;; Emacs adds the framework necessary to make `redisplay' work
+ ;; in batch mode.
+ (unless (eq so-long--active t)
+ (run-window-configuration-change-hook))))
+ (so-long-tests-assert-and-revert 'so-long-mode))
+ ;; `so-long-invisible-buffer-function' is `nil'.
+ (with-temp-buffer
+ (insert "#!emacs\n")
+ (normal-mode)
+ (so-long-tests-remember)
+ (insert (make-string (1+ so-long-threshold) ?x))
+ (let ((so-long-invisible-buffer-function nil))
+ (normal-mode))
+ (so-long-tests-assert-and-revert 'so-long-mode))
+ ;; `so-long-invisible-buffer-function' is `so-long'.
+ (with-temp-buffer
+ (insert "#!emacs\n")
+ (normal-mode)
+ (so-long-tests-remember)
+ (insert (make-string (1+ so-long-threshold) ?x))
+ (let ((so-long-invisible-buffer-function #'so-long))
+ (normal-mode))
+ (so-long-tests-assert-and-revert 'so-long-mode))
+ ;; `so-long-invisible-buffer-function' is `ignore'.
+ (with-temp-buffer
+ (insert "#!emacs\n")
+ (normal-mode)
+ (so-long-tests-remember)
+ (insert (make-string (1+ so-long-threshold) ?x))
+ (let ((so-long-invisible-buffer-function #'ignore))
+ (normal-mode))
+ (should (eq major-mode 'emacs-lisp-mode))
+ (display-buffer (current-buffer))
+ (unless (version< emacs-version "27")
+ ;; See the "Invisible buffer" case earlier in this function.
+ (redisplay)
+ (when noninteractive
+ (unless (eq so-long--active t)
+ (run-window-configuration-change-hook))))
+ (should (eq major-mode 'emacs-lisp-mode))))
+
(ert-deftest so-long-tests-actions ()
"Test each of the standard actions."
(dolist (action (mapcar #'car so-long-action-alist))
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(normal-mode)
(so-long-tests-remember)
"Targeted major modes."
;; Test the `so-long-target-modes' user option.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
(insert (make-string (1+ so-long-threshold) ?x))
;; Nil target modes.
"Custom predicate function."
;; Test the `so-long-predicate' user option.
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert "#!emacs\n")
;; Always false.
(let ((so-long-predicate #'ignore))
;; valid for the file-locals to be on the second line after the shebang,
;; but with the *.el filename we no longer need the shebang.
(with-temp-buffer
+ (display-buffer (current-buffer))
(setq buffer-file-name (expand-file-name "so-long-tests-data.el"))
(insert ";; -*- so-long-action:so-long-minor-mode; -*-\n")
(put 'so-long-action 'safe-local-variable #'symbolp)
(normal-mode)
(so-long-tests-remember))
(with-temp-buffer
+ (display-buffer (current-buffer))
(setq buffer-file-name (concat (make-temp-name "so-long-tests-") ".el"))
(insert ";; -*- so-long-action:so-long-minor-mode; eval:(so-long) -*-\n")
(put 'so-long-action 'safe-local-variable #'symbolp)
;; Downgrade the action from major mode to minor mode.
(setq-default so-long-file-local-mode-function 'so-long-mode-downgrade)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
;; Do not treat the file-local mode specially.
(setq-default so-long-file-local-mode-function nil)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
(setq-default so-long-file-local-mode-function
#'so-long-tests-file-local-mode-function)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
;; Do nothing at all when a file-local mode is used.
(setq-default so-long-file-local-mode-function 'so-long-inhibit)
(with-temp-buffer
+ (display-buffer (current-buffer))
;; Remember the new-buffer state. The other cases will
;; validate the 'reverted' state against this.
(so-long-tests-remember)
;; Downgrade from major mode to minor mode.
(setq-default so-long-file-local-mode-function 'so-long-mode-downgrade)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
;; Do not treat the file-local mode specially.
(setq-default so-long-file-local-mode-function nil)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
(setq-default so-long-file-local-mode-function
#'so-long-tests-file-local-mode-function)
(with-temp-buffer
+ (display-buffer (current-buffer))
(insert ,prop-line)
(insert (make-string (1+ so-long-threshold) ?x))
(insert ,local-vars)
projects / emacs.git / commitdiff