view lisp/occur.el @ 5157:1fae11d56ad2

redo memory-usage mechanism, add way of dynamically initializing Lisp objects -------------------- ChangeLog entries follow: -------------------- lisp/ChangeLog addition: 2010-03-18 Ben Wing <ben@xemacs.org> * diagnose.el (show-memory-usage): Rewrite to take into account API changes in memory-usage functions. src/ChangeLog addition: 2010-03-18 Ben Wing <ben@xemacs.org> * alloc.c: * alloc.c (disksave_object_finalization_1): * alloc.c (lisp_object_storage_size): * alloc.c (listu): * alloc.c (listn): * alloc.c (Fobject_memory_usage_stats): * alloc.c (compute_memusage_stats_length): * alloc.c (Fobject_memory_usage): * alloc.c (Ftotal_object_memory_usage): * alloc.c (malloced_storage_size): * alloc.c (common_init_alloc_early): * alloc.c (reinit_alloc_objects_early): * alloc.c (reinit_alloc_early): * alloc.c (init_alloc_once_early): * alloc.c (syms_of_alloc): * alloc.c (reinit_vars_of_alloc): * buffer.c: * buffer.c (struct buffer_stats): * buffer.c (compute_buffer_text_usage): * buffer.c (compute_buffer_usage): * buffer.c (buffer_memory_usage): * buffer.c (buffer_objects_create): * buffer.c (syms_of_buffer): * buffer.c (vars_of_buffer): * console-impl.h (struct console_methods): * dynarr.c (Dynarr_memory_usage): * emacs.c (main_1): * events.c (clear_event_resource): * extents.c: * extents.c (compute_buffer_extent_usage): * extents.c (extent_objects_create): * extents.h: * faces.c: * faces.c (compute_face_cachel_usage): * faces.c (face_objects_create): * faces.h: * general-slots.h: * glyphs.c: * glyphs.c (compute_glyph_cachel_usage): * glyphs.c (glyph_objects_create): * glyphs.h: * lisp.h: * lisp.h (struct usage_stats): * lrecord.h: * lrecord.h (enum lrecord_type): * lrecord.h (struct lrecord_implementation): * lrecord.h (MC_ALLOC_CALL_FINALIZER_FOR_DISKSAVE): * lrecord.h (DEFINE_DUMPABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_FROB_BLOCK_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_FROB_BLOCK_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_SIZABLE_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_FROB_BLOCK_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_FROB_BLOCK_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_INTERNAL_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_SIZABLE_INTERNAL_LISP_OBJECT): * lrecord.h (MAKE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_MODULE_LISP_OBJECT): * lrecord.h (DEFINE_DUMPABLE_MODULE_SIZABLE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_MODULE_LISP_OBJECT): * lrecord.h (DEFINE_NODUMP_MODULE_SIZABLE_LISP_OBJECT): * lrecord.h (MAKE_MODULE_LISP_OBJECT): * lrecord.h (INIT_LISP_OBJECT): * lrecord.h (INIT_MODULE_LISP_OBJECT): * lrecord.h (UNDEF_LISP_OBJECT): * lrecord.h (UNDEF_MODULE_LISP_OBJECT): * lrecord.h (DECLARE_LISP_OBJECT): * lrecord.h (DECLARE_MODULE_API_LISP_OBJECT): * lrecord.h (DECLARE_MODULE_LISP_OBJECT): * lstream.c: * lstream.c (syms_of_lstream): * lstream.c (vars_of_lstream): * marker.c: * marker.c (compute_buffer_marker_usage): * mc-alloc.c (mc_alloced_storage_size): * mc-alloc.h: * mule-charset.c: * mule-charset.c (struct charset_stats): * mule-charset.c (compute_charset_usage): * mule-charset.c (charset_memory_usage): * mule-charset.c (mule_charset_objects_create): * mule-charset.c (syms_of_mule_charset): * mule-charset.c (vars_of_mule_charset): * redisplay.c: * redisplay.c (compute_rune_dynarr_usage): * redisplay.c (compute_display_block_dynarr_usage): * redisplay.c (compute_glyph_block_dynarr_usage): * redisplay.c (compute_display_line_dynarr_usage): * redisplay.c (compute_line_start_cache_dynarr_usage): * redisplay.h: * scrollbar-gtk.c (gtk_compute_scrollbar_instance_usage): * scrollbar-msw.c (mswindows_compute_scrollbar_instance_usage): * scrollbar-x.c (x_compute_scrollbar_instance_usage): * scrollbar.c (compute_scrollbar_instance_usage): * scrollbar.h: * symbols.c: * symbols.c (reinit_symbol_objects_early): * symbols.c (init_symbols_once_early): * symbols.c (reinit_symbols_early): * symbols.c (defsymbol_massage_name_1): * symsinit.h: * ui-gtk.c: * ui-gtk.c (emacs_gtk_object_getprop): * ui-gtk.c (emacs_gtk_object_putprop): * ui-gtk.c (ui_gtk_objects_create): * unicode.c (compute_from_unicode_table_size_1): * unicode.c (compute_to_unicode_table_size_1): * unicode.c (compute_from_unicode_table_size): * unicode.c (compute_to_unicode_table_size): * window.c: * window.c (struct window_stats): * window.c (compute_window_mirror_usage): * window.c (compute_window_usage): * window.c (window_memory_usage): * window.c (window_objects_create): * window.c (syms_of_window): * window.c (vars_of_window): * window.h: Redo memory-usage mechanism, make it general; add way of dynamically initializing Lisp object types -- OBJECT_HAS_METHOD(), similar to CONSOLE_HAS_METHOD(). (1) Create OBJECT_HAS_METHOD(), OBJECT_HAS_PROPERTY() etc. for specifying that a Lisp object type has a particular method or property. Call such methods with OBJECT_METH, MAYBE_OBJECT_METH, OBJECT_METH_OR_GIVEN; retrieve properties with OBJECT_PROPERTY. Methods that formerly required a DEFINE_*GENERAL_LISP_OBJECT() to specify them (getprop, putprop, remprop, plist, disksave) now instead use the dynamic-method mechanism. The main benefit of this is that new methods or properties can be added without requiring that the declaration statements of all existing methods be modified. We have to make the `struct lrecord_implementation' non-const, but I don't think this should have any effect on speed -- the only possible method that's really speed-critical is the mark method, and we already extract those out into a separate (non-const) array for increased cache locality. Object methods need to be reinitialized after pdump, so we put them in separate functions such as face_objects_create(), extent_objects_create() and call them appropriately from emacs.c The only current object property (`memusage_stats_list') that objects can specify is a Lisp object and gets staticpro()ed so it only needs to be set during dump time, but because it references symbols that might not exist in a syms_of_() function, we initialize it in vars_of_(). There is also an object property (`num_extra_memusage_stats') that is automatically initialized based on `memusage_stats_list'; we do that in reinit_vars_of_alloc(), which is called after all vars_of_() functions are called. `disksaver' method was renamed `disksave' to correspond with the name normally given to the function (e.g. disksave_lstream()). (2) Generalize the memory-usage mechanism in `buffer-memory-usage', `window-memory-usage', `charset-memory-usage' into an object-type- specific mechanism called by a single function `object-memory-usage'. (Former function `object-memory-usage' renamed to `total-object-memory-usage'). Generalize the mechanism of different "slices" so that we can have different "classes" of memory described and different "slices" onto each class; `t' separates classes, `nil' separates slices. Currently we have three classes defined: the memory of an object itself, non-Lisp-object memory associated with the object (e.g. arrays or dynarrs stored as fields in the object), and Lisp-object memory associated with the object (other internal Lisp objects stored in the object). This isn't completely finished yet and we might need to further separate the "other internal Lisp objects" class into two classes. The memory-usage mechanism uses a `struct usage_stats' (renamed from `struct overhead_stats') to describe a malloc-view onto a set of allocated memory (listing how much was requested and various types of overhead) and a more general `struct generic_usage_stats' (with a `struct usage_stats' in it) to hold all statistics about object memory. `struct generic_usage_stats' contains an array of 32 Bytecounts, which are statistics of unspecified semantics. The intention is that individual types declare a corresponding struct (e.g. `struct window_stats') with the same structure but with specific fields in place of the array, corresponding to specific statistics. The number of such statistics is an object property computed from the list of tags (Lisp symbols describing the statistics) stored in `memusage_stats_list'. The idea here is to allow particular object types to customize the number and semantics of the statistics where completely avoiding consing. This doesn't matter so much yet, but the intention is to have the memory usage of all objects computed at the end of GC, at the same time as other statistics are currently computed. The values for all statistics for a single type would be added up to compute aggregate values for all objects of a specific type. To make this efficient, we can't allow any memory allocation at all. (3) Create some additional functions for creating lists that specify the elements directly as args rather than indirectly through an array: listn() (number of args given), listu() (list terminated by Qunbound). (4) Delete a bit of remaining unused C window_config stuff, also unused lrecord_type_popup_data.
author Ben Wing <ben@xemacs.org>
date Thu, 18 Mar 2010 10:50:06 -0500
parents b4f4e0cc90f1
children ed74d2ca7082 308d34e9f07d
line wrap: on
line source

;;; occur.el --- Show all lines in the current buffer containing a match for REGEXP.

;; Copyright (C) 1985, 1986, 1987, 1992, 1994, 1996, 1997, 2000, 2001,
;;   2002, 2003, 2004, 2005 Free Software Foundation, Inc.

;; Maintainer: XEmacs Development Team
;; Keywords: internal

;; This file is part of XEmacs.

;; XEmacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; XEmacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with XEmacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Synched up with: FSF 22.0.50.1 (CVS)

(require 'next-error)
(defun query-replace-descr (string)
  (mapconcat 'isearch-text-char-description string ""))

(defvar occur-mode-map ()
  "Keymap for `occur-mode'.")
(if occur-mode-map
    ()
  (setq occur-mode-map (make-sparse-keymap))
  (set-keymap-name occur-mode-map 'occur-mode-map) ; XEmacs
  (define-key occur-mode-map 'button2 'occur-mode-mouse-goto) ; XEmacs
  (define-key occur-mode-map "\C-c\C-c" 'occur-mode-goto-occurrence)
  (define-key occur-mode-map "\C-m" 'occur-mode-goto-occurrence)
  (define-key occur-mode-map "o" 'occur-mode-goto-occurrence-other-window)
  (define-key occur-mode-map "\C-o" 'occur-mode-display-occurrence)
  (define-key occur-mode-map "\M-n" 'occur-next)
  (define-key occur-mode-map "\M-p" 'occur-prev)
  (define-key occur-mode-map "r" 'occur-rename-buffer)
  (define-key occur-mode-map "c" 'clone-buffer)
  (define-key occur-mode-map "g" 'revert-buffer)
  (define-key occur-mode-map "q" 'quit-window)
  (define-key occur-mode-map "z" 'kill-this-buffer)
  (define-key occur-mode-map "\C-c\C-f" 'next-error-follow-minor-mode))

(defvar occur-revert-arguments nil
  "Arguments to pass to `occur-1' to revert an Occur mode buffer.
See `occur-revert-function'.")

(defcustom occur-mode-hook nil ; XEmacs
  "Hook run when entering Occur mode."
  :type 'hook
  :group 'matching)

(defcustom occur-hook nil
  "Hook run by Occur when there are any matches."
  :type 'hook
  :group 'matching)

(put 'occur-mode 'mode-class 'special)
;;;###autoload
(defun occur-mode ()
  "Major mode for output from \\[occur].
\\<occur-mode-map>Move point to one of the items in this buffer, then use
\\[occur-mode-goto-occurrence] to go to the occurrence that the item refers to.
Alternatively, click \\[occur-mode-mouse-goto] on an item to go to it.

\\{occur-mode-map}"
  (interactive)
  (kill-all-local-variables)
  (use-local-map occur-mode-map)
  (setq major-mode 'occur-mode)
  (setq mode-name (gettext "Occur")) ; XEmacs
  (set (make-local-variable 'revert-buffer-function) 'occur-revert-function)
  (make-local-variable 'occur-revert-arguments)
  (add-hook 'change-major-mode-hook 'turn-off-font-lock t t)
  (setq next-error-function 'occur-next-error)
  (require 'mode-motion) ; XEmacs
  (setq mode-motion-hook 'mode-motion-highlight-line) ; XEmacs
  (run-mode-hooks 'occur-mode-hook))

(defun occur-revert-function (ignore1 ignore2)
  "Handle `revert-buffer' for Occur mode buffers."
  (apply 'occur-1 (append occur-revert-arguments (list (buffer-name)))))

;; FSF Version of next function:
; (defun occur-mode-mouse-goto (event)
;   "In Occur mode, go to the occurrence whose line you click on."
;   (interactive "e")
;   (let (pos)
;     (save-excursion
;       (set-buffer (window-buffer (posn-window (event-end event))))
;       (save-excursion
; 	(goto-char (posn-point (event-end event)))
; 	(setq pos (occur-mode-find-occurrence))))
;     (pop-to-buffer (marker-buffer pos))
;     (goto-char pos)))

(defun occur-mode-mouse-goto (event)
  "Go to the occurrence highlighted by mouse.
This function should be bound to a mouse key in the `*Occur*' buffer."
  (interactive "e")
  (let ((window-save (selected-window))
	(frame-save (selected-frame)))
    ;; preserve the window/frame setup
    (unwind-protect
	(progn
	  (mouse-set-point event)
	  (occur-mode-goto-occurrence))
      (select-frame frame-save)
      (select-window window-save))))

(defun occur-mode-find-occurrence ()
  (let ((pos (get-text-property (point) 'occur-target)))
    (unless pos
      (error "No occurrence on this line"))
    (unless (buffer-live-p (marker-buffer pos))
      (error "Buffer for this occurrence was killed"))
    pos))

(defun occur-mode-goto-occurrence ()
  "Go to the occurrence the current line describes."
  (interactive)
  (let ((pos (occur-mode-find-occurrence)))
    (pop-to-buffer (marker-buffer pos))
    (goto-char pos)))

(defun occur-mode-goto-occurrence-other-window ()
  "Go to the occurrence the current line describes, in another window."
  (interactive)
  (let ((pos (occur-mode-find-occurrence)))
    (switch-to-buffer-other-window (marker-buffer pos))
    (goto-char pos)))

(defun occur-mode-display-occurrence ()
  "Display in another window the occurrence the current line describes."
  (interactive)
  (let ((pos (occur-mode-find-occurrence))
	window
	;; Bind these to ensure `display-buffer' puts it in another window.
	same-window-buffer-names
	same-window-regexps)
    (setq window (display-buffer (marker-buffer pos)))
    ;; This is the way to set point in the proper window.
    (save-selected-window
      (select-window window)
      (goto-char pos))))

(defun occur-find-match (n search message)
  (if (not n) (setq n 1))
  (let ((r))
    (while (> n 0)
      (setq r (funcall search (point) 'occur-match))
      (and r
           (get-text-property r 'occur-match)
           (setq r (funcall search r 'occur-match)))
      (if r
          (goto-char r)
        (error message))
      (setq n (1- n)))))

(defun occur-next (&optional n)
  "Move to the Nth (default 1) next match in an Occur mode buffer."
  (interactive "p")
  (occur-find-match n #'next-single-property-change "No more matches"))

(defun occur-prev (&optional n)
  "Move to the Nth (default 1) previous match in an Occur mode buffer."
  (interactive "p")
  (occur-find-match n #'previous-single-property-change "No earlier matches"))

(defun occur-next-error (&optional argp reset)
  "Move to the Nth (default 1) next match in an Occur mode buffer.
Compatibility function for \\[next-error-framework-next-error] invocations."
  (interactive "p")
  ;; we need to run occur-find-match from within the Occur buffer
  (with-current-buffer
      ;; Choose the buffer and make it current.
      (if (next-error-buffer-p (current-buffer))
	  (current-buffer)
	(next-error-find-buffer nil nil
				(lambda ()
				  (eq major-mode 'occur-mode))))

    (goto-char (cond (reset (point-min))
		     ((< argp 0) (line-beginning-position))
		     ((line-end-position))))
    (occur-find-match
     (abs argp)
     (if (> 0 argp)
	 #'previous-single-property-change
       #'next-single-property-change)
     "No more matches")
    ;; In case the *Occur* buffer is visible in a nonselected window.
    (set-window-point (get-buffer-window (current-buffer)) (point))
    (occur-mode-goto-occurrence)))

(defface match
  '((((class color) (background light))
     (:background "Tan"))
    (((class color) (background dark))
     (:background "RoyalBlue3"))
    (((class color))
     (:background "blue" :foreground "white"))
    (((type tty) (class mono))
     (:inverse-video t))
    (t (:background "gray")))
  "Face used to highlight matches permanently."
  :group 'matching
  :version "22.1")

(defcustom list-matching-lines-default-context-lines 0
  "*Default number of context lines included around `list-matching-lines' matches.
A negative number means to include that many lines before the match.
A positive number means to include that many lines both before and after."
  :type 'integer
  :group 'matching)

;;;###autoload
(defalias 'list-matching-lines 'occur)

(defcustom list-matching-lines-face 'match
  "*Face used by \\[list-matching-lines] to show the text that matches.
If the value is nil, don't highlight the matching portions specially."
  :type 'face
  :group 'matching)

(defcustom list-matching-lines-buffer-name-face 'underline
  "*Face used by \\[list-matching-lines] to show the names of buffers.
If the value is nil, don't highlight the buffer names specially."
  :type 'face
  :group 'matching)

(defun occur-accumulate-lines (count &optional keep-props)
  (save-excursion
    (let ((forwardp (> count 0))
	  result beg end)
      (while (not (or (zerop count)
		      (if forwardp
			  (eobp)
			(bobp))))
	(setq count (+ count (if forwardp -1 1)))
	(setq beg (line-beginning-position)
	      end (line-end-position))
	(if (and keep-props (if-boundp 'jit-lock-mode jit-lock-mode)
		 (text-property-not-all beg end 'fontified t))
	    (if-fboundp 'jit-lock-fontify-now
		(jit-lock-fontify-now beg end)))
	(push
	 (funcall (if keep-props
		      #'buffer-substring
		    #'buffer-substring-no-properties)
		  beg end)
	 result)
	(forward-line (if forwardp 1 -1)))
      (nreverse result))))

(defun occur-read-primary-args ()
  (list (let* ((default (or (symbol-near-point)
			    (and regexp-history
				 (car regexp-history))))
	       (minibuffer-history-minimum-string-length 0)
	       (input
		 (if default
		     ;; XEmacs: rewritten for I18N3 snarfing
		     (read-from-minibuffer
		      (format "List lines matching regexp (default `%s'): "
			      default) nil nil nil 'regexp-history nil
                              default)
		   (read-from-minibuffer
		    "List lines matching regexp: "
		    nil nil nil
		    'regexp-history))))
	  (if (equal input "")
	      default
	    input))
	(when current-prefix-arg
	  (prefix-numeric-value current-prefix-arg))))

;;;###autoload
(defun occur-rename-buffer (&optional unique-p interactive-p)
  "Rename the current *Occur* buffer to *Occur: original-buffer-name*.
Here `original-buffer-name' is the buffer name were Occur was originally run.
When given the prefix argument, or called non-interactively, the renaming
will not clobber the existing buffer(s) of that name, but use
`generate-new-buffer-name' instead.  You can add this to `occur-hook'
if you always want a separate *Occur* buffer for each buffer where you
invoke `occur'."
  (interactive "P\np")
  (with-current-buffer
      (if (eq major-mode 'occur-mode) (current-buffer) (get-buffer "*Occur*"))
    (rename-buffer (concat "*Occur: "
                           (mapconcat #'buffer-name
                                      (car (cddr occur-revert-arguments)) "/")
                           "*")
                   (or unique-p (not interactive-p)))))

;;;###autoload
(defun occur (regexp &optional nlines)
  "Show all lines in the current buffer containing a match for REGEXP.
This function can not handle matches that span more than one line.

Each line is displayed with NLINES lines before and after, or -NLINES
before if NLINES is negative.
NLINES defaults to `list-matching-lines-default-context-lines'.
Interactively it is the prefix arg.

The lines are shown in a buffer named `*Occur*'.
It serves as a menu to find any of the occurrences in this buffer.
\\<occur-mode-map>\\[describe-mode] in that buffer will explain how.

If REGEXP contains upper case characters (excluding those preceded by `\\'),
the matching is case-sensitive."
  (interactive (occur-read-primary-args))
  (occur-1 regexp nlines (list (current-buffer))))

;;;###autoload
(defun multi-occur (bufs regexp &optional nlines)
  "Show all lines in buffers BUFS containing a match for REGEXP.
This function acts on multiple buffers; otherwise, it is exactly like
`occur'."
  (interactive
   (cons
    (let* ((bufs (list (read-buffer "First buffer to search: "
				    (current-buffer) t)))
	   (buf nil)
;	   (ido-ignore-item-temp-list bufs)
	   )
      (while (not (string-equal
		   (setq buf (read-buffer
			      (if (and-boundp 'read-buffer-function
				       '(eq read-buffer-function 'ido-read-buffer))
				  "Next buffer to search (C-j to end): "
				"Next buffer to search (RET to end): ")
			      nil t))
		   ""))
	(add-to-list 'bufs buf)
;	(setq ido-ignore-item-temp-list bufs)
	)
      (nreverse (mapcar #'get-buffer bufs)))
    (occur-read-primary-args)))
  (occur-1 regexp nlines bufs))

;;;###autoload
(defun multi-occur-by-filename-regexp (bufregexp regexp &optional nlines)
  "Show all lines matching REGEXP in buffers named by BUFREGEXP.
See also `multi-occur'."
  (interactive
   (cons
    (let* ((default (car regexp-history))
	   (input
	    (read-from-minibuffer
	     "List lines in buffers whose filename matches regexp: "
	     nil
	     nil
	     nil
	     'regexp-history)))
      (if (equal input "")
	  default
	input))
    (occur-read-primary-args)))
  (when bufregexp
    (occur-1 regexp nlines
	     (delq nil
		   (mapcar (lambda (buf)
			     (when (and (buffer-file-name buf)
					(string-match bufregexp
						      (buffer-file-name buf)))
			       buf))
			   (buffer-list))))))

(defun occur-1 (regexp nlines bufs &optional buf-name)
  (unless buf-name
    (setq buf-name "*Occur*"))
  (let (occur-buf
	(active-bufs (delq nil (mapcar #'(lambda (buf)
					   (when (buffer-live-p buf) buf))
				       bufs))))
    ;; Handle the case where one of the buffers we're searching is the
    ;; output buffer.  Just rename it.
    (when (member buf-name (mapcar 'buffer-name active-bufs))
      (with-current-buffer (get-buffer buf-name)
	(rename-uniquely)))

    ;; Now find or create the output buffer.
    ;; If we just renamed that buffer, we will make a new one here.
    (setq occur-buf (get-buffer-create buf-name))

    (with-current-buffer occur-buf
      (occur-mode)
      (let ((inhibit-read-only t))
	(erase-buffer)
	(let ((count (occur-engine
		      regexp active-bufs occur-buf
		      (or nlines list-matching-lines-default-context-lines)
		      (and case-fold-search
			   (no-upper-case-p regexp t))
		      list-matching-lines-buffer-name-face
		      nil list-matching-lines-face t)))
	  (let* ((bufcount (length active-bufs))
		 (diff (- (length bufs) bufcount)))
	    (message "Searched %d buffer%s%s; %s match%s for `%s'"
		     bufcount (if (= bufcount 1) "" "s")
		     (if (zerop diff) "" (format " (%d killed)" diff))
		     (if (zerop count) "no" (format "%d" count))
		     (if (= count 1) "" "es")
		     regexp))
	  (setq occur-revert-arguments (list regexp nlines bufs))
          (if (= count 0)
              (kill-buffer occur-buf)
            (display-buffer occur-buf)
            (setq next-error-last-buffer occur-buf)
            (setq buffer-read-only t)
            (set-buffer-modified-p nil)
            (run-hooks 'occur-hook)))))))

(defun occur-engine-add-prefix (lines)
  (mapcar
   #'(lambda (line)
       (concat "       :" line "\n"))
   lines))

(defun occur-engine (regexp buffers out-buf nlines case-fold-search
			    title-face prefix-face match-face keep-props)
  (with-current-buffer out-buf
    (let ((globalcount 0)
	  ;; Don't generate undo entries for creation of the initial contents.
	  (buffer-undo-list t)
	  (coding nil))
      ;; Map over all the buffers
      (dolist (buf buffers)
	(when (buffer-live-p buf)
	  (let ((matches 0)	;; count of matched lines
		(lines 1)	;; line count
		(matchbeg 0)
		(origpt nil)
		(begpt nil)
		(endpt nil)
		(marker nil)
		(curstring "")
		(headerpt (with-current-buffer out-buf (point))))
	    (save-excursion
	      (set-buffer buf)
	      (or coding
		  ;; Set CODING only if the current buffer locally
		  ;; binds buffer-file-coding-system.
		  (not (local-variable-p 'buffer-file-coding-system (current-buffer)))
		  (setq coding buffer-file-coding-system))
	      (save-excursion
		(goto-char (point-min)) ;; begin searching in the buffer
		(while (not (eobp))
		  (setq origpt (point))
		  (when (setq endpt (re-search-forward regexp nil t))
		    (setq matches (1+ matches)) ;; increment match count
		    (setq matchbeg (match-beginning 0))
		    (setq lines (+ lines (1- (count-lines origpt endpt))))
		    (save-excursion
		      (goto-char matchbeg)
		      (setq begpt (line-beginning-position)
			    endpt (line-end-position)))
		    (setq marker (make-marker))
		    (set-marker marker matchbeg)
		    (if (and keep-props
			     (if-boundp 'jit-lock-mode jit-lock-mode)
			     (text-property-not-all begpt endpt 'fontified t))
			(if-fboundp #'jit-lock-fontify-now
			    (jit-lock-fontify-now begpt endpt)))
		    (setq curstring (buffer-substring begpt endpt))
		    ;; Depropertize the string, and maybe
		    ;; highlight the matches
		    (let ((len (length curstring))
			  (start 0))
		      (unless keep-props
			(set-text-properties 0 len nil curstring))
		      (while (and (< start len)
				  (string-match regexp curstring start))
			(add-text-properties
			 (match-beginning 0) (match-end 0)
			 (append
			  `(occur-match t)
			  (when match-face
			    ;; Use `face' rather than `font-lock-face' here
			    ;; so as to override faces copied from the buffer.
			    `(face ,match-face)))
			 curstring)
			(setq start (match-end 0))))
		    ;; Generate the string to insert for this match
		    (let* ((out-line
			    (concat
			     ;; Using 7 digits aligns tabs properly.
			     (apply #'propertize (format "%7d:" lines)
				    (append
				     (when prefix-face
				       `(font-lock-face prefix-face))
				     '(occur-prefix t)))
			     ;; We don't put `mouse-face' on the newline,
			     ;; because that loses.  And don't put it
			     ;; on context lines to reduce flicker.
			     (propertize curstring 'mouse-face 'highlight)
			     "\n"))
			   (data
			    (if (= nlines 0)
				;; The simple display style
				out-line
			      ;; The complex multi-line display
			      ;; style.  Generate a list of lines,
			      ;; concatenate them all together.
			      (apply #'concat
				     (nconc
				      (occur-engine-add-prefix (nreverse (cdr (occur-accumulate-lines (- (1+ (abs nlines))) keep-props))))
				      (list out-line)
				      (if (> nlines 0)
					  (occur-engine-add-prefix
					   (cdr (occur-accumulate-lines (1+ nlines) keep-props)))))))))
		      ;; Actually insert the match display data
		      (with-current-buffer out-buf
			(let ((beg (point))
			      (end (progn (insert data) (point))))
			  (unless (= nlines 0)
			    (insert "-------\n"))
			  (add-text-properties
			   beg end
			   `(occur-target ,marker help-echo "mouse-2: go to this occurrence")))))
		    (goto-char endpt))
		  (if endpt
		      (progn
			(setq lines (1+ lines))
			;; On to the next match...
			(forward-line 1))
		    (goto-char (point-max))))))
	    (when (not (zerop matches)) ;; is the count zero?
	      (setq globalcount (+ globalcount matches))
	      (with-current-buffer out-buf
		(goto-char headerpt)
		(let ((beg (point))
		      end)
		  (insert (format "%d match%s for \"%s\" in buffer: %s\n"
				  matches (if (= matches 1) "" "es")
				  regexp (buffer-name buf)))
		  (setq end (point))
		  (add-text-properties beg end
				       (append
					(when title-face
					  `(font-lock-face ,title-face))
					`(occur-title ,buf))))
		(goto-char (point-min)))))))
      (if coding
	  ;; CODING is buffer-file-coding-system of the first buffer
	  ;; that locally binds it.  Let's use it also for the output
	  ;; buffer.
	  (set-buffer-file-coding-system coding))
      ;; Return the number of matches
      globalcount)))

(provide 'occur)