/* undo handling for GNU Emacs.
- Copyright (C) 1990, 1993, 1994 Free Software Foundation, Inc.
+ Copyright (C) 1990, 1993, 1994, 2000, 2002, 2003, 2004,
+ 2005, 2006 Free Software Foundation, Inc.
This file is part of GNU Emacs.
+GNU Emacs 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.
+
GNU Emacs is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY. No author or distributor
-accepts responsibility to anyone for the consequences of using it
-or for whether it serves any particular purpose or works at all,
-unless he says so in writing. Refer to the GNU Emacs General Public
-License for full details.
+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.
-Everyone is granted permission to copy, modify and redistribute
-GNU Emacs, but only under the conditions described in the
-GNU Emacs General Public License. A copy of this license is
-supposed to have been given to you along with GNU Emacs so you
-can know your rights and responsibilities. It should be in a
-file named COPYING. Among other things, the copyright notice
-and this notice must be preserved on all copies. */
+You should have received a copy of the GNU General Public License
+along with GNU Emacs; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA. */
#include <config.h>
#include "lisp.h"
#include "buffer.h"
#include "commands.h"
+#include "window.h"
+
+/* Limits controlling how much undo information to keep. */
+
+EMACS_INT undo_limit;
+EMACS_INT undo_strong_limit;
+
+Lisp_Object Vundo_outer_limit;
+
+/* Function to call when undo_outer_limit is exceeded. */
+
+Lisp_Object Vundo_outer_limit_function;
/* Last buffer for which undo information was recorded. */
Lisp_Object last_undo_buffer;
Lisp_Object Qinhibit_read_only;
+/* Marker for function call undo list elements. */
+
+Lisp_Object Qapply;
+
/* The first time a command records something for undo.
it also allocates the undo-boundary object
which will be added to the list at the end of the command.
an undo-boundary. */
Lisp_Object pending_boundary;
+/* Record point as it was at beginning of this command (if necessary)
+ And prepare the undo info for recording a change.
+ PT is the position of point that will naturally occur as a result of the
+ undo record that will be added just after this command terminates. */
+
+static void
+record_point (pt)
+ int pt;
+{
+ int at_boundary;
+
+ /* Allocate a cons cell to be the undo boundary after this command. */
+ if (NILP (pending_boundary))
+ pending_boundary = Fcons (Qnil, Qnil);
+
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
+ Fundo_boundary ();
+ XSETBUFFER (last_undo_buffer, current_buffer);
+
+ if (CONSP (current_buffer->undo_list))
+ {
+ /* Set AT_BOUNDARY to 1 only when we have nothing other than
+ marker adjustment before undo boundary. */
+
+ Lisp_Object tail = current_buffer->undo_list, elt;
+
+ while (1)
+ {
+ if (NILP (tail))
+ elt = Qnil;
+ else
+ elt = XCAR (tail);
+ if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt))))
+ break;
+ tail = XCDR (tail);
+ }
+ at_boundary = NILP (elt);
+ }
+ else
+ at_boundary = 1;
+
+ if (MODIFF <= SAVE_MODIFF)
+ record_first_change ();
+
+ /* If we are just after an undo boundary, and
+ point wasn't at start of deleted range, record where it was. */
+ if (at_boundary
+ && BUFFERP (last_point_position_buffer)
+ /* If we're called from batch mode, this could be nil. */
+ && current_buffer == XBUFFER (last_point_position_buffer))
+ {
+ /* If we have switched windows, use the point value
+ from the window we are in. */
+ if (! EQ (last_point_position_window, selected_window))
+ last_point_position = marker_position (XWINDOW (selected_window)->pointm);
+
+ if (last_point_position != pt)
+ current_buffer->undo_list
+ = Fcons (make_number (last_point_position), current_buffer->undo_list);
+ }
+}
+
/* Record an insertion that just happened or is about to happen,
for LENGTH characters at position BEG.
(It is possible to record an insertion before or after the fact
because we don't need to record the contents.) */
+void
record_insert (beg, length)
int beg, length;
{
if (EQ (current_buffer->undo_list, Qt))
return;
- /* Allocate a cons cell to be the undo boundary after this command. */
- if (NILP (pending_boundary))
- pending_boundary = Fcons (Qnil, Qnil);
-
- if (current_buffer != XBUFFER (last_undo_buffer))
- Fundo_boundary ();
- XSETBUFFER (last_undo_buffer, current_buffer);
-
- if (MODIFF <= SAVE_MODIFF)
- record_first_change ();
+ record_point (beg);
/* If this is following another insertion and consecutive with it
in the buffer, combine the two. */
if (CONSP (current_buffer->undo_list))
{
Lisp_Object elt;
- elt = XCONS (current_buffer->undo_list)->car;
+ elt = XCAR (current_buffer->undo_list);
if (CONSP (elt)
- && INTEGERP (XCONS (elt)->car)
- && INTEGERP (XCONS (elt)->cdr)
- && XINT (XCONS (elt)->cdr) == beg)
+ && INTEGERP (XCAR (elt))
+ && INTEGERP (XCDR (elt))
+ && XINT (XCDR (elt)) == beg)
{
- XSETINT (XCONS (elt)->cdr, beg + length);
+ XSETCDR (elt, make_number (beg + length));
return;
}
}
}
/* Record that a deletion is about to take place,
- for LENGTH characters at location BEG. */
+ of the characters in STRING, at location BEG. */
-record_delete (beg, length)
- int beg, length;
+void
+record_delete (beg, string)
+ int beg;
+ Lisp_Object string;
{
- Lisp_Object lbeg, lend, sbeg;
- int at_boundary;
+ Lisp_Object sbeg;
+ if (EQ (current_buffer->undo_list, Qt))
+ return;
+
+ if (PT == beg + SCHARS (string))
+ {
+ XSETINT (sbeg, -beg);
+ record_point (PT);
+ }
+ else
+ {
+ XSETFASTINT (sbeg, beg);
+ record_point (beg);
+ }
+
+ current_buffer->undo_list
+ = Fcons (Fcons (string, sbeg), current_buffer->undo_list);
+}
+
+/* Record the fact that MARKER is about to be adjusted by ADJUSTMENT.
+ This is done only when a marker points within text being deleted,
+ because that's the only case where an automatic marker adjustment
+ won't be inverted automatically by undoing the buffer modification. */
+
+void
+record_marker_adjustment (marker, adjustment)
+ Lisp_Object marker;
+ int adjustment;
+{
if (EQ (current_buffer->undo_list, Qt))
return;
if (NILP (pending_boundary))
pending_boundary = Fcons (Qnil, Qnil);
- if (current_buffer != XBUFFER (last_undo_buffer))
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
Fundo_boundary ();
XSETBUFFER (last_undo_buffer, current_buffer);
- at_boundary = (CONSP (current_buffer->undo_list)
- && NILP (XCONS (current_buffer->undo_list)->car));
-
- if (MODIFF <= SAVE_MODIFF)
- record_first_change ();
-
- if (point == beg + length)
- XSETINT (sbeg, -beg);
- else
- XSETFASTINT (sbeg, beg);
- XSETFASTINT (lbeg, beg);
- XSETFASTINT (lend, beg + length);
-
- /* If we are just after an undo boundary, and
- point wasn't at start of deleted range, record where it was. */
- if (at_boundary
- && last_point_position != XFASTINT (sbeg)
- && current_buffer == XBUFFER (last_point_position_buffer))
- current_buffer->undo_list
- = Fcons (make_number (last_point_position), current_buffer->undo_list);
-
current_buffer->undo_list
- = Fcons (Fcons (Fbuffer_substring (lbeg, lend), sbeg),
+ = Fcons (Fcons (marker, make_number (adjustment)),
current_buffer->undo_list);
}
/* Record that a replacement is about to take place,
for LENGTH characters at location BEG.
- The replacement does not change the number of characters. */
+ The replacement must not change the number of characters. */
+void
record_change (beg, length)
int beg, length;
{
- record_delete (beg, length);
+ record_delete (beg, make_buffer_string (beg, beg + length, 1));
record_insert (beg, length);
}
\f
Record the file modification date so that when undoing this entry
we can tell whether it is obsolete because the file was saved again. */
+void
record_first_change ()
{
Lisp_Object high, low;
if (EQ (current_buffer->undo_list, Qt))
return;
- if (current_buffer != XBUFFER (last_undo_buffer))
+ if (!BUFFERP (last_undo_buffer)
+ || current_buffer != XBUFFER (last_undo_buffer))
Fundo_boundary ();
XSETBUFFER (last_undo_buffer, current_buffer);
/* Record a change in property PROP (whose old value was VAL)
for LENGTH characters starting at position BEG in BUFFER. */
+void
record_property_change (beg, length, prop, value, buffer)
int beg, length;
Lisp_Object prop, value, buffer;
}
DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0,
- "Mark a boundary between units of undo.\n\
-An undo command will stop at this point,\n\
-but another undo command will undo to the previous boundary.")
- ()
+ doc: /* Mark a boundary between units of undo.
+An undo command will stop at this point,
+but another undo command will undo to the previous boundary. */)
+ ()
{
Lisp_Object tem;
if (EQ (current_buffer->undo_list, Qt))
{
/* If we have preallocated the cons cell to use here,
use that one. */
- XCONS (pending_boundary)->cdr = current_buffer->undo_list;
+ XSETCDR (pending_boundary, current_buffer->undo_list);
current_buffer->undo_list = pending_boundary;
pending_boundary = Qnil;
}
}
/* At garbage collection time, make an undo list shorter at the end,
- returning the truncated list.
- MINSIZE and MAXSIZE are the limits on size allowed, as described below.
- In practice, these are the values of undo-limit and
- undo-strong-limit. */
-
-Lisp_Object
-truncate_undo_list (list, minsize, maxsize)
- Lisp_Object list;
- int minsize, maxsize;
+ returning the truncated list. How this is done depends on the
+ variables undo-limit, undo-strong-limit and undo-outer-limit.
+ In some cases this works by calling undo-outer-limit-function. */
+
+void
+truncate_undo_list (b)
+ struct buffer *b;
{
+ Lisp_Object list;
Lisp_Object prev, next, last_boundary;
int size_so_far = 0;
+ /* Make sure that calling undo-outer-limit-function
+ won't cause another GC. */
+ int count = inhibit_garbage_collection ();
+
+ /* Make the buffer current to get its local values of variables such
+ as undo_limit. Also so that Vundo_outer_limit_function can
+ tell which buffer to operate on. */
+ record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+ set_buffer_internal (b);
+
+ list = b->undo_list;
+
prev = Qnil;
next = list;
last_boundary = Qnil;
- /* Always preserve at least the most recent undo record.
- If the first element is an undo boundary, skip past it.
-
- Skip, skip, skip the undo, skip, skip, skip the undo,
- Skip, skip, skip the undo, skip to the undo bound'ry.
- (Get it? "Skip to my Loo?") */
- if (CONSP (next) && NILP (XCONS (next)->car))
+ /* If the first element is an undo boundary, skip past it. */
+ if (CONSP (next) && NILP (XCAR (next)))
{
/* Add in the space occupied by this element and its chain link. */
size_so_far += sizeof (struct Lisp_Cons);
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
- while (CONSP (next) && ! NILP (XCONS (next)->car))
+
+ /* Always preserve at least the most recent undo record
+ unless it is really horribly big.
+
+ Skip, skip, skip the undo, skip, skip, skip the undo,
+ Skip, skip, skip the undo, skip to the undo bound'ry. */
+
+ while (CONSP (next) && ! NILP (XCAR (next)))
{
Lisp_Object elt;
- elt = XCONS (next)->car;
+ elt = XCAR (next);
/* Add in the space occupied by this element and its chain link. */
size_so_far += sizeof (struct Lisp_Cons);
if (CONSP (elt))
{
size_so_far += sizeof (struct Lisp_Cons);
- if (STRINGP (XCONS (elt)->car))
+ if (STRINGP (XCAR (elt)))
size_so_far += (sizeof (struct Lisp_String) - 1
- + XSTRING (XCONS (elt)->car)->size);
+ + SCHARS (XCAR (elt)));
}
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
+
+ /* If by the first boundary we have already passed undo_outer_limit,
+ we're heading for memory full, so offer to clear out the list. */
+ if (INTEGERP (Vundo_outer_limit)
+ && size_so_far > XINT (Vundo_outer_limit)
+ && !NILP (Vundo_outer_limit_function))
+ {
+ Lisp_Object temp = last_undo_buffer, tem;
+
+ /* Normally the function this calls is undo-outer-limit-truncate. */
+ tem = call1 (Vundo_outer_limit_function, make_number (size_so_far));
+ if (! NILP (tem))
+ {
+ /* The function is responsible for making
+ any desired changes in buffer-undo-list. */
+ unbind_to (count, Qnil);
+ return;
+ }
+ /* That function probably used the minibuffer, and if so, that
+ changed last_undo_buffer. Change it back so that we don't
+ force next change to make an undo boundary here. */
+ last_undo_buffer = temp;
+ }
+
if (CONSP (next))
last_boundary = prev;
+ /* Keep additional undo data, if it fits in the limits. */
while (CONSP (next))
{
Lisp_Object elt;
- elt = XCONS (next)->car;
+ elt = XCAR (next);
/* When we get to a boundary, decide whether to truncate
- either before or after it. The lower threshold, MINSIZE,
+ either before or after it. The lower threshold, undo_limit,
tells us to truncate after it. If its size pushes past
- the higher threshold MAXSIZE as well, we truncate before it. */
+ the higher threshold undo_strong_limit, we truncate before it. */
if (NILP (elt))
{
- if (size_so_far > maxsize)
+ if (size_so_far > undo_strong_limit)
break;
last_boundary = prev;
- if (size_so_far > minsize)
+ if (size_so_far > undo_limit)
break;
}
if (CONSP (elt))
{
size_so_far += sizeof (struct Lisp_Cons);
- if (STRINGP (XCONS (elt)->car))
+ if (STRINGP (XCAR (elt)))
size_so_far += (sizeof (struct Lisp_String) - 1
- + XSTRING (XCONS (elt)->car)->size);
+ + SCHARS (XCAR (elt)));
}
/* Advance to next element. */
prev = next;
- next = XCONS (next)->cdr;
+ next = XCDR (next);
}
/* If we scanned the whole list, it is short enough; don't change it. */
if (NILP (next))
- return list;
-
+ ;
/* Truncate at the boundary where we decided to truncate. */
- if (!NILP (last_boundary))
- {
- XCONS (last_boundary)->cdr = Qnil;
- return list;
- }
+ else if (!NILP (last_boundary))
+ XSETCDR (last_boundary, Qnil);
+ /* There's nothing we decided to keep, so clear it out. */
else
- return Qnil;
+ b->undo_list = Qnil;
+
+ unbind_to (count, Qnil);
}
\f
DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0,
- "Undo N records from the front of the list LIST.\n\
-Return what remains of the list.")
- (n, list)
+ doc: /* Undo N records from the front of the list LIST.
+Return what remains of the list. */)
+ (n, list)
Lisp_Object n, list;
{
struct gcpro gcpro1, gcpro2;
Lisp_Object next;
- int count = specpdl_ptr - specpdl;
+ int count = SPECPDL_INDEX ();
register int arg;
+ Lisp_Object oldlist;
+ int did_apply = 0;
+
#if 0 /* This is a good feature, but would make undo-start
unable to do what is expected. */
Lisp_Object tem;
list = Fcdr (list);
#endif
- CHECK_NUMBER (n, 0);
+ CHECK_NUMBER (n);
arg = XINT (n);
next = Qnil;
GCPRO2 (next, list);
+ /* I don't think we need to gcpro oldlist, as we use it only
+ to check for EQ. ++kfs */
- /* Don't let read-only properties interfere with undo. */
+ /* In a writable buffer, enable undoing read-only text that is so
+ because of text properties. */
if (NILP (current_buffer->read_only))
specbind (Qinhibit_read_only, Qt);
+ /* Don't let `intangible' properties interfere with undo. */
+ specbind (Qinhibit_point_motion_hooks, Qt);
+
+ oldlist = current_buffer->undo_list;
+
while (arg > 0)
{
- while (1)
+ while (CONSP (list))
{
- next = Fcar (list);
- list = Fcdr (list);
+ next = XCAR (list);
+ list = XCDR (list);
/* Exit inner loop at undo boundary. */
if (NILP (next))
break;
{
Lisp_Object car, cdr;
- car = Fcar (next);
- cdr = Fcdr (next);
+ car = XCAR (next);
+ cdr = XCDR (next);
if (EQ (car, Qt))
{
/* Element (t high . low) records previous modtime. */
(not matching the actual disk file)
then don't mark unmodified. */
if (mod_time != base_buffer->modtime)
- break;
+ continue;
#ifdef CLASH_DETECTION
Funlock_buffer ();
#endif /* CLASH_DETECTION */
Fset_buffer_modified_p (Qnil);
}
-#ifdef USE_TEXT_PROPERTIES
else if (EQ (car, Qnil))
{
- /* Element (nil prop val beg . end) is property change. */
+ /* Element (nil PROP VAL BEG . END) is property change. */
Lisp_Object beg, end, prop, val;
prop = Fcar (cdr);
Fput_text_property (beg, end, prop, val, Qnil);
}
-#endif /* USE_TEXT_PROPERTIES */
else if (INTEGERP (car) && INTEGERP (cdr))
{
/* Element (BEG . END) means range was inserted. */
- Lisp_Object end;
if (XINT (car) < BEGV
|| XINT (cdr) > ZV)
Fgoto_char (car);
Fdelete_region (car, cdr);
}
+ else if (EQ (car, Qapply))
+ {
+ /* Element (apply FUN . ARGS) means call FUN to undo. */
+ struct buffer *save_buffer = current_buffer;
+
+ car = Fcar (cdr);
+ cdr = Fcdr (cdr);
+ if (INTEGERP (car))
+ {
+ /* Long format: (apply DELTA START END FUN . ARGS). */
+ Lisp_Object delta = car;
+ Lisp_Object start = Fcar (cdr);
+ Lisp_Object end = Fcar (Fcdr (cdr));
+ Lisp_Object start_mark = Fcopy_marker (start, Qnil);
+ Lisp_Object end_mark = Fcopy_marker (end, Qt);
+
+ cdr = Fcdr (Fcdr (cdr));
+ apply1 (Fcar (cdr), Fcdr (cdr));
+
+ /* Check that the function did what the entry said it
+ would do. */
+ if (!EQ (start, Fmarker_position (start_mark))
+ || (XINT (delta) + XINT (end)
+ != marker_position (end_mark)))
+ error ("Changes to be undone by function different than announced");
+ Fset_marker (start_mark, Qnil, Qnil);
+ Fset_marker (end_mark, Qnil, Qnil);
+ }
+ else
+ apply1 (car, cdr);
+
+ if (save_buffer != current_buffer)
+ error ("Undo function switched buffer");
+ did_apply = 1;
+ }
else if (STRINGP (car) && INTEGERP (cdr))
{
/* Element (STRING . POS) means STRING was deleted. */
error ("Changes to be undone are outside visible portion of buffer");
SET_PT (pos);
- /* Insert before markers so that if the mark is
- currently on the boundary of this deletion, it
- ends up on the other side of the now-undeleted
- text from point. Since undo doesn't even keep
- track of the mark, this isn't really necessary,
- but it may lead to better behavior in certain
- situations. */
- Finsert_before_markers (1, &membuf);
+ /* Now that we record marker adjustments
+ (caused by deletion) for undo,
+ we should always insert after markers,
+ so that undoing the marker adjustments
+ put the markers back in the right place. */
+ Finsert (1, &membuf);
SET_PT (pos);
}
}
+ else if (MARKERP (car) && INTEGERP (cdr))
+ {
+ /* (MARKER . INTEGER) means a marker MARKER
+ was adjusted by INTEGER. */
+ if (XMARKER (car)->buffer)
+ Fset_marker (car,
+ make_number (marker_position (car) - XINT (cdr)),
+ Fmarker_buffer (car));
+ }
}
}
arg--;
}
+
+ /* Make sure an apply entry produces at least one undo entry,
+ so the test in `undo' for continuing an undo series
+ will work right. */
+ if (did_apply
+ && EQ (oldlist, current_buffer->undo_list))
+ current_buffer->undo_list
+ = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list);
+
UNGCPRO;
return unbind_to (count, list);
}
-
+\f
+void
syms_of_undo ()
{
Qinhibit_read_only = intern ("inhibit-read-only");
staticpro (&Qinhibit_read_only);
+ Qapply = intern ("apply");
+ staticpro (&Qapply);
+
pending_boundary = Qnil;
staticpro (&pending_boundary);
defsubr (&Sprimitive_undo);
defsubr (&Sundo_boundary);
+
+ DEFVAR_INT ("undo-limit", &undo_limit,
+ doc: /* Keep no more undo information once it exceeds this size.
+This limit is applied when garbage collection happens.
+When a previous command increases the total undo list size past this
+value, the earlier commands that came before it are forgotten.
+
+The size is counted as the number of bytes occupied,
+which includes both saved text and other data. */);
+ undo_limit = 20000;
+
+ DEFVAR_INT ("undo-strong-limit", &undo_strong_limit,
+ doc: /* Don't keep more than this much size of undo information.
+This limit is applied when garbage collection happens.
+When a previous command increases the total undo list size past this
+value, that command and the earlier commands that came before it are forgotten.
+However, the most recent buffer-modifying command's undo info
+is never discarded for this reason.
+
+The size is counted as the number of bytes occupied,
+which includes both saved text and other data. */);
+ undo_strong_limit = 30000;
+
+ DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit,
+ doc: /* Outer limit on size of undo information for one command.
+At garbage collection time, if the current command has produced
+more than this much undo information, it discards the info and displays
+a warning. This is a last-ditch limit to prevent memory overflow.
+
+The size is counted as the number of bytes occupied, which includes
+both saved text and other data. A value of nil means no limit. In
+this case, accumulating one huge undo entry could make Emacs crash as
+a result of memory overflow.
+
+In fact, this calls the function which is the value of
+`undo-outer-limit-function' with one argument, the size.
+The text above describes the behavior of the function
+that variable usually specifies. */);
+ Vundo_outer_limit = make_number (3000000);
+
+ DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function,
+ doc: /* Function to call when an undo list exceeds `undo-outer-limit'.
+This function is called with one argument, the current undo list size
+for the most recent command (since the last undo boundary).
+If the function returns t, that means truncation has been fully handled.
+If it returns nil, the other forms of truncation are done.
+
+Garbage collection is inhibited around the call to this function,
+so it must make sure not to do a lot of consing. */);
+ Vundo_outer_limit_function = Qnil;
}
+
+/* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a
+ (do not change this comment) */
HCoop / bpt / emacs.git / blobdiff