X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/177c0ea74342272645959b82cf219faa0b3dba16..ee6bb6939fe507dc98986bfc23794da6110f61ef:/src/undo.c diff --git a/src/undo.c b/src/undo.c index fa802fe205..3313c8e306 100644 --- a/src/undo.c +++ b/src/undo.c @@ -1,5 +1,6 @@ /* undo handling for GNU Emacs. - Copyright (C) 1990, 1993, 1994, 2000 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. @@ -15,20 +16,36 @@ GNU General Public License for more details. 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., 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ +the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ #include #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. @@ -84,12 +101,19 @@ record_point (pt) /* 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 != pt - /* If we're called from batch mode, this could be nil. */ && BUFFERP (last_point_position_buffer) + /* If we're called from batch mode, this could be nil. */ && current_buffer == XBUFFER (last_point_position_buffer)) - current_buffer->undo_list - = Fcons (make_number (last_point_position), current_buffer->undo_list); + { + /* 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, @@ -291,29 +315,35 @@ but another undo command will undo to the previous boundary. */) } /* 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 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. */ @@ -323,6 +353,13 @@ truncate_undo_list (list, minsize, maxsize) prev = next; next = XCDR (next); } + + /* 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; @@ -342,24 +379,49 @@ truncate_undo_list (list, minsize, maxsize) prev = next; 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 = 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; } @@ -380,16 +442,15 @@ truncate_undo_list (list, minsize, maxsize) /* 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)) - { - XSETCDR (last_boundary, 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); } DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, @@ -402,6 +463,8 @@ Return what remains of the list. */) Lisp_Object next; 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. */ @@ -418,6 +481,8 @@ Return what remains of the list. */) 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 */ /* In a writable buffer, enable undoing read-only text that is so because of text properties. */ @@ -427,6 +492,8 @@ Return what remains of the list. */) /* Don't let `intangible' properties interfere with undo. */ specbind (Qinhibit_point_motion_hooks, Qt); + oldlist = current_buffer->undo_list; + while (arg > 0) { while (CONSP (list)) @@ -471,7 +538,7 @@ Return what remains of the list. */) } 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); @@ -495,6 +562,41 @@ Return what remains of the list. */) 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. */ @@ -538,19 +640,84 @@ Return what remains of the list. */) 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); } - + 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) */