X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/cbc1b668f313eac593d1de971d9c425629a41e28..03da5d089a8ed035cec443a27259e7d21487a22e:/src/undo.c diff --git a/src/undo.c b/src/undo.c index ceaf3b421d..9839906ca7 100644 --- a/src/undo.c +++ b/src/undo.c @@ -1,5 +1,6 @@ /* undo handling for GNU Emacs. - Copyright (C) 1990, 1993, 1994 Free Software Foundation, Inc. + Copyright (C) 1990, 1993, 1994, 2000, 2002, 2003, 2004, + 2005 Free Software Foundation, Inc. This file is part of GNU Emacs. @@ -15,8 +16,8 @@ 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 @@ -24,11 +25,26 @@ Boston, MA 02111-1307, USA. */ #include "buffer.h" #include "commands.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. @@ -36,6 +52,62 @@ Lisp_Object Qinhibit_read_only; 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 + && last_point_position != pt + /* If we're called from batch mode, this could be nil. */ + && BUFFERP (last_point_position_buffer) + && current_buffer == XBUFFER (last_point_position_buffer)) + 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 @@ -50,29 +122,20 @@ record_insert (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; } } @@ -92,53 +155,20 @@ record_delete (beg, string) Lisp_Object string; { Lisp_Object sbeg; - int at_boundary; 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 (CONSP (current_buffer->undo_list)) + if (PT == beg + SCHARS (string)) { - /* 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) - { - elt = XCONS (tail)->car; - if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCONS (elt)->car))) - break; - tail = XCONS (tail)->cdr; - } - at_boundary = NILP (elt); + XSETINT (sbeg, -beg); + record_point (PT); } else - at_boundary = 0; - - if (MODIFF <= SAVE_MODIFF) - record_first_change (); - - if (PT == beg + XSTRING (string)->size) - XSETINT (sbeg, -beg); - else - XSETFASTINT (sbeg, beg); - - /* 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); + { + XSETFASTINT (sbeg, beg); + record_point (beg); + } current_buffer->undo_list = Fcons (Fcons (string, sbeg), current_buffer->undo_list); @@ -161,7 +191,8 @@ record_marker_adjustment (marker, adjustment) 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); @@ -195,7 +226,8 @@ record_first_change () 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); @@ -248,10 +280,10 @@ record_property_change (beg, length, 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)) @@ -264,7 +296,7 @@ but another undo command will undo to the previous boundary.") { /* 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; } @@ -275,75 +307,113 @@ 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 (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; + + /* Normally the function this calls is undo-outer-limit-truncate. */ + if (! NILP (call1 (Vundo_outer_limit_function, + make_number (size_so_far)))) + { + /* 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; } @@ -352,40 +422,42 @@ truncate_undo_list (list, minsize, maxsize) 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); } 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; @@ -397,21 +469,29 @@ Return what remains of the list.") 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; @@ -422,8 +502,8 @@ Return what remains of the list.") { 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. */ @@ -448,10 +528,9 @@ Return what remains of the list.") #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); @@ -463,11 +542,9 @@ Return what remains of the list.") 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) @@ -477,6 +554,41 @@ 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. */ @@ -520,18 +632,84 @@ 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) */