--- /dev/null
+/* Buffer insertion/deletion and gap motion for GNU Emacs.
+ Copyright (C) 1985, 1986 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 1, or (at your option)
+any later version.
+
+GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+
+#include "config.h"
+#include "lisp.h"
+#include "buffer.h"
+#include "window.h"
+
+/* Nonzero means don't allow protected fields to be modified. */
+
+extern int check_protected_fields;
+
+/* Move gap to position `pos'.
+ Note that this can quit! */
+
+move_gap (pos)
+ int pos;
+{
+ if (pos < GPT)
+ gap_left (pos, 0);
+ else if (pos > GPT)
+ gap_right (pos);
+}
+
+/* Move the gap to POS, which is less than the current GPT.
+ If NEWGAP is nonzero, then don't update beg_unchanged and end_unchanged. */
+
+gap_left (pos, newgap)
+ register int pos;
+ int newgap;
+{
+ register unsigned char *to, *from;
+ register int i;
+ int new_s1;
+
+ pos--;
+
+ if (!newgap)
+ {
+ if (unchanged_modified == MODIFF)
+ {
+ beg_unchanged = pos;
+ end_unchanged = Z - pos - 1;
+ }
+ else
+ {
+ if (Z - GPT < end_unchanged)
+ end_unchanged = Z - GPT;
+ if (pos < beg_unchanged)
+ beg_unchanged = pos;
+ }
+ }
+
+ i = GPT;
+ to = GAP_END_ADDR;
+ from = GPT_ADDR;
+ new_s1 = GPT - BEG;
+
+ /* Now copy the characters. To move the gap down,
+ copy characters up. */
+
+ while (1)
+ {
+ /* I gets number of characters left to copy. */
+ i = new_s1 - pos;
+ if (i == 0)
+ break;
+ /* If a quit is requested, stop copying now.
+ Change POS to be where we have actually moved the gap to. */
+ if (QUITP)
+ {
+ pos = new_s1;
+ break;
+ }
+ /* Move at most 32000 chars before checking again for a quit. */
+ if (i > 32000)
+ i = 32000;
+#ifdef GAP_USE_BCOPY
+ if (i >= 128
+ /* bcopy is safe if the two areas of memory do not overlap
+ or on systems where bcopy is always safe for moving upward. */
+ && (BCOPY_UPWARD_SAFE
+ || to - from >= 128))
+ {
+ /* If overlap is not safe, avoid it by not moving too many
+ characters at once. */
+ if (!BCOPY_UPWARD_SAFE && i > to - from)
+ i = to - from;
+ new_s1 -= i;
+ from -= i, to -= i;
+ bcopy (from, to, i);
+ }
+ else
+#endif
+ {
+ new_s1 -= i;
+ while (--i >= 0)
+ *--to = *--from;
+ }
+ }
+
+ /* Adjust markers, and buffer data structure, to put the gap at POS.
+ POS is where the loop above stopped, which may be what was specified
+ or may be where a quit was detected. */
+ adjust_markers (pos + 1, GPT, GAP_SIZE);
+ GPT = pos + 1;
+ QUIT;
+}
+
+gap_right (pos)
+ register int pos;
+{
+ register unsigned char *to, *from;
+ register int i;
+ int new_s1;
+
+ pos--;
+
+ if (unchanged_modified == MODIFF)
+ {
+ beg_unchanged = pos;
+ end_unchanged = Z - pos - 1;
+ }
+ else
+ {
+ if (Z - pos - 1 < end_unchanged)
+ end_unchanged = Z - pos - 1;
+ if (GPT - BEG < beg_unchanged)
+ beg_unchanged = GPT - BEG;
+ }
+
+ i = GPT;
+ from = GAP_END_ADDR;
+ to = GPT_ADDR;
+ new_s1 = GPT - 1;
+
+ /* Now copy the characters. To move the gap up,
+ copy characters down. */
+
+ while (1)
+ {
+ /* I gets number of characters left to copy. */
+ i = pos - new_s1;
+ if (i == 0)
+ break;
+ /* If a quit is requested, stop copying now.
+ Change POS to be where we have actually moved the gap to. */
+ if (QUITP)
+ {
+ pos = new_s1;
+ break;
+ }
+ /* Move at most 32000 chars before checking again for a quit. */
+ if (i > 32000)
+ i = 32000;
+#ifdef GAP_USE_BCOPY
+ if (i >= 128
+ /* bcopy is safe if the two areas of memory do not overlap
+ or on systems where bcopy is always safe for moving downward. */
+ && (BCOPY_DOWNWARD_SAFE
+ || from - to >= 128))
+ {
+ /* If overlap is not safe, avoid it by not moving too many
+ characters at once. */
+ if (!BCOPY_DOWNWARD_SAFE && i > from - to)
+ i = from - to;
+ new_s1 += i;
+ bcopy (from, to, i);
+ from += i, to += i;
+ }
+ else
+#endif
+ {
+ new_s1 += i;
+ while (--i >= 0)
+ *to++ = *from++;
+ }
+ }
+
+ adjust_markers (GPT + GAP_SIZE, pos + 1 + GAP_SIZE, - GAP_SIZE);
+ GPT = pos + 1;
+ QUIT;
+}
+
+/* Add `amount' to the position of every marker in the current buffer
+ whose current position is between `from' (exclusive) and `to' (inclusive).
+ Also, any markers past the outside of that interval, in the direction
+ of adjustment, are first moved back to the near end of the interval
+ and then adjusted by `amount'. */
+
+adjust_markers (from, to, amount)
+ register int from, to, amount;
+{
+ Lisp_Object marker;
+ register struct Lisp_Marker *m;
+ register int mpos;
+
+ marker = current_buffer->markers;
+
+ while (!NULL (marker))
+ {
+ m = XMARKER (marker);
+ mpos = m->bufpos;
+ if (amount > 0)
+ {
+ if (mpos > to && mpos < to + amount)
+ mpos = to + amount;
+ }
+ else
+ {
+ if (mpos > from + amount && mpos <= from)
+ mpos = from + amount;
+ }
+ if (mpos > from && mpos <= to)
+ mpos += amount;
+ m->bufpos = mpos;
+ marker = m->chain;
+ }
+}
+\f
+/* Make the gap INCREMENT characters longer. */
+
+make_gap (increment)
+ int increment;
+{
+ unsigned char *result;
+ Lisp_Object tem;
+ int real_gap_loc;
+ int old_gap_size;
+
+ /* If we have to get more space, get enough to last a while. */
+ increment += 2000;
+
+ result = BUFFER_REALLOC (BEG_ADDR, (Z - BEG + GAP_SIZE + increment));
+ if (result == 0)
+ memory_full ();
+ BEG_ADDR = result;
+
+ /* Prevent quitting in move_gap. */
+ tem = Vinhibit_quit;
+ Vinhibit_quit = Qt;
+
+ real_gap_loc = GPT;
+ old_gap_size = GAP_SIZE;
+
+ /* Call the newly allocated space a gap at the end of the whole space. */
+ GPT = Z + GAP_SIZE;
+ GAP_SIZE = increment;
+
+ /* Move the new gap down to be consecutive with the end of the old one.
+ This adjusts the markers properly too. */
+ gap_left (real_gap_loc + old_gap_size, 1);
+
+ /* Now combine the two into one large gap. */
+ GAP_SIZE += old_gap_size;
+ GPT = real_gap_loc;
+
+ Vinhibit_quit = tem;
+}
+\f
+/* Insert a string of specified length before point.
+ DO NOT use this for the contents of a Lisp string!
+ prepare_to_modify_buffer could relocate the string. */
+
+insert (string, length)
+ register unsigned char *string;
+ register length;
+{
+ register Lisp_Object temp;
+
+ if (length < 1)
+ return;
+
+ /* Make sure point-max won't overflow after this insertion. */
+ XSET (temp, Lisp_Int, length + Z);
+ if (length + Z != XINT (temp))
+ error ("maximum buffer size exceeded");
+
+ prepare_to_modify_buffer (point, point);
+
+ if (point != GPT)
+ move_gap (point);
+ if (GAP_SIZE < length)
+ make_gap (length - GAP_SIZE);
+
+ record_insert (point, length);
+ MODIFF++;
+
+ bcopy (string, GPT_ADDR, length);
+
+ GAP_SIZE -= length;
+ GPT += length;
+ ZV += length;
+ Z += length;
+ SET_PT (point + length);
+
+ signal_after_change (point-length, 0, length);
+}
+
+/* Function to insert part of the text of a string (STRING)
+ consisting of LENGTH characters at position POS.
+ It does not work to use `insert' for this. */
+
+insert_from_string (string, pos, length)
+ Lisp_Object string;
+ register int pos, length;
+{
+ register Lisp_Object temp;
+ struct gcpro gcpro1;
+
+ if (length < 1)
+ return;
+
+ /* Make sure point-max won't overflow after this insertion. */
+ XSET (temp, Lisp_Int, length + Z);
+ if (length + Z != XINT (temp))
+ error ("maximum buffer size exceeded");
+
+ GCPRO1 (string);
+ prepare_to_modify_buffer (point, point);
+
+ if (point != GPT)
+ move_gap (point);
+ if (GAP_SIZE < length)
+ make_gap (length - GAP_SIZE);
+
+ record_insert (point, length);
+ MODIFF++;
+ UNGCPRO;
+
+ bcopy (XSTRING (string)->data, GPT_ADDR, length);
+
+ GAP_SIZE -= length;
+ GPT += length;
+ ZV += length;
+ Z += length;
+ point += length;
+
+ signal_after_change (point-length, 0, length);
+}
+
+/* Insert the character C before point */
+
+void
+insert_char (c)
+ unsigned char c;
+{
+ insert (&c, 1);
+}
+
+/* Insert the null-terminated string S before point */
+
+void
+insert_string (s)
+ char *s;
+{
+ insert (s, strlen (s));
+}
+
+/* Like `insert' except that all markers pointing at the place where
+ the insertion happens are adjusted to point after it.
+ Don't use this function to insert part of a Lisp string,
+ since gc could happen and relocate it. */
+
+insert_before_markers (string, length)
+ unsigned char *string;
+ register int length;
+{
+ register int opoint = point;
+ insert (string, length);
+ adjust_markers (opoint - 1, opoint, length);
+}
+
+/* Insert part of a Lisp string, relocating markers after. */
+
+insert_from_string_before_markers (string, pos, length)
+ Lisp_Object string;
+ register int pos, length;
+{
+ register int opoint = point;
+ insert_from_string (string, pos, length);
+ adjust_markers (opoint - 1, opoint, length);
+}
+\f
+/* Delete characters in current buffer
+ from FROM up to (but not including) TO. */
+
+del_range (from, to)
+ register int from, to;
+{
+ register int numdel;
+
+ /* Make args be valid */
+ if (from < BEGV)
+ from = BEGV;
+ if (to > ZV)
+ to = ZV;
+
+ if ((numdel = to - from) <= 0)
+ return;
+
+ /* Make sure the gap is somewhere in or next to what we are deleting. */
+ if (from > GPT)
+ gap_right (from);
+ if (to < GPT)
+ gap_left (to, 0);
+
+ prepare_to_modify_buffer (from, to);
+
+ /* Relocate point as if it were a marker. */
+ if (from < point)
+ {
+ if (point < to)
+ SET_PT (from);
+ else
+ SET_PT (point - numdel);
+ }
+
+ record_delete (from, numdel);
+ MODIFF++;
+
+ /* Relocate all markers pointing into the new, larger gap
+ to point at the end of the text before the gap. */
+ adjust_markers (to + GAP_SIZE, to + GAP_SIZE, - numdel - GAP_SIZE);
+
+ GAP_SIZE += numdel;
+ ZV -= numdel;
+ Z -= numdel;
+ GPT = from;
+
+ if (GPT - BEG < beg_unchanged)
+ beg_unchanged = GPT - BEG;
+ if (Z - GPT < end_unchanged)
+ end_unchanged = Z - GPT;
+
+ signal_after_change (from, numdel, 0);
+}
+\f
+modify_region (start, end)
+ int start, end;
+{
+ prepare_to_modify_buffer (start, end);
+
+ if (start - 1 < beg_unchanged || unchanged_modified == MODIFF)
+ beg_unchanged = start - 1;
+ if (Z - end < end_unchanged
+ || unchanged_modified == MODIFF)
+ end_unchanged = Z - end;
+ MODIFF++;
+}
+
+/* Check that it is okay to modify the buffer between START and END.
+ Run the before-change-function, if any. */
+
+prepare_to_modify_buffer (start, end)
+ Lisp_Object start, end;
+{
+ if (!NULL (current_buffer->read_only))
+ Fbarf_if_buffer_read_only ();
+
+ if (check_protected_fields)
+ Fregion_fields (start, end, Qnil, Qt);
+
+#ifdef CLASH_DETECTION
+ if (!NULL (current_buffer->filename)
+ && current_buffer->save_modified >= MODIFF)
+ lock_file (current_buffer->filename);
+#else
+ /* At least warn if this file has changed on disk since it was visited. */
+ if (!NULL (current_buffer->filename)
+ && current_buffer->save_modified >= MODIFF
+ && NULL (Fverify_visited_file_modtime (Fcurrent_buffer ()))
+ && !NULL (Ffile_exists_p (current_buffer->filename)))
+ call1 (intern ("ask-user-about-supersession-threat"),
+ current_buffer->filename);
+#endif /* not CLASH_DETECTION */
+
+ signal_before_change (start, end);
+}
+\f
+static Lisp_Object
+before_change_function_restore (value)
+ Lisp_Object value;
+{
+ Vbefore_change_function = value;
+}
+
+static Lisp_Object
+after_change_function_restore (value)
+ Lisp_Object value;
+{
+ Vafter_change_function = value;
+}
+
+/* Signal a change to the buffer immediatly before it happens.
+ START and END are the bounds of the text to be changed,
+ as Lisp objects. */
+
+signal_before_change (start, end)
+ Lisp_Object start, end;
+{
+ /* If buffer is unmodified, run a special hook for that case. */
+ if (current_buffer->save_modified >= MODIFF
+ && !NULL (Vfirst_change_function))
+ {
+ call0 (Vfirst_change_function);
+ }
+ /* Now in any case run the before-change-function if any. */
+ if (!NULL (Vbefore_change_function))
+ {
+ int count = specpdl_ptr - specpdl;
+ Lisp_Object function;
+
+ function = Vbefore_change_function;
+ record_unwind_protect (after_change_function_restore,
+ Vafter_change_function);
+ record_unwind_protect (before_change_function_restore,
+ Vbefore_change_function);
+ Vafter_change_function = Qnil;
+ Vbefore_change_function = Qnil;
+
+ call2 (function, start, end);
+ unbind_to (count, Qnil);
+ }
+}
+
+/* Signal a change immediatly after it happens.
+ POS is the address of the start of the changed text.
+ LENDEL is the number of characters of the text before the change.
+ (Not the whole buffer; just the part that was changed.)
+ LENINS is the number of characters in the changed text. */
+
+signal_after_change (pos, lendel, lenins)
+ int pos, lendel, lenins;
+{
+ if (!NULL (Vafter_change_function))
+ {
+ int count = specpdl_ptr - specpdl;
+ Lisp_Object function;
+ function = Vafter_change_function;
+
+ record_unwind_protect (after_change_function_restore,
+ Vafter_change_function);
+ record_unwind_protect (before_change_function_restore,
+ Vbefore_change_function);
+ Vafter_change_function = Qnil;
+ Vbefore_change_function = Qnil;
+
+ call3 (function, make_number (pos), make_number (pos + lenins),
+ make_number (lendel));
+ unbind_to (count, Qnil);
+ }
+}
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