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b45433b3 JB |
1 | /* Buffer insertion/deletion and gap motion for GNU Emacs. |
2 | Copyright (C) 1985, 1986 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Emacs; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | #include "config.h" | |
22 | #include "lisp.h" | |
23 | #include "buffer.h" | |
24 | #include "window.h" | |
25 | ||
26 | /* Nonzero means don't allow protected fields to be modified. */ | |
27 | ||
28 | extern int check_protected_fields; | |
29 | ||
30 | /* Move gap to position `pos'. | |
31 | Note that this can quit! */ | |
32 | ||
33 | move_gap (pos) | |
34 | int pos; | |
35 | { | |
36 | if (pos < GPT) | |
37 | gap_left (pos, 0); | |
38 | else if (pos > GPT) | |
39 | gap_right (pos); | |
40 | } | |
41 | ||
42 | /* Move the gap to POS, which is less than the current GPT. | |
43 | If NEWGAP is nonzero, then don't update beg_unchanged and end_unchanged. */ | |
44 | ||
45 | gap_left (pos, newgap) | |
46 | register int pos; | |
47 | int newgap; | |
48 | { | |
49 | register unsigned char *to, *from; | |
50 | register int i; | |
51 | int new_s1; | |
52 | ||
53 | pos--; | |
54 | ||
55 | if (!newgap) | |
56 | { | |
57 | if (unchanged_modified == MODIFF) | |
58 | { | |
59 | beg_unchanged = pos; | |
60 | end_unchanged = Z - pos - 1; | |
61 | } | |
62 | else | |
63 | { | |
64 | if (Z - GPT < end_unchanged) | |
65 | end_unchanged = Z - GPT; | |
66 | if (pos < beg_unchanged) | |
67 | beg_unchanged = pos; | |
68 | } | |
69 | } | |
70 | ||
71 | i = GPT; | |
72 | to = GAP_END_ADDR; | |
73 | from = GPT_ADDR; | |
74 | new_s1 = GPT - BEG; | |
75 | ||
76 | /* Now copy the characters. To move the gap down, | |
77 | copy characters up. */ | |
78 | ||
79 | while (1) | |
80 | { | |
81 | /* I gets number of characters left to copy. */ | |
82 | i = new_s1 - pos; | |
83 | if (i == 0) | |
84 | break; | |
85 | /* If a quit is requested, stop copying now. | |
86 | Change POS to be where we have actually moved the gap to. */ | |
87 | if (QUITP) | |
88 | { | |
89 | pos = new_s1; | |
90 | break; | |
91 | } | |
92 | /* Move at most 32000 chars before checking again for a quit. */ | |
93 | if (i > 32000) | |
94 | i = 32000; | |
95 | #ifdef GAP_USE_BCOPY | |
96 | if (i >= 128 | |
97 | /* bcopy is safe if the two areas of memory do not overlap | |
98 | or on systems where bcopy is always safe for moving upward. */ | |
99 | && (BCOPY_UPWARD_SAFE | |
100 | || to - from >= 128)) | |
101 | { | |
102 | /* If overlap is not safe, avoid it by not moving too many | |
103 | characters at once. */ | |
104 | if (!BCOPY_UPWARD_SAFE && i > to - from) | |
105 | i = to - from; | |
106 | new_s1 -= i; | |
107 | from -= i, to -= i; | |
108 | bcopy (from, to, i); | |
109 | } | |
110 | else | |
111 | #endif | |
112 | { | |
113 | new_s1 -= i; | |
114 | while (--i >= 0) | |
115 | *--to = *--from; | |
116 | } | |
117 | } | |
118 | ||
119 | /* Adjust markers, and buffer data structure, to put the gap at POS. | |
120 | POS is where the loop above stopped, which may be what was specified | |
121 | or may be where a quit was detected. */ | |
122 | adjust_markers (pos + 1, GPT, GAP_SIZE); | |
123 | GPT = pos + 1; | |
124 | QUIT; | |
125 | } | |
126 | ||
127 | gap_right (pos) | |
128 | register int pos; | |
129 | { | |
130 | register unsigned char *to, *from; | |
131 | register int i; | |
132 | int new_s1; | |
133 | ||
134 | pos--; | |
135 | ||
136 | if (unchanged_modified == MODIFF) | |
137 | { | |
138 | beg_unchanged = pos; | |
139 | end_unchanged = Z - pos - 1; | |
140 | } | |
141 | else | |
142 | { | |
143 | if (Z - pos - 1 < end_unchanged) | |
144 | end_unchanged = Z - pos - 1; | |
145 | if (GPT - BEG < beg_unchanged) | |
146 | beg_unchanged = GPT - BEG; | |
147 | } | |
148 | ||
149 | i = GPT; | |
150 | from = GAP_END_ADDR; | |
151 | to = GPT_ADDR; | |
152 | new_s1 = GPT - 1; | |
153 | ||
154 | /* Now copy the characters. To move the gap up, | |
155 | copy characters down. */ | |
156 | ||
157 | while (1) | |
158 | { | |
159 | /* I gets number of characters left to copy. */ | |
160 | i = pos - new_s1; | |
161 | if (i == 0) | |
162 | break; | |
163 | /* If a quit is requested, stop copying now. | |
164 | Change POS to be where we have actually moved the gap to. */ | |
165 | if (QUITP) | |
166 | { | |
167 | pos = new_s1; | |
168 | break; | |
169 | } | |
170 | /* Move at most 32000 chars before checking again for a quit. */ | |
171 | if (i > 32000) | |
172 | i = 32000; | |
173 | #ifdef GAP_USE_BCOPY | |
174 | if (i >= 128 | |
175 | /* bcopy is safe if the two areas of memory do not overlap | |
176 | or on systems where bcopy is always safe for moving downward. */ | |
177 | && (BCOPY_DOWNWARD_SAFE | |
178 | || from - to >= 128)) | |
179 | { | |
180 | /* If overlap is not safe, avoid it by not moving too many | |
181 | characters at once. */ | |
182 | if (!BCOPY_DOWNWARD_SAFE && i > from - to) | |
183 | i = from - to; | |
184 | new_s1 += i; | |
185 | bcopy (from, to, i); | |
186 | from += i, to += i; | |
187 | } | |
188 | else | |
189 | #endif | |
190 | { | |
191 | new_s1 += i; | |
192 | while (--i >= 0) | |
193 | *to++ = *from++; | |
194 | } | |
195 | } | |
196 | ||
197 | adjust_markers (GPT + GAP_SIZE, pos + 1 + GAP_SIZE, - GAP_SIZE); | |
198 | GPT = pos + 1; | |
199 | QUIT; | |
200 | } | |
201 | ||
202 | /* Add `amount' to the position of every marker in the current buffer | |
203 | whose current position is between `from' (exclusive) and `to' (inclusive). | |
204 | Also, any markers past the outside of that interval, in the direction | |
205 | of adjustment, are first moved back to the near end of the interval | |
206 | and then adjusted by `amount'. */ | |
207 | ||
208 | adjust_markers (from, to, amount) | |
209 | register int from, to, amount; | |
210 | { | |
211 | Lisp_Object marker; | |
212 | register struct Lisp_Marker *m; | |
213 | register int mpos; | |
214 | ||
215 | marker = current_buffer->markers; | |
216 | ||
d427b66a | 217 | while (!NILP (marker)) |
b45433b3 JB |
218 | { |
219 | m = XMARKER (marker); | |
220 | mpos = m->bufpos; | |
221 | if (amount > 0) | |
222 | { | |
223 | if (mpos > to && mpos < to + amount) | |
224 | mpos = to + amount; | |
225 | } | |
226 | else | |
227 | { | |
228 | if (mpos > from + amount && mpos <= from) | |
229 | mpos = from + amount; | |
230 | } | |
231 | if (mpos > from && mpos <= to) | |
232 | mpos += amount; | |
233 | m->bufpos = mpos; | |
234 | marker = m->chain; | |
235 | } | |
236 | } | |
237 | \f | |
238 | /* Make the gap INCREMENT characters longer. */ | |
239 | ||
240 | make_gap (increment) | |
241 | int increment; | |
242 | { | |
243 | unsigned char *result; | |
244 | Lisp_Object tem; | |
245 | int real_gap_loc; | |
246 | int old_gap_size; | |
247 | ||
248 | /* If we have to get more space, get enough to last a while. */ | |
249 | increment += 2000; | |
250 | ||
251 | result = BUFFER_REALLOC (BEG_ADDR, (Z - BEG + GAP_SIZE + increment)); | |
252 | if (result == 0) | |
253 | memory_full (); | |
254 | BEG_ADDR = result; | |
255 | ||
256 | /* Prevent quitting in move_gap. */ | |
257 | tem = Vinhibit_quit; | |
258 | Vinhibit_quit = Qt; | |
259 | ||
260 | real_gap_loc = GPT; | |
261 | old_gap_size = GAP_SIZE; | |
262 | ||
263 | /* Call the newly allocated space a gap at the end of the whole space. */ | |
264 | GPT = Z + GAP_SIZE; | |
265 | GAP_SIZE = increment; | |
266 | ||
267 | /* Move the new gap down to be consecutive with the end of the old one. | |
268 | This adjusts the markers properly too. */ | |
269 | gap_left (real_gap_loc + old_gap_size, 1); | |
270 | ||
271 | /* Now combine the two into one large gap. */ | |
272 | GAP_SIZE += old_gap_size; | |
273 | GPT = real_gap_loc; | |
274 | ||
275 | Vinhibit_quit = tem; | |
276 | } | |
277 | \f | |
278 | /* Insert a string of specified length before point. | |
279 | DO NOT use this for the contents of a Lisp string! | |
280 | prepare_to_modify_buffer could relocate the string. */ | |
281 | ||
282 | insert (string, length) | |
283 | register unsigned char *string; | |
284 | register length; | |
285 | { | |
286 | register Lisp_Object temp; | |
287 | ||
288 | if (length < 1) | |
289 | return; | |
290 | ||
291 | /* Make sure point-max won't overflow after this insertion. */ | |
292 | XSET (temp, Lisp_Int, length + Z); | |
293 | if (length + Z != XINT (temp)) | |
294 | error ("maximum buffer size exceeded"); | |
295 | ||
296 | prepare_to_modify_buffer (point, point); | |
297 | ||
298 | if (point != GPT) | |
299 | move_gap (point); | |
300 | if (GAP_SIZE < length) | |
301 | make_gap (length - GAP_SIZE); | |
302 | ||
303 | record_insert (point, length); | |
304 | MODIFF++; | |
305 | ||
306 | bcopy (string, GPT_ADDR, length); | |
307 | ||
308 | GAP_SIZE -= length; | |
309 | GPT += length; | |
310 | ZV += length; | |
311 | Z += length; | |
312 | SET_PT (point + length); | |
313 | ||
314 | signal_after_change (point-length, 0, length); | |
315 | } | |
316 | ||
7e1ea612 JB |
317 | /* Function to insert part of the text of a string (STRING) consisting |
318 | of LENGTH characters at position POS. | |
319 | It does not work to use `insert' for this, becase a GC could happen | |
320 | before we bcopy the stuff into the buffer, and relocate the string | |
321 | without insert noticing. */ | |
b45433b3 JB |
322 | insert_from_string (string, pos, length) |
323 | Lisp_Object string; | |
324 | register int pos, length; | |
325 | { | |
326 | register Lisp_Object temp; | |
327 | struct gcpro gcpro1; | |
328 | ||
329 | if (length < 1) | |
330 | return; | |
331 | ||
332 | /* Make sure point-max won't overflow after this insertion. */ | |
333 | XSET (temp, Lisp_Int, length + Z); | |
334 | if (length + Z != XINT (temp)) | |
335 | error ("maximum buffer size exceeded"); | |
336 | ||
337 | GCPRO1 (string); | |
338 | prepare_to_modify_buffer (point, point); | |
339 | ||
340 | if (point != GPT) | |
341 | move_gap (point); | |
342 | if (GAP_SIZE < length) | |
343 | make_gap (length - GAP_SIZE); | |
344 | ||
345 | record_insert (point, length); | |
346 | MODIFF++; | |
347 | UNGCPRO; | |
348 | ||
349 | bcopy (XSTRING (string)->data, GPT_ADDR, length); | |
350 | ||
351 | GAP_SIZE -= length; | |
352 | GPT += length; | |
353 | ZV += length; | |
354 | Z += length; | |
d427b66a | 355 | SET_PT (point + length); |
b45433b3 JB |
356 | |
357 | signal_after_change (point-length, 0, length); | |
358 | } | |
359 | ||
360 | /* Insert the character C before point */ | |
361 | ||
362 | void | |
363 | insert_char (c) | |
364 | unsigned char c; | |
365 | { | |
366 | insert (&c, 1); | |
367 | } | |
368 | ||
369 | /* Insert the null-terminated string S before point */ | |
370 | ||
371 | void | |
372 | insert_string (s) | |
373 | char *s; | |
374 | { | |
375 | insert (s, strlen (s)); | |
376 | } | |
377 | ||
378 | /* Like `insert' except that all markers pointing at the place where | |
379 | the insertion happens are adjusted to point after it. | |
380 | Don't use this function to insert part of a Lisp string, | |
381 | since gc could happen and relocate it. */ | |
382 | ||
383 | insert_before_markers (string, length) | |
384 | unsigned char *string; | |
385 | register int length; | |
386 | { | |
387 | register int opoint = point; | |
388 | insert (string, length); | |
389 | adjust_markers (opoint - 1, opoint, length); | |
390 | } | |
391 | ||
392 | /* Insert part of a Lisp string, relocating markers after. */ | |
393 | ||
394 | insert_from_string_before_markers (string, pos, length) | |
395 | Lisp_Object string; | |
396 | register int pos, length; | |
397 | { | |
398 | register int opoint = point; | |
399 | insert_from_string (string, pos, length); | |
400 | adjust_markers (opoint - 1, opoint, length); | |
401 | } | |
402 | \f | |
403 | /* Delete characters in current buffer | |
404 | from FROM up to (but not including) TO. */ | |
405 | ||
406 | del_range (from, to) | |
407 | register int from, to; | |
408 | { | |
409 | register int numdel; | |
410 | ||
411 | /* Make args be valid */ | |
412 | if (from < BEGV) | |
413 | from = BEGV; | |
414 | if (to > ZV) | |
415 | to = ZV; | |
416 | ||
417 | if ((numdel = to - from) <= 0) | |
418 | return; | |
419 | ||
420 | /* Make sure the gap is somewhere in or next to what we are deleting. */ | |
421 | if (from > GPT) | |
422 | gap_right (from); | |
423 | if (to < GPT) | |
424 | gap_left (to, 0); | |
425 | ||
426 | prepare_to_modify_buffer (from, to); | |
427 | ||
428 | /* Relocate point as if it were a marker. */ | |
429 | if (from < point) | |
430 | { | |
431 | if (point < to) | |
432 | SET_PT (from); | |
433 | else | |
434 | SET_PT (point - numdel); | |
435 | } | |
436 | ||
437 | record_delete (from, numdel); | |
438 | MODIFF++; | |
439 | ||
440 | /* Relocate all markers pointing into the new, larger gap | |
441 | to point at the end of the text before the gap. */ | |
442 | adjust_markers (to + GAP_SIZE, to + GAP_SIZE, - numdel - GAP_SIZE); | |
443 | ||
444 | GAP_SIZE += numdel; | |
445 | ZV -= numdel; | |
446 | Z -= numdel; | |
447 | GPT = from; | |
448 | ||
449 | if (GPT - BEG < beg_unchanged) | |
450 | beg_unchanged = GPT - BEG; | |
451 | if (Z - GPT < end_unchanged) | |
452 | end_unchanged = Z - GPT; | |
453 | ||
454 | signal_after_change (from, numdel, 0); | |
455 | } | |
456 | \f | |
457 | modify_region (start, end) | |
458 | int start, end; | |
459 | { | |
460 | prepare_to_modify_buffer (start, end); | |
461 | ||
462 | if (start - 1 < beg_unchanged || unchanged_modified == MODIFF) | |
463 | beg_unchanged = start - 1; | |
464 | if (Z - end < end_unchanged | |
465 | || unchanged_modified == MODIFF) | |
466 | end_unchanged = Z - end; | |
467 | MODIFF++; | |
468 | } | |
469 | ||
470 | /* Check that it is okay to modify the buffer between START and END. | |
471 | Run the before-change-function, if any. */ | |
472 | ||
473 | prepare_to_modify_buffer (start, end) | |
474 | Lisp_Object start, end; | |
475 | { | |
d427b66a | 476 | if (!NILP (current_buffer->read_only)) |
b45433b3 JB |
477 | Fbarf_if_buffer_read_only (); |
478 | ||
479 | if (check_protected_fields) | |
480 | Fregion_fields (start, end, Qnil, Qt); | |
481 | ||
482 | #ifdef CLASH_DETECTION | |
d427b66a | 483 | if (!NILP (current_buffer->filename) |
b45433b3 JB |
484 | && current_buffer->save_modified >= MODIFF) |
485 | lock_file (current_buffer->filename); | |
486 | #else | |
487 | /* At least warn if this file has changed on disk since it was visited. */ | |
d427b66a | 488 | if (!NILP (current_buffer->filename) |
b45433b3 | 489 | && current_buffer->save_modified >= MODIFF |
d427b66a JB |
490 | && NILP (Fverify_visited_file_modtime (Fcurrent_buffer ())) |
491 | && !NILP (Ffile_exists_p (current_buffer->filename))) | |
b45433b3 JB |
492 | call1 (intern ("ask-user-about-supersession-threat"), |
493 | current_buffer->filename); | |
494 | #endif /* not CLASH_DETECTION */ | |
495 | ||
496 | signal_before_change (start, end); | |
497 | } | |
498 | \f | |
499 | static Lisp_Object | |
500 | before_change_function_restore (value) | |
501 | Lisp_Object value; | |
502 | { | |
503 | Vbefore_change_function = value; | |
504 | } | |
505 | ||
506 | static Lisp_Object | |
507 | after_change_function_restore (value) | |
508 | Lisp_Object value; | |
509 | { | |
510 | Vafter_change_function = value; | |
511 | } | |
512 | ||
513 | /* Signal a change to the buffer immediatly before it happens. | |
514 | START and END are the bounds of the text to be changed, | |
515 | as Lisp objects. */ | |
516 | ||
517 | signal_before_change (start, end) | |
518 | Lisp_Object start, end; | |
519 | { | |
520 | /* If buffer is unmodified, run a special hook for that case. */ | |
521 | if (current_buffer->save_modified >= MODIFF | |
d427b66a | 522 | && !NILP (Vfirst_change_function)) |
b45433b3 JB |
523 | { |
524 | call0 (Vfirst_change_function); | |
525 | } | |
526 | /* Now in any case run the before-change-function if any. */ | |
d427b66a | 527 | if (!NILP (Vbefore_change_function)) |
b45433b3 JB |
528 | { |
529 | int count = specpdl_ptr - specpdl; | |
530 | Lisp_Object function; | |
531 | ||
532 | function = Vbefore_change_function; | |
533 | record_unwind_protect (after_change_function_restore, | |
534 | Vafter_change_function); | |
535 | record_unwind_protect (before_change_function_restore, | |
536 | Vbefore_change_function); | |
537 | Vafter_change_function = Qnil; | |
538 | Vbefore_change_function = Qnil; | |
539 | ||
540 | call2 (function, start, end); | |
541 | unbind_to (count, Qnil); | |
542 | } | |
543 | } | |
544 | ||
545 | /* Signal a change immediatly after it happens. | |
546 | POS is the address of the start of the changed text. | |
547 | LENDEL is the number of characters of the text before the change. | |
548 | (Not the whole buffer; just the part that was changed.) | |
549 | LENINS is the number of characters in the changed text. */ | |
550 | ||
551 | signal_after_change (pos, lendel, lenins) | |
552 | int pos, lendel, lenins; | |
553 | { | |
d427b66a | 554 | if (!NILP (Vafter_change_function)) |
b45433b3 JB |
555 | { |
556 | int count = specpdl_ptr - specpdl; | |
557 | Lisp_Object function; | |
558 | function = Vafter_change_function; | |
559 | ||
560 | record_unwind_protect (after_change_function_restore, | |
561 | Vafter_change_function); | |
562 | record_unwind_protect (before_change_function_restore, | |
563 | Vbefore_change_function); | |
564 | Vafter_change_function = Qnil; | |
565 | Vbefore_change_function = Qnil; | |
566 | ||
567 | call3 (function, make_number (pos), make_number (pos + lenins), | |
568 | make_number (lendel)); | |
569 | unbind_to (count, Qnil); | |
570 | } | |
571 | } |