Commit | Line | Data |
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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" | |
679194a6 | 23 | #include "intervals.h" |
b45433b3 JB |
24 | #include "buffer.h" |
25 | #include "window.h" | |
26 | ||
27 | /* Nonzero means don't allow protected fields to be modified. */ | |
28 | ||
29 | extern int check_protected_fields; | |
30 | ||
31 | /* Move gap to position `pos'. | |
32 | Note that this can quit! */ | |
33 | ||
34 | move_gap (pos) | |
35 | int pos; | |
36 | { | |
37 | if (pos < GPT) | |
38 | gap_left (pos, 0); | |
39 | else if (pos > GPT) | |
40 | gap_right (pos); | |
41 | } | |
42 | ||
43 | /* Move the gap to POS, which is less than the current GPT. | |
44 | If NEWGAP is nonzero, then don't update beg_unchanged and end_unchanged. */ | |
45 | ||
46 | gap_left (pos, newgap) | |
47 | register int pos; | |
48 | int newgap; | |
49 | { | |
50 | register unsigned char *to, *from; | |
51 | register int i; | |
52 | int new_s1; | |
53 | ||
54 | pos--; | |
55 | ||
56 | if (!newgap) | |
57 | { | |
58 | if (unchanged_modified == MODIFF) | |
59 | { | |
60 | beg_unchanged = pos; | |
61 | end_unchanged = Z - pos - 1; | |
62 | } | |
63 | else | |
64 | { | |
65 | if (Z - GPT < end_unchanged) | |
66 | end_unchanged = Z - GPT; | |
67 | if (pos < beg_unchanged) | |
68 | beg_unchanged = pos; | |
69 | } | |
70 | } | |
71 | ||
72 | i = GPT; | |
73 | to = GAP_END_ADDR; | |
74 | from = GPT_ADDR; | |
75 | new_s1 = GPT - BEG; | |
76 | ||
77 | /* Now copy the characters. To move the gap down, | |
78 | copy characters up. */ | |
79 | ||
80 | while (1) | |
81 | { | |
82 | /* I gets number of characters left to copy. */ | |
83 | i = new_s1 - pos; | |
84 | if (i == 0) | |
85 | break; | |
86 | /* If a quit is requested, stop copying now. | |
87 | Change POS to be where we have actually moved the gap to. */ | |
88 | if (QUITP) | |
89 | { | |
90 | pos = new_s1; | |
91 | break; | |
92 | } | |
93 | /* Move at most 32000 chars before checking again for a quit. */ | |
94 | if (i > 32000) | |
95 | i = 32000; | |
96 | #ifdef GAP_USE_BCOPY | |
97 | if (i >= 128 | |
98 | /* bcopy is safe if the two areas of memory do not overlap | |
99 | or on systems where bcopy is always safe for moving upward. */ | |
100 | && (BCOPY_UPWARD_SAFE | |
101 | || to - from >= 128)) | |
102 | { | |
103 | /* If overlap is not safe, avoid it by not moving too many | |
104 | characters at once. */ | |
105 | if (!BCOPY_UPWARD_SAFE && i > to - from) | |
106 | i = to - from; | |
107 | new_s1 -= i; | |
108 | from -= i, to -= i; | |
109 | bcopy (from, to, i); | |
110 | } | |
111 | else | |
112 | #endif | |
113 | { | |
114 | new_s1 -= i; | |
115 | while (--i >= 0) | |
116 | *--to = *--from; | |
117 | } | |
118 | } | |
119 | ||
120 | /* Adjust markers, and buffer data structure, to put the gap at POS. | |
121 | POS is where the loop above stopped, which may be what was specified | |
122 | or may be where a quit was detected. */ | |
123 | adjust_markers (pos + 1, GPT, GAP_SIZE); | |
124 | GPT = pos + 1; | |
125 | QUIT; | |
126 | } | |
127 | ||
128 | gap_right (pos) | |
129 | register int pos; | |
130 | { | |
131 | register unsigned char *to, *from; | |
132 | register int i; | |
133 | int new_s1; | |
134 | ||
135 | pos--; | |
136 | ||
137 | if (unchanged_modified == MODIFF) | |
138 | { | |
139 | beg_unchanged = pos; | |
140 | end_unchanged = Z - pos - 1; | |
141 | } | |
142 | else | |
143 | { | |
144 | if (Z - pos - 1 < end_unchanged) | |
145 | end_unchanged = Z - pos - 1; | |
146 | if (GPT - BEG < beg_unchanged) | |
147 | beg_unchanged = GPT - BEG; | |
148 | } | |
149 | ||
150 | i = GPT; | |
151 | from = GAP_END_ADDR; | |
152 | to = GPT_ADDR; | |
153 | new_s1 = GPT - 1; | |
154 | ||
155 | /* Now copy the characters. To move the gap up, | |
156 | copy characters down. */ | |
157 | ||
158 | while (1) | |
159 | { | |
160 | /* I gets number of characters left to copy. */ | |
161 | i = pos - new_s1; | |
162 | if (i == 0) | |
163 | break; | |
164 | /* If a quit is requested, stop copying now. | |
165 | Change POS to be where we have actually moved the gap to. */ | |
166 | if (QUITP) | |
167 | { | |
168 | pos = new_s1; | |
169 | break; | |
170 | } | |
171 | /* Move at most 32000 chars before checking again for a quit. */ | |
172 | if (i > 32000) | |
173 | i = 32000; | |
174 | #ifdef GAP_USE_BCOPY | |
175 | if (i >= 128 | |
176 | /* bcopy is safe if the two areas of memory do not overlap | |
177 | or on systems where bcopy is always safe for moving downward. */ | |
178 | && (BCOPY_DOWNWARD_SAFE | |
179 | || from - to >= 128)) | |
180 | { | |
181 | /* If overlap is not safe, avoid it by not moving too many | |
182 | characters at once. */ | |
183 | if (!BCOPY_DOWNWARD_SAFE && i > from - to) | |
184 | i = from - to; | |
185 | new_s1 += i; | |
186 | bcopy (from, to, i); | |
187 | from += i, to += i; | |
188 | } | |
189 | else | |
190 | #endif | |
191 | { | |
192 | new_s1 += i; | |
193 | while (--i >= 0) | |
194 | *to++ = *from++; | |
195 | } | |
196 | } | |
197 | ||
198 | adjust_markers (GPT + GAP_SIZE, pos + 1 + GAP_SIZE, - GAP_SIZE); | |
199 | GPT = pos + 1; | |
200 | QUIT; | |
201 | } | |
202 | ||
203 | /* Add `amount' to the position of every marker in the current buffer | |
204 | whose current position is between `from' (exclusive) and `to' (inclusive). | |
205 | Also, any markers past the outside of that interval, in the direction | |
206 | of adjustment, are first moved back to the near end of the interval | |
207 | and then adjusted by `amount'. */ | |
208 | ||
209 | adjust_markers (from, to, amount) | |
210 | register int from, to, amount; | |
211 | { | |
212 | Lisp_Object marker; | |
213 | register struct Lisp_Marker *m; | |
214 | register int mpos; | |
215 | ||
216 | marker = current_buffer->markers; | |
217 | ||
d427b66a | 218 | while (!NILP (marker)) |
b45433b3 JB |
219 | { |
220 | m = XMARKER (marker); | |
221 | mpos = m->bufpos; | |
222 | if (amount > 0) | |
223 | { | |
224 | if (mpos > to && mpos < to + amount) | |
225 | mpos = to + amount; | |
226 | } | |
227 | else | |
228 | { | |
229 | if (mpos > from + amount && mpos <= from) | |
230 | mpos = from + amount; | |
231 | } | |
232 | if (mpos > from && mpos <= to) | |
233 | mpos += amount; | |
234 | m->bufpos = mpos; | |
235 | marker = m->chain; | |
236 | } | |
237 | } | |
238 | \f | |
239 | /* Make the gap INCREMENT characters longer. */ | |
240 | ||
241 | make_gap (increment) | |
242 | int increment; | |
243 | { | |
244 | unsigned char *result; | |
245 | Lisp_Object tem; | |
246 | int real_gap_loc; | |
247 | int old_gap_size; | |
248 | ||
249 | /* If we have to get more space, get enough to last a while. */ | |
250 | increment += 2000; | |
251 | ||
252 | result = BUFFER_REALLOC (BEG_ADDR, (Z - BEG + GAP_SIZE + increment)); | |
253 | if (result == 0) | |
254 | memory_full (); | |
255 | BEG_ADDR = result; | |
256 | ||
257 | /* Prevent quitting in move_gap. */ | |
258 | tem = Vinhibit_quit; | |
259 | Vinhibit_quit = Qt; | |
260 | ||
261 | real_gap_loc = GPT; | |
262 | old_gap_size = GAP_SIZE; | |
263 | ||
264 | /* Call the newly allocated space a gap at the end of the whole space. */ | |
265 | GPT = Z + GAP_SIZE; | |
266 | GAP_SIZE = increment; | |
267 | ||
268 | /* Move the new gap down to be consecutive with the end of the old one. | |
269 | This adjusts the markers properly too. */ | |
270 | gap_left (real_gap_loc + old_gap_size, 1); | |
271 | ||
272 | /* Now combine the two into one large gap. */ | |
273 | GAP_SIZE += old_gap_size; | |
274 | GPT = real_gap_loc; | |
275 | ||
276 | Vinhibit_quit = tem; | |
277 | } | |
278 | \f | |
279 | /* Insert a string of specified length before point. | |
280 | DO NOT use this for the contents of a Lisp string! | |
281 | prepare_to_modify_buffer could relocate the string. */ | |
282 | ||
283 | insert (string, length) | |
284 | register unsigned char *string; | |
285 | register length; | |
286 | { | |
287 | register Lisp_Object temp; | |
288 | ||
289 | if (length < 1) | |
290 | return; | |
291 | ||
292 | /* Make sure point-max won't overflow after this insertion. */ | |
293 | XSET (temp, Lisp_Int, length + Z); | |
294 | if (length + Z != XINT (temp)) | |
295 | error ("maximum buffer size exceeded"); | |
296 | ||
297 | prepare_to_modify_buffer (point, point); | |
298 | ||
299 | if (point != GPT) | |
300 | move_gap (point); | |
301 | if (GAP_SIZE < length) | |
302 | make_gap (length - GAP_SIZE); | |
303 | ||
304 | record_insert (point, length); | |
305 | MODIFF++; | |
306 | ||
307 | bcopy (string, GPT_ADDR, length); | |
308 | ||
679194a6 JA |
309 | /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */ |
310 | offset_intervals (current_buffer, point, length); | |
311 | ||
b45433b3 JB |
312 | GAP_SIZE -= length; |
313 | GPT += length; | |
314 | ZV += length; | |
315 | Z += length; | |
316 | SET_PT (point + length); | |
317 | ||
318 | signal_after_change (point-length, 0, length); | |
319 | } | |
320 | ||
679194a6 JA |
321 | /* Insert the part of the text of STRING, a Lisp object assumed to be |
322 | of type string, consisting of the LENGTH characters starting at | |
323 | position POS. If the text of STRING has properties, they are absorbed | |
324 | into the buffer. | |
325 | ||
326 | It does not work to use `insert' for this, because a GC could happen | |
7e1ea612 JB |
327 | before we bcopy the stuff into the buffer, and relocate the string |
328 | without insert noticing. */ | |
679194a6 | 329 | |
b45433b3 JB |
330 | insert_from_string (string, pos, length) |
331 | Lisp_Object string; | |
332 | register int pos, length; | |
333 | { | |
334 | register Lisp_Object temp; | |
335 | struct gcpro gcpro1; | |
336 | ||
337 | if (length < 1) | |
338 | return; | |
339 | ||
340 | /* Make sure point-max won't overflow after this insertion. */ | |
341 | XSET (temp, Lisp_Int, length + Z); | |
342 | if (length + Z != XINT (temp)) | |
343 | error ("maximum buffer size exceeded"); | |
344 | ||
345 | GCPRO1 (string); | |
346 | prepare_to_modify_buffer (point, point); | |
347 | ||
348 | if (point != GPT) | |
349 | move_gap (point); | |
350 | if (GAP_SIZE < length) | |
351 | make_gap (length - GAP_SIZE); | |
352 | ||
353 | record_insert (point, length); | |
354 | MODIFF++; | |
355 | UNGCPRO; | |
356 | ||
357 | bcopy (XSTRING (string)->data, GPT_ADDR, length); | |
358 | ||
679194a6 JA |
359 | /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */ |
360 | offset_intervals (current_buffer, point, length); | |
361 | ||
b45433b3 JB |
362 | GAP_SIZE -= length; |
363 | GPT += length; | |
364 | ZV += length; | |
365 | Z += length; | |
679194a6 JA |
366 | |
367 | /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */ | |
368 | graft_intervals_into_buffer (XSTRING (string)->intervals, point, | |
369 | current_buffer); | |
370 | ||
d427b66a | 371 | SET_PT (point + length); |
b45433b3 JB |
372 | |
373 | signal_after_change (point-length, 0, length); | |
374 | } | |
375 | ||
376 | /* Insert the character C before point */ | |
377 | ||
378 | void | |
379 | insert_char (c) | |
380 | unsigned char c; | |
381 | { | |
382 | insert (&c, 1); | |
383 | } | |
384 | ||
385 | /* Insert the null-terminated string S before point */ | |
386 | ||
387 | void | |
388 | insert_string (s) | |
389 | char *s; | |
390 | { | |
391 | insert (s, strlen (s)); | |
392 | } | |
393 | ||
394 | /* Like `insert' except that all markers pointing at the place where | |
395 | the insertion happens are adjusted to point after it. | |
396 | Don't use this function to insert part of a Lisp string, | |
397 | since gc could happen and relocate it. */ | |
398 | ||
399 | insert_before_markers (string, length) | |
400 | unsigned char *string; | |
401 | register int length; | |
402 | { | |
403 | register int opoint = point; | |
404 | insert (string, length); | |
405 | adjust_markers (opoint - 1, opoint, length); | |
406 | } | |
407 | ||
408 | /* Insert part of a Lisp string, relocating markers after. */ | |
409 | ||
410 | insert_from_string_before_markers (string, pos, length) | |
411 | Lisp_Object string; | |
412 | register int pos, length; | |
413 | { | |
414 | register int opoint = point; | |
415 | insert_from_string (string, pos, length); | |
416 | adjust_markers (opoint - 1, opoint, length); | |
417 | } | |
418 | \f | |
419 | /* Delete characters in current buffer | |
420 | from FROM up to (but not including) TO. */ | |
421 | ||
422 | del_range (from, to) | |
423 | register int from, to; | |
424 | { | |
425 | register int numdel; | |
426 | ||
427 | /* Make args be valid */ | |
428 | if (from < BEGV) | |
429 | from = BEGV; | |
430 | if (to > ZV) | |
431 | to = ZV; | |
432 | ||
433 | if ((numdel = to - from) <= 0) | |
434 | return; | |
435 | ||
436 | /* Make sure the gap is somewhere in or next to what we are deleting. */ | |
437 | if (from > GPT) | |
438 | gap_right (from); | |
439 | if (to < GPT) | |
440 | gap_left (to, 0); | |
441 | ||
442 | prepare_to_modify_buffer (from, to); | |
443 | ||
be09561e RS |
444 | record_delete (from, numdel); |
445 | MODIFF++; | |
446 | ||
679194a6 JA |
447 | /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */ |
448 | offset_intervals (current_buffer, point, - numdel); | |
449 | ||
b45433b3 JB |
450 | /* Relocate point as if it were a marker. */ |
451 | if (from < point) | |
452 | { | |
453 | if (point < to) | |
454 | SET_PT (from); | |
455 | else | |
456 | SET_PT (point - numdel); | |
457 | } | |
458 | ||
b45433b3 JB |
459 | /* Relocate all markers pointing into the new, larger gap |
460 | to point at the end of the text before the gap. */ | |
461 | adjust_markers (to + GAP_SIZE, to + GAP_SIZE, - numdel - GAP_SIZE); | |
462 | ||
463 | GAP_SIZE += numdel; | |
464 | ZV -= numdel; | |
465 | Z -= numdel; | |
466 | GPT = from; | |
467 | ||
468 | if (GPT - BEG < beg_unchanged) | |
469 | beg_unchanged = GPT - BEG; | |
470 | if (Z - GPT < end_unchanged) | |
471 | end_unchanged = Z - GPT; | |
472 | ||
473 | signal_after_change (from, numdel, 0); | |
474 | } | |
475 | \f | |
476 | modify_region (start, end) | |
477 | int start, end; | |
478 | { | |
479 | prepare_to_modify_buffer (start, end); | |
480 | ||
481 | if (start - 1 < beg_unchanged || unchanged_modified == MODIFF) | |
482 | beg_unchanged = start - 1; | |
483 | if (Z - end < end_unchanged | |
484 | || unchanged_modified == MODIFF) | |
485 | end_unchanged = Z - end; | |
486 | MODIFF++; | |
487 | } | |
488 | ||
489 | /* Check that it is okay to modify the buffer between START and END. | |
679194a6 JA |
490 | Run the before-change-function, if any. If intervals are in use, |
491 | verify that the text to be modified is not read-only, and call | |
492 | any modification properties the text may have. */ | |
b45433b3 JB |
493 | |
494 | prepare_to_modify_buffer (start, end) | |
495 | Lisp_Object start, end; | |
496 | { | |
d427b66a | 497 | if (!NILP (current_buffer->read_only)) |
b45433b3 JB |
498 | Fbarf_if_buffer_read_only (); |
499 | ||
679194a6 | 500 | #if 0 /* Superceded by interval code */ |
b45433b3 JB |
501 | if (check_protected_fields) |
502 | Fregion_fields (start, end, Qnil, Qt); | |
679194a6 JA |
503 | #endif |
504 | ||
505 | /* Only defined if Emacs is compiled with USE_TEXT_PROPERTIES */ | |
506 | verify_interval_modification (current_buffer, start, end); | |
b45433b3 JB |
507 | |
508 | #ifdef CLASH_DETECTION | |
d427b66a | 509 | if (!NILP (current_buffer->filename) |
b45433b3 JB |
510 | && current_buffer->save_modified >= MODIFF) |
511 | lock_file (current_buffer->filename); | |
512 | #else | |
513 | /* At least warn if this file has changed on disk since it was visited. */ | |
d427b66a | 514 | if (!NILP (current_buffer->filename) |
b45433b3 | 515 | && current_buffer->save_modified >= MODIFF |
d427b66a JB |
516 | && NILP (Fverify_visited_file_modtime (Fcurrent_buffer ())) |
517 | && !NILP (Ffile_exists_p (current_buffer->filename))) | |
b45433b3 JB |
518 | call1 (intern ("ask-user-about-supersession-threat"), |
519 | current_buffer->filename); | |
520 | #endif /* not CLASH_DETECTION */ | |
521 | ||
522 | signal_before_change (start, end); | |
523 | } | |
524 | \f | |
525 | static Lisp_Object | |
526 | before_change_function_restore (value) | |
527 | Lisp_Object value; | |
528 | { | |
529 | Vbefore_change_function = value; | |
530 | } | |
531 | ||
532 | static Lisp_Object | |
533 | after_change_function_restore (value) | |
534 | Lisp_Object value; | |
535 | { | |
536 | Vafter_change_function = value; | |
537 | } | |
538 | ||
539 | /* Signal a change to the buffer immediatly before it happens. | |
540 | START and END are the bounds of the text to be changed, | |
541 | as Lisp objects. */ | |
542 | ||
543 | signal_before_change (start, end) | |
544 | Lisp_Object start, end; | |
545 | { | |
546 | /* If buffer is unmodified, run a special hook for that case. */ | |
547 | if (current_buffer->save_modified >= MODIFF | |
dbc4e1c1 JB |
548 | && !NILP (Vfirst_change_hook) |
549 | && !NILP (Vrun_hooks)) | |
550 | call1 (Vrun_hooks, Qfirst_change_hook); | |
551 | ||
b45433b3 | 552 | /* Now in any case run the before-change-function if any. */ |
d427b66a | 553 | if (!NILP (Vbefore_change_function)) |
b45433b3 JB |
554 | { |
555 | int count = specpdl_ptr - specpdl; | |
556 | Lisp_Object function; | |
557 | ||
558 | function = Vbefore_change_function; | |
559 | record_unwind_protect (after_change_function_restore, | |
560 | Vafter_change_function); | |
561 | record_unwind_protect (before_change_function_restore, | |
562 | Vbefore_change_function); | |
563 | Vafter_change_function = Qnil; | |
564 | Vbefore_change_function = Qnil; | |
565 | ||
566 | call2 (function, start, end); | |
567 | unbind_to (count, Qnil); | |
568 | } | |
569 | } | |
570 | ||
571 | /* Signal a change immediatly after it happens. | |
572 | POS is the address of the start of the changed text. | |
573 | LENDEL is the number of characters of the text before the change. | |
574 | (Not the whole buffer; just the part that was changed.) | |
575 | LENINS is the number of characters in the changed text. */ | |
576 | ||
577 | signal_after_change (pos, lendel, lenins) | |
578 | int pos, lendel, lenins; | |
579 | { | |
d427b66a | 580 | if (!NILP (Vafter_change_function)) |
b45433b3 JB |
581 | { |
582 | int count = specpdl_ptr - specpdl; | |
583 | Lisp_Object function; | |
584 | function = Vafter_change_function; | |
585 | ||
586 | record_unwind_protect (after_change_function_restore, | |
587 | Vafter_change_function); | |
588 | record_unwind_protect (before_change_function_restore, | |
589 | Vbefore_change_function); | |
590 | Vafter_change_function = Qnil; | |
591 | Vbefore_change_function = Qnil; | |
592 | ||
593 | call3 (function, make_number (pos), make_number (pos + lenins), | |
594 | make_number (lendel)); | |
595 | unbind_to (count, Qnil); | |
596 | } | |
597 | } |