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comparison src/marker.c @ 428:3ecd8885ac67 r21-2-22

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Import from CVS: tag r21-2-22
author cvs
date Mon, 13 Aug 2007 11:28:15 +0200
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427:0a0253eac470 428:3ecd8885ac67
1 /* Markers: examining, setting and killing.
2 Copyright (C) 1985, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
3
4 This file is part of XEmacs.
5
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
9 later version.
10
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21 /* Synched up with: FSF 19.30. */
22
23 /* This file has been Mule-ized. */
24
25 /* Note that markers are currently kept in an unordered list.
26 This means that marker operations may be inefficient if
27 there are a bunch of markers in the buffer. This probably
28 won't have a significant impact on redisplay (which uses
29 markers), but if it does, it wouldn't be too hard to change
30 to an ordered gap array. (Just copy the code from extents.c.)
31 */
32
33 #include <config.h>
34 #include "lisp.h"
35
36 #include "buffer.h"
37
38 static Lisp_Object
39 mark_marker (Lisp_Object obj)
40 {
41 struct Lisp_Marker *marker = XMARKER (obj);
42 Lisp_Object buf;
43 /* DO NOT mark through the marker's chain.
44 The buffer's markers chain does not preserve markers from gc;
45 Instead, markers are removed from the chain when they are freed
46 by gc.
47 */
48 if (!marker->buffer)
49 return (Qnil);
50
51 XSETBUFFER (buf, marker->buffer);
52 return (buf);
53 }
54
55 static void
56 print_marker (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
57 {
58 struct Lisp_Marker *marker = XMARKER (obj);
59 char buf[200];
60
61 if (print_readably)
62 error ("printing unreadable object #<marker 0x%lx>", (long) marker);
63
64 write_c_string (GETTEXT ("#<marker "), printcharfun);
65 if (!marker->buffer)
66 write_c_string (GETTEXT ("in no buffer"), printcharfun);
67 else
68 {
69 sprintf (buf, "at %ld in ", (long) marker_position (obj));
70 write_c_string (buf, printcharfun);
71 print_internal (marker->buffer->name, printcharfun, 0);
72 }
73 sprintf (buf, " 0x%lx>", (long) marker);
74 write_c_string (buf, printcharfun);
75 }
76
77 static int
78 marker_equal (Lisp_Object obj1, Lisp_Object obj2, int depth)
79 {
80 struct Lisp_Marker *marker1 = XMARKER (obj1);
81 struct Lisp_Marker *marker2 = XMARKER (obj2);
82
83 return ((marker1->buffer == marker2->buffer) &&
84 (marker1->memind == marker2->memind ||
85 /* All markers pointing nowhere are equal */
86 !marker1->buffer));
87 }
88
89 static unsigned long
90 marker_hash (Lisp_Object obj, int depth)
91 {
92 unsigned long hash = (unsigned long) XMARKER (obj)->buffer;
93 if (hash)
94 hash = HASH2 (hash, XMARKER (obj)->memind);
95 return hash;
96 }
97
98 static const struct lrecord_description marker_description[] = {
99 { XD_LISP_OBJECT, offsetof(struct Lisp_Marker, next), 3 },
100 { XD_END }
101 };
102
103 DEFINE_BASIC_LRECORD_IMPLEMENTATION ("marker", marker,
104 mark_marker, print_marker, 0,
105 marker_equal, marker_hash, marker_description,
106 struct Lisp_Marker);
107
108 /* Operations on markers. */
109
110 DEFUN ("marker-buffer", Fmarker_buffer, 1, 1, 0, /*
111 Return the buffer that MARKER points into, or nil if none.
112 Return nil if MARKER points into a dead buffer or doesn't point anywhere.
113 */
114 (marker))
115 {
116 struct buffer *buf;
117 CHECK_MARKER (marker);
118 /* Return marker's buffer only if it is not dead. */
119 if ((buf = XMARKER (marker)->buffer) && BUFFER_LIVE_P (buf))
120 {
121 Lisp_Object buffer;
122 XSETBUFFER (buffer, buf);
123 return buffer;
124 }
125 return Qnil;
126 }
127
128 DEFUN ("marker-position", Fmarker_position, 1, 1, 0, /*
129 Return the position MARKER points at, as a character number.
130 Return `nil' if marker doesn't point anywhere.
131 */
132 (marker))
133 {
134 CHECK_MARKER (marker);
135 return XMARKER (marker)->buffer ? make_int (marker_position (marker)) : Qnil;
136 }
137
138 #if 0 /* useful debugging function */
139
140 static void
141 check_marker_circularities (struct buffer *buf)
142 {
143 struct Lisp_Marker *tortoise, *hare;
144
145 tortoise = BUF_MARKERS (buf);
146 hare = tortoise;
147
148 if (!tortoise)
149 return;
150
151 while (1)
152 {
153 assert (hare->buffer == buf);
154 hare = hare->next;
155 if (!hare)
156 return;
157 assert (hare->buffer == buf);
158 hare = hare->next;
159 if (!hare)
160 return;
161 tortoise = tortoise->next;
162 assert (tortoise != hare);
163 }
164 }
165
166 #endif
167
168 static Lisp_Object
169 set_marker_internal (Lisp_Object marker, Lisp_Object pos, Lisp_Object buffer,
170 int restricted_p)
171 {
172 Bufpos charno;
173 struct buffer *b;
174 struct Lisp_Marker *m;
175 int point_p;
176
177 CHECK_MARKER (marker);
178
179 point_p = POINT_MARKER_P (marker);
180
181 /* If position is nil or a marker that points nowhere,
182 make this marker point nowhere. */
183 if (NILP (pos) ||
184 (MARKERP (pos) && !XMARKER (pos)->buffer))
185 {
186 if (point_p)
187 signal_simple_error ("Can't make point-marker point nowhere",
188 marker);
189 if (XMARKER (marker)->buffer)
190 unchain_marker (marker);
191 return marker;
192 }
193
194 CHECK_INT_COERCE_MARKER (pos);
195 if (NILP (buffer))
196 b = current_buffer;
197 else
198 {
199 CHECK_BUFFER (buffer);
200 b = XBUFFER (buffer);
201 /* If buffer is dead, set marker to point nowhere. */
202 if (!BUFFER_LIVE_P (XBUFFER (buffer)))
203 {
204 if (point_p)
205 signal_simple_error
206 ("Can't move point-marker in a killed buffer", marker);
207 if (XMARKER (marker)->buffer)
208 unchain_marker (marker);
209 return marker;
210 }
211 }
212
213 charno = XINT (pos);
214 m = XMARKER (marker);
215
216 if (restricted_p)
217 {
218 if (charno < BUF_BEGV (b)) charno = BUF_BEGV (b);
219 if (charno > BUF_ZV (b)) charno = BUF_ZV (b);
220 }
221 else
222 {
223 if (charno < BUF_BEG (b)) charno = BUF_BEG (b);
224 if (charno > BUF_Z (b)) charno = BUF_Z (b);
225 }
226
227 if (point_p)
228 {
229 #ifndef moving_point_by_moving_its_marker_is_a_bug
230 BUF_SET_PT (b, charno); /* this will move the marker */
231 #else /* It's not a feature, so it must be a bug */
232 signal_simple_error ("DEBUG: attempt to move point via point-marker",
233 marker);
234 #endif
235 }
236 else
237 {
238 m->memind = bufpos_to_memind (b, charno);
239 }
240
241 if (m->buffer != b)
242 {
243 if (point_p)
244 signal_simple_error ("Can't change buffer of point-marker", marker);
245 if (m->buffer != 0)
246 unchain_marker (marker);
247 m->buffer = b;
248 marker_next (m) = BUF_MARKERS (b);
249 marker_prev (m) = 0;
250 if (BUF_MARKERS (b))
251 marker_prev (BUF_MARKERS (b)) = m;
252 BUF_MARKERS (b) = m;
253 }
254
255 return marker;
256 }
257
258
259 DEFUN ("set-marker", Fset_marker, 2, 3, 0, /*
260 Position MARKER before character number NUMBER in BUFFER.
261 BUFFER defaults to the current buffer.
262 If NUMBER is nil, makes marker point nowhere.
263 Then it no longer slows down editing in any buffer.
264 If this marker was returned by (point-marker t), then changing its position
265 moves point. You cannot change its buffer or make it point nowhere.
266 Returns MARKER.
267 */
268 (marker, number, buffer))
269 {
270 return set_marker_internal (marker, number, buffer, 0);
271 }
272
273
274 /* This version of Fset_marker won't let the position
275 be outside the visible part. */
276 Lisp_Object
277 set_marker_restricted (Lisp_Object marker, Lisp_Object pos, Lisp_Object buffer)
278 {
279 return set_marker_internal (marker, pos, buffer, 1);
280 }
281
282
283 /* This is called during garbage collection,
284 so we must be careful to ignore and preserve mark bits,
285 including those in chain fields of markers. */
286
287 void
288 unchain_marker (Lisp_Object m)
289 {
290 struct Lisp_Marker *marker = XMARKER (m);
291 struct buffer *b = marker->buffer;
292
293 if (b == 0)
294 return;
295
296 #ifdef ERROR_CHECK_GC
297 assert (BUFFER_LIVE_P (b));
298 #endif
299
300 if (marker_next (marker))
301 marker_prev (marker_next (marker)) = marker_prev (marker);
302 if (marker_prev (marker))
303 marker_next (marker_prev (marker)) = marker_next (marker);
304 else
305 BUF_MARKERS (b) = marker_next (marker);
306
307 #ifdef ERROR_CHECK_GC
308 assert (marker != XMARKER (b->point_marker));
309 #endif
310
311 marker->buffer = 0;
312 }
313
314 Bytind
315 bi_marker_position (Lisp_Object marker)
316 {
317 struct Lisp_Marker *m = XMARKER (marker);
318 struct buffer *buf = m->buffer;
319 Bytind pos;
320
321 if (!buf)
322 error ("Marker does not point anywhere");
323
324 /* FSF claims that marker indices could end up denormalized, i.e.
325 in the gap. This is way bogus if it ever happens, and means
326 something fucked up elsewhere. Since I've overhauled all this
327 shit, I don't think this can happen. In any case, the following
328 macro has an assert() in it that will catch these denormalized
329 positions. */
330 pos = memind_to_bytind (buf, m->memind);
331
332 #ifdef ERROR_CHECK_BUFPOS
333 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
334 abort ();
335 #endif
336
337 return pos;
338 }
339
340 Bufpos
341 marker_position (Lisp_Object marker)
342 {
343 struct buffer *buf = XMARKER (marker)->buffer;
344
345 if (!buf)
346 error ("Marker does not point anywhere");
347
348 return bytind_to_bufpos (buf, bi_marker_position (marker));
349 }
350
351 void
352 set_bi_marker_position (Lisp_Object marker, Bytind pos)
353 {
354 struct Lisp_Marker *m = XMARKER (marker);
355 struct buffer *buf = m->buffer;
356
357 if (!buf)
358 error ("Marker does not point anywhere");
359
360 #ifdef ERROR_CHECK_BUFPOS
361 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
362 abort ();
363 #endif
364
365 m->memind = bytind_to_memind (buf, pos);
366 }
367
368 void
369 set_marker_position (Lisp_Object marker, Bufpos pos)
370 {
371 struct buffer *buf = XMARKER (marker)->buffer;
372
373 if (!buf)
374 error ("Marker does not point anywhere");
375
376 set_bi_marker_position (marker, bufpos_to_bytind (buf, pos));
377 }
378
379 static Lisp_Object
380 copy_marker_1 (Lisp_Object marker, Lisp_Object type, int noseeum)
381 {
382 REGISTER Lisp_Object new;
383
384 while (1)
385 {
386 if (INTP (marker) || MARKERP (marker))
387 {
388 if (noseeum)
389 new = noseeum_make_marker ();
390 else
391 new = Fmake_marker ();
392 Fset_marker (new, marker,
393 (MARKERP (marker) ? Fmarker_buffer (marker) : Qnil));
394 XMARKER (new)->insertion_type = !NILP (type);
395 return new;
396 }
397 else
398 marker = wrong_type_argument (Qinteger_or_marker_p, marker);
399 }
400
401 RETURN_NOT_REACHED (Qnil) /* not reached */
402 }
403
404 DEFUN ("copy-marker", Fcopy_marker, 1, 2, 0, /*
405 Return a new marker pointing at the same place as MARKER.
406 If argument is a number, makes a new marker pointing
407 at that position in the current buffer.
408 The optional argument TYPE specifies the insertion type of the new marker;
409 see `marker-insertion-type'.
410 */
411 (marker, type))
412 {
413 return copy_marker_1 (marker, type, 0);
414 }
415
416 Lisp_Object
417 noseeum_copy_marker (Lisp_Object marker, Lisp_Object type)
418 {
419 return copy_marker_1 (marker, type, 1);
420 }
421
422 DEFUN ("marker-insertion-type", Fmarker_insertion_type, 1, 1, 0, /*
423 Return insertion type of MARKER: t if it stays after inserted text.
424 nil means the marker stays before text inserted there.
425 */
426 (marker))
427 {
428 CHECK_MARKER (marker);
429 return XMARKER (marker)->insertion_type ? Qt : Qnil;
430 }
431
432 DEFUN ("set-marker-insertion-type", Fset_marker_insertion_type, 2, 2, 0, /*
433 Set the insertion-type of MARKER to TYPE.
434 If TYPE is t, it means the marker advances when you insert text at it.
435 If TYPE is nil, it means the marker stays behind when you insert text at it.
436 */
437 (marker, type))
438 {
439 CHECK_MARKER (marker);
440
441 XMARKER (marker)->insertion_type = ! NILP (type);
442 return type;
443 }
444
445 /* #### What is the possible use of this? It looks quite useless to
446 me, because there is no way to find *which* markers are positioned
447 at POSITION. Additional bogosity bonus: (buffer-has-markers-at
448 (point)) will always return t because of the `point-marker'. The
449 same goes for the position of mark. Bletch!
450
451 Someone should discuss this with Stallman, but I don't have the
452 stomach. In fact, this function sucks so badly that I'm disabling
453 it by default (although I've debugged it). If you want to use it,
454 use extents instead. --hniksic */
455 #if 0
456 xxDEFUN ("buffer-has-markers-at", Fbuffer_has_markers_at, 1, 1, 0, /*
457 Return t if there are markers pointing at POSITION in the current buffer.
458 */
459 (position))
460 {
461 struct Lisp_Marker *marker;
462 Memind pos;
463
464 /* A small optimization trick: convert POS to memind now, rather
465 than converting every marker's memory index to bufpos. */
466 pos = bytind_to_memind (current_buffer,
467 get_buffer_pos_byte (current_buffer, position,
468 GB_COERCE_RANGE));
469
470 for (marker = BUF_MARKERS (current_buffer);
471 marker;
472 marker = marker_next (marker))
473 {
474 /* We use marker->memind, so we don't have to go through the
475 unwieldy operation of creating a Lisp_Object for
476 marker_position() every time around. */
477 if (marker->memind == pos)
478 return Qt;
479 }
480
481 return Qnil;
482 }
483 #endif /* 0 */
484
485 #ifdef MEMORY_USAGE_STATS
486
487 int
488 compute_buffer_marker_usage (struct buffer *b, struct overhead_stats *ovstats)
489 {
490 struct Lisp_Marker *m;
491 int total = 0;
492 int overhead;
493
494 for (m = BUF_MARKERS (b); m; m = m->next)
495 total += sizeof (struct Lisp_Marker);
496 ovstats->was_requested += total;
497 overhead = fixed_type_block_overhead (total);
498 /* #### claiming this is all malloc overhead is not really right,
499 but it has to go somewhere. */
500 ovstats->malloc_overhead += overhead;
501 return total + overhead;
502 }
503
504 #endif /* MEMORY_USAGE_STATS */
505
506
507 void
508 syms_of_marker (void)
509 {
510 DEFSUBR (Fmarker_position);
511 DEFSUBR (Fmarker_buffer);
512 DEFSUBR (Fset_marker);
513 DEFSUBR (Fcopy_marker);
514 DEFSUBR (Fmarker_insertion_type);
515 DEFSUBR (Fset_marker_insertion_type);
516 #if 0 /* FSFmacs crock */
517 DEFSUBR (Fbuffer_has_markers_at);
518 #endif
519 }
520
521 void
522 init_buffer_markers (struct buffer *b)
523 {
524 Lisp_Object buf;
525
526 XSETBUFFER (buf, b);
527 b->mark = Fmake_marker ();
528 BUF_MARKERS (b) = 0;
529 b->point_marker = Fmake_marker ();
530 Fset_marker (b->point_marker,
531 /* For indirect buffers, point is already set. */
532 b->base_buffer ? make_int (BUF_PT (b)) : make_int (1),
533 buf);
534 }
535
536 void
537 uninit_buffer_markers (struct buffer *b)
538 {
539 /* Unchain all markers of this buffer
540 and leave them pointing nowhere. */
541 REGISTER struct Lisp_Marker *m, *next;
542 for (m = BUF_MARKERS (b); m; m = next)
543 {
544 m->buffer = 0;
545 next = marker_next (m);
546 marker_next (m) = 0;
547 marker_prev (m) = 0;
548 }
549 BUF_MARKERS (b) = 0;
550 }