xref: /openbsd/usr.bin/mg/line.c (revision a6445c1d)
1 /*	$OpenBSD: line.c,v 1.54 2014/11/16 04:16:41 guenther Exp $	*/
2 
3 /* This file is in the public domain. */
4 
5 /*
6  *		Text line handling.
7  *
8  * The functions in this file are a general set of line management
9  * utilities. They are the only routines that touch the text. They
10  * also touch the buffer and window structures to make sure that the
11  * necessary updating gets done.
12  *
13  * Note that this code only updates the dot and mark values in the window
14  * list.  Since all the code acts on the current window, the buffer that
15  * we are editing must be displayed, which means that "b_nwnd" is non-zero,
16  * which means that the dot and mark values in the buffer headers are
17  * nonsense.
18  */
19 
20 #include "def.h"
21 
22 #include <limits.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 /*
27  * Allocate a new line of size `used'.  lrealloc() can be called if the line
28  * ever needs to grow beyond that.
29  */
30 struct line *
31 lalloc(int used)
32 {
33 	struct line *lp;
34 
35 	if ((lp = malloc(sizeof(*lp))) == NULL)
36 		return (NULL);
37 	lp->l_text = NULL;
38 	lp->l_size = 0;
39 	lp->l_used = used;	/* XXX */
40 	if (lrealloc(lp, used) == FALSE) {
41 		free(lp);
42 		return (NULL);
43 	}
44 	return (lp);
45 }
46 
47 int
48 lrealloc(struct line *lp, int newsize)
49 {
50 	char *tmp;
51 
52 	if (lp->l_size < newsize) {
53 		if ((tmp = realloc(lp->l_text, newsize)) == NULL)
54 			return (FALSE);
55 		lp->l_text = tmp;
56 		lp->l_size = newsize;
57 	}
58 	return (TRUE);
59 }
60 
61 /*
62  * Delete line "lp".  Fix all of the links that might point to it (they are
63  * moved to offset 0 of the next line.  Unlink the line from whatever buffer
64  * it might be in, and release the memory.  The buffers are updated too; the
65  * magic conditions described in the above comments don't hold here.
66  */
67 void
68 lfree(struct line *lp)
69 {
70 	struct buffer	*bp;
71 	struct mgwin	*wp;
72 
73 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
74 		if (wp->w_linep == lp)
75 			wp->w_linep = lp->l_fp;
76 		if (wp->w_dotp == lp) {
77 			wp->w_dotp = lp->l_fp;
78 			wp->w_doto = 0;
79 		}
80 		if (wp->w_markp == lp) {
81 			wp->w_markp = lp->l_fp;
82 			wp->w_marko = 0;
83 		}
84 	}
85 	for (bp = bheadp; bp != NULL; bp = bp->b_bufp) {
86 		if (bp->b_nwnd == 0) {
87 			if (bp->b_dotp == lp) {
88 				bp->b_dotp = lp->l_fp;
89 				bp->b_doto = 0;
90 			}
91 			if (bp->b_markp == lp) {
92 				bp->b_markp = lp->l_fp;
93 				bp->b_marko = 0;
94 			}
95 		}
96 	}
97 	lp->l_bp->l_fp = lp->l_fp;
98 	lp->l_fp->l_bp = lp->l_bp;
99 	if (lp->l_text != NULL)
100 		free(lp->l_text);
101 	free(lp);
102 }
103 
104 /*
105  * This routine is called when a character changes in place in the current
106  * buffer. It updates all of the required flags in the buffer and window
107  * system. The flag used is passed as an argument; if the buffer is being
108  * displayed in more than 1 window we change EDIT to HARD. Set MODE if the
109  * mode line needs to be updated (the "*" has to be set).
110  */
111 void
112 lchange(int flag)
113 {
114 	struct mgwin	*wp;
115 
116 	/* update mode lines if this is the first change. */
117 	if ((curbp->b_flag & BFCHG) == 0) {
118 		flag |= WFMODE;
119 		curbp->b_flag |= BFCHG;
120 	}
121 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
122 		if (wp->w_bufp == curbp) {
123 			wp->w_rflag |= flag;
124 			if (wp != curwp)
125 				wp->w_rflag |= WFFULL;
126 		}
127 	}
128 }
129 
130 /*
131  * Insert "n" bytes from "s" at the current location of dot.
132  * In the easy case all that happens is the text is stored in the line.
133  * In the hard case, the line has to be reallocated.  When the window list
134  * is updated, take special care; I screwed it up once.  You always update
135  * dot in the current window.  You update mark and a dot in another window
136  * if it is greater than the place where you did the insert. Return TRUE
137  * if all is well, and FALSE on errors.
138  */
139 int
140 linsert_str(const char *s, int n)
141 {
142 	struct line	*lp1;
143 	struct mgwin	*wp;
144 	RSIZE	 i;
145 	int	 doto, k;
146 
147 	if ((k = checkdirty(curbp)) != TRUE)
148 		return (k);
149 
150 	if (curbp->b_flag & BFREADONLY) {
151 		dobeep();
152 		ewprintf("Buffer is read only");
153 		return (FALSE);
154 	}
155 
156 	if (!n)
157 		return (TRUE);
158 
159 	lchange(WFFULL);
160 
161 	/* current line */
162 	lp1 = curwp->w_dotp;
163 
164 	/* special case for the end */
165 	if (lp1 == curbp->b_headp) {
166 		struct line *lp2, *lp3;
167 
168 		/* now should only happen in empty buffer */
169 		if (curwp->w_doto != 0)
170 			panic("bug: linsert_str");
171 		/* allocate a new line */
172 		if ((lp2 = lalloc(n)) == NULL)
173 			return (FALSE);
174 		/* previous line */
175 		lp3 = lp1->l_bp;
176 		/* link in */
177 		lp3->l_fp = lp2;
178 		lp2->l_fp = lp1;
179 		lp1->l_bp = lp2;
180 		lp2->l_bp = lp3;
181 		for (i = 0; i < n; ++i)
182 			lp2->l_text[i] = s[i];
183 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
184 			if (wp->w_linep == lp1)
185 				wp->w_linep = lp2;
186 			if (wp->w_dotp == lp1)
187 				wp->w_dotp = lp2;
188 			if (wp->w_markp == lp1)
189 				wp->w_markp = lp2;
190 		}
191 		undo_add_insert(lp2, 0, n);
192 		curwp->w_doto = n;
193 		return (TRUE);
194 	}
195 	/* save for later */
196 	doto = curwp->w_doto;
197 
198 	if ((lp1->l_used + n) > lp1->l_size) {
199 		if (lrealloc(lp1, lp1->l_used + n) == FALSE)
200 			return (FALSE);
201 	}
202 	lp1->l_used += n;
203 	if (lp1->l_used != n)
204 		memmove(&lp1->l_text[doto + n], &lp1->l_text[doto],
205 		    lp1->l_used - n - doto);
206 
207 	/* Add the characters */
208 	for (i = 0; i < n; ++i)
209 		lp1->l_text[doto + i] = s[i];
210 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
211 		if (wp->w_dotp == lp1) {
212 			if (wp == curwp || wp->w_doto > doto)
213 				wp->w_doto += n;
214 		}
215 		if (wp->w_markp == lp1) {
216 			if (wp->w_marko > doto)
217 				wp->w_marko += n;
218 		}
219 	}
220 	undo_add_insert(curwp->w_dotp, doto, n);
221 	return (TRUE);
222 }
223 
224 /*
225  * Insert "n" copies of the character "c" at the current location of dot.
226  * In the easy case all that happens is the text is stored in the line.
227  * In the hard case, the line has to be reallocated.  When the window list
228  * is updated, take special care; I screwed it up once.  You always update
229  * dot in the current window.  You update mark and a dot in another window
230  * if it is greater than the place where you did the insert. Return TRUE
231  * if all is well, and FALSE on errors.
232  */
233 int
234 linsert(int n, int c)
235 {
236 	struct line	*lp1;
237 	struct mgwin	*wp;
238 	RSIZE	 i;
239 	int	 doto;
240 	int s;
241 
242 	if (!n)
243 		return (TRUE);
244 
245 	if ((s = checkdirty(curbp)) != TRUE)
246 		return (s);
247 
248 	if (curbp->b_flag & BFREADONLY) {
249 		dobeep();
250 		ewprintf("Buffer is read only");
251 		return (FALSE);
252 	}
253 
254 	lchange(WFEDIT);
255 
256 	/* current line */
257 	lp1 = curwp->w_dotp;
258 
259 	/* special case for the end */
260 	if (lp1 == curbp->b_headp) {
261 		struct line *lp2, *lp3;
262 
263 		/* now should only happen in empty buffer */
264 		if (curwp->w_doto != 0) {
265 			dobeep();
266 			ewprintf("bug: linsert");
267 			return (FALSE);
268 		}
269 		/* allocate a new line */
270 		if ((lp2 = lalloc(n)) == NULL)
271 			return (FALSE);
272 		/* previous line */
273 		lp3 = lp1->l_bp;
274 		/* link in */
275 		lp3->l_fp = lp2;
276 		lp2->l_fp = lp1;
277 		lp1->l_bp = lp2;
278 		lp2->l_bp = lp3;
279 		for (i = 0; i < n; ++i)
280 			lp2->l_text[i] = c;
281 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
282 			if (wp->w_linep == lp1)
283 				wp->w_linep = lp2;
284 			if (wp->w_dotp == lp1)
285 				wp->w_dotp = lp2;
286 			if (wp->w_markp == lp1)
287 				wp->w_markp = lp2;
288 		}
289 		undo_add_insert(lp2, 0, n);
290 		curwp->w_doto = n;
291 		return (TRUE);
292 	}
293 	/* save for later */
294 	doto = curwp->w_doto;
295 
296 	if ((lp1->l_used + n) > lp1->l_size) {
297 		if (lrealloc(lp1, lp1->l_used + n) == FALSE)
298 			return (FALSE);
299 	}
300 	lp1->l_used += n;
301 	if (lp1->l_used != n)
302 		memmove(&lp1->l_text[doto + n], &lp1->l_text[doto],
303 		    lp1->l_used - n - doto);
304 
305 	/* Add the characters */
306 	for (i = 0; i < n; ++i)
307 		lp1->l_text[doto + i] = c;
308 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
309 		if (wp->w_dotp == lp1) {
310 			if (wp == curwp || wp->w_doto > doto)
311 				wp->w_doto += n;
312 		}
313 		if (wp->w_markp == lp1) {
314 			if (wp->w_marko > doto)
315 				wp->w_marko += n;
316 		}
317 	}
318 	undo_add_insert(curwp->w_dotp, doto, n);
319 	return (TRUE);
320 }
321 
322 /*
323  * Do the work of inserting a newline at the given line/offset.
324  * If mark is on the current line, we may have to move the markline
325  * to keep line numbers in sync.
326  * lnewline_at assumes the current buffer is writable. Checking for
327  * this fact should be done by the caller.
328  */
329 int
330 lnewline_at(struct line *lp1, int doto)
331 {
332 	struct line	*lp2;
333 	struct mgwin	*wp;
334 	int	 	 nlen, tcurwpdotline;
335 
336 	lchange(WFFULL);
337 
338 	curwp->w_bufp->b_lines++;
339 	/* Check if mark is past dot (even on current line) */
340 	if (curwp->w_markline > curwp->w_dotline  ||
341 	   (curwp->w_dotline == curwp->w_markline &&
342 	    curwp->w_marko >= doto))
343 		curwp->w_markline++;
344 
345 	tcurwpdotline = curwp->w_dotline;
346 
347 	/* If start of line, allocate a new line instead of copying */
348 	if (doto == 0) {
349 		/* new first part */
350 		if ((lp2 = lalloc(0)) == NULL)
351 			return (FALSE);
352 		lp2->l_bp = lp1->l_bp;
353 		lp1->l_bp->l_fp = lp2;
354 		lp2->l_fp = lp1;
355 		lp1->l_bp = lp2;
356 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
357 			if (wp->w_linep == lp1)
358 				wp->w_linep = lp2;
359 			if (wp->w_dotline >= tcurwpdotline)
360 				wp->w_dotline++;
361 		}
362 		undo_add_boundary(FFRAND, 1);
363 		undo_add_insert(lp2, 0, 1);
364 		undo_add_boundary(FFRAND, 1);
365 		return (TRUE);
366 	}
367 
368 	/* length of new part */
369 	nlen = llength(lp1) - doto;
370 
371 	/* new second half line */
372 	if ((lp2 = lalloc(nlen)) == NULL)
373 		return (FALSE);
374 	if (nlen != 0)
375 		bcopy(&lp1->l_text[doto], &lp2->l_text[0], nlen);
376 	lp1->l_used = doto;
377 	lp2->l_bp = lp1;
378 	lp2->l_fp = lp1->l_fp;
379 	lp1->l_fp = lp2;
380 	lp2->l_fp->l_bp = lp2;
381 	/* Windows */
382 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
383 		if (wp->w_dotp == lp1 && wp->w_doto >= doto) {
384 			wp->w_dotp = lp2;
385 			wp->w_doto -= doto;
386 			wp->w_dotline++;
387 		} else if (wp->w_dotline > tcurwpdotline)
388 			wp->w_dotline++;
389 		if (wp->w_markp == lp1 && wp->w_marko >= doto) {
390 			wp->w_markp = lp2;
391 			wp->w_marko -= doto;
392 		}
393 	}
394 	undo_add_boundary(FFRAND, 1);
395 	undo_add_insert(lp1, llength(lp1), 1);
396 	undo_add_boundary(FFRAND, 1);
397 	return (TRUE);
398 }
399 
400 /*
401  * Insert a newline into the buffer at the current location of dot in the
402  * current window.
403  */
404 int
405 lnewline(void)
406 {
407 	int s;
408 
409 	if ((s = checkdirty(curbp)) != TRUE)
410 		return (s);
411 	if (curbp->b_flag & BFREADONLY) {
412 		dobeep();
413 		ewprintf("Buffer is read only");
414 		return (FALSE);
415 	}
416 	return (lnewline_at(curwp->w_dotp, curwp->w_doto));
417 }
418 
419 /*
420  * This function deletes "n" bytes, starting at dot. (actually, n+1, as the
421  * newline is included) It understands how to deal with end of lines, etc.
422  * It returns TRUE if all of the characters were deleted, and FALSE if
423  * they were not (because dot ran into the end of the buffer).
424  * The "kflag" indicates either no insertion, or direction  of insertion
425  * into the kill buffer.
426  */
427 int
428 ldelete(RSIZE n, int kflag)
429 {
430 	struct line	*dotp;
431 	RSIZE		 chunk;
432 	struct mgwin	*wp;
433 	int		 doto;
434 	char		*cp1, *cp2;
435 	size_t		 len;
436 	char		*sv = NULL;
437 	int		 end;
438 	int		 s;
439 	int		 rval = FALSE;
440 
441 	if ((s = checkdirty(curbp)) != TRUE)
442 		return (s);
443 	if (curbp->b_flag & BFREADONLY) {
444 		dobeep();
445 		ewprintf("Buffer is read only");
446 		goto out;
447 	}
448 	len = n;
449 	if ((sv = calloc(1, len + 1)) == NULL)
450 		goto out;
451 	end = 0;
452 
453 	undo_add_delete(curwp->w_dotp, curwp->w_doto, n, (kflag & KREG));
454 
455 	while (n != 0) {
456 		dotp = curwp->w_dotp;
457 		doto = curwp->w_doto;
458 		/* Hit the end of the buffer */
459 		if (dotp == curbp->b_headp)
460 			goto out;
461 		/* Size of the chunk */
462 		chunk = dotp->l_used - doto;
463 
464 		if (chunk > n)
465 			chunk = n;
466 		/* End of line, merge */
467 		if (chunk == 0) {
468 			if (dotp == blastlp(curbp))
469 				goto out;
470 			lchange(WFFULL);
471 			if (ldelnewline() == FALSE)
472 				goto out;
473 			end = strlcat(sv, "\n", len + 1);
474 			--n;
475 			continue;
476 		}
477 		lchange(WFEDIT);
478 		/* Scrunch text */
479 		cp1 = &dotp->l_text[doto];
480 		memcpy(&sv[end], cp1, chunk);
481 		end += chunk;
482 		sv[end] = '\0';
483 		for (cp2 = cp1 + chunk; cp2 < &dotp->l_text[dotp->l_used];
484 		    cp2++)
485 			*cp1++ = *cp2;
486 		dotp->l_used -= (int)chunk;
487 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
488 			if (wp->w_dotp == dotp && wp->w_doto >= doto) {
489 				/* NOSTRICT */
490 				wp->w_doto -= chunk;
491 				if (wp->w_doto < doto)
492 					wp->w_doto = doto;
493 			}
494 			if (wp->w_markp == dotp && wp->w_marko >= doto) {
495 				/* NOSTRICT */
496 				wp->w_marko -= chunk;
497 				if (wp->w_marko < doto)
498 					wp->w_marko = doto;
499 			}
500 		}
501 		n -= chunk;
502 	}
503 	if (kchunk(sv, (RSIZE)len, kflag) != TRUE)
504 		goto out;
505 	rval = TRUE;
506 out:
507 	free(sv);
508 	return (rval);
509 }
510 
511 /*
512  * Delete a newline and join the current line with the next line. If the next
513  * line is the magic header line always return TRUE; merging the last line
514  * with the header line can be thought of as always being a successful
515  * operation.  Even if nothing is done, this makes the kill buffer work
516  * "right". If the mark is past the dot (actually, markline > dotline),
517  * decrease the markline accordingly to keep line numbers in sync.
518  * Easy cases can be done by shuffling data around.  Hard cases
519  * require that lines be moved about in memory.  Return FALSE on error and
520  * TRUE if all looks ok. We do not update w_dotline here, as deletes are done
521  * after moves.
522  */
523 int
524 ldelnewline(void)
525 {
526 	struct line	*lp1, *lp2, *lp3;
527 	struct mgwin	*wp;
528 	int s;
529 
530 	if ((s = checkdirty(curbp)) != TRUE)
531 		return (s);
532 	if (curbp->b_flag & BFREADONLY) {
533 		dobeep();
534 		ewprintf("Buffer is read only");
535 		return (FALSE);
536 	}
537 
538 	lp1 = curwp->w_dotp;
539 	lp2 = lp1->l_fp;
540 	/* at the end of the buffer */
541 	if (lp2 == curbp->b_headp)
542 		return (TRUE);
543 	/* Keep line counts in sync */
544 	curwp->w_bufp->b_lines--;
545 	if (curwp->w_markline > curwp->w_dotline)
546 		curwp->w_markline--;
547 	if (lp2->l_used <= lp1->l_size - lp1->l_used) {
548 		bcopy(&lp2->l_text[0], &lp1->l_text[lp1->l_used], lp2->l_used);
549 		for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
550 			if (wp->w_linep == lp2)
551 				wp->w_linep = lp1;
552 			if (wp->w_dotp == lp2) {
553 				wp->w_dotp = lp1;
554 				wp->w_doto += lp1->l_used;
555 			}
556 			if (wp->w_markp == lp2) {
557 				wp->w_markp = lp1;
558 				wp->w_marko += lp1->l_used;
559 			}
560 		}
561 		lp1->l_used += lp2->l_used;
562 		lp1->l_fp = lp2->l_fp;
563 		lp2->l_fp->l_bp = lp1;
564 		free(lp2);
565 		return (TRUE);
566 	}
567 	if ((lp3 = lalloc(lp1->l_used + lp2->l_used)) == NULL)
568 		return (FALSE);
569 	bcopy(&lp1->l_text[0], &lp3->l_text[0], lp1->l_used);
570 	bcopy(&lp2->l_text[0], &lp3->l_text[lp1->l_used], lp2->l_used);
571 	lp1->l_bp->l_fp = lp3;
572 	lp3->l_fp = lp2->l_fp;
573 	lp2->l_fp->l_bp = lp3;
574 	lp3->l_bp = lp1->l_bp;
575 	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
576 		if (wp->w_linep == lp1 || wp->w_linep == lp2)
577 			wp->w_linep = lp3;
578 		if (wp->w_dotp == lp1)
579 			wp->w_dotp = lp3;
580 		else if (wp->w_dotp == lp2) {
581 			wp->w_dotp = lp3;
582 			wp->w_doto += lp1->l_used;
583 		}
584 		if (wp->w_markp == lp1)
585 			wp->w_markp = lp3;
586 		else if (wp->w_markp == lp2) {
587 			wp->w_markp = lp3;
588 			wp->w_marko += lp1->l_used;
589 		}
590 	}
591 	free(lp1);
592 	free(lp2);
593 	return (TRUE);
594 }
595 
596 /*
597  * Replace plen characters before dot with argument string.  Control-J
598  * characters in st are interpreted as newlines.  There is a casehack
599  * disable flag (normally it likes to match case of replacement to what
600  * was there).
601  */
602 int
603 lreplace(RSIZE plen, char *st)
604 {
605 	RSIZE	rlen;	/* replacement length		 */
606 	int s;
607 
608 	if ((s = checkdirty(curbp)) != TRUE)
609 		return (s);
610 	if (curbp->b_flag & BFREADONLY) {
611 		dobeep();
612 		ewprintf("Buffer is read only");
613 		return (FALSE);
614 	}
615 	undo_boundary_enable(FFRAND, 0);
616 
617 	(void)backchar(FFARG | FFRAND, (int)plen);
618 	(void)ldelete(plen, KNONE);
619 
620 	rlen = strlen(st);
621 	region_put_data(st, rlen);
622 	lchange(WFFULL);
623 
624 	undo_boundary_enable(FFRAND, 1);
625 	return (TRUE);
626 }
627 
628 /*
629  * Allocate and return the supplied line as a C string
630  */
631 char *
632 linetostr(const struct line *ln)
633 {
634 	int	 len;
635 	char	*line;
636 
637 	len = llength(ln);
638 	if (len == INT_MAX)  /* (len + 1) overflow */
639 		return (NULL);
640 
641 	if ((line = malloc(len + 1)) == NULL)
642 		return (NULL);
643 
644 	(void)memcpy(line, ltext(ln), len);
645 	line[len] = '\0';
646 
647 	return (line);
648 }
649